Following an extremely productive and satisfying six weeks in Singapore last summer, I made another trip back on March 3, 2006. I stayed till April 10, a total of 5 weeks. This trip was, in fact, even more fruitful and enjoyable than the previous one, in terms of my observations and other activities as well. Besides revisiting my favourite locations, I explored a number of new places this time. Most importantly, I found things I never expected to find, and saw many things for the first time. Yet another mystery hornet, a specimen of the elusive paper wasps Polistes stigma and Parapolybia varia and a hornet nest with a diameter of nearly 5 feet!, among others, made this a period of time forever etched in my memory.
I kept a journal of this trip, which was updated every night. Therefore, I have decided to write this trip report in journal format, with much of the text actually copied from my daily entries (only on days in which I was able to go out to watch wasps or observed something interesting; there is no need to bore the reader with details of my everyday life!) Warning: If you are busy or have a short attention span, please note that this is going to be very long!
Once again, the locations I described would be familiar to anyone from Singapore. For non-Singapore readers, it would be helpful to know that most of the locations I visited were quite well-vegetated, clean and unpolluted, but at the same time still not far from urban areas. Singapore air has a reputation for being comparatively clean. Furthermore, Singapore is also known as the Garden City. Even in the heart of the city, in areas such as the Central Business District and the upmarket and touristy area of Orchard Road, tall tropical trees can be seen spreading their branches across the pavements and roads. This may be the reason for the remarkable variety of insect life here, despite the increasingly urbanized landscape. In Marina Square (a high-end, ultra-modern shopping mall in the heart of the city), I found no less than 3 species of Stenogastrine wasps and 2 Eumenines (potter wasps) feeding from flowers on a pedestrian bridge, directly above a busy road!
The very first morning back in Singapore, I took a walk around my apartment block. There is a small grassy clearing with many ornamental tropical flowers such as various Heliconia. For the first time, I tried setting up pan traps. This method involves using coloured plastic dishes (usually brilliant yellow and blue colours), which serve to lure (mainly Hymenopteran) insects visually. The dishes are partially filled with soapy water. This causes the insects to drown upon landing.
I returned barely an hour later and found a small, metallic blue Sphecid wasp already inside! I have never seen this species before; it does not appear to be related to the Ampulex group of cockroach hunting jewel wasps, or the small blue mud dauber (probably a species of Chalybion)common locally. Unfortunately, I dropped this specimen on the way home. Six hours later, I found another small Sphecid wasp in the trap; this one was red and black.
For some reason, the traps attracted the attention of weaver ants (Oecophylla smaragdina), a tropical ant known for aggressive defense of its territories. They congregated around the trap and ferociously attacked other insects that approached. Some of them fell in and drowned too. This was probably the reason for the poor catch. Still, the result was indeed encouraging.
Besides these, I managed to net a couple of large species near my apartment block; a female carpenter bee Xylocopa confusa, and a male Polistes sagittarius! The latter was a surprise, as I have never encountered males at this time of the year (at least in Hong Kong). This possibly suggests that reproduction takes place throughout the year in the tropics. I have a couple of specimens from my previous trip, so I won't need many more of these species.
Later in the afternoon, while shopping near a market complex, I saw a large and impressive Vespid form flying slowly and seemingly thoroughly investigating the canvas. Vespa tropica! I had searched for this species during my previous trip in the summer of 2005, but only saw it three times in more than a month, and did not manage to capture any. This worker flew slowly and steadily at head level; however, I was there to shop and to get my dinner, and I was not prepared! I did not have my net with me, and I did not dare risk using my bare hands to catch her! The weird thing was that she flew up towards a tall tree and disappeared in the foliage nearly 30 feet above ground level, and almost immediately, another two flew out. Possibly a nest site? Vespa tropica is generally ground nesting, but it does sometimes nest above ground in the tropics (a contact from a local forum kindly contributed a photo of such a nest previously). The tree is too high and the foliage too thick, and I decided against climbing the tree for fear of angering a colony of these hornets, which have very severe stings. Vespa tropica in Singapore seem distinctly larger and less shy than those back in Hong Kong.
All this happened on my first day in Singapore; it has already been so productive. Also, the weather is quite comfortable at the moment, although still more hot and humid than I'm used to after being away for so long. From past experience, I can say that March is about the only pleasant period in Singapore. It is relatively cool and dry (still a warm 31 degrees Celsius and 85% relative humidity), while much of the year is either oppressively hot and/or constantly raining. The following weeks are going to be great.
I went downstairs at 7:50 a.m. to set the traps again. Barely an hour later, the trap collected an Evaniid wasp. These are small harmless wasps which parasitise cockroach egg cases.
I checked on the traps again just before lunch, and to my chagrin, a group of common mynahs were messing with my traps, tossing them around! I clapped my hands in an attempt to scare them away, but the water, along with any possible catch, had been poured out. I had to set them up again. If the birds come back and cause more trouble, I shall have to change location. Also, by the time I went back at 5 p.m., the weaver ants had once again invaded the traps. I still can't figure out why the traps are so attractive to ants, which have fairly poor eyesight compared to the target species. Still, I caught a number of unidentified small Hymenopterans, mostly of the parasitic or non-stinging type. I have put them aside for one of my contacts who will be able to put them to good use.
I happened to catch sight of a pair of black-naped orioles, a beautiful yellow bird which can be found throughout Singapore. One of them flew from one tree to another, with a large wasp in its beak. The other was apparently attempting to get food as well, but came under attack by three or four Polistes sagittarius. There must be a nest in this tree, although it was too tall for me to see clearly. The birds had probably attacked the nest in an attempt to find something to eat.
I then took a trip to a nearby park in the afternoon. The park features a boardwalk over a mangrove swamp, and I was surprised to find some attractive Scoliid wasps. They were metallic blue with bright orange heads. I saw yet another Vespa tropica worker, but I was not able to ready my net in time. I did manage to catch a small, attractive stout-bodied potter wasp.
Once again, I set the pan traps, this time at 7 a.m. I spent most of the day visiting relatives, and had no time to go outdoors. By the time I returned at 10 p.m., the trap collected lots of small unidentified Hymenopteran insects. Among these I found a nice Ceratina sp. (dwarf carpenter bee).
Lots of Polistes sagittarius were swarming around a tree near my apartment block. I approached cautiously and wasn't attacked, so it was probably nothing to do with disturbance to a nest. I observed some of them fighting aggressively, sometimes falling to the ground. There might have been a nest in the tree, but I couldn't locate it. I also saw the giant carpenter bee Xylocopa latipes feeding from flowers on the same tree.
Finally, the Xylocopa confusa which I caught died today, and I found several large, beige-coloured mites on it, crawling between the thorax and abdomen. These are not exactly parasites; I will try to find the info I once read from a certain book. They are present on many species of Xylocopa, and some of these bees even have special "mite pouches" in which they reside! From past experience, when mites appear around and leave the bee's body, the bee's time is up. The mites from the larger Xylocopa latipes are even bigger and bright red!
I skipped setting the pan traps today, but spent the whole afternoon in the Botanic Gardens. I saw several Ropalidia sp., some Stenogastrine wasps, Xylocopa latipes and lots of stingless bees. I did not attempt to collect any of these, having many specimens from my previous trip. One of my main targets on this trip is Vespa tropica. I have specimens from Hong Kong but not a single one from Singapore.
The hunt for Vespa tropica today was tiring, unsuccessful, and I must say, rather hilarious! I saw this large hornet six times today. On three occasions, the hornet flew unhurriedly around trees and shrubs, only to disappear the minute I approached! Another two flew past me, and I gave chase. Just as I came close enough and swung my net, they simply vanished (usually by flying vertically upwards). Later, I approached one cautiously and netted it, only for it to crawl out under the edge of my net! I was soaked with sweat and out of breath, and the weather didn't help. It was hotter than the past few days had been, and there were also some slight thundery showers. Finally, while in the washroom, I was washing my hands (obviously without net in hand), and another Vespa tropica flew into the washroom, circled me twice and flew out! Needless to say, I couldn't do much with my soapy hands, and just watched as she flew out unhurriedly. I don't understand why these wasps are so elusive and hard to catch here, and why they always appear when I'm not ready. A jinx on me? Still, it was a great experience! I am quite confident I will catch Vespa tropica; I still have more than a month to go.
I spent part of the afternoon near the Boardwalk in Changi, at the eastern tip of the island. I managed to find the three large and beautiful species of beach wasps, and had a great time observing them.
On my previous trip in May-July 2005, I found the original spot where I first discovered them vacated. I later managed to find them at another location nearby. This time, they have all returned to the original location, and do not seem to be present at the new place. I managed to take a couple of photos of the very large black Sphex sp. digging a burrow, but these photos turned out very poor once enlarged on my monitor. This species is very alert and hard to approach; they fly around in an alarmed manner upon the slightest movement. Unfortunately my very versatile long zoom lens is spoilt. I am using my 90mm, a great lens in itself but sometimes I have to approach far too close for comfort.
I also managed to get photos of the 2 Bembix sp., and made some very interesting observations in the process. During a one hour period, I saw these wasps return with prey (flies), which had been stung and paralysed. In an attempt to see what species these wasps caught, I slipped a plastic bag over the wasp when she landed. When she flew up, I gently separated her from her prey, then released her. I found a total of three consistently used species: the greenbottle (probably Chrysomya sp.), fleshfly (Sarcophaga sp.) and a type of striped hoverfly. The wasps behaved weirdly when separated from their prey. They stood on the area surrounding the burrows they were digging, looking lost and seemingly not knowing what to do. I returned the prey to them, and it was fascinating to observe what they did. They would grab the fly out of my hand without hesitation, and though it had already been paralysed, they flew up a short distance, giving the prey a few stings. They then resumed digging and bringing the flies into the burrow at top speed. The photos below show one of these species with prey, and a paralysed hoverfly I took from one of them to photograph.
Today was exceptionally hot! I had thought that the weather would have been more pleasant than usual, which has been the case over the past few days. However, exceptionally strong sunlight and high temperature (even by Singapore standards) made it extremely uncomfortable; sweat ran down my face and arms in rivers, and I found it hard to steady the camera without it slipping. Still, I managed to stay in a squatting position on the beach for nearly an hour.
I spent the whole day at Sentosa with family friends from Hong Kong who are here for a week's vacation. They did not bother much about the standard tourist attractions though, being more interested in taking photos and walking through the nature trails on the island. I also brought both my film and digital cameras, since I was certain I could get some good shots. The four of us (myself, my mother and our friends) spent much time out in the parks over the next few days.
I kept a close eye out for bees and wasps, and I saw many indeed. I photographed the large brown potter wasp (Delta sp.), and also saw a stout-bodied potter (Rhynchium haemmorhoidale). There were several carpenter bees (Xylocopa latipes and Xylocopa confusa) around as well. Honeybees were swarming around the roof of one of the tourist attractions.
I stumbled across some weird things again today. In the forest trail, I saw several small black and yellow wasps return to a crevice in a log. They look like Vespula species, which probably don't belong to this region! Of course, I need to get a specimen to confirm this, since they are small and fly quite fast. Around six of them flew into the rotten log; I waited, hoping to intercept one some distance from the spot with my net (I have heard how defensive these wasps, known as yellowjackets, can be near the nest). Strangely, no others emerged or returned for another five minutes or so.
Secondly, at one of the bus stops, I saw, once again, what I suspect to be Vespa velutina. The sunlight made it quite hard to get a close look, and the wasps flew fast, but the yellow legs and orange front part of the head are distinctive. They behaved in the same way Vespa velutina do back in Hong Kong. While walking to the bus stop, one flew around me, staring me straight in the face. The minute I reached for my net, she disappeared. Later, at the same bus stop, I watched with amusement as another one came in and disturbed a group of students on excursion. Unfortunately I wasn't able to catch them for species confirmation. I have thus seen this species a total of six times; twice in 2002 and once in 2003 at the Botanic Gardens, once last year at Sentosa and twice this year, again at Sentosa.
We spent much time in the nature trail and also in the Butterfly Park. The weather was still quite hot (34 degrees Celsius), so we spent much time in search of cool refreshments too.
In the evening, I bought some food from a fast food outlet and had a quick dinner on a bench back at the visitor arrival area. While I was eating and had both hands occupied, a single Vespa tropica flew past slowly; if I had my net in hand I would have landed her in an instant. Apparently the jinx is still on me!
I spent another day with our friends in the Botanic Gardens. Maybe it was because we were there earlier than usual, when the weather was at its hottest, but there were less birds, butterflies and insects than usual. We spent much time walking in search of wildlife to photograph.
I did not make any new sightings; there were the usual Ropalidia and Stenogastrine wasps, honeybees and large carpenter bees (Xylocopa). However, as we passed a group of trees, I saw something which nearly made me drop everything I was carrying. There, on one of the branches, was a huge hornet's nest, the biggest I have ever seen. It was nearly 5 feet in diameter both horizontally and vertically. What surprised me more was the fact that the nest belonged to Vespa tropica! I saw them clearly from where I was standing, but of course, I did not dare to catch them so close to the nest. So indeed, this species does often nest above ground in this region. The nest was roughly 7 feet off the ground, and upon close inspection, it had actually fallen from a greater height, so that it was now supported by the lower branches; it was slightly broken in some parts. The nest envelope of Vespa tropica shows no imbrication (arc-shaped markings on the outer surface) and is much more brittle than that of Vespa affinis. The colony seemed to be coming to an end; the workers leaving and returning were far fewer in number than one would expect from a nest of this size.
You might wonder why I did not attempt to collect wasps from this nest since I badly wanted a local specimen of Vespa tropica. The nest was in fact very defensive despite the fact that it was in decline. Standing 3 metres (10 feet) from the nest, I was already approached and circled aggressively by some workers. Many people in Singapore claim that Vespa affinis is the most aggressive of the three common local hornets, but in my experience large colonies Vespa tropica can be more defensive and hold a wider defensive radius! Coupled with a more highly toxic venom and much more painful sting (in my experience, 3 to 5 times worse on average than a Vespa affinis sting!), I did not dare take the risk.
Yet another day spent with friends. We first visited Fort Canning Park, which, though in the middle of the city, turned up some interesting finds. First, I saw a large potter wasp, which appeared to be Phimenes flavopictus! Also, while photographing some birds, we were disturbed by a curious Vespa velutina! This time, both my mother (who, thanks to my influence, has also developed a fondness for nature in general and hornets in particular) saw it closely, and we were 100% positive of its identity. On a close look, it is similar to the Hong Kong form in appearance, but appears more reddish in colour, especially on the abdomen; it also has a rather velvety gold sheen under the sunlight. Now I just need a specimen as proof. Needless to say, the wasp flew away the moment I pulled out my net. Now a new task looms ahead; to find out Vespa velutina's nesting habits and life cycle in Singapore, and why its appearance is so patchy and limited (this is a very common species in Hong Kong and elsewhere throughout its range).
We then headed off to MacRitchie Reservoir, which links to several nature trails. Here, I found a hornet's nest on a tree! It has a coarsely imbricate nest envelope (large, wide arc-shaped sections making up the outer surface), and this suggests that this nest probably belongs to either Vespa affinis or Vespa analis. In fact, I think it is the nest of Vespa analis; this species has even more prominent arc-shaped markings on the nest than that of Vespa affinis. I did not see any wasps anywhere near, however, so I was unable to determine which species inhabited this nest.
It was also at MacRitchie that I caught a new Pompillid. It is attractively coloured; mainly black, orange legs and wings and a bright yellow head.
There were also Xylocopa sp. and Ropalidia here. While walking the trail, I was followed persistently by one of the Ropalidia species. I still do not know what triggered this off. She followed so close to my head, keeping pace with me, and for a distance of nearly 50 metres! In fact, there was a point when I thought she intended to attack me, but she left after this.
Later, heading off to a small restaurant in a quiet countryside area, I was able to catch a couple of the large brown Delta sp. (potter wasps) just before dinner,
We returned to MacRitchie Reservoir once again, in an attempt to find more things to photograph. Shortly after alighting from the taxi, we photographed a male of Xylocopa confusa who was hovering around some bushes, guarding his territory. It was not easy because he hovered just long enough for me to focus, and then changed position before I could shoot. I ended up with not a single good shot. Still, I shall return and try again.
Going by a different route this time, I netted another new Pompillid; this is small and grey.
Our friends had returned to Hong Kong the day before. Today I visited my aunt and also spent a couple of hours wandering around her condominium estate. This place has always been quite full of insect life, despite its urban setting and proximity to the expressway, and the frequent insecticidal fogging carried out by the maintenance department.
I caught a large female of the stout-bodied potter wasp Rhynchium haemorrhoidale. The male of this species appears to be far smaller than the female. The females average 14 to 20mm, while most males I have seen are merely 10 to 11mm in length! Now I have both a male and female of this species.
A small hornet-like shape darted among some plants, and I netted her immediately out of reflex. It was a good thing I did so, for it was a worker of Vespa affinis, and although I already have specimens, this is the smallest I have ever seen! She is merely 17mm in length, the size of average Vespa bicolor workers back in Hong Kong. She must be one of the early brood of a new colony.
Another frustrating day at the Botanic Gardens. I came so close to netting several individuals of Vespa tropica, but as before, I missed by mere inches each time. The curse is still on me. When will I ever break it?
I took a closer look at the huge nest today. Apparently it was built higher, approximately 14 feet; the original attachment can still be seen on a high branch. It has now fallen to around 7 feet, and is supported only by some branches. The huge nest has surprisingly little activity, and is already starting to disintegrate. It looks smaller already because much of the nest surface has broken off. But amazingly, there is a new nest starting just three feet away from the old nest, at approximately 10 feet above ground. Unfortunately it is virtually impossible to move through this patch of trees to photograph this.
I managed to observe and photograph some Ropalidia and Stenogastrine wasps. Known as hover wasps, the Stenogastrines fly soundlessly, frequently hovering, and are difficult to detect due to their thin, inconspicuous appearance. However, with care not to scare them with quick movements, they are easy to observe near flowers. As I watched them, it suddenly struck me how much their movements resemble that of the traditional Chinese art of lion dance. They hover and make short jerky movements (they can move sideways and backwards in flight), and sometimes make darts at each other in mid-flight; a video clip of these wasps in action would certainly go well with the drumbeats!
Above: One of the common Ropalidia species
Below: Two different species of Stenogastrine wasps
Another day at the beach in Changi. I observed and photographed the various species of Sphecid wasps on the beach, but did not note anything new. The large and impressive all-black Sphex species were also present. They are very hard to approach and fly off when I came within 5 feet of their burrows. Strangely enough, they would fly round but not return to their digging. Only when I moved a distance away did they return and resume enlarging their burrows. It was interesting to note that they would disappear inside and not reemerge for some time. When they did, they carried compacted balls of sand, which they discarded several inches from the nest entrance. With much patience, I finally managed to get two usable (though still not very good) shots of this magnificent creature.
If you look closely enough at the first photo, you can see the sand being sent flying by the wasp's legs.
On the trunk of a small thin tree, I found two nests of Xylocopa confusa. I did not find much else in this area.
While waiting to join family members for dinner, I took a walk around Fort Canning Park, where I saw quite a few weird things. This area seems quite promising.
After a long walk in the hot and extremely humid weather, I took a rest under a shelter. It was a good thing I did so. Almost immediately, a large, dark wasp flew around. It was the large brown potter wasp Delta sp. This wasp had apparently already constructed several separate nests on one of the wooden beams, and was starting on another. I attempted to photograph her in this process, but she was extremely nervous and would fly away when I approached. I found many solitary wasps quick to flee upon any disturbance while building their nests, and they would usually return only when I moved a distance away. Were they watching me from somewhere? How come they seemed to return the moment I was out of sight? These are some more questions I have yet to find an answer to.
While waiting around the corner for the wasp to return, I spotted a large, robust bee flying around the wooden beams, seemingly searching for its nest site or scouting for possible nesting sites. What shocked me was that this bee was the size and shape of a typical Xylocopa carpenter bee (roughly 20 to 25mm in length, heavy-bodied and relatively hairless), but was metallic green! I was so shocked that I dropped my net. I quickly retrieved it and netted the bee, but unfortunately, it simply evaded my net by flying downwards; it then beat a hasty retreat. I made a mental note to return to this area and stake out. (For those who asked out of curiousity: No, it wasn't a beetle. There are several large beetles with metallic green colouration and fast flight. But I can easily tell the difference between a bee and a beetle, especially when I did have a good look at this creature.)
A short while later, yet another large wasp flew around inside the shelter. I looked up and came face to face with the largest Vespa tropica I have ever seen! She was magnificent; at least as big as a large Vespa ducalis. She must have been a queen (I have a queen specimen caught in Hong Kong, but that cannot compare with this individual in size). Showing the typical colour of Southeast Asian specimens, her jet black colour and bright orange band, combined with her unbelievably large size, once again shocked me into dropping my net. Upon retrieving it, I aligned the net and prepared to sweep, but in the blink of an eye, she disappeared! I was at a loss to explain where she went. I did not see her under the roof or on the wooden beams of the shelter, and I didn't see her leave the area. Furthermore, she was flying very slowly and steadily. Nevertheless, it was a pleasure just to see her and the mystery green bee.
Once again, I visited Pasir Ris Park. I am most familiar with this place, having hung out there frequently in younger days. In recent times, I have also extensively worked this area, but did not find anything new. Today, I was fortunate. For the first time, I personally saw Vespa analis. While walking under some trees, a medium-sized hornet, only slightly smaller than Vespa tropica, flew past. It wasn't flying fast, and I saw a jet black body with a bright yellow-orange tip on the end of the abdomen. I whipped out my net and, breaking into a sprint, gave chase. The hornet seemed to realise it was being pursued, for it put on an added burst of speed. Still, I ran at a decent pace and was hot on its heels; I soon got close enough, and lifted my net, ready to sweep downwards. The hornet chose this moment to make a nearly vertical dart upwards, easily evading me. Still, I felt fortunate to have at least seen this with my own eyes; I only knew of its existence from books and others' experiences before.
It seemed that my luck had not run out. It started raining, quite suddenly, and I was forced to take shelter under the roof of a small building. A typical potter wasp shape floated past me, heading straight for a mud nest under the ceiling. I would have easily dismissed it as the common brown Delta sp., but something made me take a closer look. For the third time in two days, I dropped my net again!
The long, slender wasp turned out to be Phimenes flavopictus, the beautiful and fairly uncommon black and yellow potter wasp which can also be found in Hong Kong and elsewhere in Asia. Formerly, I had only seen this species in Fort Canning and Sentosa. This time, I retrieved my net in a split second, and cautiously moved to block what I anticipated to be her flight path. Upon laying another layer of mud on her nest, she took off at a slightly different angle, but, I swiftly intercepted her and netted her with unusual accuracy. This is probably one of my most precious specimens from Singapore to date. Also, I caught this in an area I was close to giving up on. This taught me an important lesson; visit each place regularly and never give up. I can never tell when something rare and unexpected will turn up in an area where I would least expect it!
Checking some websites and searching through some old stamp albums, this species apparently is known from Singapore; it appears on a local stamp under the scientific name of Delta arcuata. I do not know which is correct, since the specimen I caught is completely identical to those from Hong Kong. Since Phimenes flavopictus is the generally accepted name in Taiwan and elsewhere in the region (the Mainland Chinese call it Phi flavopictus), I shall use this for now, unless proven otherwise.
It rained island-wide virtually the whole day. This provided a refreshing change, with slightly cooler weather, and so I braved the rain and visited the Botanic Gardens. In this kind of weather, my favourite tactic is to hang around under a shelter and wait for something interesting to appear, upon which I rush out to catch it. I waited for some time, but didn't see anything new. Surprisingly, Xylocopa latipes actually braved the rain to forage. I also saw Stenogastrine wasps and several Ropalidia. Just when I was about to give up, a large hornet with an orange band flew past and flew in circles around a tree, inspecting it closely. Thinking Vespa tropica, I rushed out, netted it and brought it back to the shelter, only to find it was actually a very large Vespa affinis queen. What a disappointment!
It was still early, so I took a taxi to another urban park in the West. This place has rather dense vegetation in many areas, and used to be a favourite for many of my friends in search of spiders. There was a constant light drizzle, and though I didn't see hornets, I did see several different solitary wasps, including potters, Sphecids and Scoliids. The place looks promising, and I hope to find time to return again.
Below: One of the many Sphecid wasps present here.
Again I visited the Changi Boardwalk. It was raining heavily at my place, but was dry at Changi, a mere 15 minute's drive away!
The opposite of yesterday's incident happened today. A medium-sized hornet flew around a tree, quite close to me, and I dismissed it as Vespa affinis. I am thankful that I somehow readied my net and captured it without thinking. It turned out to be Vespa tropica! This was a very small worker, and probably very old, judging by her tattered and torn wings. Still, it is my first Vespa tropica specimen from Singapore, and I was overjoyed. Hopefully the curse is now broken! Here she is in a posed photograph back at home.
I ended up at the Boardwalk once again. I spent a couple of hours photographing the wasps on the beach. Later, around 6 p.m., I saw a very large hornet flying around a palm tree, and suspecting Vespa tropica, I rushed toward the area to wait for it to reemerge. Another hornet flew out, a much smaller one though. I quickly netted it and indeed it was Vespa tropica. Apparently, after my first catch two days ago, the "curse" has been broken, and this was one of the most effortless captures I have ever made. It was a good thing, too, that I managed to net this hornet gently and without force. I suspect there is a nest somewhere in between this group of palm trees. I saw a very large individual, something like the first return just as I was about to leave. The space in between was too dark and covered with dense foliage, so I couldn't see through, and I certainly didn't want to risk pulling the foliage and palm fronds apart if there might be a nest inside. I can only return on another day when it is very bright and try to locate the nest.
It was already raining when I left the house, and by the time I got into a taxi, the rain was pouring heavily in droves. Barely 10 minutes later, on the expressway, the rain stopped and the sky turned bright. This is a classic example of equatorial weather! My destination was the Botanic Gardens, and upon reaching, it was apparent it had rained earlier. The sun was now blazing; although dark clouds were also present and there were frequent claps of thunder, it did not rain again.
The coconut trees seem to be blooming again. For the past few weeks, the large coconut fruit have been hanging prominently on the trees, but there were no flowers, and not a single bee seemed to be feeding from these trees. Now, the flowers are just starting to appear, and already stingless bees and honeybees are coming in ever-increasing numbers. At several coconut trees in the Botanic Gardens, I also saw Vespa affinis and Polistes sagittarius feeding from the coconut flowers. Among the Vespa affinis, I saw several males. I managed to catch one.
Something new today: Polistes stigma! I had previously seen photos of this wasp on some local nature and photography websites, but never saw it in person myself. In fact, there seem to be two local colour forms, one mainly black and the other prettily marked with red, yellow and black. Both forms look different from the common form found in Hong Kong. While at Pasir Ris Park, I saw this small, attractive wasp land on some wooden railings. I managed to photograph it and then captured it. I saw three or four others later, although they were flying too high to either photograph or catch. Still, I suspect there must be a nest nearby, or maybe it is just their preferred habitat. I started searching the nearby vegetation, looking under broad leaves (where the majority of local nests have been photographed), but my hunt was interrupted by a sudden thunderstorm. I will return and search the area thoroughly another time.
It rained much of the day, and I only managed to visit the boardwalk again at nearly 6. Still, this short outing proved quite successful. Just before dinner, I managed to collect a blue-banded bee (Amegilla sp.) and a sweat bee (Halictidae: Nomia sp.) with metallic green and orange stripes.
I spent a whole day at Sentosa, and stayed at one of the hotels there. The view from my room and the whole hotel area is beautiful, with lots of greenery, trees and flowery shrubs. But I didn't expect to find anything here, since I saw garden staff spraying the plants with pesticides.
The weather was beautifully bright in the early afternoon, although a little hot. I started off at the beach near the hotel, where I photographed some Scoliid wasps. One looked like a species I had collected on my previous trip but was nearly 3 times the size! (30mm as compared to 10 - 11mm). I also managed to get shots of a Rhynchium haemorrhoidale (stout-bodied potter wasp) feeding from flowers. I then walked through the rainforest trail, and ended up along a cycling track. It was here that I saw a thin, yellowish wasp-like insect fly pass, which I dismissed as an ichneumon at first (there are many different species here and I frequently see them), This insect seemed weak and landed on the ground, and I am so thankful that I took a second look. Parapolybia! Almost certainly Parapolybia varia.
I have seen references regarding the status of Parapolybia varia, and it is indeed found in Singapore (in fact, one subspecies was described as Parapolybia varia singapurensis (formerly referred to as Icaria singapurensis and then Polybia orientalis, indicating this subspecies/variant was first found in Singapore). I have been searching in vain for Parapolybia on all my previous outings, and today, when I was searching for other things (my main targets being Vespa velutina and Vespa analis), this individual turned up right in front of me. I find it strange that despite Singapore being such a small place, I am finding new species one by one but only over a long period.
This specimen looks similar to the same species in Hong Kong, but is slightly smaller, with perhaps more yellow. I did not dare to risk photographing it, for fear that it will fly and disappear in the room. The Polistes stigma I caught last Sunday gave me a huge headache when it flew round and round my room and then decided to hide inside my air-conditioner unit. I had to dismantle the unit to get it back.
At 4:15, a repeat of Sunday's sudden downpour happened. The fine weather suddenly took a change for the worse, lightning struck continuously and defeaning thunderclaps sounded repeatedly. I spent the remaining part of the afternoon in shelter. Just when I was thinking of searching the area for Parapolybia nests!
Here's a photo of this specimen.
My second day at Sentosa was not as productive, simply because the rain came earlier. At around 2 p.m., I was exploring a part of the beach which I had never visited before. The hot sun blazed down on me as I followed a couple of Scoliid wasps with my camera; the sky was blue. I was looking forward to a wonderful afternoon in the sun, when in a matter of minutes (no exaggeration, that's how fast it took!), tall thunder-clouds appeared on the horizon, and I had to run for shelter, knowing the rain would start in mere minutes. I had barely entered a sheltered area when the downpour began. I spent most of the afternoon watching the rain! I did see several species of potter wasps, but was unable to catch them. I managed to photograph a female stout-bodied potter wasp (Rhynchium haemorrhoidale).
Another visit to my aunt's condominium estate. For the first time, I saw Vespa tropica in this area; a large worker appeared to be foraging among coconut trees and the building roof near the swimming pool.
Interestingly enough, I found an empty Polistes nest which had apparently been abandoned or attacked, either by natural predators or pesticides. Possibly the work of Vespa tropica? Another thing worth mentioning is that the size of this nest and its cells do not fit either species I have found; the cells are too small for Polistes sagittarius but too big for Polistes stigma. This possibly means another species, which isn't really surprising now. If only I had found it weeks earlier; it looks quite new and undamaged.
Had an appointment in the city and was unable to visit any parks or outdoor places. I did take a short walk near my place and caught a male Polistes sagittarius. There are still lots of them around. I also observed male Polistes sagittarius engaging in some type of territorial combat! The males would each stake out a territory, usually a certain branch or other perch, and attack any other males which entered the area. The two would then fall together and grapple, following which the loser would flee hurriedly. They did not attack females or other flying insects. The fighting is somewhat reminiscent of Xylocopa (carpenter bees), of of the fights between the enormous males of Polistes gigas, although on a less violent and injurious level.
Taking another walk near my place, I found another Polistes sagittarius specimen, this time a female.
I took an early morning walk around the estate around 7 a.m. The mango trees have started flowering, and seem to be teeming with insect life. It is quite strange that I have always overlooked this very common tree planted around most housing estates.
This morning, there were lots of honeybees and butterflies at the flowers. Other species I noticed were Polistes sagittarius, Rhynchium haemorrhoidale, the large brown Delta sp. and several other potter wasps. Best of all, I found Phimenes flavopictus - lots of them! They seem far more common here than in Hong Kong. I was fortunate enough to witness a mating; a large female feeding from flowers was suddenly approached by a male; the two hovered and circled each other for some time, then the male mounted the female and both spiralled up into the sky. The mating resembled that of Xylocopa sp. carpenter bees.
I also witnessed three females capture caterpillars. The small green caterpillars were abundant on the flowers (not the leaves) of the mango tree. The female wasps appeared to be feeding on the nectar themselves, but when they came across a caterpillar, they would pounce, sting it and then fly away after getting a good grip on the prey. I later managed to catch one.
Finally, I observed some brown butterflies chasing Phimenes flavopictus! I couldn't help laughing; it is easy to think that butterflies are weak creatures which are preyed upon by almost every other creature, but it should be noted that many species are in fact strongly territorial. They usually direct their aggression on other butterflies, but apparently they chase other flying insects too. And it is only fitting that they chase Phimenes flavopictus, seeing that this is one of the major predators on their offspring! (They do not attack adult butterflies or other insects). Still, I have never seen a butterfly attempt to chase a Vespa (hornet) species such as Vespa affinis!
I spent much of the afternoon at Marina South, a popular recreational venue which is built on reclaimed land. Much greenery and secondary forest has spread across much of this area, which also has a large park. I spent some time in the park, and netted a large Vespa affinis queen; unfortunately, I was careless during the transfer and lost her. I also found a large mud-dauber wasp (Sceliphron sp.) building her nest on the wall of the park's washroom!
I walked through the park and ended up at the carpark just behind the stretch comprising numerous dining and entertainment outlets. From a distance, I saw a large hornet flying near one of the restaurants, and I sprinted across the carpark. Even from a distance, the hornet, which had been cruising unhurriedly among some ornamental plants, saw me and hurriedly turned tail and fled. I chased her across a whole row of restaurants before catching up with her some distance away, under the canvas awning from the roof of one of the restaurants. She started to fly higher, and in a final attempt, I leapt high and netted her. She turned out to be the very largest Vespa affinis queen I ever saw (this was why I gave chase, assuming she was Vespa tropica). She measured a shocking 34mm! I took some time to transfer her into a holding container, and suddenly became aware of a row of amused faces looking at me from the various restaurants. It is common to hear of hornets chasing people, but I don’t think many people have ever seen someone chase a hornet!
Unfortunately, her left antenna is broken, and the right wing of the Sceliphron I caught also shows extensive damage. I wonder why; it cannot be my capturing technique, since I usually use a swift but gentle sweep and most of my specimens are undamaged. Still, these are two useful and beautiful specimens.
This area looks very promising, with neat urban areas meeting large patches of forest and wild grassy areas. Unfortunately my outing was cut short by yet another thunderstorm.
This time, I visited Pasir Ris Park in the later part of morning, instead of in the afternoon. Reaching there around 10 a.m., I proceeded to the area where I found Polistes stigma, but did not see any today. However, walking near some wooden shelters covered with creeping plants, I found a starting nest of the common brown and yellow Ropalidia, with just one female, as well as two nests of Stenogastrine wasps! I had quite a good time observing and photographing them. Interestingly, whenever the Ropalidia left her nest to forage, one of the Stenogastrine wasps would fly over and land on it! I could not establish the reason for this. She did not eat or capture any of the other wasp's eggs or larvae; she simply rested on it as if it were her own nest. The Ropalidia chased her off upon returning, but she did it again once the original occupant left.
A large Vespa tropica also circled the area, no doubt foraging for prey. Finally, I caught another small Nomia sweat bee; this one has bright orange stripes!.
Later in the afternoon, I went to the Botanic Gardens one more time. The sky was clear and bright when I arrived, but turned dark once I reached the Bukit Timah Core. The great old Vespa tropica nest has started to disintegrate badly and is a mere shadow of what it used to be. However, some of the hornets keep returning to it, adamantly refusing to leave. Another group have done much work on the new nest starting just above. I hope that there will be a nice new nest by the time I come to Singapore again.
I spent a couple of hours hunting around Portsdown Road. I managed to catch a female Xylocopa confusa, two Megachiliid bees and a beautiful metallic purple-blue small Pompillid (spider-hunting wasp). The area looked quite promising; I saw many other species of Sphecid wasps I had never seen before. For the first time, too, I caught sight of what appears to be the black form of Polistes stigma. I wanted to search for nests of this or other species, but had to leave the area quick due to a sudden change of weather.
I spent a short period in the morning at Changi, this time further in, nearer to Changi Village. I was trying to photograph some birds, and didn't manage to catch anything, although I saw some solitary bees flying around. It soon got too hot and I had to be home for lunch today, so I hailed a taxi by the main road. As I got in, I saw an individual of Vespa analis flying around the curb, where I had been standing just moments earlier, before disappearing into some ornamental bushes! Such wrong timing, always. I only have a few more days to go and I wonder if I will successfully obtain even one specimen on this trip.
I returned to MacRitchie Reservoir and walked the 5 km long trail where I last saw the hornet's nest in the tree, intending to hang around and see whether there was any new activity. I walked at a brisk pace, but did not manage to find the same tree. Lots of trees seemed to have fallen, possibly as a result of lightning strike. I suspect the tree in question had fallen too. Either that or park staff had already removed the nest AND the sign. In the end, I walked the full 5 km in 40 minutes without seeing much. My walking pace had now quickened till I was almost running, mainly due to the darkening clouds and not-so-distant thunder. I then took a taxi to Alexandra Hospital. This top-class private hospital has designed a butterfly trail, a revolutionary idea to provide a form of therapy for patients. This has worked well and on top of that, the trail has now become popular with nature photographers. Unfortunately, I didn't get to see the trail because it was raining heavily by the time I reached. I spent the rest of the afternoon in the hospital cafeteria. The rain did not stop till evening.
I visited the Alexandra Hospital trail today. I was thankful that the weather was fine. The trail is a pleasantly designed easy walk; flowering plants designed to attract butterflies are specially planted everywhere. There was a huge variety of butterflies and other insects, but it wasn't easy to photograph anything today because workers were cutting the grass. Loud noises from the grass cutters and grass flying everywhere made the insects skittish and difficult to approach. It was here that I found two weird wasps.
I saw a female Polistes sagittarius cruising lazily through the bushes. What was unusual about this otherwise common wasp was the fact that she was fully light brown with a yellow band on the second abdominal segment! (Typical Polistes sagittarius in Singapore are black with the yellow band). Is this just an aberration or a separate colour form, as what I have already seen with Polistes stigma? Speaking of which, I saw another individual of the black form of Polistes stigma.
Later, I saw another unusual hornet which I can't identify. It was medium-sized to fairly large (slightly larger than a Vespa affinis worker, roughly 26 to 29mm), and fully brown, with no distinct separate colouring (black, red or yellow). Its flight was faster than Vespa affinis and Vespa tropica (but slower than Vespa velutina); it attempted to catch some butterflies but hurriedly fled when I tried to approach and photograph.
I did not attempt to catch any of these three wasps, even though I badly needed specimens, due to the fact that catching in this specially designated trail was likely prohibited. What a pity, though.
I did not expect to be able to go outdoors much during my last two days in Singapore. However, during a gathering, my uncle suddenly mentioned that there was a nest of bees or wasps in a tree in his garden. Listening to his description of the nest, at least I could be sure it was a social species; there were lots of them. I was thus delighted to have a chance to see something interesting and probably new before I left. I followed him to his house, armed with two cameras. I was in for a pleasant surprise.
The nest was in a juniper tree, around 5 feet off the ground, and turned out to be that of Apis andreniformis, the dwarf honeybee. (Note that I previously identified this species as Apis florea, which is a better known species of dwarf honeybee but is not found in Singapore). I have seen this species and its nests in Singapore in the past, but have been unsuccessful in my search for it ever since I became seriously involved with these insects and learned how to photograph them. This nest was fair-sized by Apis andreniformis standards, probably a mature nest.
Apis andreniformis is noticeably smaller and more slender than the common honeybees (Apis cerana and Apis mellifera). They are also not considered very dangerous. For one thing, they are quite gentle, and only actual vibration to the nest or constant provocation near the nest will result in an attack. Furthermore their stings do not penetrate human skin easily. Even when they land a successful sting, the pain is trivial and merely feels like an ant bite, although with slightly more swelling. Thus, a nest in such a location would not generally be of harm. I wished, for one moment that this house was mine, so I could continue to observe them every day! However, my uncle wanted them gone, whether they were harmless or not. So I called a pest control operator, whom I met on my previous trip last year. He took care of the nest within minutes, using a kind of fumigant aerosol. Bees started flying everywhere, then dropping all over the floor. Within a few minutes, the nest was empty. We then broke the branch on which the nest was hung on.
The structure of the nest was fascinating, to say the least. There were three distinct sections. The cells in the first section (the second largest), right at the top, were full of honey; it seemed that they were used solely for this purpose. The largest section was in the middle, containing brood cells with larvae and pupae. Some new bees were already beginning to hatch, and these were all workers.
The last section, right at the bottom, contained cells that were distinctly larger. Some large black bees were already struggling out of these cells; these were the drones. There were many drones in the nest; most had also fallen and started to die. Right below the drone cells were some long, cylindrical vertical cells. These were the queen cells. This is the first time I have examined a nest of any type of honeybee so closely; it is most interesting. The presence of queen cells indicates that the nest was probably indeed mature, and in fact, swarming would have taken place shortly after.
The honey in the cells looked so tempting, but just too bad it had been contaminated with insecticide!
Strangely, I couldn’t find any queens. I collected hundreds of workers and males, some of which I made dried specimens of immediately. I placed many of them into alcohol, to be stored for later use in case anyone wants them. A fantastic end to this trip!
As I prepared to leave in the morning, an unusual potter wasp came into my balcony. She was black with numerous shining white markings! She hovered busily, carefully inspecting the potted plants and shelves there; I think she may have been scouting for a nest site. I had already kept all my equipment, and could neither catch nor photograph her. Still, I was pleased to see her. It was almost as if she turned up to bid me farewell!
I reached Hong Kong late at night. The weather is warm now, but distinctly cooler than Singapore; it is still spring.