Cycling, macintosh, natural history and life in Singapore - Archives
Sat 27 Aug 2005
Potter wasp at the door
Category : Singapore Naturalist
22 Aug 2005 - A potter wasp decided to build a nest on the door. Where the grill blocks it from corridor view, and about 1.5 meters above the ground, it began construction today.
I discovered the activity when I nearly bumped into the mother wasp as I walked out the door. I backed off from the large insect hovering in front of my face and then saw the beginnings of the nest - the mud base had been completed.
I realised it was a harmless potter wasp, but the species remains unknown - I hardly got a clear look at her. Solitary females in this group (Oder Hymenoptera: Family Vespidae: Subfamily Eumeninae) build nests of mud and different species make nests of different shape, size and design. Later they lay a single egg or a clutch of eggs inside the nest, or one egg per chamber in multi-chambered nests.
When I returned that evening, the single-chambered pot-shaped nest was complete, with an unplugged opening. There were some mud stains around the pot, and I thought of the individual moist balls of mud that she had hauled over that day, one by one, to slowly build this nest. Amazing!
23 Aug 2005 - Next morning, again after 7am, I swung the door open to find her hovering in the area. Careful not to disturb her further, she left anyway. Had she been scared off? Or the nest deemed unsuitable for use?
That evening, the nest was still empty. Unsuccessful hunt or abandoned nest? Or did she have another nest to maintain elsewhere a well?
24 Aug 2005 - Hooray! She's back! She visited again after 7am, but the door was already open. I closed the door to return it to its 'rightful position' but she flew off anyway. had the morning inspection disruptive enough to cause the nest to be abandoned? Or had she finished her inspection by the time I came out the door?
I returned home in the evening to a pleasant surprise. The pot-nest opening was sealed! She must have spent a busy day catching prey (caterpillars or spiders), paralysing them and sealing them in with her egg or eggs--when the wasp larvae emerge, they will have fresh meat to feed on. Definitely not want to be the prey!
Hope to catch emergence! Lots of things can go wrong of course, disease, parasitism, inadequate nutrition, poor weather conditions, etc. Well, we'll see.
25 Aug 2005 - I do not expect any more activity, thinking this si a single-celled nest but the next morning I find she has laid down the base plate of a second cell. this time I must try to get a peek of the poor prey - a cell this large, it is likely to be a caterpillar. You know, the prey is paralysed, and still twitch, so you can spot the movement. I always feel so wretchedly sad for them!
I return to examine the cell at midday and sure enough, in the cell now resides a juicy caterpillar, twitching as it struggles against the paralysing venom, poor fella. I could not make out the identity or even the number of prey.
By evening, there seemed to be another caterpillar. It was the stuff of science fiction horror nightmares, a greenish-tinged twitching prey, helplessly awaiting an egg that it would eventually watch develop into a hungry larva! Horrors!
Oh wait, didn't they already use that idea in Alien?
I have seen brown and green colours and it has finally dawned on me that the abdomen is brown, the thorax seems enlarged and green and the head a kind of orangy-brown. There must be three fat, juicy caterpillars in there by now.