I have a friend visiting from England and he says that wasps don't bite they sting. I live in Canada and I've always been told that wasps bite. My friend says I'm wrong. Am I?
Wasps in Europe certainly sting. While many wasps have a powerful bite, I can't think of any that do so as a primary means of defence.
Of couse numerous other insects like many flies do indeed bite, and there may be some confusion here. Also, there are of course hundreds of common wasp species both in Europe and the Americas so you could easily have come across a biting wasp in the past.
I might add that the North American 'yellowjacket' is the equivalent to what we in Britain refer to as a common wasp (Vespula vulgaris). All of the European social wasps (the majority of which have the classic black and yellow stripes) sting as a means of defense, by using a modified ovipositor (egg laying tube) connected to a poison sac. The lack of barbs on the sting (unlike the famous honey bee, for instance) enables the wasp to sting a foe multiple times.
The 'social wasps' form only a very small percentage of the total number of wasp species on the planet, the majority of the rest being parasitic or parisititoid egg layers (laying their eggs in or on host species such as spiders or caterpillars). Again, the ovipositor is modified for the different requirements. Ichneumonid wasps have particularly long ovipositors for boring through bark and wood to lay their eggs on beetle grubs living within, whilst spider-hunting wasps sting and paralyse their victims, drag them to a burrow and lay an egg on the still living spider.
As a short aside, there is a funky wasp that preys on cockroaches. Cockroaches have a ‘scuttle’ mechanism when a light comes on or they’re threatened (quite obviously). However, when attacked by this particular wasp, the wasp stings the cockroach in the thorax and causes it’s front legs to temporarily buckle. As the ‘roach collapses forwards, the wasp stings the ‘roach for a second time, this time using a very precise sting into the ‘brain’ of the cockroach and injecting venom. This turns off the ‘scuttle’ mechanism, whereupon the wasp leads the placid cockroach to a selected hole / borrow, where the wasp lays an egg inside the cockroach. Grisly but very cool! Read more about the experiment to demonstrate this here: http://www.bgu.ac.il/life/Faculty/Liber .2003b.pdf
In short, the ‘wasps’ as a group have diverse uses for their ‘stings’ but none of the social wasps bite as a defence mechanism and as far as I’m aware, none of the other wasps bite for anything other than prey dismemberment. Here is a brief overview I've just found about Hymenoptera: http://www.sel.barc.usda.gov/hym/overview.html
Last edited by Dave Warburton (16th Aug 2007 15:00:09)
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