entomology conference snippets

last month, an international entomology congress took place in innsbruck (entomologists are biologists who study insects).
here are some interesting tidbits from various presentations:

male scorpionflies (panorpa sp.) produce a mix of specific aldehydes to attract females. coincidentally, the two main aldehydes are also released by freshly cut cucumbers, which means that females are sexually attracted to cucumbers. :-)

once the female scorpionfly has found a potential mate, the male is required to offer …”a gift” in order to mate: little balls of saliva*.
the more salivary mass, the longer (up to 7 hours!) they’re allowed to mate. (maybe i should give that strategy a try?)
*referred to it as “bonbons” by the lecturer.

many plants produce specific volatile chemicals as a reaction to herbivore infestation. parasitic wasps such as cotesia sp. have been shown to learn that there’s a connection between these volatiles and the occurrence of their host insects, so they rely on the chemicals for searching wide areas, and then switch to “the usual methods” to track down their prey on the infested plants.

“bee orchids” (also called “sexually deceptive orchids”, e.g. ophrys sp.) trick male insects (bees, wasps, beetles and other insects) into pollinating them by pretending to be sexual partners.
the flowers mimic female insects in shape, colour and scent. males flying by are so attracted to them that they try to copulate with the flowers. in the process, they also pick up the pollen (resp. pollinate the flower).

there are currently more than 2400 alien animal species and more than 3600 kinds of alien plant in europe. numbers are increasing.

suocerathrips linguis is a species of thrips with …let’s just call it “rough sex”: males sometimes cut off the females’ wings during copulation. this might be a strategy to reduce sperm competition – it makes it harder for the females to find other males after mating. (i’m certainly not giving *that* strategy a try!)

entomopathogenic fungi (fungi that are parasitic to insects, entomophtorales) have, over time, evolved to a point where they can actually change their host’s behaviour: shortly before it dies – but only in the evening* – the infected insect usually crawls up to the top of the twig that it’s sitting on (thus increasing the fungal spores’ range).
this kind of behaviour is not known from healthy individuals. when the insect dies, the fungus sometimes even fastens it with rhizoids (branching hyphae).
*because (1) there’s less predation as it gets darker, and (2) spore dispersal often depends on thaw.

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