Nick Upton's picture

Parasitic wasp on mating Chalkhill blues

Observed: 31st July 2011 By: Nick UptonNick Upton’s reputation in InvertebratesNick Upton’s reputation in InvertebratesNick Upton’s reputation in InvertebratesNick Upton’s reputation in Invertebrates
Chalkhillbluesmate
parasitic wasp
parasiticwaspb
Description:

This tiny wasp was perched on the wings of a male chalkhill blue as it mated. Some kind of parasite at a guess.. Some Trichogrammatidae butterfly egg parasites are known to cue in on chemicals transferred to females by males during mating (they are attracted to the female after mating) and I wonder if something similar is going on here. Does anyone know of Chalkhill parasites?

Identifications
Species interactions

No interactions present.

Comments

BDeed's picture

Very interesting

Can't say i can help, but this is very interesting and something i wasn't even aware of! Thank you for sharing, i look forward to reading any responses you get.

Nick Upton's picture

Chalcid wasp

Many thanks; OK will do. Here's a link to the story of how Trichogramma brassicae uses chemical signals to find mated female Cabbage whites and rides on them until they lay eggs. http://www.pnas.org/content/106/3/820.full. I've also posted my images on a specialist Hymenopteran site based in Germany and will pass on any feedback I get from there as well. These blues could do without extra problems - if this is indeed a parasite - but at least it would be a natural one!

Nick Upton, naturalist and photographer.

DavidNotton's picture

To find host records of chalcidoids

Many host records are to be found in the Universal Chalcioidea Database written by Dr John Noyes and hosted on the NHM website: http://www.nhm.ac.uk/research-curation/research/projects/chalcidoids/

Nick Upton's picture

Chalcidoid wasp

Many thanks for your input and advice David. I'd wondered if it might be Eulophidae based on images I'd checked, but as you say, they're so small that microscopy is a must to be sure of much! I've now checked out the database you mention and there is currently no chalcidoid associate of Lysandra coridon listed. Trichogramma brassica (the species whose chemical attraction to cabbage whites has been studied) is listed as a parasite of Common blues, and there were lots of those mating nearby on the same day, but that has kinked antennae from what I can make out. I'm sure a lot of tiny parasites get overlooked, literally and this will no doubt remain unidentified, but getting a steer on the family helps!

Nick Upton, naturalist and photographer.

DavidNotton's picture

parasites of lycaenids

Riding on a host is called phoresy. This behaviour is also found in a number of genera of parasitic wasps of the family Scelionidae, which are also egg parasitoids.

Also you may be interested to know that the non-phoretic but attractively patterned ichneumonid wasp Listrodromus nycthemerus is quite easy to obtain by rearing holly blue larvae.

Nick Upton's picture

Phoretic wasps

Thanks for the extra insights. I think life for many insects must be a constant battle against parasitoids... I once watched a shield bug guarding her eggs (in the Caribbean) trying to protect her eggs from hordes of tiny wasps, maybe Scelionidae, by wiping them away with her legs. They just kept coming back from all sides...

Nick Upton, naturalist and photographer.