A chrysidid trap

[Villu]

Hi!

I just wanted to share my experiences with trapping Chrysididae.

Having observed behavior of the chrysidids, which search for the hosts living in dry wood as they always go up along dead tree trunks I thought it could be used for trapping them. Then I found that traps taking advantage of this habit have been designed already. Have a look at the end of this page for example:
http://www.insecte.org/spip.php?article77&artsuite=2

There are two kinds of "Les pièges à migration verticale" at the bottom of this page, one of them designed especially for chrysidids. Then I decided to make my own. I thought that the traps at this French site cover too little of the trunk and therefore many would go by the trap without entering. Also I thought that there must be some sort of obstacle to avoid insects to escape from below after they are already inside the trap and failed escaping from the top. This is what I came up with:

My trap goes around the trunk and opening below is quite small reducing the chance that some will exit there.

There are few disadvantages of this design too: It is quite large making it inconvenient to transport and set up. Suitable trunks for this trap are not easy to find in some areas. Also chance of being spotted by curious trespassers is high.

This trap does not collect as many specimens as malaise trap does but nearly all specimens are interesting and I like that selectivity. I have collected many interesting chrysidids with it but also all other wood nesting wasps and bees and their parasites. For example this year I got nice series of Orussus abietinus, which is quite rare around here. Beside Hymenoptera it collects other wood-related insects like cerambycid and buprestid beetles etc.

I have some thoughts how to improve the design of this trap and next year I'll have several of them collecting insects for me.

Regards,
Villu

[Euchroeus]

WOW VIllu

thanks for sharing your experiments!

It looks very good.
Thanks also for the French web-site, I didn't know it.
Do you use other collecting traps or systems?

Cheers
Paolo

[jeromec]

I used yellow traps on the ground, in sandy soils areas (France, Ile de France) : 2 captured Chrysis bicolor, while nothing flew.
At the beginning, I had determined them as C. illigeri (but by using the article on the chrysidid of the North of Europe and your book, I arrived in C. bicolor).

On the same area, I found some Tachysphex pompiliformis & Cerceris (arenaria & a big specimen of an other species) + Crossocerus 4-maculatus & Alysson spinosus (and some others species).