Erigone atra

Chemical cues from spiders are also used by non-arachnid predators to locate their prey. For example, the ichneumonid wasp Gelisfestinans parasitizes the spider Erigone atra, which lives in wheat fields. Contact with the silk of its host elicits increased searching behavior from the parasitoid, whereas contact with silk from other spider species does not, indicating a high degree of specificity (Baarlen et al.,... 

Baarlen, P. V., Topping, C. J. and Sunderland, K. D. (1996). Host location by Gelis festinans, an eggsac parasitoid of the linyphiid spider Erigone atra. Entomologica Experimentalis etApplicata 81 155-163. 

---