The widow and the vapourer

While collecting brambles to feed my ever-hungry stick-insects, I noticed a batch of insect eggs on top of a silk mat and tunnel which had knitted two of the leaves together. Of course I had to have a closer look and the eggs were of the vapourer moth Orgyia antiqua, while the tunnel contained a spider which I think is probably one of the Steatoda 'false widows' which are mostly harmless but recently seen in many a tabloid frenzy about deadly spiders - I could probably ID it to species but not without pulling it out of its retreat and I'd rather leave it be as I suspect it found the ready-made moth cocoon to be a handy basis for a web (or maybe it happened the other way around). However the moth eggs do lead onto some interesting biology/ecology.

Vapourer eggs on the female moth's cocoon, under which a spider web/tunnel has been created

Entrance to the spider's retreat - I wonder if the black hairs round the entrance are from a vapourer caterpillar or something else. The flask-shaped moth eggs are clearly visible, including the dark dimple and band at the top.

The spider, probably Steatoda sp. is just visible within

Female vapourers are wingless and do not disperse as adults. Instead when they emerge from their pupal cocoon, they emit pheromones to attract the winged males (they are highly active flying zig-zag routes during the day, and sometimes at night, to find females) and once mated lay their eggs on their old cocoon. The larvae, which feed on various trees and shrubs, are highly distinctive with tufts of yellowish hairs on their dorsal surface and longer, narrower tufts at both ends. The adults are less spectacular and images of them can be seen on the excellent UKMoths site here.

Vapourer moth larva

Vapourer moth larva

Vapourer moth larva