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Tail Secretions  - Parcoblatta

Tail Secretions - Parcoblatta
Perry County, Pennsylvania, USA
3rd-5th instars seem to produce a secretion on the posterior end, which coats the last few terga and the cerci. It is sticky, and likely to be a predator repellent. Whenever the roach molts, the secretion is left behind on the shell. Adults and young nymphs do not seem to possess this, which I cannot make sense of

Nice image
Apparently the defensive actions of the secretions (originating from Type V abdominal glands) are the result of both the adhesive properties of the proteinaceous material (gumming up mouthparts of attacking centipedes, etc.) as well as from repellant/toxic compounds that are exuded. I don’t know that adults are entirely unable to produce these defensive secretions, but seeing that pale posterior suggests to me that I’m looking at a nymph rather than an apterous female, e.g.:

I've added a thumb of your image to the predator/parasitoid section on the main Cockroach Info Page.

It is very sticky. In fact, the roaches often get stuck to each other if you put them in too close of proximity. Can even be deadly because they get so stressed that they don't recover, and die