Egg‐hatching in thrips (Insecta: Thysanoptera)

Abstract

The hatching of eggs of thrips (Insecta: Thysanoptera) was investigated for three thripids, Thrips tabuci Lindeman, Frankliniella fusca (Hinds) and Kakothrips pisivorus (Westwood), and for a phlaeothripid, Haplothrips leucanthemi (Schrank). An embryonic cuticle with hatching spines was found in these thripids, and distinct lids were discovered on eggs of the first two species of thripid. At least one species of phlaeothripid lacks hatching spines. Haplothrips leucanthemi eggs did not have a distinct lid; the eggs split along lines of weakness following the pattern left by the follicle cells. Kakothrips pisivorus was observed and photographed during hatching. The larva emerged most of the way out of the egg while still enclosed in embryonic cuticle. Expansion and contraction of the pronotum split the embryonic cuticle, which was then forced down to the tip of the abdomen by peristaltic movements, freeing in turn the antennae and legs. The embryonic cuticle was left poking out of the oviposition hole.