Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

Potato Tuber Moth (Phthorimaea operculella, Zell.).

Abstract

Phthorimaea operculella, Zell., is found in Cyprus wherever potatoes are grown, being a more serious pest of this crop than of tobacco, of which it attacks the leaves and stems, or of tomato, of which it also infests the fruit. Brief descriptions are given of the stages. At 80-85°F. the life-cycle from oviposition to emergence occupies 21 days, but during the winter, at 55-62°F., the pupal stage alone may last 50 days. The females lay about 150 eggs singly or in batches of 3-4. When they are laid on the lower surface of the leaves or on the shoots, the larvae cause the formation of dry, brown, blistered areas by feeding within the leaflets, which may die, or kill the parts of the plant above the point of entry in petioles or thin stems. When the eggs are laid on the tubers, in cracks in the skin or round the eyes, the larvae construct tunnels, at first near the surface but later more deeply, which facilitate the entrance of fungi and bacteria. Successive generations are able to breed within the tubers, infestation of which 'is most serious in storage. The presence of the larvae is usually indicated by small mounds of frass ejected from the burrows. Control measures, which are discussed, aim chiefly at protecting the tubers from ovipositing females in stores or in fields during harvest, or when uncovered by cracks in the soil owing to lack of careful irrigation or cultivation. Larvae may migrate to tubers placed in heaps or baskets after harvesting if they are covered with leaves and stems and may also penetrate the cracks in the soil of dry ground and attack tubers ready for harvest [cf. also R.A.E., A 20437].