Plodia interpunctella

Plodia interpunctella (Hubner, 1813)
(one synonym: Tinea zeae)
Indian Meal Moth
PHYCITINI , PHYCITINAE , PYRALIDAE

Don Herbison-Evans ( donherbisonevans@yahoo.com )
&
Stella Crossley

This Caterpillar is white with a brown head, and sparse long white hairs. It is a pest both in Australia and overseas, of any stored foodstuff, for example:

grain,

dried fruit, and

nuts.

In infesting these foodstuffs, it makes a sparse cocoon of silk.

When one Caterpillar encounters another, they each produce a small amount of brown liquid from the mouth, and this causes the Caterpillars to walk apart. This appears to be a mechanism that prevents overcrowding of the Caterpillars. Unfortunately for the Caterpillars, this mandibular secretion also attracts parasitoid wasps such as the Ichneumonid Venturia canescens.

The caterpillar typically walks several metres from its foodstuff to pupate in a silk cocoon.

(Photo: copyright and courtesy of Joyce Gross, Berkeley Natural History Museums, University of California,)

The adult is brown, with a pale basal area on each forewing demarked by a dark line. The hindwings are plain off-white. The moths have a wingspan of about 1 cm.

(Specimen: courtesy of the The Australian Museum)

The adult females are attracted to lay eggs on substrates contaminated by wandering fifth instar larvae. The adults use ultrasonic sounds (~80 Khz) in their courtship behaviour. They also use pheromones (specific sex-attractant substances) which have been determined. Pheromone traps can be purchased to control the moths. The authors found that these can have an embarrassing effect if used in a home, as some pheromone condenses on clothing. Then when one then walks around a supermarket (where inevitably there will be some of these moths present) they cluster and flutter around one's body.

Attempts have also been made to control the pest using :

light and heat [Rutter RR, Ferkovich SM],

ultrasound [Huang F, Taylor R]

gamma ray irradiation [Ashrafi SH, Roppel RM],

Pyriproxyfen (egg hatching preventative) [Silhacek D],

Organophosphate Dust [Mejia D],

a Granulovirus ( BACULOVIRIDAE ) [Russell DL],

the bacterium Bacillus thuringiensis ( BACILLACEAE ) or its toxin [Oppert B, Loseva O, Candas M, Bulla LA],

the fungi Beauveria bassiana, Paecilomyces farinosus and Paecilomyces fumosoroseus [Bischoff, R],

the egg-parasitoid wasp Trichogramma evanescens ( TRICHOGRAMMATIDAE ) [Scholler M, Prozell SJ],

the wasp Bracon hebetor ( BRACONIDAE ) [Baker J, Brower J],

the wasp Venturia canescens ( ICHNEUMONIDAE ) [Dreissen G, Bernstein C, Van Alphen JJM, Kacelnik A]

the Warehouse Pirate Bug Xylocoris flavipes ( ANTHOCORIDAE ) [Semple RL, et al],

the predacious bug Joppeicus paradoxus ( JOPPEICIDAE ) [Miyanpshita A, Imamura T, Visarathanonth P],

using Transgenic Corn [Sedlacek JD, Komaravalli SR, Hanley AM, Price BD, Davis PM].

This species originated in Europe, but now occurs world-wide, for example:

U.K., and

U.S.A., and

over the whole of Australia (having been introduced by unfortunate accident).