Plodia interpunctella (Hübner)
Common name: Indian-meal moth.
Systematic position: Insecta, Holometabola, Lepidoptera, Pyralidae.
Morphology: Adults are 8–10 mm in length The anterior third of their forewings is greysh, the distal two thirds are reddish brown, with a copper hue. The larvae are mostly grey with a brown head, 12–14 mm long, with 5 pairs of prolegs.
Life history: A life cycle requires about 4-6 weeks in summer, much longer in winter, and several annual generations can be completed; the actual duration usually depends also on the diet (commodity). The exposure of the larval stages to low temperatures (below 20°C) can induce diapause, and various moth strains differ in their tendency to enter diapause. Fecundity depends on diet; about 100 on wheat, 175 on broken maize, but 260, 275, and 280 when the young larvae were reared on walnuts, almonds, and wheat bran, respectively. The eggs are laid on the food singly or in small groups. The emerging larvae that feed on grain usually occur in the upper parts of stacked bags. As they grow they spin webs, leaving silk threads as they move within the commodity, in which they pupate within cocoons. The adults, which are attracted by and move towards food odors, live for about one week. They do not usually migrate, but occasionally undertake long-distance foraging flights, during the twilight hours.
Economic importance: Plodia interpunctella is a major pest of stored products, causing serious quantity and quality losses. It infests many dry foodstuffs of vegetable origin, including dried fruits and nuts, cereals, flour, bread, rice and others. It also feeds on pet (including bird) foods. Damage is due to product loss, soiling it and engulfing it in webbing which reduces its value, and to engendering consumer complaints. In addition, the larvae can bite through plastic and cardboard containers in order to gain access to the sealed products and damage them.
Monitoring: The primary adult sampling tools are pheromone, and/or sticky traps, water traps and mark and recapture. Larvae can be sampled with food traps or corrugated cardboard traps.
Mechanical control: Sanitation, surface insecticidal treatments, sealing cracks and crevices in the storehouse, inert dusts, modified atmosheres and heat treatments can reduce infestations. Insect-resistant food packaging can prevent the invasion of the larval stages.
Auto-confusion: This system was successfully used in Greece to reduce pest infestations in retail stores and feed mills.
Irradiation: Irradiating infested moth-infested dates with doses of 450 Gy caused larval death. Irradiating hazelnuts (Corylus avellana L. ) with 1000 Gy killed all pest eggs and immatures.
Physical control: Storage at 10°C killed most moths, the surviving adults producing fewer eggs which had lower viability. Some types of diatomaceous earth were lethal to the pest, but mortality decreased with increased humidity, which prevented the drying action of this compound. The pest may also be killed by keeping the infested commodity for a week at freezing temperature or by brief heating in a microwave
Chemical control: Pest strains have developed resistance to organophosphates and to Bacillus thuringiensis. Spinosade still seems to be effective. The combination of pyrethrin and an insect growth regulator (methoprene) applied as aerosol controlled the pest in storage facilities.
Biological control: Species of Trichogramma are major enemies of P interpunctella. Trichogramma evanescens Westwood forages for pest eggs to a depth of 8 cm in wheat or oats grains, less in rice grains. Other Trichogramma spp. suppressed about 57% of the pest population in peanuts. Effective pest control has in some cases been achieved with Habrobracon hebetor. New strains of B. thuringiensis studied in Turkey seem to be promising. The microsporidian pathogen, Nosema plodiae Kellen and Lindegren, infected the pest’s larvae, which became stunted and often died before pupating. Baculoviruses, which are disseminated by healthy adults, decreased the moth’s reproduction and egg viability. The fecundity of moths infected by Entomopathogenic nematodes was reduced by at least 44%; the larvae were less susceptible.
Alper, M., Gűnes, H., Çöl, B. and Tunca, H. 2016. Bioactivities of cry gene positive Bacillus thuringiensis (Berliner) (Bacillales: Bacillaceae) strains on Ephestia kuehniella Zeller, 1879 and Plodia interpunctella (Hübner, 1813) (Lepidoptera: Pyralidae). Türkiye Entomoloji Dergisi 40: 365-375.
Azelmat, K., Sayaha, F., Mouhibb, M., Ghailania, N. and El-Garroujb, D. 2005. Effects of gamma irradiation on fourth‐instar Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae). Journal of Stored Products Research 41: 423–431.
Brower, J.H. 1988. Population suppression of the almond moth and the Indian meal moth (Lepidoptera: Pyralidae) by release of Trichogramma pretiosum (Hymenoptera: Trichogrammatidae) into simulated peanut storages. Journal of Economic Entomology 81: 944-948.
Campbell, J.F., Mullen, M.A. and Dowdy, A.K. 2002. Monitoring stored-product pests in food processing plants with pheromone trapping, contour mapping, and mark-recapture. Journal of Economic Entomology 95: 1089-1101.
Jenson, E.A., Arthur, F.H. and Nechols, J.R. 2010. Methoprene and synergized pyrethrins as aerosol treatments to control Plodia interpunctella (Hübner), the Indian meal moth (Lepidoptera: Pyralidae). Journal of Stored Products Research 46: 103-110.
Kellen, W.R. and Lindegren, J.E. 1968. Biology of Nosema plodiae sp. n., a microsporidian pathogen of the Indian-meal moth, Plodia interpunctell (Hübner), (Lepidoptera: Phycitidae). Journal of Invertebrate Pathology 11: 104-111.
Mbata, G.N. and Shapiro-Ilan, D.I. 2005. Laboratory evaluation of virulence of Heterorhabditid nematodes to Plodia interpunctella Hübner (Lepidoptera: Pyralidae). Environmental Entomology 34: 676-682.
Mewis, I. and Ulrichs, Ch. 2001. Action of amorphous diatomaceous earth against different stages of the stored product pests Tribolium confusum, Tenebrio molitor, Sitophilus granaries and Plodia Interpunctella. Journal of Stored Products Research 37: 153-164.
Mohandass, S., Arthur, F.H., Zhu, K.Y. and Throne, J.E. 2007. Biology and management of Plodia interpunctella (Lepidoptera: Pyralidae) in stored products. Journal of Stored Products Research 43 302-311.
Nansen, C., Davidson, D. and Porter, P. 2009. Using water bottles for trapping of Indianmeal moth: exemplified by a study in stored peanuts. Entomologia Experimentalis et Appicata 133: 251–259.
Nasir, M.F. Ulrichs, Ch., Prozell, S. and Schöller, M. 2017. Laboratory studies on parasitism of Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae) by two species of Trichogramma Westwood (Hymenoptera: Trichogrammatidae) in different grains, and evaluation of traps for their monitoring. Journal of Stored Products Research 74: 6-12.
Ozyardimci, B. Cetinkaya, N., Denli, E., Ic. E. and Alabay, M. 2006. Inhibition of egg and larval development of the Indian meal moth Plodia interpunctella (Hübner) and almond moth Ephestia cautella (Walker) by gamma radiation in decorticated hazelnuts. Journal of Stored Products Research 42: 183-196.
Schöller, M., Prozell, S., Al-Kirshi, A.G., Reichmuth, Ch., 1997. Towards biological control as a major component of integrated pest management in stored product protection. Journal of Stored Products Research 33: 81–97.
Trematerra, P., Athanassiou, C.G., Kavallieratos, N.G. and Buchelos, C.Th. 2013. Efficacy of the auto-confusion system for mating disruption of Ephestia kuehniella (Zeller) and Plodia interpunctella (Hübner). Journal of Stored Products Research 55: 90-98.
Vail, P.V., Hoffmann, D.F. and Tebbets, J.S., 1993. Autodissemination of Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae) granulosis virus by healthy adults. Journal of Stored Products Research 29: 71–74.