Ephestia kuehniella (Zeller)
Common name: Mediterranean flour moth, mill moth.
Systematic position: Insecta, Holometabola, Lepidoptera, Pyralidae.
Morphology: Adults are 12-18 mm in length, the forewings pale grey with darker transverse, zig-zag like bars. The larva is 12-16 mm long, color greyish-yellow to pink, head red-brown, the abdomen with 5 pairs of prolegs.
Distribution: Cosmopolitan, more common in temperate zones.
Life history: Ephestia kuehniella often lives near cultivated fields, farms or storage bins, feeding on dry diets, such as harvested grains, biscuits and similar substrates. Females place their ca 150-200 (or even much more) eggs in the commodity (e.g. flour) wherein the emergent larvae live, feed and produce much webbing. After several weeks they spin a cocoon to pupate therein. In the laboratory development was fastest at 25ºC and 75% RH, but the duration of development of various populations in different regions is variable, dependent on larval density, temperature, diet quality and the degree of variation within the specific population. In cooler regions the pest may undergo a winter diapause. The pest raises 5-6 annual generations and the adults, which usually hide in shaded sites, live 2-3 weeks.
Economic importance: Ephestia kuehniella feeds on flour, bran, whole grains, dry fruits, biscuits and even animal feed. The copious amounts of excreted webbing clog up commodities, animal feed dispensers and packaging machinery, requiring further processing and greatly increasing costs. Although usually controlled, the pest can rapidly build up large populations and cause much damage if suitable control measures are not applied.
Management:
Monitoring: The occurrence of groups of larval or pupal residues, bound by webbing, located on the tops of the commodity, or between dry fruits, indicates the pest’s presence. Various light traps or pheromone traps can be used for detecting the presence and emergence of adults, and their density in storage facilities.
Commodity (wheat) susceptibility: The pest’s slower development and lower fecundity on different wheat flour varieties may reduce its damage and enhance the activities of the natural enemies.
Horticultural methods
Mating disruption: Pheromone -baited traps placed in a Polish mill reduced moth catches by about 90% during one year, the reduction being larger during the following year. Similar results were obtained by auto-confusion in Greece.
Fumigation and Modified atmosheres: Ozone fumigation killed almost all adults, pupae and larvae of E. kuehniella, but only 62% of the eggs. Other fumigants to kill the pest in flour stores include methyl bromide and phosphine. However, larvae in diapause at low temperatures may be tolerant to fumigants. Most pest stages exposed for 1 hour at 25°C to carbon dioxide in a climatic chamber at high pressure, died. Various essential oils, applied as fumigants, were toxic to the pest, especially those of lemon and of Origanum majorana L. (Marjoram) (Lamiaceae).
Chemical control: Diatomaceous earth can be applied against E. kuehniella, its efficacy being more pronounced at higher temperatures.
Biological control: Promising results have been obtained with various natural enemies. These include parasitoids, consisting of Trichogramma spp., Venturia canescens and Apanteles sp. Predators include Blattisocius tarsalis and several phytoseiids. The application of entomopathogenic nematodes in wheat resulted in up to 78% E. kuehniella mortality. Several generalist predators were also assayed with varying results.
References
Athanassiou, C.G., Kavallieratos, N.G., Menti, H. and Karanastasi, E. 2010. Mortality of four stored product pests in stored wheat when exposed to doses of three entomopathogenic nematodes. Journal of Economic Entomology 103: 977–984.
Coșkuncu, K. S. and Kovancı, B. 2005. The adult population fluctuations of Ephestia kuehniella Zeller (Lepidoptera: Pyralidae) in flour factories in Bursa province. Türkiye Entomoloji Dergisi 29: 35-48.
Cox, P.D., Bell, C.H., Pearson, J. and Beirne, M.A. 1984. The effect of diapause on the tolerance of larvae of Ephestia kuehniella to methyl bromide and phosphine. Journal of Stored Products Research 20: 215-219.
Daumal, J. and Pintureau, B. 1985. Study of the variability of the duration of development in Ephestia kuehniella Zeller (Lep. Pyralidae). Acta Oecologica, Oecologia Applicata 6: 367-380.
Işikber, A.A. and Öztekin S. 2009. Comparison of susceptibility of two stored-product insects, Ephestia kuehniella Zeller and Tribolium confusum du Val to gaseous ozone. Journal of Stored Products Research 45: 159-164.
Jacob, T.A. and Cox, P.D. 1977. The influence of temperature and humidity on the life-cycle of Ephestia kuehniella Zeller (Lepidoptera: Pyralidae). Journal of Stored Products Research 13: 107-118.
Karaborklu, S. and Yılmaz, S. 2011. Chemical composition and fumigant toxicity of some essential oils against Ephestia kuehniella. Journal of Economic Entomology 104:1212-1219.
Momen, F.M. and El-Laithy, A.Y. 2007. Suitability of the flour moth Ephestia kuehniella (Lepidoptera: Pyralidae) for three predatory phytoseiid mites (Acari: Phytoseiidae) in Egypt. International Journal of Tropical Insect Science 27: 102-107.
Nielsen, P.S. 1998. The effect of a diatomaceous earth formulation on the larvae of Ephestia kuehniella Zeller. Journal of Stored Products Research 34: 113-121.
Riudavets, J., Castañé, C., Alomar, O., Pons, M.J. and Gabarra, R. 2010. The use of carbon dioxide at high pressure to control nine stored-product pests. Journal of Stored Products Research 46:228-233.
Schöller, M., Hassan, S.A. and Reichmuth, C. 1996. Efficacy assessment of Trichogramma evanescens and T. embryophagum (Hym.: Trichogrammatidae), for control of stored products moth pests in bulk wheat. Entomophaga 41:125-132..
Sieminska, E. and Löfstedt, C. 2009. Long‐term pheromone‐mediated mating disruption of the Mediterranean flour moth, Ephestia kuehniella. Entomologia Experimentalis et Applicata 131: 294-299.
Tarlack, P., Mehrkhou, F. and Mousavi, M. 2015. Life history and fecundity rate of Ephestia kuehniella (Lepidoptera: Pyralidae) on different wheat flour varieties. Archives of Phytopathology and Plant Protection 48: 95-103.
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.
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