Potential of Hymenopteran larval and egg parasitoids to control stored-product beetle and moth infestation in jute bags.
The control of stored-product moths in bagged commodities is difficult because the developmental stages of the moths are protected by the bagging material from control measures such as the application of contact insecticides. Studies were carried out to assess the ability of Hymenopteran parasitoids to locate their hosts inside jute bags in the laboratory. The ability of different parasitoids to penetrate jute bags containing rice was investigated in a controlled climate chamber. Few Habrobracon hebetor (Say) (Hymenoptera: Braconidae) passed through the jute material while a high percentage of Lariophagus distinguendus (Förster), Anisopteromalus calandrae (Howard) (Hymenoptera: Pteromalidae), Theocolax elegans (Westwood) (Hymenoptera: Pteromalidae) and Trichogramma evanescens Westwood (Hymenoptera: Trichogrammatidae) were able to enter the Petri-dishes. Significantly more L. distinguendus and T. elegans entered compared to H. hebetor. There was significant difference in the mean percentage parasitoids invading depending on species. Head capsules and/or thorax widths were measured in order to determine whether the opening in the jute material would be large enough for entry of the parasitoids. These morphometric data differed depending on parasitoid species and sex. The parasitoid Venturia canescens (Gravenhorst) (Hymenoptera: Ichneumonidae) did not enter the bags, but located host larvae inside the jute bags and parasitized rice moths Corcyra cephalonica larvae by stinging through the jute material. Venturia canescens significantly reduced the number of C. cephalonica adults emerging from the bagged rice; therefore, it could be released in storage rooms containing bagged rice for biological control of C. cephalonica. The use of parasitoids to suppress stored-product insect pests in bagged commodities could become a valuable supplement to the use of synthetic pesticides.
Division Urban Plant Ecophysiology, Faculty of Life Sciences,Humboldt-University of Berlin,Lentzeallee 55/57, 14195 Berlin,Germany.
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Adarkwah
Division Urban Plant Ecophysiology, Faculty of Life Sciences,Humboldt-University of Berlin,Lentzeallee 55/57, 14195 Berlin,Germany.
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Ulrichs
Division Urban Plant Ecophysiology, Faculty of Life Sciences,Humboldt-University of Berlin,Lentzeallee 55/57, 14195 Berlin,Germany.
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Schaarschmidt
Department of Agronomy, Faculty of Agriculture,University for Development Studies,P.O. Box TL 1882, Tamale,Ghana.
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Badii
Department of Agronomy, Faculty of Agriculture,University for Development Studies,P.O. Box TL 1882, Tamale,Ghana.
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Addai
Department of Crop Science,University of Ghana, School of Agriculture, College of Agriculture & Consumer Sciences,Legon, P.O. Box 68, Accra,Ghana.
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Obeng-Ofori
Division Urban Plant Ecophysiology, Faculty of Life Sciences,Humboldt-University of Berlin,Lentzeallee 55/57, 14195 Berlin,Germany.
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Schöller
D000818:Animals; D001837:Body Weights and Measures; D001517:Coleoptera / Q000469:parasitology*; D032381:Corchorus; D018857:Food Packaging; D009036:Moths / Q000469:parasitology*; D010572:Pest Control, Biological / Q000379:methods*; D014863:Wasps / Q000033:anatomy & histology / Q000502:physiology*