Phillip K. Harein

Establishment and characterization of a cell line from embryos of the Indianmeal moth, Plodia interpunctella

Abstract A cell line, UMN-PIE-1181, initiated in November, 1981, from embryos of a malathion-resistant strain of Indianmeal moth, Plodia interpunctella , was in the 83rd passage on January 28, 1985. The line consists of single, small, fibroblastlike cells that are polyploid with chromosome numbers ranging from 56 to 180. Growth rate is dependent on seeding density, there being no growth at or below seeding densities of 2 × 10 5 5 , ml ; optimum growth requires a fetal bovine serum concentration of at least 5%. Twenty-nine isozymes were examined. Five enzymes from the cell lines resolved well and subsequently were compared to enzymes extracted from 4-day-old embryos and other life stages of the insects. Phosphomannose isomerase, malic enzyme, malate dehydrogenase, phosphoglucose isomerase, and glucose-6-phosphate dehydrogenase in extracts from the cultured cells and from the insects had identical patterns. Two bands for glutamate-oxalacetate transaminase, present in the cell line, were not observed in the tissue extracts. Furthermore, lactate dehydrogenase from the cultured cells appeared as four bands but was not detectable in any of the samples run from the various life stages of the insects.

Exploratory Tests with Bromodan as a Protectant for Wheat Against Stored-Product Insects

Bromodan (5-(bromomethyl)-l,2,3,4,7,7-hexachloro-2-norbornene) was tested as a protectant for Soft Red Winter wheat against infestation by 3 species of stored-product insects. Immediately after treatment a deposit of 20 ppm killed all rice weevils, sitophilus oryzac (L.), and cigarette beetles, Lasioderma serricorne (L.), and a deposit of 80 ppm killed all confused flour beetles, Tribolium confusum Jacquclin duVal. Eight months after treatment at the rate of 20, 40, and 80 ppm, respectively, rice weevil mortalities of 12, 66, and 100% were obtained. Based on development of progeny, a deposit of 20 ppm prevented reproduction of each species.