Bagworm Larvae Research Articles

Juniper, Bagworm Control, Zanesville, Ohio, 1975

Abstract A commercial planting of 5'-7' tall junipers with a uniform infestation of middle-instar bagworm larvae was selected for insecticide evaluation. Population density was ca. 1 larva/10 cm of branch tip. Larvae carried bags ca. 1-1.5 cm long at time of application. Treatments were applied to each of 4 single tree replicates July 7, 1975, under sunny skies, 85°F and calm. A Myers hydraulic sprayer operating at 200 psi was used to apply ca. 1 gallon of finished spray/tree (= spraying to runoff). Treatment effectiveness was evaluated July 10, by inspecting ten 20 cm tips/tree.

Parasitism, Predation, and Disease in the Bagworm, Thyridopteryx ephemeraeformis (Haworth) (Lepidoptera:Psychidae)1

Approximately 43% of the larval bagworm population in the Athens, Ga., area were killed by naturally occurring biotic factors during the period July through Sept., 1970. About 71% were killed in 1971 and 66% in 1972. Nineteen insect species including parasitoids, hyperparasites, and scavengers were reared from dead bagworm larvae and pupae. The bagworm is a new host record for 9 of these insects. Bagworm pathogens included bacilliform bacteria, a polyhedrosis virus, and fungi belonging to the genera Aspergillus, Penicillium, Geotrichum, Paecilomyces, Hirsutella, Beauveria, Cordyceps, Scopulariopsis , and Pestalotia . An inverse relationship existed between the levels of fungal disease and parasitism in larval populations. During 1971 a high level of fungal disease (51%) and a low level of parasitism (10%) were recorded. In 1970 and 1972, high levels of parasitism (29% and 46%, respectively) and low levels of fungal disease (13% and 17%, respectively) were recorded. It appears that fungi contributed most heavily to bagworm mortality during wet periods and that insect parasitoids were the predominant mortality factor during dry periods.

Bagworms: Effectiveness of Several Insecticide Formulations Against the Larvae of Three Species12

Susceptibility of three species of bagworm larvae to several insecticide formulations was determined under laboratory conditions. Out of the test compounds chlorpyrifos-methyl and Salithion® (2-methoxy-4H-1,3,2-benzodioxaphosphorin 2-sulfide) emulsifiable concentrate formulations were found to be most toxic to three species of bagworms. There was a high correlation in species susceptibility to insecticide between Prodenia litura F. and Cryptothelea minuscula Butler and between Calospilos miranda Butler and C. minuscula. In field tests excellent control was obtained of C. minuscula infesting plum trees, Prunus mume Sieb. et Zucc., with chlorpyrifosmethyl and Salithion water emulsion sprays at an active ingredient concentration of 0.044 percent and 0.05 percent, respectively.