The chalcid wasp Chouioia cunea Yang (Hymenoptera: Eulophidae) is one of the most dominant pupal parasitoids of Hyphantria cunea (Drury) (Lepidoptera: Arctiidae), an invasive pest of many forestry trees and agricultural crops. For mass rearing C. cunea for biological control purposes, the pupae of Antheraea pernyi (Guérin-Méneville) (Lepidoptera: Saturniidae) have been widely used as a substitu...

Toshiaki Shimizu* and Naokuni Takeda Laboratory of Applied Entomology, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183, Japan Department of Biomedical Science, COSMO Research Institute, Gongendo, Satte, Saitama, 340-01, Japan Z. Naturforsch. 53c, 927-931 (1998); received May 14/June 12, 1998 Melatonin, Mamestra brassicae, Testis, HPLC-ECD, Metabolic Path...

Overwintering larvae of the rice stem borer, Chilo suppressalis accumulate glycerol and are freezing tolerant to about -25 degrees C. However, non-diapausing larvae cannot accumulate glycerol and are killed by freezing. We compared the extent of tissue damage, the effects of glycerol concentration, and the transport of glycerol and water in fat body tissues from these larvae at selected freezin...

Data on offspring production by the alfalfa leafcutting bee, Megachile rotundata (F.), from three site-years were used to examine predictions of parental investment and sex ratio theory. In northern Utah, spring-emergent adults produce two types of offspring: those that develop directly to the adult stage and emerge in midsummer, and those that develop to the prepupal stage and enter diapause u...

Diapause is an actively induced dormancy that has evolved in Metazoa to resist environmental stresses. In temperate regions, many diapausing insects overwinter at low temperatures by blocking embryonic, larval or adult development. Despite its Afro-tropical origin, Drosophila melanogaster migrated to temperate regions of Asia and Europe where females overwinter as adults by arresting gonadal de...

James A. Fordyce* and Chris C. Nice Section of Evolution and Ecology, Center for Population Biology, University of California, Davis, CA 95616, USA Department of Biology, Southwest Texas State University, San Marcos, TX 78666, USA *Correspondence: E-mail: [email protected] Abstract Most butterflies that overwinter as diapausing eggs have evolved oviposition behaviours where egg placement is...