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Full-Text Articles in Entomology
Ecdysteroid Titers In Mated And Unmated Drosophila Melanogaster Females, Lawrence G. Harshman, Anne M. Loeb, Beth A. Johnson
Ecdysteroid Titers In Mated And Unmated Drosophila Melanogaster Females, Lawrence G. Harshman, Anne M. Loeb, Beth A. Johnson
Lawrence G. Harshman Publications
Radioimmunoassay was used to determine ecdysteroid titers in mated or unmated Drosophila melanogaster females. Whole-body ecdysteroid titers increase after mating and this response is more pronounced after 12–24 hours than it is immediately after mating. In one experiment, females were mated to transgenic males deficient in accessory gland proteins to test whether these peptides mediate the observed increase in female whole-body ecdysteroid titers. Females mated to such transgenic males do not show a pronounced increase in whole-body ecdysteroid titers. The effect of mating on female hemolymph ecdysteroid titers was also investigated. Hemolymph ecdysteroid titers decrease after mating. The ecdysteroid titer …
Plant Hybrid Zones And Insect Host Range Expansion, Diana Pilson
Plant Hybrid Zones And Insect Host Range Expansion, Diana Pilson
Diana Pilson Publications
The hybrid bridge hypothesis suggests that plant hybrids ‘‘bridge’’ the genetic gap between actual and potential host species, and that, for this reason, herbivorous insects are more likely to evolve an expanded host range in the presence of hybrids. While intuitively appealing, the hypothesis has two implicit assumptions: that phenotypic gaps between potential hosts limit host range, and that characters controlling host use are additively inherited in plant hybrids. Evaluation of these assumptions suggests that operation of the hybrid bridge hypothesis is relatively uncommon. In addition, the hypothesis has not been well integrated into existing theoretical and empirical work on …