Life Sciences Commons^™

Viability Of Pre-Adult Stages In Drosophila Melanogaster, Khadijeh Shakerifar

Masters Theses

The pre-adult viability of four pure strains and two hybrid strains was determined for Drosophila melanogaster. The data fail to show significant mortality and the ratios of the duration of the three different stages remained approximately constant. There are many factors which have been found to affect survivorship; one factor is density. As density of population within a limited and closed universe increases, the rate of mortality would increase and viability would generally decrease. However, our densities were well within the range having no effect on viability. Under the conditions these experiments were performed, no genetic or environmental factors …

Interrelationships Of Hypera Postica (Gyllenhal) (Coleoptera: Curculionidae) And Bathyplectes Curculionis (Thomson) (Hymenoptera: Ichneumonidae) In Illinois With Emphasis On Host-Parasite Densities, Distribution Of Parasites Within Available Hosts And Estimates Of Percent Parasitism, Robert John Barney

Masters Theses

In an attempt to better understand the host-parasite relationship of the alfalfa weevil, Hypera postica (Gyllenhal) (Coleoptera: Curculionidae) and Bathyplectes curculionis (Thomson) (Hymenoptera: Ichneumonidae), all life stages of the parasite were monitored throughout the spring. Sampling was conducted on a degree day basis from early March to late May in an alfalfa field in Mason County, Illinois.

Dissections of host alfalfa weevil larvae revealed 2nd and 3rd host instars were preferred larvae for oviposition. Peak parasite densities were found to precede peak total host larval densities, but coincided with peak densities of the preferred 2nd and 3rd instars. Larger host …

Seasonal Diversities Of Lotic And Lentic Benthic Insect Populations, Jerry E. Bindel

Masters Theses

The benthic insect populations from Lake Charleston and the Embarras River above and below Lake Charleston were examined twice monthly for seasonal differences in number of organisms, number of taxa and species diversity from October 13, 1976 to February 16, 1977. The water quality parameters of alkalinity, carbon dioxide, dissolved oxygen, pH and temperature were also examined for each site to determine if any parameter showed a sufficient deviation as to exert an influence on the benthic insect populations. Low dissolved oxygen and high carbon dioxide values were noted and occurred at times corresponding to lower numbers of taxa and …