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Biomedical subjects

G C Labrecque

Publications and source records attributed to G C Labrecque.

7 recordsLinked to original sources

Cytogenetic and other effects of the chemosterilants tepa, metepa, apholate an hempa in insects (a review).

A review of the literature revealed that the chemosterilants tepa (tris(1-aziridinyl)phosphine oxide), metepa (tris(2-methyl-1-aziridinyl) phosphineoxide), apholate (2,2,4,4,6,6-hexakis(1-aziridinyl)-2,2,4,4,6,6-hexahydro-1,3,5,2,4,6-triazatriphosphorine), and hempa (hexamethylmelamine) affected both reproductive and somatic tissues in over 65 species of insects. The effects were cytological, physiological, and genetic and varied from slight to severe. In some cases the deleterious effects may have been species-specific, but in general, they appeared to be dose-dependent. More than 150 publications are cited.

Animals↗

Influence of seasonal changes in climate on dispersal of released Culex pipiens fatigans: a study in villages in Delhi Union Territory, India.

Studies on Culex pipiens fatigans dispersal were conducted during the hot, cold, rainy, and post-rainy seasons in 2 villages in the Delhi area in order to improve techniques and to determine the optimum time of release. Releases from one central point and from a number of points were evaluated. No directional effect on dispersal was observed. Dispersal was most rapid and extensive in the hot season and slowest and most limited during the cold season, when the released mosquitos tended to remain near the release sites. No significant difference was noticed between male and female dispersal, and both sexes showed a uniform dispersal pattern 2 days after release.

Animals↗

Dispersal and survival in the field of chemosterilized, irradiated, and cytoplasmically incompatible male Culex pipiens fatigans.

Comparative field studies were made on the dispersal and survival of chemosterilized, irradiated, and cytoplasmically incompatible (D3 strain) male Culex pipiens fatigans. There was no significant difference in dispersal patterns and daily survival rates between laboratory colony males and wild males, and between chemosterilized or irradiated males and untreated males. Although there was no difference in dispersal between adults of the D3 strain and the laboratory colony of the Delhi strain, the former had a lower daily survival rate.

Animals↗

Insect sterility in population dynamics research.

This paper reviews and discusses a technique that can be used to study the dynamics of populations under the influence of favourable or unfavourable environmental factors or the stress of population control. It is encouraging for those interested in the sterility approach to pest control that the reproductive success of insects with a reputedly high biotic potential is limited to relatively low rates under field conditions. Further studies are needed under other conditions, in other areas, and with other species.

Animals↗

Studies on the population dynamics of the housefly, Musca domestica L.

The population level and potential rate of increase of a population of houseflies, Musca domestica L., on Grand Turk Island was studied for about 2 years to determine what changes occurred when no control was applied (the first year) and when the population was totally suppressed by the application of chemosterilant baits (the second year). During the first year the population was relatively stable (the highest density occurred in June and the lowest in January) and the difference between the high and low levels was only 3-fold. When chemosterilant baits were applied over a 40-week period and total suppression was achieved, calculations based on the sterility achieved and the resulting control revealed that the population showed potential rates of increase ranging up to 4-fold during the period from June through October and from 4-fold to 11-fold from December through April. Thus, in the field, the potential rates of increase of the housefly are low despite its high biotic potential.

Animals↗