THE INFLUENCE OF SANITATION ON GERMAN COCKROACH POPULATIONS
Abstract
Sanitation is a non-chemical control method often recommended for the German cockroach Blattella germanica (L.). This study examines the influence of sanitation on German cockroach populations under laboratory and field conditions. In the laboratory, sanitation was examined by dividing it into 3 key factors: food, water and harborage. In mock kitchen chambers, the removal of all possible combinations of these factors were tested using marked cockroaches. The results were then used in designing a sanitation regime which was tested on cockroaches in urban housing. The results of the laboratory key factor analysis indicate water is the most critical factor. The removal of water, either alone or in combination with other key factors, affects the adult mortality 1 week after its removal, and subsequently. The removal of food was intermediate in reducing cockroach populations within treated chambers. Mortality was not significant at week 2, but was significant when analyzed for the first 3 weeks. Harborage was not significant in reducing population estimates in treated chambers. Mortality was not significant in chambers where harborage was removed. Also, the removal of harboarage did not enhance the effects of a treatment when it was included in a combination. The field sanitation regime consisted of extensive habitat modification including professional janitorial cleaning and minor structural repair. The analysis of the field data show no significant difference between treated (clean) and untreated apartments. The results do indicate that the cockroach populations were highly disrupted by the sanitation regime. This disruption led to variability in the sampling methods. Variability was also attributed to a low number of replications, the short time frame of the study and the complexity of the field situation. In addition, there was predation by resident populations of the hose mouse, Mus musculus, on cockroaches in the sampling traps. The problems associated with house mouse populations should be noted for further field trap sampling.
Degree
Ph.D.
Subject Area
Entomology
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