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Please use this identifier to cite or link to this item: http://hdl.handle.net/123456789/3097

Title: The relative toxicity of some pesticides on African Honeybee, Apis Mellifera Adansonii in Ghana
Authors: Kabenlah-Egya Appoh, Emmanuel
Issue Date: 28-Feb-1999
Series/Report no.: 2641;
Abstract: The African honeybee, Apis mellqera adaflSoflhi (L.) forages on several food and cash crops in Ghana. The pest and diseases of these crop species are controlled by blanket use of pesticides some of which may be very toxic to the bees. Laboratory experiments were conducted to determine the relative toxicity of the most frequently used of these pesticides. The pesticides were selected based on a field questionnaire survey data on aspects of farming and beekeeping in some districts of Ashanti Region. The survey data revealed that three pesticides namely Karate 2.5EC, Kocide 101 and Unden 200EC were the frequently used pesticides in this part of the country. The contact and oral toxicity of these pesticides were evaluated in the laboratory. For contact toxicity test, the different concentrations were applied to the abdomen using microapplicator. Oral toxicity was evaluated by feeding starved bees on the different concentrations of the pesticides. The results clearly indicated that the contact and oral toxicity of the pesticides to the bees increased with concentration and their bioactivity also decreased with post-treatment period. The pesticides could be arranged according to their toxicity after six hours exposure, in descending order as follows: Unden 200EC > Karate 2.5EC > Kocide 101. The LD50 of the pesticides depended on the route of entry of the pesticides into the bees. Generally, topical application had a distinctly lower toxicity to the bees than oral administration of the pesticides. Kocide 101 which has been found to be non-toxic to European honeybee was found to be toxic to African honeybees at very high concentration in this study. The questionnaire data indicated that all the three pesticides are used by Ghanaian farmers as oral pesticides. Their toxicity recorded in the laboratory could be magnified in field conditions because honeybees foraging for contaminated nectar and pollen could be killed. This situation may be aggravated by the fact that majority of the farmers claimed that they crop twice in a year, during the major and minor rainy seasons. Some of the hazards involved in the use of the pesticides mentioned in the survey were skin bums, nervous and respiratory disorders, headache, vomiting and hunger. Chemical control remains the only effective method of controlling most insect pests, weeds and diseases. To obviate the need for these chemicals as production inputs, agricultural planning for both commercial and subsistence farms should aim at minimising the exposure of humans and other non-target organisms to these chemicals.
Description: A thesis submitted to the Board of Postgraduate Studies, Kwame Nkrumah University of Science and Technology, Kumasi, in partial fulfilment of the requirement for the award of the Degree of Master of Science in Environmental Science, 1999
URI: http://hdl.handle.net/123456789/3097
Appears in Collections:College of Science

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