Prospects of a fungus-contamination device for the control of tsetse fly Glossina fuscipes fuscipes

• Published in: Biocontrol science and technology 2006-01, Vol.16 (1-2), p.129-139
• Main Authors: Maniania, N.K, Ekesi, S, Odulaja, A, Okech, M.A, Nadel, D.J
• Format: Article
• Language: English
• Subjects: biological control; biological control agents; Contamination device; control autodissemination; disease incidence; entomopathogenic fungi; equipment performance; Glossina fuscipes; Glossina fuscipes fuscipes; hematophagous insects; insect control; insect traps; insect vectors; Metarhizium anisopliae; microbial contamination; mortality; pest control equipment; pesticide delivery system
• ISSN: 0958-3157; 1360-0478
• DOI: 10.1080/09583150500258503

The prospects of the fungus Metarhizium anisopliae (Metsch.) Sorok. applied in contamination devices (Cds) to control tsetse fly Glossina fuscipes fuscipes Newstead was tested in a field experiment in Lake Victoria from 2 March 1999 to 31 August 2000. One hundred and sixty pyramidal traps mounted with Cds were deployed along the lakeshore and rivers on Mfangano Island. Contamination devices were loaded with 1.5-2.0 g of dry conidia/Cd. On the second island, Nzenze Island, four pyramidal traps fitted with plastic bags were deployed and served as the conventional 'trap and kill' population suppression method. A third island, Ngodhe Island, remained untreated and served as a control. Cds were recharged monthly with fresh conidia; plastic bags were also changed monthly. The apparent changes in population density were monitored weekly using biconical traps set at random on the three islands. To assess the incidence of M. anisopliae in tsetse flies on Mfangano Island, flies captured during monitoring were maintained in the laboratory and their mortality recorded. Fly population was reduced to 82.4 and 95.8% relative to untreated control on Mfangano and Nzenze islands, respectively, during the experimental period. Compared to the fungus-treated island, the number of flies caught in monitoring traps increased considerably in 'trap kill' treatment at 5 months after the treatments were removed. The incidence of M. anisopliae in fly populations was low during the 12 weeks following the initiation of the experiment but increased afterward until termination of the treatment. M. anisopliae could still be recovered from fly populations at 3 months after termination of the treatment, although the incidence was low. The results of this study have shown that application of M. anisopliae in a contamination device can suppress the population of G. fuscipes fuscipes comparable to the 'trap and kill' technology.