Effect of two entomopathogenic fungi in controlling Aleurodicus cocois (Curtis, 1846) (Hemiptera: Aleyrodidae)
Aleurodicus cocois (Curtis, 1846), the coconut whitefly, is a very damaging pest in Peru, mainly in avocado trees (Persea americana Mill.). It has been determined that entomopathogenic fungi can infect and kill white flies and can be used as biological control agents. The object of this research was to determine if there is any synergic action of the entomopathogenic fungi Paecilomyces fumosoroseus (Wize) Brown & Smith 1957 and Verticillium lecanii (Zimmerman, 1892) Viégas 1939, in controlling A. cocois. Plastic sterile dishes were prepared where 5 mL 2% agar were used for each stage; leaves infested with A. cocois were placed upon these. Three different treatments were applied by sprinkling: P. fumosoroseus (P), V. lecanii (V) or the mixture of the two fungi. These treatments were evaluated at one, two and seven days in the case of nymph I and eggs, and after four, eight and 12 days for nymph II, NIII and NIV. The lethal effect of V. lecanii on the second nymph instar of A. cocois was better than that of P. fumosoroseus and than the mixture of both fungi; the highest mortality percentage appeared from day eight to day 12. A small increase was observed in the effect of the mixture of the two entomopathogenic fungi on the IV nymph instar, and the effect of P. fumosoroseus was the lowest.