Avaliação do potencial de controle biológico do Metarhizium anisopliae sobre Boophilus microplus em teste de estábulo

Abstract

(GRISI et al., 2002). Enquanto o controle dos carrapatos for baseado principalmente no uso de produtos químicos, a pecuária enfrentará crises sucessivas por conseqüência da seleção de cepas resistentes, a menos que novas alternativas e métodos de controle sejam introduzidos. A solução mais lógica para o manejo da resistência é a redução no uso de acaricidas (WHARTON, 1967).Os entomopatógenos, que são considerados como importantes fatores na redução da população de pragas, ocorrem naturalmente no ambiente, e podem ser introduzidos ou aplicados. Portanto há a necessidade da conservação da população desses agentes microbianos, e para tal é importante conhecer a Veterinária, v. 16, n. 4, p. 243-245, 2007. Departamento de Parasitologia Animal, Instituto de Veterinária, Universidade Federal Rural do Rio de Janeiro, Km 7 da BR 465, Seropédica, RJ 23890-000, Brasil. E-mail: vaniabit@ufrrj.brThe aim of the present study was to evaluate the capacity of the fungus Metarhizium anisopliae to control Boophilus microplus tick in pen trials. Infested calves were held in individual pen and treated with fungus suspension through aspersion bath. The results were evaluated based on ticks' mortality rate for 28 days after treatment, and on the analysis of biology of tick's samples which were transferred to an incubation chamber. It was reported 33% of mortality during the total period analyzed, and the production of eggs and nutritional rates were decreased only for a short period after treatment.

Commercial formulation of Metarhizium anisopliae for the control of Rhipicephalus microplus in a pen study

“…Therefore, a smaller number of ticks were collected during the last week of the experiment (third week after treatment), during which the larvae present on the cattle on the day of treatment would have reached the adult stage. Previous studies have shown a difference in susceptibility to acaripathogenic fungi between different developmental stages of ticks (Castro et al, 1997;Kaaya and Hassan, 2000;Bahiense et al, 2007;Camargo et al, 2012). Kaaya and Hassan (2000), while assessing the effect of oil formulations of Beauveria bassiana and M. anisopliae on Rhipicephalus appendiculatus and Amblyomma variegatum in pastures, observed mortality of 100%, 80-100% and 80-90% in larvae, nymphs and adults, respectively, demonstrating that the immature developmental stages of ticks are more susceptible to acaripathogenic fungi.…”

Riboflavin induces Metarhizium spp. to produce conidia with elevated tolerance to UV ‐B, and upregulates photolyases, laccases and polyketide synthases genes

“…Among these fungi, Metarhizium is the most investigated genus for microbial control of arthropod pests and vertebrate‐disease vectors (Zimmermann ; Bahiense et al . ; Fernandes and Bittencourt ; Gindin et al . ; Sousa et al .…”

Evaluation of entomopathogenic fungi as biological control agents Rhipicephalus (Boophilus) microplus (Canestrini, 1887) (Acari: Ixodidae)

“…Bahiense et al (2007) suggested that lower percentages of control are expected with biological control methods than with methods of chemical control. It is important to note that this difference is compensated, since the objective of biological control is to maintain pests at economically acceptable levels, while protecting the environment and the native enemies of a given pest.…”

“…Entomological pathogens are considered to be an important factor in the reduction of pest species; these agents may occur naturally or may be introduced into the agroecosystems (Bahiense et al 2007). The fungi Metarhizium anisopliae (Metschnikoff, 1879) Sorokin, 1883 (Ascomycota: Nectriaceae) and Beauveria bassiana (Balsamo) Vuillemim, 1912 (Ascomycota: Clavicipitaceae) are promising agents for the biological control of ticks, thus in recent years a number of studies have investigated the relationships between entomopathogenic fungi and different species of tick (Bittencourt et al 1994, Bittencourt et al 1996, Bittencourt et al 1997, Correia et al 1998, Bittencourt et al 1999, Frazzon et al 2000, Bahiense y Bittencourt 2004, Basso et al 2005, Lopes et al 2007, Bahiense 2007.…”