When using the emulsion concentrate of M. azedarach, some effect on the reproduction of the tick was expected because this plant works to regulate the neuroendocrine system, mainly interfering with the hormone levels ( Schmidt et al., 1998). Moreover, studies carried out by Borges et al. (2003) and Sousa et al. (2008) demonstrated Bortezomib order an inhibition of egg production and/or embryogenesis when R. microplus engorged females were immersed in extracts of M. azedarach fruits. In this study, although an appropriate formulation that was active in laboratory studies was used ( Sousa, 2008), the lack of effect on

reproductive parameters was identical to that observed by Borges et al. (2005) in a test similar to the one developed by our group. Pereira and Famadas, 2004 and Pereira and Famadas, 2006, evaluating the efficiency of the extract of roots of the plant Dahlstedtia pentaphylla (Taub.) Burk. (Leguminosae, Papilionoideae, Millettiae) against R. microplus, observed 100% effectiveness in laboratory tests with a total inhibition of reproductive parameters. However, when evaluating infested animals, the results observed were far below those found in in vitro animals and with no effect on reproduction.The biological control of ticks using entomopathogenic fungi shows promising

results. Among the fungi studied, B. bassiana and M. anisopliae stand out, because they are pathogenic in in vitro tests for several species of ticks, such as Amblyomma cooperi ( Reis et al., 2003), Amblyomma cajennense ( Reis selleck chemicals et al., 2004), Amblyomma variegatum ( Maranga et al., 2005), R. sanguineus ( Prette et al., 2005),

and Rhipicephalus microplus ( Bittencourt et al., 1997). most However, most tests done in the field with entomopathogenic fungi to control ticks in South America have shown low efficacy ( Fernandes and Bittencourt, 2008), except for a polymerized cellulose gel and B. bassiana conidia formulation used directly on the ears of horses to control D. nitens infestations ( Souza et al., 2009).The low efficacy of fungi in field tests is related to biotic and abiotic factors that can influence the survival, spread, and infection of the host ( Goettel et al., 2000). The abiotic factors are essential for survival of fungi. Among them, solar UV radiation is considered to be the most important ( Cagan and Svercel, 2001) because it can inactivate the conidia, causing gene mutations and lethal damage to DNA ( Nicholson et al., 2000). According to Leite et al. (2002), even commercial products that exhibit high activity in laboratory tests do not have the same effectiveness in the field due to the adverse conditions. The great number of compounds ( Evans, 1996) and the degradation effects of light, temperature, pH, and microorganisms ( Mulla and Su, 1999) make the production of a vegetal extract difficult.