Virulence of Metarhizium anisopliae (Deuteromycotina: Hyphomycetes) on Anastrepha ludens (Diptera: Tephritidae): Laboratory and Field Trials
ABSTRACT Twenty isolates of the fungus Metarhizium anisopliae (Metsch). Sorkin (Ma) were evaluated to determine their virulence against last instar and adult emergence of Mexican fruit fly, Anastrepha ludens (Loew). Larvae were exposed by immersion in a conidial suspension at a concentration of 10(8) UFC/ml under laboratory conditions. Larvae and pupae cumulative mortality rates ranged from 37.9 to 98.75%. Thirteen isolates caused mortality rates > 83.7%, and their LT50 values ranged from 1.8 to 6.2 d. The Ma2, Ma8, and Ma16 isolates were evaluated at seven different concentrations ranging from 10(1) to 10(7) UFC/ml, showing LC50 values from 3.7 to 4.8 x 10(5) UFC/ml. In a field-cage experiment, 200 ml of a conidial suspension of Ma2, at a concentration of 2.5 x 10(6) UFC/ml, was applied on 2,500 cm2 soil surface (2 x 10(5) UFC/cm2). The fungus reduced adult emergence, 22% fewer adults emerging in a sandy loam soil, and 43% fewer in loam soil, compared with the controls. M. anisopliae may offer a preferable alternative to chemicals as a biological control agent against A. ludens.
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ABSTRACT: The pathogenicity of six Metarhizium spp., four Beauveria bassiana (Balsamo) Vuillemin, and four Tolypocladium cylindrosporum Gams (Ascomycota: Hypocreales) fungal pathogens exposed to third-instar Delia radicum L. was evaluated in laboratory bioassays. The presence of intra-and inter-generic variations concerning the pathogenicity of the isolates was investigated. Results show that all Metarhizium spp. and T. cylindrosporum isolates caused a noteworthy mortality to the third instar and consequently reduced adult eclosion. The well-known standard, F52 strain (identified as Metarhizium brunneum), resulted in up to 79% reduction in D. radicum eclosion. The other Metarhizium isolates in-cluding UAMH 9197 (Metarhizium anisopliae) and UAMH 2801 (M. brunneum), as well as T. cylindro-sporum DAOM 167325 and DAOM 183952, produced a mean eclosion reduction of >50%. While the pathogenicity of Metarhizium spp. and T. cylindrosporum is similar, the B. bassiana isolates are undoubt-edly less pathogenic. Based on the results obtained with the selected isolates, no intrageneric differences relative to the pathogenicity of the isolates appeared to be present. Globally, this study deepened the knowledge about D. radicum susceptibility toward Hypocreales entomopathogenic fungi, chiefly T. cylindrosporum. The implications of this study regarding the development of a biological control agent are discussed.Journal of Economic Entomology 01/2015; DOI:10.1093/jee/tou019 · 1.61 Impact Factor
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ABSTRACT: Approximately 4,000 known/described species of fruit flies (Tephritidae) are distributed in tropical, subtropical, and temperate regions of world, out of which 200 species are economically important and damaging/spoiling not only to fruits but also to a number of vegetable crops. Despite their tremendous importance, a limited amount of information is available on the ecology and behaviour of fruit flies especially when compared to fruit fly species complex. It is necessary to understand the ecology and behaviour before the formulation of management strategy. The present review may serves as a baseline data for scientists engaged in fruit fly management programs. Key themes include: (1) demography and population dynamics and, (2) behaviour (e.g. sexual, mating, oviposition, and feeding). The excess of literature on monitoring and management of fruit flies are available, which includes male sterilization and annihilation, mass trapping, chemical baits, mating disruption, and biological control. But few of them are easily adopted by users and give satisfactory control of fruit flies and rest are not easily adopted or if used does not give effective control, because of the lack of knowledge about the ecology and behaviour of fruit flies. If the information on population dynamics, behavior, and the related ecological factors are not jointly gathered, it is almost impossible to carry out an appropriate pest control at the right time and place. We hope that this synthesis will lay the groundwork for future ecological and behavioural studies of fruit fly species, populations, communities, and control.09/2012; 15(3). DOI:10.1007/s12892-011-0091-6