Pathogenicity of Metarhizium anisopliae for Ceratitis capitata (Wied.) (Diptera: Tephritidae) in soil with different pesticides

Abstract

e incubados a 27 ± 0,5ºC por nove dias, para iniciar a emergência dos adultos, e mais quatro dias à temperatura ambiente. A sobrevivência total do inseto foi substancialmente afetada. Observou-se a atividade patogênica a partir da fase pupal, com o fungo reduzindo (P < 0,05) a sobrevivência, o que também ocorreu na fase de adultos. A fase larval não foi afetada (P >0,05) pelo fungo. A presença de agrotóxicos no solo teve discreta ação na atividade de M. anisopliae; apenas com conídios secos incorporados, os fungicidas clorotalonil e tebuconazole reduziram em 86,2% e 82,5%, respectivamente, a sobrevivência total de C. capitata, enquanto no controle a redução foi de 95,0%. A forma de aplicação dos conídios não influenciou a sobrevivência total do inseto, mas a aplicação da suspensão de conídios na superfície do solo reduziu a sobrevivência nas fases de pupa e adulto. PALAVRAS-CHAVE: Controle biológico, controle microbiano, fungo entomopatogênico, mosca-.....das-frutas ABSTRACT -This research intended to investigate if the presence of pesticides in the soil could affect the pathogenicity of Metarhizium anisopliae Metsch. (Sorokin) for Ceratitis capitata (Wied.) and assess the effect of conidia application as suspension or dry conidia. The fungicides chlorothalonyl and tebuconazol, the acaricide abamectin, the insecticide trichlorfon, and the herbicide ametrin were applied at the manufacturer-recommended doses. Soil samples were placed in glass flasks and were given the fungus as conidial suspension or dry. After pesticide application, 20 3 rd -instar larvae were placed in the soil. The flasks were sealed with voile fabric and incubated at 27 ± 0.5 o C for nine days, until adult emergence; incubation continued for four more days at room temperature. The total insect survival was significantly affected and pathogenic activity was detected from the pupa stage on. Pupa survival was reduced (P<0.05); the same occurred during the adult phase. No effect was observed at the larval stage. The pesticides applied to the soil affected the activity of M. anisopliae slightly: only in the dry conidia assay the fungicides chlorothalonyl and tebuconazole reduced (86.2% and 82.5%, respectively) the survival period of C. capitata compared to the control (95.0%). The techniques used for conidia application did not influence the total insect survival rate, but conidial suspension applied on soil surface reduced survival during the pupae and adult phases.

Impact of fungicides on Metarhizium anisopliae in the rhizosphere, bulk soil and in vitro

“…(Diptera: Tephritidae) was significantly reduced when the fungicides chlorothalonyl and tebuconazol were applied to soil. This was not the case in the acaricide, insecticide and herbicide treatment (Mochi et al 2006). Based on fungal respiratory activity, the toxic action of a range of pesticides (acaricides, fungicides, insecticides and herbicides) on M. anisopliae in the soil is small, suggesting little negative impact on the fungal activity resulting from their use (Mochi et al 2005).…”

“…There have been a number of studies performed to determine the in vitro impact of agro-chemicals (fungicides, herbicides, insecticides and acaricides) on a wide variety of entomopathogenic fungi (Loria et al 1983;Li and Holdom 1994;Todorova et al 1998;Batista Filho et al 2001;Wei et al 2004;Mochi et al 2005Mochi et al , 2006Klingen and Westrum 2007;Luz et al 2007). Moorhouse et al (1992) performed a detailed study of both the in vitro and in situ effects of fungicides and insecticides on M. anisopliae (275-86) for BVW control.…”

Microbial control of arthropod pests of tropical tree fruits

“…elucidated the effect of various factors on the activity of the fungus that included temperature, moisture, gender, life stage and fly species. Mochi et al (2006) investigated the effect of fungicides, acaricides, insecticides and herbicides on M. anisopliae activity against C. capitata pupal and adult mortality occurred in soil treated with the fungus with and without pesticides. No larval mortality was observed.…”

Selection of a Bacillus pumilus Strain Highly Active against Ceratitis capitata (Wiedemann) Larvae

“…Unfortunately, very few microorganisms that exhibit activity against C. capitata have been described; the organisms that have been described include the fungi Mucor hiemalis (40), Metarhizium anisopliae, and Beauveria bassiana (5,18,22,23,39,52,55), the bacteria Serratia marcescens (11) and Saccharopolyspora spinosa (50), the microsporidian parasite Octosporea muscaedomesticae (53), and the entomopathogenic nematodes Heterorhabditis bacteriophora, Heterorhabditis zealandica, and Steinernema khoisanae (47). Notwithstanding these reports, no efficient product that can be applied in the field is commercially available yet.…”