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.
- SourceAvailable from: Abdessamad Imoulan
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- "Because, it is considered as considerable reservoir of entomopathogenic fungi and as an important favorable environment to target soil-dwelling life stages of fruit fly pest (Jackson et al. 2000; Ekesi et al. 2007), it was suggested that the introduction of conidia to the soil surface could be a useful strategy for fruit fly insects control (Lezama-Gutiérrez et al. 2000; Ekesi et al. 2002; Dimbi et al. 2003). This method seems to be logical, since the larvae at end of the third instar leave the fruits and fall on the ground and become immediately vulnerable to pathogens occurring in the soil (Gutiérrez et al. 2000). Moreover, entomopathogenic fungi have been shown to be effective against soilinhabiting life stages of pests (Rath et al. 1995; Jackson et al. 2000; Lacey et al. 2003), since the persistence of conidia is less affected by the environmental of soil (Garrido-Jurado et al. 2011; Coombes et al. 2013). "
ABSTRACT: The Mediterranean fruit fly, Ceratitis capitata Wiedemann (Diptera: Tephritidae), is the major tephritid pest in Morocco. This pest survives in Moroccan forests Argania spinosa and continually invades the nearest agricultural areas. Entomopathogenic fungi are an interesting tool for fruit fly control and hold a useful alternative to conventional insecticides. However, primary selection of effective pathogens should be taken in laboratory condition prior to applying them in the field. Here, we used third late instar larvae of C. capitata to investigate the effectiveness of 15 local Beauveria bassiana isolates. Results showed that all isolates were able to infect the larval stage, producing a large mortality rate in puparia ranging from 65 to 95 % and caused significant reduction in adult emergence. The fungal treatments revealed that the mycosis occurred also in adults escaping infection as pupariating larvae. The percentage of mycosed puparia was highest in strain TAM6.2 (95 %) followed by ERS4.16 (90 %), therefore they were the most virulent. Median lethal concentration (LC50) was studied for five isolates at four concentrations ranging from 10(5) to 10(8) conidia ml(-1). The results showed that the slopes of regression lines for B. bassiana ERS4.16 (slope = 0.386) and TAM6.2 (slope = 0.41) were the most important and had the lowest LC50 values (2.85 × 10(3) and 3.16 × 10(3) conidia ml(-1) respectively). This investigation suggests that the soil of Argan forests contains pathogenic B. bassiana isolates and highlights for the first time their potential as biological control toward C. capitata larval stage in Morocco.World Journal of Microbiology and Biotechnology (Formerly MIRCEN Journal of Applied Microbiology and Biotechnology) 10/2013; 30(3). DOI:10.1007/s11274-013-1514-y · 1.35 Impact Factor
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- "Laboratory studies showed that M. anisopliae is pathogenic for C. capitata eggs (Castilho 2000), larvae (Gutiérrez et al. 2000), and adults (Garcia et al. 1984, 1985). "
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 3rd-instar larvae were placed in the soil. The flasks were sealed with voile fabric and incubated at 27 +/- 0.5 masculineC 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.Neotropical Entomology 05/2006; 35(3):382-9. DOI:10.1590/S1519-566X2006000300014 · 0.85 Impact Factor
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- "Entomopathogenic fungi are being developed as alternatives to chemical pesticides for the control of fruit flies (García et al., 1984; Castillo et al., 2000; Lezama-Gutierrez et al., 2000; Ekesi et al., 2002). However, entomopathogenic fungi are subject to a number of biotic and abiotic factors that influence their survival and ability to cause diseases (Hall and Papierok, 1982; Benz, 1987; Carruthers and Soper, 1987; Inglis et al., 2001). "
ABSTRACT: The effect of temperatureon conidial germination, mycelial growth, andsusceptibility of adults of three tephritidfruit flies, Ceratitis capitata(Wiedemann), C. fasciventris (Bezzi) andC. cosyra (Walker) to six isolatesof Metarhizium anisopliae were studied inthe laboratory. There were significantdifferences among the isolates in the effect oftemperature on both germination and growth.Over 80% of conidia germinated at 20, 25 and30C, while between 26 and 67% conidiagerminated at 35C and less than 10% at15C within 24 hours. Radial growth was slowat 15C and 35C with all of theisolates. The optimum temperature forgermination and mycelial growth was 25C. Mortality caused by the six fungal isolatesagainst the three fruit fly species varied withtemperature, isolate, and fruit fly species.Fungal isolates were more effective at 25, 30and 35C than at 20C. The LT90values decreased with increasing temperature upto the optimum temperature of 30C. Therewere significant differences in susceptibilitybetween fly species to fungal infection at allthe temperatures tested.BioControl 01/2004; 49(1):83-94. DOI:10.1023/B:BICO.0000009397.84153.79 · 2.25 Impact Factor