Efficacy of Metarhizium anisopliae and Bacillus thuringiensis against tomato leafminer Tuta absoluta Meyrick (Lepidoptera: Gelechiidae)

Spyridon Mantzoukas^1,2*, Nikoleta-Kleio Denaxa^1,3 and Ioannis Lagogiannis²

¹Department of Agricultural Technology, Technological Institute of Western Greece, Amaliada.

²Department of Pharmacy, School of Health Sciences, University of Patras, Patras, Greece.

³Faculty of Crop Science, Laboratory of Pomology, Agricultural University of Athens, Iera Odos, Athens, Greece.

Corresponding Author Email: mantzoukas@upatras.gr

DOI : http://dx.doi.org/10.12944/CARJ.7.1.05

Abstract:

Susceptibility of Tuta absoluta Meyrick (Lepidoptera: Gelechiidae) populations to Metarhizium anisopliae and Bacillus thuringiensis (Bt) were evaluated under laboratory conditions. T. absoluta larvae were treated either individually or in combination with a single dose rate of B. thuringiensis (0.5 μL/L) and three conidial suspensions viz. 1x10⁴, 1x10⁶ and 1x10⁸ spores/mL of M. anisopliae. Larval mortality, pupation, adult emergence, mycosis and sporulation varied depending on the application of different quantities of M. anisopliae alone and in combination with B. thuringiensis. Maximum mortality (100%) was achieved in 2^nd instar larvae when M. anisopliae (1x10⁸ spores/mL) and B. thuringiensis (0.5µL/L) were applied synergistically,while 4^th instar larvae recorded a 95.45% mortality. Compared with the untreated checks, mortality, pupation and adult emergence of both 2^nd and 4^th instar larvae were significantly reduced with the combined application of M. anisopliae (1x10⁸ spores/mL) and B. thuringiensis (0.5µL/L). Μycosis was most prevalent on 2^nd and 4^th instar larvae, exceeding 88 and 80% respectively,after exposure to 1×10⁴ conidia/mL. The results indicate that the entomopathogenic fungi and the insecticidal protein produced by B. thuringiensis can be used in combination as biocontrol agents for the management of T. absoluta.

Keywords:

Bacillus Thuringiensis; Biological Control; Metarhizium Anisopliae; Tomato; Tuta Absoluta

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