Effect of isolates of Beauveria bassiana pathogenic to leafhopper cacao Horiola picta (Hemiptera: Mambracidae)


Ana Fernanda Cipriano da Silva, Simone Maria da Costa de Oliveira Moreira, Rosiane do Socorro da Silva Cunha, Djair Alves Moreira, Angelica Teodoro, Antonio Henrique Cardoso do Nascimento and Walter Santos Evangelista Júnior


The leafhopper Horiola picta (Membracidae: Smiliinae: Trogopini) is a cocoa secondary pest of Transamazônica and Xingu region, and microbial control is an alternative to keep these populations below the economic injury level. This study aimed to evaluate the virulence of isolates GC 157 and GC 165 of Beauveria bassiana under different conidia concentrations in insect adulthood. The following concentrations were used: 1×104, 1×105, 1×106, 1×107,1×108 conidia ml-1 and the control to inoculate the insects were fed with cocoa shoots and young fruit, exchanged daily. For the effect of B. bassiana on H. picta adults performance differences were observed between the concentrations 104 a 108 conidia ml-1, around 70.31 to 90.31% of total mortality respectively to isolated CG 157, and the isolated CG 165 was obtained 62,50% from the concentration 104 conidia mL-1, reaching 82% mortality with a concentration of 108 conidia mL-1. However, both the isolated CG 157 as CG 165, show good infective capacity. Confirmed mortality ranges from 27,2% a 72,2% both for isolated as CG157 to CG165 and showed positive linear correlation (R ² = 0.97) and (R² = 0.98) respectively. The lethal time (LT50) for CG157 and CG165 isolated according to Lethal Concentration (LC50) of 104 conidia-1 was 1.075 days for the isolated CG157 and 2.30 days for the CG 165 isolated.


Biological Control, Microbial Control, Cocoa, Leafhopper

Amaz. Jour. of Plant Resear. 4(1): 456-461. March 2020
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