Potencial de extratos à base de acetogeninas e Bacillus sp. no manejo de Zaprionus indianus (Gupta, 1970) (Diptera: Drosophilidae)

Abstract

Zaprionus indianus (Gupta, 1970), Is notable for causing great damages in the production of fig purple’s fruits (ficus carica). The damages are caused by the females in the processo of fruit ripening through oviposition in the ostiolar region, that after the hatching of the larvae, they penetrate into the fruits, making them improper. For the fig tree crop, there is no records about the chemical or biological products for the management of the fig fruit fly. So, the objective of this study was to evaluate the lethal, sublethal and oviposition toxicity of acetogenin-based bio- insecticides based on Annona (Annona mucosa Jacq., Annona muricata L. e Annona sylvatica A. St.-Hil) (discriminant concentration of 2,000 mg L-1) on Z. indianus compared to commercial insecticide of natural origin [lemonade derived from Azadirachta indica (Azamax™ 1,2g/L – 3,6 mL of active ingrediente (i.a) mL per liter)] and a synthetic insecticide based on spinosyn (Spinetoram - Delegate ™ 250 WG - 7.5 mg i.a. L-1). In addition, to verify the toxicity of bacterial isolates Bacillus thuringiensis var. israelesis (Bti), Bacillus thuringiensis Kurstaki (Btk), Bacillus thuringiensis oswaldocruzi (Bto) and Bacillus circulans (Bc) when in mixtures with food attractions on adults of Z. indianus and toxicity on the parasitoids Trichopria anastrephae Lima, 1940 and Pachycrepoideus vindemmiae (Rondani, 1875) in ingestion bioassays. A. mucosa caused mortality higher than 95% in ingestion bioassay and topical application, being equivalent to the synthetic insecticide espinoteram. In repellency bioassay, A. mucosa, Azamax™ 1,2 EC and Delegate™ 250WG doing a significant reduction (83, 88 and 95%, respectively) in the quantity of eggs by artificial fruit. As well as, together with extracts A. sylvatica, A. auricata and Azamax™ results in a reduction of 50% egg viability. In the fields, A. Mucosa and Azamax™ 1,2 EC influenced negatively the infestation of Z. indianus in the fig fruit, doing this a significant reduction of the larvae/fruit numbers (3,6 and 2,29 larvae/fruit, respectively) about the tratament control (only water) (11 larvae/fruit), but, were statistically lower than the insecticide Delegate ™ 250 WG (0.71 larvae / fruit). In the ingestion bioessay, Z. indianus ‘s adults mixed (formulation) showed high susceptibility to Bt isolates when in mixture (formulation) with the attractive 50% grape juice, 7% sugar cane molasses and 7% hydrolyzed protein, however, only the Bto isolate caused 100% mortality, 72 hours after exposure (HAE). In the use of the lethal concentrations (CLs90) of the Bto isolate with the food attractions, there was a significant reduction in total fecundity (between 40 to 50%) and viability of eggs (between 35 and 57%) of Z. indianus females were fed the formulations containing Bto + food attractions in ingestion bioassay. However, did not showed toxicity about adults of T. anastrephae and P. vindemmiae (mortality < 20%). In conclusion that A. mucosa, A. indica (Azamax™ 1,2 EC) and espinoteram (Delegate™ 250 WG) and the isolates Bti, Bto, Btk and Bc in formulation with food atractives grape juice 50%, sugarcane molasses and 7% hydrolyzed protein 7% proved to be promising alternatives for the management of Z. indianus.