Resumen

The tetranortriterpenoid, azadirachtin, and the entomopathogenic virus, nucleopolyhedrovirus, are used as safe and new control measures for combating agricultural insect pests instead of the use of synthetic insecticides. They can be mixed together as an integrated pest management strategy. Thus, the current investigation was designed to determine the mortality, duration and weight gain of Spodoptera littoralis (Boisduval) (Lepidoptera: Noctuidae) larvae, and the yield of Spodoptera littoralis multicapsid nucleopolyhedrovirus (SpliMNPV) (Baculoviridae) when the fourth larval instars were treated individually with the LC50 of azadirachtin and of SpliMNPV, and in combination with each other using the LC25, compared to non-treated larvae (control). The results obtained showed that combined treatment significantly enhanced the larval mortality by about 58.40 %, i.e. potentiation. Both individual and combined treatment significantly decreased the larval weight gain, whereas the larval duration was significantly increased, with the highest change in case of combined treatment. Azadirachtin–NPV mixture significantly decreased the viral yield (number of polyhedral inclusion bodies/g fresh larval body weight) by about 36.05 % compared to the individual treatment with the NPV. It can be concluded that although azadirachtin enhanced the pathogenicity (% larval kill) of SpliMNPV to S. littoralis, azadirachtin– SpliMNPV mixture is unlikely to be useful for the mass production of this viral isolate. Thus, these laboratory observations require validation in field studies under commercial growing conditions.

Palabras clave: Spodoptera littoralis azadirachtin duration weight gain mortality nucleopolyhedroviruses viral yield.

2018-10-23   |   156 visitas   |   Evalua este artículo 0 valoraciones

Vol. 6 Núm.2. Enero 2014 Pags. 93-100 Ecologia Balkanica 2014; 6(2)