Insecticidal Activity of an Indian Botanical Insecticide ULTRA ACT® against the Olive Pest Bactrocera oleae (Diptera: Tephritidae) in Tunisia

Abstract

Bactrocera oleae is the most economically damaging insect of olive in the Mediterranean. As a reliable alternative to synthetic chemical insecticides, botanical pesticides from plant extracts are also considered natural control methods safe for the environment and human health. In practical applications up to date, studies demonstrating toxically effects of biological control agents on the insect have been carried out in organic farming systems based on some industrial microbial formulations. But much less attention has been given to botanical insecticides against B. oleae. Thus, a certified botanical insecticide issue from various plants and approved per Indian and International organic standards was tested against larvae and pupae of the olive pest Bactrocera oleae in the east of Tunisia under laboratory conditions. The experiments were conducted with 3 normal treatments and 1 control. Two techniques were used for larvae and pupae: direct contact using concentration from 0.5; 0.750; 1 and 1.5 mg/l and fumigation treatment using 2 mg/l conducted in rectangular boxes (25°C - 27°C, 75% - 85% RH and 14:10 LD photo period). For larval stages, LC50 and LC90 values for Ultra-Act were 0.45 and 1.22 mg/L in direct contact and 1.5 - 2 mg/l with fumigation, respectively. For pupal stage, the ID25 and ID50 values were estimated to be 0.71 mg and 1.26 mg respectively corresponding to the inhibition of emergence of 25% and 50% of B. oleae adults from pupa. Our results indicate that sprayed Ultra-Act product has the potential to control the three olive fly instar larvae. Pupal emergency was decreased significantly with fumigation treatment. In conclusion, Ultra-Act is a promising botanical insecticide against B. oleae that could be used as a successful alternative for chemicals in integrated control methods of this pest in Tunisia.