Fumigant toxicity of essential oil from Lantana camara against Almond moth, Cadra cautella (Walker)

Abstract

Lantana camara is a common weed species in tropics and sub tropics and coastal locations of Asia. The fumigant toxicity of essential oil extracted from leaves of plant was tested against almond moth, Cadra cautella (Walker) (Lepidoptera, Phycitidae). Concentrations of essential oil relative to the wheat grains were 5, 10, 25, 50, 100 and 200 μl/l used against early eggs (0–24 hrs.), late eggs (2–3 days), early larvae (5–7 days), mid larvae (10–12days), late larvae (18–20 days) and early adult (0–24 hrs.) and late adults (2–3 days) stage of C. cautella. The different concentrations of essential oil were applied to Whatman No. 1 with 2.5 cm in diameter filter paper and then pasted on the inner surface of the lid with adhesive tape in the bottom of fumigation flask ten eggs, larvae and adults of different ages with 20 wheat seeds were kept before keeping the treated filter paper, the lid was closed and sealed to create airtight condition in the chamber. The concentrations of essential oil were tested against different stages of test insect and one control with insect and wheat grain but without essential oil was maintained. The experiment was repeated thrice and observation was made at 6, 12, 24 and 48 hrs. of exposure period. Early eggs showed lower LC50 value of 48.56 μl/L compared to 77.75 μl/L with late eggs. The larval LC50 values ranged between 29–39 μl/L. Susceptibility of adult stage was also increased and the LC50 values being 15.23 and 11.21 μl/L for early and late adult stages, respectively.