THE SELECTIVE TOXICITY OF CERTAIN INSECTICIDES ON THE APHID PREDATOR HIPPODAMIA CONVERGENS

Barakat, Mohamed I.; El-Esnawy, Badria I.A.; Ahmed, Sayed A.

doi:10.21608/sinjas.2017.78837

THE SELECTIVE TOXICITY OF CERTAIN INSECTICIDES ON THE APHID PREDATOR HIPPODAMIA CONVERGENS

Authors

¹ Stat. Ismailia Agric. Res., Inst. Plant Prot. Res., Cent. Agric. Res., Giza, Egypt.

² Dept. Plant Prod., Fac. Environ. Agric. Sci., Arish Univ., Egypt.

10.21608/sinjas.2017.78837

Abstract

The toxic effect of four insecticides i.e. actara, cam mek, neomyl and malathion were evaluated in laboratory against the cabbage aphids Brevicoryne brassicae.The side effect of the tested insecticides was estimated on the predator Hippodamia convergens. The obtained values on aphids at LC₅₀ were 112.75, 126.29, 164.84 and 213.24 ppm for actara, cam mek, neomyl and malathion respectively. At LC₉₀ level, cam mek recorded 452 ppm followed by actara 1590.89 ppm, neomyl 3611.84 ppm and malathion 3839.13 ppm. The toxicity values on the predator, that malathion was the most toxic compound based on LC₅₀ (2.69 ppm) followed by cam mek (4.24 ppm), neomyl (10.26 ppm), and actara (32.15 ppm), whereas the LC₉₀ values were 196.1 ppm (neomyl), 237.4 ppm (malathion), 608.92 ppm (actara) and 1183.9 ppm (cam mek). The general selectivity ratio of the tested insecticides which avoid the difference in selective toxicity values between LC₅₀ and LC₉₀ level were calculated. The ratios were 2.64, 0.38, 9.96 and 16.28 ppm for actara, cam mek, neomyl, and malathion, respectively. Cam mek can be considered the effective compound against the cabbage aphid’s Brevicoryne brassicae (as the main target) and simultaneously safe for the prevailing predator.

Keywords