Evaluation of some plant extracts against poplar leaf aphid, Chaitophorus populialbae (Homoptera : Aphididae) under laboratory conditions

Abstract

The research was conducted at Laboratory Department, College of Agriculture, University of Tikrit, Iraq. The laboratory conditions were 33±2°C, 65±5% relative humidity (rh) and 14: 10 light: dark photo-period. Second and fourth instars of nymph were reared at laboratory. Strains of Chaitophorus populialbae were exposed to different concentrations of plant extracts (3, 5, 7, 9 and 11%). Each experiment was replicated three times in petri plates of 9 cm diameter. The extract of Ricinus communis plants gave high mortality reaching to 46, 36 and 41% in second instar, fourth instar and average mortality, respectively compared to control aqueous extract. The water extract of R. communis scored reasonable nymphs mortality ranging from 61.11 and 53.33% in second instar, 47.78 and 42.22% in fourthinstaratextractconcentrationof11and9%, respectively. The extractconcentration of 3% gave lowest mortality of 21.11% in second instar and 14.44% in fourth instar compared with zero mortality under control. The high mortality of nymps in second instar reached to 66.67, 60.00 and 56.67% with 11% concentration of extracts of R. communis, Datura innoxia and Calotropis procera plants, respectively. At fourth stage instar, 11% concentration of extracts of R. communis, D. innoxia and C. procera plants caused significantly highermortality of 53.33, 46.67 and 43.33%, respectively, compared to control. Therefore, farmers can use extracts of R. communis, D. innoxia and C. procera plants for both controlling insects and plant diseases.