Effects of a juvenile hormone analog, pyriproxyfen, on the apterous form of Lipaphis erysimi

Abstract

Effects of a juvenile hormone analog, pyriproxyfen, on various developmental stadia of the apterous form of the turnip aphid, Lipaphis erysimi (Kaltenbach), were bioassayed at three concentrations (50, 100, and 150 mg [AI]/l) in the laboratory. Supernumerary-molted nymphs with 1-3 extra molts were found when the first three nymphal instars were treated, and all these nymphs died prematurely. In contrast, all treated fourth instar nymphs molted normally to adults. The longevity of all pyriproxyfen-treated L. erysimi nymphs and adults and the fecundity of treated adults were reduced by ≈50%. Higher concentrations of pyriproxyfen (100 and 150 mg [AI]/l) caused sterility in adults from treated fourth instars; whereas the lowest concentration (50 mg [AI]/l) did not cause any adult sterility. A majority of adults from treated fourth instars and treated adults produced normal nymphs, and some adults produced dead nymphs with normal appendages or dead and deformed nymphs without any appendages. Normal nymphs produced by the adults from treated adults or treated at fourth instars developed more slowly from first instar to adult than the water-treated nymphs, and all adults in the new generation apparently reproduced normally. The potential role of pyriproxyfen in a vegetable aphid IPM program was discussed.

Physiological and Biochemical Effect of Pyriproxyfen on Indian Meal Moth Plodia Interpunctella (Hübner) (Lepidoptera: Pyralidae)

“…The current study demonstrated that the longevity of the adults emerging from treated larvae was significantly reduced compared to the control. The result corresponded to those reported for Lipaphis orsini (Liu and Chen 2001), Thrips tabaci (Thysanoptera: Thripidae) (Liu 2003) and Bicyclus anyana (Steigenga et al 2006). The percent of emerged adults from the larval treatment was reduced which was similar to the results of Richardson and Lagos (2007) on Aphis glycines (Heteroptera: Aphididae) and Arthur (2004) on Rhyzopertha dominica (Coleoptera: Bostrichidae).…”

The ecological impact of four IGR insecticides in adults of Hyposoter didymator (Hym., Ichneumonidae): pharmacokinetics approach

“…Bars within the same time moment followed by the same letter are significantly similar (P B 0.01) Ecological impact of IGR insecticides on H. didymator 185 et al (2002) also found that pyriproxyfen penetrated fast but it was harmless to adults of the predator Chrysoperla carnea (Stephens) by topical treatment and Bozsik (2006) also reported the harmlessness of this insecticide to adults of Coccinella septempunctata L. after dermal exposure. However, immature stages of Chrysoperla rufilbris (Burmeister) and Lipaphis erysimi (Kaltenbach) were susceptible to pyriproxyfen because the survival rate, developmental time and molting rate were reduced (Liu and Chen 2001;Chen and Lui 2002). The lack of effects of pyriproxyfen on adults of most of the insects even though juvenoids are known to play a role in reproductive events and its harmfulness in juvenile stages could therefore, be expected based on its juvenile hormone mimicking action (Ishaaya et al 1994).…”

Control of Myzus persicae and Lipaphis erysimi (Hemiptera: Aphididae) by adults and larvae of a flightless strain of Harmonia axyridis (Coleoptera: Coccinellidae) on non-heading Brassica cultivars in the greenhouse

“…The turnip aphid, Lipaphis erysimi (Kaltenbach), is one of the most important pests of Brassica leafy vegetables worldwide (Blande et al 2008), especially in the USA (Liu and Chen 2001), Japan (Nagasaka et al 2003), and India (Dutta et al 2005). High densities of these aphids cause actively growing leaves to curl, thereby forming pockets and folds that provide shelter to the aphids and, consequently, protection against insecticide treatments (Liu and Chen 2001). In addition, aphid control has become less effective due to the evolution of insecticide resistance in natural populations.…”