Persistence, Penetration, and Surface Availability of Cypermethrin and Its Major Degradation Products in Elm Bark

Abstract

The initial residues of cis-A, trans-C, cis-B, and trans-D cypermethrin in elm bark treated with a 400× aqueous dilution of Ripcord 40 EC (1.0 g of active ingredient/L) to runoff ranged from 29 to 58, from 24 to 53, from 25 to 35, and from 17 to 25 μg/g, respectively. These residues dissipated quickly with half-lives of 1.60−12.0 days for the faster dissipation phase. The dissipation of cypermethrin during the later period became much slower, with dissipation half-lives of 209−365 days. Cypermethrin residues in elm bark remained 100% effective against the native elm bark beetle for ∼60 days after application. Laboratory tests indicated that cypermethrin residues in the bark were 100% effective in preventing elm bark beetles from making overwintering tunnels for up to 627 days (fall application) and 433 days (spring application). No penetration of cypermethrin to the cambium layer or wood tissue was detected during the experimental period of 791 days. Total cypermethrin residue absorbed from treated elm bark during a 1 min contact period did not exceed the acceptable daily intake for humans. Keywords: Cypermethrin; degradation products; elm bark; elm bark beetle; residue; effectiveness; penetration; contact availability

Effect of the combined treatment of insecticides and an attractant for the control of Phloeotribus scarabaeoides, a pest of Olea europea

“…Its persistence was nevertheless lower than that of two pyrethroid insecticides previously studied, deltamethrin and cypermethrin,7, 8 for which half‐lives ranged from 35 to 45 days. These results agree with data reported in other cultures 18. 20…”

“…The dissipation of the insecticides can be well described by a first‐order exponential equation: The fitting of the data gave correlation coefficients >0.9, except for methidathion, and shows that insecticide degradation follows this equation (Table 1), as has been reported for many other pesticides 17. 18 Insecticide half‐life ( t 1/2 ) can be calculated as …”

“…Nevertheless, no P scarabaeoides emerged from the treated logs (Table 2), which is an indication that the treatment was also effective even if the reproduction gallery had already started. Jin and Webster18 reported that, although cypermethrin lacked the ability to penetrate elm bark, it was, nevertheless, effective for the control of the elm bark beetle.…”

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“…Cypermethrin effect the sperm concentration and motility, hormones and weights of testes as well as causing itching, restlessness and head shaking and other nervous disorders [11] . Cypermethrin effect the nervous system of the animals and is considered as a stomach poison [12] . Newborn animals were found to be more sensitive to cypermethrin comparatively to adult animals because liver enzymes which are responsible for the breakdown of cypermethrin in the body are not completely formed in the newborns [13] .…”

Persistence and risk assessment of cypermethrin residues on chilli (Capsicum annuum L.)

“…The cis-isomers are considered to be more acutely toxic than the trans-isomers and are used to control many pests, for instance, lepidopterous pests of cotton, fruit, and vegetable crops. This extremely hydrophobic insecticide is both a stomach poison and a contact insecticide (Jin and Webster 1988) that affects the nervous system of insects by affecting voltage-dependent sodium channels and inhibiting ATPase enzyme.…”