Insecticidal activity of alpha-cypermethrin against small banded pine weevil Pissodes castaneus (Coleoptera: Curculionidae) in forest plantations and thickets

Abstract

Scots pine (Pinus sylvestris) plantations and thickets damaged by biotic and abiotic factors are particularly attractive to small-banded pine weevil Pissodes castaneus, whose larvae excavate feeding tunnels in the stems of young trees, causing their death. There are no chemical methods that can be applied to protect forest plantations and thickets against this pest. Therefore, the studies were undertaken aimed at the assessment of the efficacy of alpha-cypermethrin used to reduce the numbers of this pest within restock areas. The scope of work included laboratory and field estimation of insecticidal activity of alpha-cypermethrin.In laboratory, the beetles of P. castaneus were reared on P. sylvestris twigs treated with five concentrations of alpha-cypermethrin (0.0001-1%) formulated as Fastac Forest 15 SC. Insect mortality was calculated during 7-day rearing and median lethal concentration LC 50 was calculated. The field treatments consisted of spraying of four-year old Scots pines with the insecticide in concentrations of 2% and 4%.In laboratory conditions, the insecticide used at five different concentrations caused a 7-95% mortality of the beetles (LC 50 = 0.266%), while field sprays resulted in a 1.5-3.5-fold reduction in the colonization of trees and in higher pest mortality rates.The results indicate the possibility of using of alpha-cypermethrin in protecting the forest against P. castaneus and can be the basis for the development of chemical method used in the forestry practice.

Pine Pitch Canker and Insects: Regional Risks, Environmental Regulation, and Practical Management Options

“…The chemical control of bark and root borers (Pissodes spp.) can be carried out in small trees (four years), and consists of spraying insects with insecticide [253]. According to these authors, significant reductions in attacks were achieved due to the mortality of the insects when synthetic pyrethroids were used.…”

Evaluation of attractants and traps for monitoring small banded pine weevil Pissodes castaneus

“…The methods for the population reduction of this pest are based mainly on finding and removing the colonized trees from forests (Skrzecz, ). When there was a mass occurrence of weevils in Poland (from 1980–90), the protection of reforestations and young trees was achieved by the use of chemical treatments, mainly pyrethroids (Prokocka, Skrzecz, Sowińska, Wolski, & Janiszewski, ). However, this type of treatment is not currently used due to the lack of plant protection products registered for forest protection against P. castaneus and the lack of procedures specifying the optimal dates of chemical applications.…”