The role of fungus Beauveria bassiana in reducing the number of Pissodes castaneus (Col., Curculionidae) in young forests

Abstract

Small banded pine weevil Pissodes castaneus is one of the most dangerous pests of Pinus sylvestris plantations and thickets. The lack of effective and environmentally safe methods of limiting the number of the pest justified to undertake the studies aimed at the laboratory and field evaluation of biological activity of entomopathogenic fungus Beauveria bassiana used to reduce the numbers of small banded pine weevil.In laboratory, the beetles were reared on the sections of fresh Scots pine twigs that were treated with five suspensions containing from 1 × 10 4 to 1 × 10 8 conidia of B. bassiana in 1 ml. During the 3-week rearing, insect mortality was determined and median lethal concentration LC 50 was calculated. The field treatments consisted of spraying 4-year-old P. sylvestris trees with two formulations of fungus containing 1 × 10 8 conidia ml −1 of suspension. Treatments consisted of spraying 4-year-old P. sylvestris trees with two fungus formulations containing 1 × 10 8 conidia ml −1 . High insecticidal activity of B. bassiana was found because the pathogen caused the death of 14-94% of P. castaneus beetles, LC 50 = 6.51 × 10 5 conidia ml −1. Field treatments did not result in the reduction of plant damage caused by small banded pine weevil; therefore, the spraying of trees with B. bassiana cannot be recommended to protect the young stands of P. sylvestris against pest.

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

“…Vuill. Similar laboratory results were obtained by Skrzecz et al (); however, field treatments conducted by these authors with B. bassiana did not result in the reduction of plant damage caused by the small banded pine weevil.…”

Pine Pitch Canker and Insects: Relationships and Implications for Disease Spread in Europe

“…Insects that infest weakened trees through regeneration feeding on twigs and buds usually do not cause major damage, but their larvae may severely damage the water and nutrient transporting tissues when feeding under the bark of the trees [161]. The importance of bark beetles and wood-boring insects increases on older forests, and while most species attack weakened trees as secondary pests, some are able to primarily attack pines.…”

A Sensitive Method for Detecting Beauveria bassiana, an Insecticidal Biocontrol Agent, Population Dynamics, and Stability in Different Substrates

“…B. bassiana is the most well studied entomopathogenic fungi and has been frequently used as a commercial mycoinsecticide in the feld [5,6]. For example, B. bassiana was used to control insect pests, including Pissodes castaneus, Ostrinia nubilalis, and Rhynchophorus ferrugineus, infeld through direct spraying [7][8][9]. It is known that B. bassiana is safe to human, natural benefcial insects, and benefcial microorganisms.…”