Control of egg and neonate larvae ofXylotrechus arvicola(Coleoptera: Cerambycidae), a new vineyard pest, under laboratory conditions

Abstract

Background and Aims: Xylotrechus arvicola (Coleoptera: Cerambycidae) is a new vineyard pest. Six insecticides were tested on X. arvicola eggs arranged in Petri dishes and in two parts of the vine: branch and trunk. Method and Results: According to the Abbott formula, on Petri dishes, chlorpyrifos had total ovicidal control, significantly different from that of pyriproxyfen (88.3%), Beauveria bassiana (84.3%) and imidacloprid (80.9%). On branches, chlorpyrifos (91.6%), pyriproxyfen (79.1%) and flufenoxuron (75.0%) showed improved toxic effect, and on trunks, chlorpyrifos (83.3%) gave the best control, significantly different from that of imidacloprid (50.0%), pyriproxyfen (45.8%) and flufenoxuron (37.5%). Larval mortality was registered from the seventh to the fourteenth day after treatment: spinosad (50.0%), imidacloprid (45.8%) and B. bassiana (33.3%) were the insecticides that showed greater larval mortality on branches. These insecticides also showed greater larval mortality on trunks, but only B. bassiana (50.0%) had a greater residual effect on trunks than on branches. Conclusions: All insecticides evaluated gave better ovicidal control when applied directly on Petri dishes than when applied on branches and trunks, where all insecticides (except chlorpyrifos and imidacloprid) show greater toxic effect when applied on branches. Spinosad and B. bassiana have the best larval residual mortality, when applied, respectively, on branches and on trunks. Significance of the Study: Beauveria bassiana is the best insecticide with residual effect on neonate larvae on trunks, where the greater thickness of the rhytidome and cracks favoured the development of this fungus to invade actively the larvae through their shell and proliferate inside.

Investigations of Trichoderma spp. and Beauveria bassiana as biological control agent for Xylotrechus arvicola, a major insect pest in Spanish vineyards

“…The selected treatments were the five isolates with the best inhibitory capacity shown in experiment 1 to which a commercial strain (GHA strain) of B. bassiana (Bassi WP, Massó SA, Barcelona, Spain) was added such a new treatment more because it has shown to control this insect pest on branches and trunks in previous studies (Rodríguez-González et al 2017a). The six fungal isolates (1 × 10 7 spores per milliliter) and distilled water (control) were sprayed over vine samples.…”

“…The larvae are white and have an average size of 22 mm in the last stage (Moreno et al 2003). Once the larva hatches from the egg, it bores galleries into the wood (Rodríguez-González et al 2017a). For this reason, larvae are only reachable by insecticides the first 24 h after hatching and in most cases only adults and eggs stages are affected by plant-protection products (Rodríguez-González et al 2016b).…”

Susceptibility of Xylotrechus arvicola (Coleoptera: Cerambycidae) to Five Cry Toxins

“…The laboratory tests are the initial steps to find them, but it is arduous to set it up precisely. We have successfully applied the bioassay protocol used on X. arvicola larvae with other pesticides [11]., However, the accuracy of the results could be discussed, since some toxicological effects do not depend on the Cry proteins, which can degrade in a long treatment period. Nevertheless, we can assess the results since we assume the generally accepted fact that the main insect toxicity effect of Cry preparation relies on the Cry proteins in the sample, and, with the reported data, we have, at least, preliminary toxic information.…”

The efficacy of European fruit lecanium, Parthenolecanium corni (Bouché, 1844) control using natural products

“…Live and dead nymphs were counted and recorded under a binocular microscope. The formula used for calculating the percent reduction of pest populations, by the tested products used the following formula after Henderson and Tilton (1955), who referred to it as a modification of Abbott (1925), as commonly used for the calculation of plant protection product efficacy (Nour-Eldin, Sholla 2015;Emami 2016;Rodríguez-González et al 2017).…”