Efficacy of Beauveria bassiana against the strawberry pests, Lygus lineolaris, Anthonomus signatus and Otiorhynchus ovatus

Abstract

There are several insect species causing serious economic losses in strawberry, Fragaria vesca L., productions. In Quebec, Canada, the tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), the strawberry bud weevil clipper, Anthonomus signatus (Say) and the strawberry root weevil, Otiorhynchus ovatus (L.) are the most important pests. We tested the susceptibility of these pests to the entomopathogenic fungus Beauveria bassiana under laboratory conditions. Sixteen isolates were evaluated for their insecticide potential against these insects. Adults of each species were infected by the immersion method. All isolates were pathogenic to adults of all three species, causing mortality rates between 23.3% and 100% at a concentration of 1 × 107 conidia/ml. Based on the screening results, isolate INRS‐CFL was selected for its insecticide potential and then used for further analyses against L. lineolaris, A. signatus and O. ovatus adults. Bioassays were performed to evaluate the lethal concentration (LC50) and the average survival time (AST) of this isolate against both insect species. Results of dose–response mortality bioassays using four concentrations – 1 × 104, 1 × 106, 1 × 108 and 1 × 109 conidia/ml – indicated a LC50 values of 5.3 × 105, 1.8 × 107 and 9.9 × 107 conidia/ml at 7 days after inoculation for L. lineolaris, A. signatus and O. ovatus respectively. Using a dose of 1 × 108 conidia/ml, the AST values were estimated at 4.41, 7.56 and 8.29 days, respectively, at a concentration of 1 × 108 conidia/ml. This study demonstrated the potential of B. bassiana for the management of L. lineolaris, A. signatus and O. ovatus. Results also suggest that the heteropteran species is more susceptible than coleopteran species to B. bassiana.

Potential Use of the Entomopathogenic Fungus Beauveria Bassiana (Ascomycota: Hypocreales), in Combination With Imidacloprid and Potassium Silicate, for the Control of Sogatella Furcifera Horvath (Homoptera: Delphacidae)

“…Results of the present research showed that the repeated use of B. bassiana caused a significant reduction in the pest population than uncontrolled plot. These results were supported by the findings of Sabbahi et al (2008) since the application of B. bassiana as a conidial spray under field conditions requires tolerance of the conidia to UV light, low relative humidity, and the ability to persist on plant foliage. Hence, multiple applications can compensate for the pathogen's intolerance to suboptimal field conditions.…”

“…Current study revealed that integration of B. bassiana and Imidacloprid along with Potassium silicate increase the efficacy after different exposure time intervals and significantly reduced the infestation losses as well as increased yield which showed the compatibility of entomopathogenic fungi with systemic insecticides. Because Potassium silicate and B. bassiana alone did not gave as satisfactory results as used in combinations, similar results were found for the entomopathogenic fungi with different pesticides (Milner et al, 2003;Sabbahi et al, 2008;Feng et al, 2003;Gatarayiha et al, 2010;Jiang et al, 2012). Similar synergistic effects were observed against Colorado potato beetle by applying entomopathogenic fungi B. bassiana with synthetic chemicals (Anderson et al, 1989).…”

Susceptibility of Dendroctonus simplex to Hypocreales fungi: towards the development of a biological control strategy

“…), the tarnished plant bug, Lygus lineolaris, the strawberry bud weevil, Anthonomus signatus , and the strawberry root weevil, Otiorhynchus ovatus (Sabbahi et al. ,b), the white pine weevil, Pissodes strobi (Trudel et al. ), the pine shoot beetle, T. piniperda (Lavallée et al.…”

Susceptibility of the Japanese beetle, Popillia japonica (Newman) (Coleoptera: Scarabaeidae), to entomopathogenic Hypocreales fungi

“…An individual isolate can exhibit a substantially restricted host range (Inglis et al 2001). Moreover, isolates recovered from a closely related species are generally more virulent than isolates from non-related species (Sabbahi et al 2008).…”