Comparative efficacy of different pesticides against mango bark beetle Hypocryphalus mangiferae Stebbing (Coleoptera: Scolytidae)

Abstract

Hypocryphalus mangiferae Stebbing is one of the most destructive insect pests of mango trees and is found to be associated with the transmission of causal organisms of mango sudden death disease. The present study was carried out to evaluate the toxicity of deltamethrin, bifenthrin, chlorpyrifos, emamectin benzoate, imidacloprid and spinosad in laboratory and field trials. Bioassay results showed that the toxicity of chlorpyrifos was significantly higher than deltamethrin but similar to bifenthrin. Deltamethrin and bifenthrin toxicity, however, increased significantly (P < 0.01) from day 1 to day 3. Spinosad was the least toxic compound while emamectin was the most toxic among new chemical insecticides tested, but its toxicity increased significantly from day 1 to day 5. Comparison of the efficacies of the insecticides using lethal times to produce 50% mortality (LT50) and 90% mortality (LT90) showed that the relative potencies of chlorpyrifos, emamectin, imidacloprid and spinosad were greater than bifenthrin and deltamethrin. The results of field trials showed the highest number of beetles emerged from the control twigs while significantly fewer beetles emerged from the twigs treated with bifenthrin (P < 0.05), which accounted for 12% for bifenthrin compared to that of the control. The present study demonstrated increased toxicities of systemic insecticides and chlorpyrifos compared to toxicities of deltamethrin and bifenthrin, suggesting these insecticides could be an alternative tool in a comprehensive H. mangiferae management program to eradicate the beetles from mango orchards.

Micronutrients Foliar and Drench Application Mitigate Mango Sudden Decline Disorder and Impact Fruit Yield

“…Symptoms of MSD disease were observed on different parts of the trees, including leaves, the bark of the stem, main trunk, and on the roots, which was found to be common among all the affected trees across four experimental areas. At the early stage of the disease infection, affected leaves on smaller branches became necrotic and gradually progressed to the main branches where gum exudation from bark of main branches was observed [7][8][9][10][11][12]31].…”

“…The occurrence of MSD is highly promoted by a beetle (Xeleborus offinis) at a relevant humidity above 80% and 25-31 • C temperature [11]. A bark beetle of mango, Hypocryphalus mangiferae, is implicated as a vector in the establishment of MSD in Pakistan [7,12,13]. Nutritional deficiency, drought, temperature fluctuations, and mechanical injuries are the principal abiotic factors that speed up MSD [14][15][16].…”

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

“…Other trials should be conducted at other stages of development of the insects, which can show other toxic responses of the insect pest to this systemic insecticide (Terriere ). The injection of systemic insecticides such as imidacloprid into the trees has been effective in preventing attacks of other beetles such as Hypocryphalus mangiferae (Coleoptera: Scolytidae) (Poland et al , Saeed et al ).…”

Eficacitatea unor pesticide în prevenirea atacului de Xylosandrus germanus (Coleoptera: Curculionidae, Scolytinae), în condiții de laborator

“…Nu am identificat date publicate cu privire la testarea vreunor produse pe bază de spinosad împotriva lui X. germanus, dar în experimente împotriva unor specii de gândaci de scoarță, precum Scolytus rugulosus (Muller, 1818) și Hypocryphalus mangiferae (Stebbing, 1914) acesta s-a dovedit a fi mult mai puțin eficace decât acetamipridul (Doerr et al 2008) și mult mai puțin toxic decât imidaclopridul, care este tot un produs din clasa neonicotinoizilor (Saeed et al 2011). În cazul femelelor de X. germanus, eficacitatea spinosadului a fost de 1,2 ori mai mare decât a acetamipridului (57,4% față de 46,6%), dar și concentrația în substanță activă a emulsiilor folosite a fost de 1,2 ori mai mare în primul caz, iar diferența de mortalitate între cele două variante nu este asigurată statistic.…”