Responses of two ladybeetles to eight fungicides used in Florida citrus: Implications for biological control

AUTOR(ES)

Michaud, J.P.

FONTE

University of Arizona Library

RESUMO

Two ladybeetles, Cycloneda sanguinea and Harmonia axyridis, were exposed in the laboratory to eight fungicide formulations commonly used in citrus production in Florida. Both benomyl and the combination of copper and petroleum oil proved toxic to larvae of C. sanguinea that were exposed to concentrations corresponding to recommended field rates, either as leaf residues or in topical spray applications. Larvae of C. sanguinea also suffered significant mortality when exposed to neem oil as a leaf residue, but not after topical application. Larvae of H. axyridis exposed to these compounds completed development with the same success as control larvae in all trials. However, H. axyridis larvae exhibited slower development following exposure to leaf residues of ferbam applied at twice the recommended rate. Exposure to azoxystrobin as a leaf residue at twice the recommended concentration resulted in accelerated larval development in both species. No compounds appeared repellent to adult beetles of either species. Adult beetles of both species were observed resting on portions of filter paper treated with fosetyl-Al more often than on untreated, control portions. Azoxystrobin, ferbam and mefenoxam similarly arrested the movement of adult C. sanguinea, whereas benomyl and the copper and petroleum oil combination arrested the movement of adult H. axyridis. The differential sensitivity of the two coccinellid species is discussed in the context of the potential displacement of the indigenous C. sanguinea by the invasive H. axyridis.

Documentos Relacionados

• IPM-compatibility of foliar insecticides for citrus: Indices derived from toxicity to beneficial insects from four orders
• Genetic variation among Phyllosticta strains isolated from citrus in Florida that are pathogenic or nonpathogenic to citrus
• Environmental and biological monitoring of exposure to ethylenebisdithiocarbamate fungicides and ethylenethiourea.
• Dispersal of the parasitic ciliate Lambornella clarki: implications for ciliates in the biological control of mosquitoes.
• Characterization and Reclassification of Yeasts Used for Biological Control of Postharvest Diseases of Fruits and Vegetables