Compatibility of Isaria fumosorosea (Hypocreales: Cordycipitaceae) Blastospores with Agricultural Chemicals Used for Management of the Asian Citrus Psyllid, Diaphorina citri (Hemiptera: Liviidae)

Abstract

Biorational insecticides are being increasingly emphasized for inclusion in integrated pest management programs for invasive insects. The entomopathogenic fungus, Isaria fumosorosea, can be used to help manage the Asian citrus psyllid with minimal impact on beneficial arthropods, but its effectiveness may be compromised by agrochemicals used to control concurrent arthropod pests and diseases. We evaluated the compatibility of I. fumosorosea blastospores with a range of spray oils and copper-based fungicides registered for use in citrus groves. Results of laboratory and greenhouse tests showed a range of responses of the fungus to the different materials, including compatibility and incompatibility. Overall, I. fumosorosea growth in vitro was reduced least by petroleum-based materials and most by botanical oils and borax, and some of the copper-based fungicides, suggesting that tank mixing of I. fumosorosea with these latter products should be avoided. However, equivalent negative effects of test materials on fungal pathogenicity were not always observed in tests with adult psyllids. We hypothesize that some oils enhanced adherence of blastospores to the insect cuticle, overcoming negative impacts on germination. Our data show that care should be taken in selecting appropriate agrochemicals for tank-mixing with commercial formulations of entomopathogenic fungi for management of citrus pests. The prospects of using I. fumosorosea for managing the invasive Asian citrus psyllid and other citrus pests are discussed.

Entomopathogenic fungi: unconventional applications

“…fumosorosea is sensitive to copper-based fungicides containing a higher (more than 40%) percentage of equivalent metallic copper (Avery et al 2013). The fungicides containing lower copper doses had no apparent impact on the growth of I. fumosorosea and I. farinosa but affected the infection capacity of the fungal EPF (D'Alessandro et al 2011;Demirci et al 2011;Avery et al 2013). Toxic effect of copper oxide (containing 53% and 46% metallic copper) was also confirmed for B. bassiana and L. muscarium (Kouassi et al 2003;Ali et al 2013).…”

Pathogenicity of Isaria fumosorosea to Bemisia tabaci, with some observations on the fungal infection process and host immune response

“…Several commercial preparations of this fungus are currently marketed in Europe and North America for control of whitefly and other soft bodied insect pests (Avery et al, 2013).…”

Efficacy of Topical Application, Leaf Residue or Soil Drench of Blastospores of Isaria fumosorosea for Citrus Root Weevil Management: Laboratory and Greenhouse Investigations

“…Infection of the red palm weevil , Rhynchophorus ferrugineus Olivier (Coleoptera: Curculionidae) by B. bassiana was determined successful through identification of conidiophores on the insect’s cuticle indicating the completion of the fungus’s life cycle within the insect [11]. Another fungal entomopathogen, Isaria fumosorosea ( Ifr ) Wise (Hypocreales: Cordycipitaceae) has also been demonstrated to infect the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), the insect vector of citrus greening disease [21,22,23,24,25,26,27,28] and other citrus pests, including the brown citrus aphid, Toxoptera citricida (Kirkaldy) (Hemiptera: Aphididae), glassy-winged sharpshooter, Homalodisca vitripennis (Germar) (Hemiptera: Cicadellidae), and DRW [29]. …”