Soil application of Beauveria bassiana GHA against apple sawfly, Hoplocampa testudinea (Hymenoptera: Tenthredinidae): Field mortality and fungal persistence

Abstract

Low impact alternatives to synthetic insecticides for the control of apple sawfly (Hoplocampa testudinea Klug) are scarce encumbering pest management in organic apple orchards. We investigated the soil persistence and field efficacy of the entomopathogenic fungus Beauveria bassiana (Balsamo) Vuillemin (BotaniGard) against apple sawfly under common organic orchard practices. We also assessed the efficacy of B. bassiana GHA and Metarhizium brunneum Petch (indigenous strain) against sawfly in the laboratory. Larvae treated with either fungus in the laboratory died faster than control larvae and displayed 49.4%-68.4% mycosis. In the field, B. bassiana density remained high in the week after application, during larval descent to the soil. Fungal density decreased to 25% at 49 d after application and to 0.4% after 55 weeks. Molecular markers revealed that the majority of fungal isolates recovered comprised the applied B. bassiana strain GHA. Larvae pupating in soil cages in the orchard for 49 d displayed 17% mycosis. The high efficacy under laboratory conditions was not seen in the field. B. bassiana application resulted in densities above the upper natural background level during the growing season, but reversion to background levels occurred within a year. It remains to be investigated whether this has a detrimental effect on nontarget organisms. Additional work is needed to bridge the knowledge gap between laboratory and field efficacy in orchards.

Molecular basis and regulatory mechanisms underlying fungal insecticides' resistance to solar ultraviolet irradiation

“…These pesticides are not only environment friendly, but also safe to honeybee populations foraging for nectar collection in agricultural and forestry landscapes, and hence are considered as alternatives to chemical pesticides in combatting arthropod pests 4–6 . Field populations of various pests have been controlled effectively by pest management programs integrated with fungal formulations at competitive application rates, including cowpea aphids, 7 greenhouse whiteflies, 8 tea leafhoppers, 9, 10 rice planthoppers, 11 western flower thrips, 12, 13 citrus psyllids, 14 citrus and cotton spider mites, 15, 16 wheat and oat wireworms, 17, 18 rice leafrollers, 19 apply sawfly 20 and fruit fly 21 . Of particular note, long‐term sustainable control of major rice insect pests, including Nilaparvata lugens , Cnaphalocrocis medinalis and Chilo suppressalis , with minimal impact on natural enemies, has been achieved successfully by the application of a Metarhizium anisopliae formulation across >6000 ha in the rice‐growing regions of China during 2011–2018 22 .…”

The Investigation of the Biological Control of Icerya purchasi Maskell, 1878 (Hemiptera: Margarodidae) with Entomopathogenic Fungi and Bacteria

“…There are many studies on B. bassiana (Kumar and Suktana, 2017), which is frequently included in Integrated Pest Management (IPM) programs due to its environmental-friendly structure, biological retention and ability to kill pests at various developmental periods in their life cycles (Diehl-Fleig, 1986;Adane et al, 1996, Loureiro andMonteiro, 2005;Marannino et al, 2006, Sabour et al, 2007Castilho, 2010;Zibae et al, 2013, Tangtrakulwanich et al, 2014Swiergiel et al, 2015). The studies have revealed that the fungal infection begins with the attachment of the spore cuticle.…”

Integration of Entomopathogenic Fungi into IPM Programs: Studies Involving Weevils (Coleoptera: Curculionoidea) Affecting Horticultural Crops

“…Although EPF can in some cases persist in the soil for long periods [ 282 ] (up to 15 years in exceptional cases [ 283 ]), a single application of EPF on the topsoil may have only short-term benefits for pest management, as the fungal density usually decreases gradually after application. This theory is supported by many studies [ 237 , 284 , 285 ]; however, despite its transient nature, the application of compost, organic fertilizer or plant growing media colonised by EPF around crops probably represents the best EPF-based technique to control weevils that have a predominantly subterranean pattern of habitat utilisation. More importantly, this solution is suitable for organic growers who are required to use only compost or organic fertilizer on their crops.…”