Biocontrol Science and Technology (2013) 23, 1053-1066

C.A. Coombes, M.P. Hill, S.D. Moore, J.F. Dames and T. Fullard (2013)
Persistence and virulence of promising entomopathogenic fungal isolates for use in citrus orchards in South Africa
Biocontrol Science and Technology 23 (9), 1053-1066
Abstract: Thaumatotibia leucotreta (Meyrick) (1912) (Lepidoptera: Tortricidae) is a key economic pest of citrus in South Africa. Although a variety of control options are available, none currently registered target the soil-dwelling life stages of the pest. Three fungal isolates, two Metarhizium anisopliae sensu lato Metschnikoff (Sorokin) isolates (G 11 3 L6 and FCM Ar 23 B3) and one Beauveria bassiana sensu lato Balsamo (Vuillemin) isolate (G Ar 17 B3) have been identified as showing the greatest potential against T. leucotreta soil-dwelling life stages. Since environmental persistence is an important factor in the success of entomopathogenic fungi against soil pests, the isolates, along with two commercial isolates (B. bassiana Eco-Bb® and M. anisopliae ICIPE 69), were subjected to a six-month field persistence trial. Every month after burial of the fungal isolates, inside net bags, in orchard soil, the number of colony forming units (CFUs) per gram of soil was measured and the viability of the conidia was assessed using bioassays. All isolates investigated were capable of persisting in the soil for the duration of the trial period and in addition, were capable of initiating infection in T. leucotreta late fifth instar larvae and subsequent pupae. However, with the exception of the commercial isolates which showed some correlation, no correlation was found between the number of CFUs recorded and percentage T. leucotreta mycosis. Persistence of entomopathogenic fungi in the field is affected by a series of factors, and although the effect of these factors was not measured, the data have provided preliminary evidence towards the persistence capability of these candidate biopesticides against T. leucotreta.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Sean D. Moore

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
environment/habitat manipulation
general biology - morphology - evolution

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Thaumatotibia leucotreta	Citrus (genus)	South Africa
Beauveria bassiana (entomopathogen)	Thaumatotibia leucotreta	Citrus (genus)	South Africa
Metarhizium anisopliae (entomopathogen)	Thaumatotibia leucotreta	Citrus (genus)	South Africa