Effect of visible light and ultraviolet light on the pathogenicity of entomopathogenic fungi to false codling moth, Thaumatotibia leucotreta (Lepidoptera: Tortricidae) larvae
Keywords:conidia, biological control, insect pests, Metarhizium, Beauveria
Entomopathogenic fungi (EPF) are effective and environment-friendly insect biological control agents. Ultraviolet (UV) light is known to have an effect on the survival of fungal conidia, and natural sunlight is potentially one of the most damaging factors undermining EPF persistence and pathogenicity. This study aimed to test the infection potential of an isolate of Beauveria bassiana and five Metarhizium species after exposure to different light treatments, on soil and leaf surfaces under laboratory and field conditions, using Thaumatotibia leucotreta (Lepidoptera: Tortricidae) as the test host. Conidia were exposed either to growth light alone, which emits the same visible light as the sun, but excluding UV light, or directly exposed to UV light for 12 h. The results indicated no negative effect on the infection potential of the conidia of most species tested. The conidia of the two Metarhizium pinghaense (5HEID and TH149) isolates showed the greatest tolerance to visible light and UV radiation exposure on both soil and leaf surfaces. Exposure of M. pinghaense isolates to visible light on soil surfaces showed pathogenicity of > 80% for both isolates, and of between 58% and 88% after exposure to UV light. On leaf surfaces, three Metarhizium isolates, M. pinghaense (5HEID and TH149) and M. majus (TH153) had > 90% pathogenicity following exposure to UV light, and M. pinghaense (TH149) and M. robertsii (6EIKEN) showed greater tolerance of > 70%, under laboratory conditions. However, the pathogenicity of the EPF isolates was very low in field trials, indicating that further trials on the use of formulations and adjuvants with the isolates are needed to improve long-term persistence and efficacy under field conditions.
Acheampong MA, Hill MP, Moore SD, Coombes CA. 2020.UV sensitivity of Beauveria bassiana and Metarhizium anisopliae isolates under investigation as potential biological control agents in South African citrus orchards. Fungal Biology 124(5): 304–310. https://doi.org/10.1016/j.funbio.2019.08.009
Arthurs S, Thomas MB. 2001. Effects of temperature and relative humidity on sporulation of Metarhizium anisopliae var. acridum in mycosed cadavers of Schistocerca gregaria. Journal of Invertebrate Pathology 78(2): 59–65. https://doi.org/10.1006/jipa.2001.5050
Brunner-Mendoza C, Reyes-Montes MR, Moonjely S, Bidochka M, Toriello C. 2019. A review on the genus Metarhizium as an entomopathogenic microbial biocontrol agent with emphasis on its use and utility in Mexico. Biocontrol Science and Technology 29(1): 83–102. https://doi.org/10.1080/09583157.2018.1531111
CABI. 2021. Invasive Species Compendium. Detailed coverage of invasive species threatening livelihoods and the environment worldwide. https://www.cabi.org/isc/datasheet/6904
Chandler D. 2017. Basic and applied research on entomopathogenic fungi. In: Lacey L, editor. Microbial Control of Insect and Mite Pests: From Theory to Practice. USA: Academic Press; p. 69–89. https://doi.org/10.1016/B978-0-12-803527-6.00005-6.
Coombes CA, Hill MP, Moore SD, Dames JF. 2016. Entomopathogenic fungi as control agents of Thaumatotibia leucotreta in citrus orchards: field efficacy and persistence. BioControl 61(6): 729–739. https://doi.org/10.1007/s10526-016-9756-x
Coombes CA, Hill MP, Moore SD, Dames JF, Fullard T. 2015. Beauveria and Metarhizium against false codling moth (Lepidoptera: Tortricidae): a step towards selecting isolates for potential development of a mycoinsecticide. African Entomology 23(1): 239–242. https://doi.org/10.4001/003.023.0107
Daiber CC. 1979a. A study of the biology of the false codling moth [(Cryptophlebia leucotreta (Meyr.)]: the cocoon. Phytophylactica ; 11: 151–157.
Daiber CC. 1979b. A study of the biology of the false codling moth [(Cryptophlebia leucotreta (Meyr.)]: the larva. Phytophylactica 11: 141–144.
Daiber CC. 1980. A study of the biology of the false codling moth Cryptophlebia leucotreta (Meyr.): the adult and generations during the year. Phytophylactica 12: 187–193.
Daiber CC. 1989. The false codling moth, Cryptophlebia leucotreta (Meyr.) (Lepidoptera, Tortricidae), in Southern Africa. Journal of Plant Diseases and Protection 96: 71–80.
Fang W, St. Leger RJ. 2012. Enhanced UV resistance and improved killing of malaria mosquitoes by photolyase transgenic entomopathogenic fungi. PLoS One. 7(8): e43069. https://doi.org/10.1371/journal.pone.0043069
Fargues J, Rougier M, Goujet R, Smits N, Coustere C, Itier B. 1997. Inactivation of conidia of Paecilomyces fumosoroseus by near-ultraviolet (UVB and UVA) and visible radiation. Journal of Invertebrate Pathology 69(1): 70–78. https://doi.org/10.1006/jipa.1996.4637
Fernandes EKK, Rangel DEN, Braga GUL, Roberts DW. 2015. Tolerance of entomopathogenic fungi to ultraviolet radiation: A review on screening of strains and their formulation. Current Genetics 61(3): 427–440. https://doi.org/10.1007/s00294-015-0492-z.
Georgala MB. 1969. Control of false codling moth and fruit flies in citrus orchards. South African Citrus Journal. 421: 3–7.
Goble TA, Dames JF, Hill MP, Moore SD. 2011. Investigation of native isolates of entomopathogenic fungi for the biological control of three citrus pests. Biocontrol Science and Technology 21(10): 1193–1211. https://doi.org/10.1080/09583157.2011.608907
Ignoffo CM. 1992. Environmental factors affecting persistence of entomopathogens. The Florida Entomologist 75(4): 516–525. https://doi.org/10.2307/3496133
Inglis GD, Enkerli J, Goettel MS. 2012. Laboratory techniques used for entomopathogenic fungi: Hypocreales. In: Lacey LA, editor. Manual of techniques in invertebrate pathology. 2nd ed. London: Academic Press. p. 189–253. https://doi.org/10.1016/B978-0-12-386899-2.00007-5
Inglis GD, Ivie TJ, Duke GM, Goettel MS. 2000. Influence of rain and conidial formulation on persistence of Beauveria bassiana on potato leaves and Colorado potato beetle larvae. Biological Control 18(1): 55–64. https://doi.org/10.1006/bcon.1999.0806
Jaronski ST. 2010. Ecological factors in the inundative use of fungal entomopathogens. BioControl 55(1): 159–185. https://doi.org/10.1007/s10526-009-9248-3
Kouassi M, Coderre D, Todorova SI. 2003. Effect of plant type on the persistence of Beauveria bassiana. Biocontrol Science & Technology 13(4): 415–427. https://doi.org/10.1080/0598315031000104532
Mathulwe LL. 2019. Control of the woolly apple aphid, Eriosoma lanigerum (Hausmann) (Hemiptera: Aphididae), using entomopathogenic fungi. MSc dissertation. Stellenbosch University, Stellenbosch.
Meyling NV, Eilenberg J. 2007. Ecology of the entomopathogenic fungi Beauveria bassiana and Metarhizium anisopliae in temperate agroecosystems: potential for conservation biological control. Biological Control 43(2): 145–155. https://doi.org/10.1016/j.BioControl 2007.07.007
Moore SD. 2021. Biological control of a phytosanitary pest (Thaumatotibia leucotreta): A case study. International Journal of Environmental Research and Public Health 18(3): 1198. https://doi.org/10.3390/ijerph18031198
Moore S, Kirkman W. 2009. Citrus orchard sanitation with emphasis on false codling moth control. SA Fruit Journal. 7(6): 57–60.
Moore S, Kirkman W, Hattingh V. 2015. The host status of lemons for the false codling moth, Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae) with particular reference to export protocols. African Entomology 23(2): 519–525. https://doi.org/10.4001/003.023.0223
Oliveira AS, Braga GUL, Rangel DEN. 2018. Metarhizium robertsii illuminated during mycelial growth produces conidia with increased germination speed and virulence. Fungal Biology 122(6): 555–562. https://doi.org/10.1016/j.funbio.2017.12.009
Onofre AB, Miniuk CM, de Barros NM, Azevedo JL. 2001. Growth and sporulation of Metarhizium flavoviride var. Flavoviride on culture media and lighting regimes. Scientia Agricola 58(3): 613–616. https://doi.org/10.1590/S0103-90162001000300026
Ortiz-Urquiza A, Keyhani NO. 2015. Stress response signalling and virulence: insight from entomopathogenic fungi. Current Genetics 61(3): 239–249. https://doi.org/10.1007/s00294-014-0439-9
Rangel DEN, Butler MJ, Torabinejad J, Anderson AJ, Braga GUL, Day AW, Roberts DW. 2006. Mutants and isolates of Metarhizium anisopliae are diverse in their relationships between conidial pigmentation and stress tolerance. Journal of Invertebrate Pathology 93(3): 170–182. https://doi.org/10.1016/j.jip.2006.06.008
Rodrigues IMW, Forim MR, da Silva MFGF, Fernandes JB, Filho AB. 2016. Effects of ultraviolet radiation on fungi Beauveria bassiana and Metarhizium anisopliae, pure and encapsulated, and bio-insecticide action on Diatraea saccharalis. Advances in Entomology 4(3): 151–162. https://doi.org/10.4236/ae.2016.43016
Roy HE, Steinkraus DC, Eilenberg J, Hajek AE, Pell JK. 2006. Bizarre interactions and endgames: entomopathogenic fungi and their arthropod hosts. Annual Reviews of Entomology 51(1): 331–357. https://doi.org/10.1146/annurev.ento.51.110104.150941
Stofberg FJ. 1954. False codling moth of citrus. Farming in South Africa. 29: 273–276.
TIBCO Software Inc. 2018. STATISTICA (data analysis software system), version 220.127.116.11. Palo Alto (CA): TIBCO Software Inc.
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