Skip to main content Accessibility help
×
Home

METARHIZIUM FLAVOVIRIDE (FI985) AS A PROMISING MYCOINSECTICIDE FOR AUSTRALIAN ACRIDIDS

  • Richard J. Milner (a1)

Abstract

Only one isolate of Metarhizium flavoviride Gams and Roszypal group 3 has been isolated from a field-infected acridid in Australia. This is isolate FI985 (ARSEF 324) obtained from a spur-throated locust, Austracris guttulosa (Walker), near Rockhampton, Queensland, in 1979. In terms of conidial size and shape as well as phialide morphology, FI985 is intermediate between Metarhizium anisopliae (Metschnikoff) Sorokin and M. flavoviride. It has been compared with other group 3 isolates using RAPDs and sequence analysis of the ITS region and found to be very similar. However the analysis shows that these group 3 isolates are genetically closer to M. anisopliae than to M. flavoviride sensu stricto. Laboratory bioassays have shown that FI985 is virulent for five species of acridid pests in Australia. Comparative bioassays with other isolates of Metarhizium, including other group 3 isolates from Africa and Asia, have not yet revealed any isolate more virulent than FI985. This isolate is amenable to mass-production on rice and has been formulated in oil as a mycoinsecticide. The results from six field tests, mostly against wingless grasshopper, Phaulacridium vittatum (SjÖstedt), using doses of 2–7 × 1012 conidia per hectare and plot sizes up to 50 ha are summarized. These trials (with the exception of the first against the Australian plague locust) have given high levels of disease-related mortality in caged samples of the target collected within 3 days of spraying. In the four trials with wingless grasshopper, population reductions were detected 10–30 days after application; however these reductions were much less than suggested by cage samples as a result of movement of the target acridids. In contrast, positive control plots sprayed with fenitrothion gave a very high initial kill (>90% in 1 day) but were then more rapidly reinvaded. Consequently, 3–4 weeks after spraying the density in the plots treated with chemical insecticide and those treated with mycoinsecticide were similar. Further field trials are needed especially against the Australian plague locust and evaluating lower doses. The results obtained to date show that a mycoinsecticide based on FI985 is likely to be effective over a wide range of target acridids and weather conditions.

Un seul isolat de Metarhizium flavoviride Gams and Roszypal du groupe 3 a été trouvé chez un criquet (Acrididae) d'Australie infecté en nature. Il s'agit de l'isolat FI985 (ARSEF 324) obtenu chez Austracris guttulosa (Walker), près de Rockhampton, Queensland, en 1979. L'isolat FI985 est intermédiaire entre Metarhizium anisopliae (Metschnikoff) Sorokin et M. flavoviride par la taille des conidies et la morphologie des phialides. L'isolat a été comparé à d'autres isolats du groupe 3 par amplification aléatoire d'ADN polymorphe (RAPD) et par analyse des séquences d'espacement interspécifique (région ITS) et il se sont tous avérés très semblables. Cependant l'analyse a démontré que ces isolats du groupe 3 sont plus apparentés génétiquement à M. anisopliae qu'à M. flavoviride sensu stricto. Des expériences en laboratoire ont démontré que l'isolat est virulent contre cinq espèces d'acridiens nuisibles en Australie. Des expériences comparatives au moyen d'autres isolats de Metarhizium, dont des isolats du groupe 3 d'Afrique et d'Asie, n'ont pas révélé d'isolat plus virulent que le FI985. Cet isolat est un bon sujet pour la production en masse sur le riz et il a servi de base à une préparation à l'huile pour servir de mycoinsecticide. Les résultats de six tests en nature, surtout contre le criquet Phaulacridium vittatum (SjÖstedt), au moyen de doses de 2–7 × l012 conidies per hectare dans des grilles échantillons pouvant atteindre 50 ha sont résumés ici. Ces expériences (à l'exception de la première contre le Criquet migrateur d'Australie), ont, après 3 jours, entraîné une forte mortalité reliée à la maladie chez des criquets cibles gardés en cage. Au cours des quatre expériences sur P. vittatum sur le terrain, des réductions des populations ont été enregistrées de 10–30 jours après le traitement, mais ces réductions se sont avérées moins importantes que celles prévues d'après les expériences sur les insectes en cage à cause des déplacements des criquets traités. En revanche, des grilles échantillons traitées au fenitrothion ont subi une forte diminution des effectifs au début (>90% en 1 jour), mais ont été réenvahies plus rapidement. Conséquemment, 3–4 semaines après les traitements, la densité dans les parcelles traitées au moyen d'un insecticide chimique et celle enregistrée dans les parcelles traitées au moyen du mycoinsecticide étaient semblables. D'autres expériences sur le terrain sont essentielles, particulièrement pour raffiner les méthodes de lutte contre le Criquet migrateur d'Australie et pour évaluer l'effet de doses plus faibles. Les résultats obtenus à ce jour indiquent qu'un mycoinsecticide à base de FI985 a de fortes chances d'être efficace dans la lutte contre bon nombre d'acridiens dans une gamme étendue de conditions climatiques. [Traduit par la Rédaction]

Copyright

References

Hide All
Baker, G.L. 1986. The ecology of mermithid nematode parasites of grasshoppers and locusts in south-eastern Australia, pp. 277–280 in Samson, R.A., Vlak, J.M., and Peters, D. (Eds.), Fundamental and Applied Aspects of Invertebrate Pathology. Foundation IVth ICIP, Wageningen, The Netherlands. 711 pp.
Baker, G.L. 1993. Locusts and Grasshoppers of the Australasian Region. The Orthopterists Society, Ste-Anne-de-Bellevue, Quebec, Canada (Macdonald Campus of McGill University). 66 pp.
Baker, G.L. 1995. Wingless Grasshopper: The Nematode Story. Video, NSW Department of Agriculture, 20 min.
Baker, G.L. and Capinera, J.L.. 1997. Nematodes and nematomorphs as control agents of grasshoppers and locusts. pp. 157–211 in Goettel, M.S., and Johnson, D.L. (Eds.), Microbial Control of Grasshoppers and Locusts. Memoirs of the Entomological Society of Canada 171: 400 pp.
Baker, G.L., Milner, R.J., Lutton, G.G. and Watson, D.M.. 1994. Preliminary field trial on the control of Phaulacridium vittatum (Sjöstedt) (Orthoptera: Acrididae) populations with Metarhizium flavoviride Gams and Rozsypal (Deuteromycetina: Hyphomycetes). Journal of the Australian Entomological Society 33: 190192.
Baker, G.L. and Pigott, R.. 1994. The impact of biotic factors on Chortoiceles terminifera (Walker) in invasion areas of south-eastern Australia. Journal of Orthopteran Research 4: 17.
Baker, G.L. and Poinar, G.O.. 1986. Mermis quirindiensis n. sp. (Nematoda: Mermithidae), a parasite of locusts and grasshoppers (Orthoptera: Acrididae) in south-eastern Australia. Revue Nematologie 9: 125134.
Bateman, R. 1997. Methods of application of microbial pesticide formulations for the control of grasshoppers and locusts, pp. 69–81 in Goettel, M.S., and Johnson, D.L. (Eds.), Microbial Control of Grasshoppers and Locusts. Memoirs of the Entomological Society of Canada 171: 400 pp.
Bidochka, M.J., Mcdonald, M.A., St. Leger, R.J. and Roberts, D.W.. 1994. Differentiation of species and strains of entomopathogenic fungi by random amplification of polymorphic DNA (RAPD). Current Genetics 21: 107113.
Bridge, P.D., Prior, C., Sagbohan, J., Lomer, C.J., Carey, M. and Buddie, A.. 1997. Molecular characterization of isolates of Metarhizium from locusts and grasshoppers. Biodiversity and Conservation. 6: 177189.
Bridge, P.D., Williams, M.A.J., Prior, C. and Patterson, R.R.M.. 1993. Morphological, biochemical and molecular characteristics of Metarhizium anisopliae and Metarhizium flavoviride. Journal of General Microbiology 139: 11631169.
Carruthers, R.I., Larkin, T., Firstencel, H. and Feng, Z.. 1992. Influence of thermal ecology on the mycosis of a rangeland grasshopper. Ecology 73: 190204.
Carruthers, R.I. and Onsager, J.A.. 1993. Perspective on the use of exotic natural enemies for biological control of pest grasshoppers (Orthoptera: Acrididae). Environmental Entomology 22: 885903.
Carruthers, R.I., Ramos, M.E., Larkin, T.S., Hostetter, D.L. and Soper, R.S.. 1997. The Entomophaga grylli (Fresenius) Batko species complex: Its biology, ecology, and use for biological control of pest grasshoppers. pp. 329–353 in Goettel, M.S., and Johnson, D.L. (Eds.), Microbial Control of Grasshoppers and Locusts. Memoirs of the Entomological Society of Canada 111: 400 pp.
Clarke, D.P. 1967. A population study of Phaulacridium vittatum Sjöst. (Acrididae). Australian Journal of Zoology 25: 455489.
Curran, J., Driver, F., Ballard, J.W.O. and Milner, R.J.. 1994. Phylogeny of Metarhizium: Analysis of ribosomal DNA sequence data. Mycological Research 98: 547552.
Glare, T.R., Milner, R.J. and Beaton, C.D.. 1996. Variation in Metarhizium: Is phialide morphology a useful taxonomic criterion? Journal of Orthopteran Research 5: 1927.
Hooper, G.H.S., Milner, R.J., Spurgin, P.A. and Prior, C.. 1995. Initial field assessment of Metarhizium flavoviride Gams and Rozsypal (Deuteromycetina: Hyphomycetes) for control of Chortoicetes terminifera (Walker) (Orthoptera: Acrididae). Journal of the Australian Entomological Society 34: 8384.
Humber, R.A. 1989. Synopsis of a revised classification for the Entomophthorales (Zygomycotina). Mycotaxon 34: 441460.
Humber, R.A. 1992. Collection of Entomopathogenic Fungal Cultures: Catalog of Strains. USDA Agricultural Research Service ARS–110: 170 pp.
Jenkins, K. 1994. Fungus raps up locusts and grasshoppers. Rural Research (Australia) 164: 47.
Lomer, C.J., Prior, C. and Kooyman, C.. 1997. Development of Metarhizium spp. for the control of grasshoppers and locusts, pp. 265–286 in Goettel, M.S., and Johnson, D.L. (Eds.), Microbial Control of Grasshoppers and Locusts. Memoirs of the Entomological Society of Canada 171: 400 pp.
Milner, R.J. 1978. On the occurrence of Entomophaga grylli, a fungal pathogen of grasshoppers in Australia. Journal of the Australian Entomological Society 17: 293296.
Milner, R.J. 1985. Field tests of a strain of Entomophaga grylli from the USA for biocontrol of the Australian wingless grasshopper, Phaulacridium vittatum. pp. 255261 in Proceedings 4th Australiasian Conference on Grassland Invertebrate Ecology, Lincoln College, Canterbury, May 1985.
Milner, R.J., Baker, G.L., Hooper, G.H.S. and Prior, C.. 1997. Development of a mycoinsecticide for the Australian plague locust. In Krall, S., Peveling, R., and Ba Baoule, (Eds.), New Strategies for Locust Control. Birkhäuser Verlag, Basel, Switzerland, pp. 177183.
Milner, R.J., Driver, F., Curran, J., Glare, T.R., Prior, C., Bridge, P.D. and Zimmermann, G.. 1994. Recent problems with the taxonomy within the genus Metarhizium, and a possible solution, pp. 109110 in Proceedings of the Vth International Colloquium on Invertebrate Pathology and Microbial Control, Montpellier, August 1994.
Milner, R.J., Hartley, T.R., Lutton, G.G. and Prior, C.. 1994. Control of Phaulacridium vittatum (Sjöstedt) (Orthoptera: Acrididae) in field cages using an oil-based spray of Metarhizium flavoviride Gams and Roszypal (Deuteromycotina: Hyphomycetes). Journal of the Australian Entomological Society 33: 165167.
Milner, R.J. and Prior, C.. 1994. Susceptibility of the Australian plague locust, Chortoicetes terminifera, and the wingless grasshopper, Phaulacridium vittatum, to the fungi Metarhizium spp. Biological Control 4: 132137.
Moulden, J.H. and D'Antuonon, M.F.. 1984. Evaluation of Nosema locustae for control of the wingless grasshopper (Phaulacridium spp.) in Western Australia, pp. 387393 in Proceedings 4th Australian Applied Entomology Research Conference, Adelaide, Sept. 1984.
Prior, C. 1997. Susceptibility of target acridids and non-target organisms to Metarhizium anisopliae and M. flavoviride. In Proceedings of Conference on New Methods in Locust Control, Bamako, March 1995. pp. 369375.
Rajakulendran, S.V., Pigott, R. and Baker, G.L.. 1993. Biology and phenology of giant grasshopper Valangra irregularis (Walker) (Orthoptera: Acrididae: Crytacanthacridinae), a pest of citrus, in central western New South Wales. Australian Entomologist 20: 8190.
Wright, D.E. 1984. Economic assessment of actual and potential damage caused to crops by the 1984 locust plague in South-eastern Australia. Journal of Environmental Management 23: 293308.

METARHIZIUM FLAVOVIRIDE (FI985) AS A PROMISING MYCOINSECTICIDE FOR AUSTRALIAN ACRIDIDS

  • Richard J. Milner (a1)

Metrics

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed