Environmental Entomology (1984) 13, 95-99

J.A. Johnson, I.M. Hall and K.Y. Arakawa (1984)
Epizootiology of Erynia phytonomi (Zygomycetes: Entomophthorales) and Beauveria bassiana (Deuteromycetes: Moniliales) parasitizing the Egyptian alfalfa weevil (Coleoptera: Curculionidae) in southern California
Environmental Entomology 13 (1), 95-99
Abstract: The incidence of Erynia phytonomi (Arthur) and Beauveria bassiana (Balsamo) in southern-California populations of the Egyptian alfalfa weevil, Hypera brunneipennis (Boheman) (Coleoptera: Curculionidae) was determined during 1979 and 1980. E. phytonomi infection normally occurred as a single epizootic in March or April after late-winter rains, and was typified by the results in the 1979 survey. Although incidence was relatively high, the epizootic occurred too late to prevent damage to the crop by feeding larvae. Abnormally heavy rainfall early in the year, such as occurred in 1980, initiated an earlier, longer epizootic, and seemed correlated with lower larval densities. E. phytonomi survived temporary dry periods occurring during the epizootic in dried host larvae, called resting larvae, on which the fungus sporulated when suitable conditions resumed. B. bassiana incidence was less affected by rainfall. Harvesting of the field, resulting in exposure of surviving larvae to soil-borne inoculum, increased the incidence of B. bassiana. Complete harvesting of the field seemed to have an immediate adverse effect on incidence of E. phytonomi, but levels of the fungus later reached new peaks.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Database assignments for author(s): Judy A. Johnson

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
population dynamics/epizootiology

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Hypera brunnipennis	Alfalfa/lucerne (Medicago sativa)	U.S.A. (SW)
Beauveria bassiana (entomopathogen)	Hypera brunnipennis	Alfalfa/lucerne (Medicago sativa)	U.S.A. (SW)
Zoophthora phytonomi (entomopathogen)	Hypera brunnipennis	Alfalfa/lucerne (Medicago sativa)	U.S.A. (SW)