Journal of Applied Microbiology (2011) 111, 939-948

N. Orduño-Cruz, A.W. Guzmán-Franco, E. Rodríguez-Leyva, J. López-Collado, J.M. Valdéz-Carrasco and G. Mora-Aguilera (2011)
Susceptibility of the cactus weevil Metamasius spinolae to Beauveria bassiana and Metarhizium anisopliae under laboratory and field conditions
Journal of Applied Microbiology 111 (4), 939-948
Abstract: Aims: To evaluate different entomopathogenic fungal isolates against the cactus weevil Metamasius spinolae under laboratory and field conditions, and select an isolate to be used as a tool in the management of this insect pest.
Methods and Results: Four experiments were carried out. The effect of temperature on the in vitro growth of eight isolates of entomopathogenic fungi (two Metarhizium anisopliae and six Beauveria bassiana) was assessed. The susceptibility of adult M. spinolae to the same isolates was evaluated. Using three selected isolates, the interaction between susceptibility and sex of the insect was studied. Finally, a field experiment was carried out to evaluate infection of adult M. spinolae by the same three isolates under natural abiotic conditions. Overall, growth rate was greatest at 25°C for all the isolates. In vitro growth of M. anisopliae was greater than B. bassiana. Mortality of adult M. spinolae was greater when inoculated with B. bassiana compared with isolates of M. anisopliae. Susceptibility had no interaction with the sex of the insect. The proportion of insects succumbing to infection was smaller when incubated under field conditions than when incubated under laboratory conditions.
Conclusions: The experiments described here showed a complex interaction between entomopathogenic fungi and M. spinolae, and these data allows us to select isolate Bb107 as a first step towards its use in the management of this pest insect.
Significance and Impact of the Study: Our results showed that entomopathogenic fungi can be used for the control of M. spinolae, which may help reduce the use of chemical insecticides and, therefore, the exposure of Opuntia ficus-indica producers to pesticides.
(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): Ariel W. Guzmán-Franco, Esteban Rodríguez-Leyva

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
evaluation - screening - selection

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Metamasius spinolae	Prickly pear (Opuntia)	Mexico
Beauveria bassiana (entomopathogen)	Metamasius spinolae	Prickly pear (Opuntia)	Mexico
Metarhizium anisopliae (entomopathogen)	Metamasius spinolae	Prickly pear (Opuntia)	Mexico