Biocontrol Science and Technology (2015) 25, 1221-1232
Alejandro Martínez-Hernández, Raquel Alatorre-Rosas, Ariel W. Guzmán-Franco and Esteban Rodríguez-Leyva (2015)
Effect of dual inoculation with nematodes and fungal pathogens on the survival of Phyllophaga polyphylla larvae (Coleoptera: Scarabaeidae)
Biocontrol Science and Technology 25 (11), 1221-1232
Abstract: Phyllophaga polyphylla (Coleoptera: Scarabaeidae) is an important pest of maize and other crops in Mexico. Previous reports showed that this pest was highly resistant to fungal and nematode infection when each pathogen was inoculated separately; in this study, we evaluated whether dual inoculation of fungi and nematodes, in all possible pair-wise combinations and orders of inoculation and including an evaluation of a time separation of 73 hours between each pathogen's inoculation, would increase mortality in P. polyphylla larvae. The pathogens were two isolates of Heterorhabditis bacteriophora applied at a concentration of 50 infective juveniles (IJ) mL–1, an isolate of Beauveria pseudobassiana and of Metarhizium pingshaense both applied at a concentration of 1 × 108 conidia mL–1. In the first experiment, the combined mortality when pathogens were dual-inoculated (13%), although significantly higher than single-inoculated treatments (8%), demonstrated that antagonistic interactions were ongoing between the pathogens, as confirmed by the chi2-test. In a separate experiment, using only the B. pseudobassiana isolate (1 × 108 conidia mL–1) and one isolate of H. bacteriophora (100 IJ mL–1), we studied the effect of different order of inoculations but included a two-week separation between inoculation of each pathogen. Mortalities obtained were similar to the previous experiment; all interactions resulted in antagonistic effects, except when the fungal pathogen was inoculated first, which resulted in an additive interaction. Understanding the mechanisms for the interaction requires further study but, for practical biological control, we suggest that more virulent fungal and nematode isolates are necessary to achieve control of P. polyphylla.
(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:
application technology
Pest and/or beneficial records:
| Beneficial | Pest/Disease/Weed | Crop/Product | Country | Quarant.
|
|---|---|---|---|---|
| Phyllophaga polyphylla | Maize/corn (Zea mays) | Mexico | ||
| Heterorhabditis bacteriophora/Photorhabdus (entomopathogen) | Phyllophaga polyphylla | Mexico | ||
| Beauveria pseudobassiana (entomopathogen) | Phyllophaga polyphylla | Mexico |
