Pathogenic fungi of planthoppers associated with rice crops in Argentina

Abstract

We conducted a survey of pathogenic fungi of planthoppers associated with rice crops in Los Hornos, Buenos Aires, Argentina, and a study of the seasonality and prevalence of these pathogens. Samples were taken in rice for two consecutive years. The plants sampled included rice Oryza sativa L. (Poaceae) and its surrounding weeds. The planthopper Oliarus dimidiatus Berg. (Hemiptera: Fulgoromorpha: Cixiidae) was the most abundant species associated with rice. Two species of entomophthoralean and one species of hypocrealean fungi infected and killed adults of O. dimidiatus in the rice agroecosystem. The fungi were identified as: Pandora sp. (Entomophthorales: Entomophthoraceae), Conidiobolus coronatus (Costantin) Batko (Entomophthorales: Ancylistaceae), and Beauveria bassiana (Balsamo-Crivelli) Vuillemin (Hypocreales: Clavicipitaceae). Pandora sp. was the most predominant pathogen collected. It was recorded from the middle of February to the middle of April 2005, and not found again until the end of March 2006. The report of Pandora sp., C. coronatus and B. bassiana represents the first records of these fungi as pathogens of hoppers associated with rice crops in Argentina.

Keywords:

• Beauveria bassiana
• Cixiidae
• Conidiobolus coronatus
• Pandora
• first records
• planthoppers
• rice crops

Acknowledgements

We thank Dr Richard Humber and Karen Hansen for the fungal cultures preservation in the USDA-ARS Collection of Entomopathogenic Fungal Cultures (ARSEF), Dr Vilma Rosato for the herbarium material preservation in the Institute of Botany Carlos Spegazzini, Ing. Rodolfo Bezus for helping with weeds identification, Ing. Marcelo Asborno for kindly providing the weather data, Dr Enrique Cabanillas (USDA-ARS, Weslaco, TX, USA) and Dr Nigel Hywel-Jones (National Science and Technology Development Agency, Pathumthani, Thailand) for their critical review of the manuscript, National Research Council (CONICET) of Argentina and National University of La Plata for the partially financial support of this research.