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ARS Home » Northeast Area » Ithaca, New York » Robert W. Holley Center for Agriculture & Health » Emerging Pests and Pathogens Research » Research » Publications at this Location » Publication #314353

Title: New insights into the amphibious life of Biomphalaria glabrata and susceptibility of its egg masses to fungal infection

item DUARTE, GLENNYHA - Federal University Of Goias
item RODRIGUES, JUSCELINO - Federal University Of Goias
item FERNANDES, EVERTON - Federal University Of Goias
item Humber, Richard
item LUZ, CHRISTIAN - Federal University Of Goias

Submitted to: Journal of Invertebrate Pathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/29/2014
Publication Date: 1/8/2015
Citation: Duarte, G., Rodrigues, J., Fernandes, E.K., Humber, R.A., Luz, C. 2015. New insights into the amphibious life of Biomphalaria glabrata and susceptibility of its egg masses to fungal infection. Journal of Invertebrate Pathology. 125:31-36.

Interpretive Summary: This is one of the first studies to address techniques to monitor the development of eggs of a semiaquatic (amphibious) snail as a means to allow some of the very first studies of possible fungal pathogens against these snails that vector (transmit) a trematode flatworm that causes a serious disease (schistosomiasis) affecting humans and livestock. The egg masses were exposed to the spores and hyphal bodies (short, vegetatively growing filaments) of two fungi that are ubiquitous and widely used pathogens affecting insects. The applications of hyphal bodies and, to a lesser extent, of the spores of Metarhizium and Beauveria could prevent the development and hatching of these eggs. This is the first report that these ubiquitous and widely applied insect pathogens show activity against a snail host, and this may be important because microbial biocontrol of snails carrying important disease-causing worms has long been an unfulfilled possibility for which no good candidates were available. Nonetheless, the manuscript acknowledges (but cannot resolve) issues that the extension of the host ranges for these fungi to non-arthropod invertebrates such as snails might potentially complicate the regulation and registration of these important and widely used insect-pathogenic fungi as biological control agents.

Technical Abstract: Egg masses of an aquatic snail, Biomphalaria glabrata, matured, and juveniles subsequently eclosed and were mobile in a stable water film of transitory habitats simulated by two different simple test devices described here. The viability of eggs maintained in an unstable film due to low ambient moisture or highly absorbent substrate, however, was diminished. The maturation of egg masses in a water film or in water was significantly prevented by the entomopathogenic fungi Beauveria bassiana and Metarhizium anisopliae. The efficiency of fungal activity depended on the fungal propagule and test environment. Hyphal bodies were more effective against egg masses than conidia. This appears to be a first report of activity of both entomopathogens against a mollusc. Both devices offer accurate and reproducible conditions to test both biological questions and the effects of substances or pathogens for possible use against B. glabrata egg masses in water films.