Submitted to: Journal of Invertebrate Pathology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 5/6/2010
Publication Date: 8/13/2010
Publication URL: http://ddr.nal.usda.gov/handle/10113/49923
Citation: Lord, J.C., Vossbrinck, C.R., Wilson, J.D. 2010. Occurrence of Nosema oryzaephili in Cryptolestes ferrugineus and transfer to the genus Paranosema. Journal of Invertebrate Pathology. 105(1):112-115. doi: http://dx.doi.org/10.106/j.jip.2010.05.005. Interpretive Summary: Beneficial pathogenic microbes are important components of the natural enemy complexes that help to keep pest populations in check. Difficulty in understanding how these organisms work is due in part to confusion about their taxonomy and host ranges. Microsporidia are primitive fungi that are common pathogens of insects. A microsporidium was found in rusty grain beetles for the first time, and its identity and pathology were unknown. Bioassays were conducted that suggested that it was a species that had been reported only from the sawtoothed grain beetle. Gene sequencing resulted in its placement in a recently created genus that includes a pathogen of the red flour beetle. This work is necessary for development of an understanding of the impact of these natural enemies on pest beetles.
Technical Abstract: A microsporidium isolated from Cryptolestes ferrugineus closely resembled Paranosema whitei and Nosema oryzaephili. Its identity as N. oryzaephili was confirmed by spore size, greater infectivity for Oryzaephilus surinamensis than for Tribolium castaneum and infectivity for Ephestia kuhniella. While the host, C. ferrugineus, was the most susceptible of the tested species to the new isolate, we did not obtain infections in C. ferrugineus with 106 spores/g of P. whitei. The physiological host range of the new isolate thus suggests that it is an isolate of N. oryzaephili. Small subunit rDNA analysis placed the new microsporidium in the genus Paranosema. The new combination Paranosema oryzaephili (Burges, Canning and Hurst) is proposed. In spite of the abundance and world-wide distribution of C.ferrugineus, this is the first report of its infection with a microsporidium. It is also the first report of P. oryzaephili from the new world.