Submitted to: Journal of Nematology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/8/2010
Publication Date: 10/15/2010
Citation: Carta, L.K., Bauchan, G.R., Hsu, C., Yuceer, C.Y. 2010. Description, Low Temperature SEM, and culture of Parasitorhabditis frontali n. sp.(Nemata: Rhabditida) from Dendroctonus frontalis Zimmermann (Coleoptera: Scolytidae). Journal of Nematology. 42(1):46-54. Interpretive Summary: The southern pine beetle is a major pest of coniferous forests in the southeastern United States. A major problem for homeowners and foresters worldwide is the lack of environmentally safe pine beetle control. Identification of the parasites of this beetle and the food sources of the parasites are critical elements to understanding the ecology important to developing new biocontrol methods. This paper reports the discovery of a new microscopic parasitic roundworm species found in southern pine beetles and its galleries. The report also describes laboratory methods for rearing the roundworm nematode upon naturally occurring fungi and bacteria. The results are significant because this newly discovered nematode and associated microorganisms could be exploited as possible biological control agents for pine beetles. This information will be used by researchers developing methods for integrated control of pine beetles.
Technical Abstract: A new Parasitorhabditis species with males and females was discovered from the southern pine beetle Dendroctonus frontalis and its galleries in loblolly pine growing in Mississippi. Females of the new species have a cupola-shaped tail with a small spike; males possess a 2 + (3+2) + 3 ray pattern on the tail fan and distinctive gubernaculum. Parasitorhabditis frontali n. sp. has some similarities to Parasitorhabditis hylurgi from Hylurgops pinifex in New York, USA, P. terebranus from Dendroctonus terebrans in Texas, USA, P. ateri isolated in Germany from the beetle Hylastes ater, and P. malii from Scolytus mali within the republic of Georgia. Many of the approximately 44 species descriptions of Parasitorhabditis are relatively inaccessible due to language or journal obscurity. Parasitorhabditis frontali n. sp. was initially grown on Malt Extract (ME) agar with its own microbial contaminants that included a bacterium, yeast and another fungus. The nematode also grew and reproduced after chunks of ME agar with nematodes and microbial contaminants were transferred to water agar. It was killed by E. coli on NGM agar plates commonly used to raise other Rhabditida. Drawings of diagnostic anatomy and low-temperature SEM images of bodies, heads, and tails are provided for cultured specimens.