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ARS Home » Pacific West Area » Hilo, Hawaii » Daniel K. Inouye U.S. Pacific Basin Agricultural Research Center » Tropical Plant Genetic Resources and Disease Research » Research » Publications at this Location » Publication #328901

Research Project: Molecular Resources for the Improvement of Tropical Ornamental and Fruit Crops

Location: Tropical Plant Genetic Resources and Disease Research

Title: Endemic Oscheius Nematodes of Hawai'i

Author
item BISEL, JUSTIN - University Of Hawaii
item Myers, Roxana
item SIPES, BRENT - University Of Hawaii

Submitted to: Journal of Nematology
Publication Type: Abstract Only
Publication Acceptance Date: 6/4/2016
Publication Date: 1/18/2017
Citation: Bisel, J., Myers, R.Y., Sipes, B. 2016. Endemic Oscheius Nematodes of Hawai'i. Journal of Nematology. 48:305.

Interpretive Summary:

Technical Abstract: Entomopathogenic nematodes (EPNs) parasitize insects utilizing mutualistic bacteria to kill the host, allowing the nematode to feed and reproduce within the insect cadaver. Consequently EPNs are highly sought after for their biological control potential. A survey for EPNs was conducted on O’ahu and Hawai’i Island using a modified baiting method. One hundred seven soil samples were collected and baited with five Tenebrio molitor (mealworm) larvae. Soil samples were observed daily for 5 days and morbid T. molitor larvae were placed on white traps. Forty-seven of the 107 locations contained at least one infected mealworm containing nematodes. Mealworm mortality was attributed to EPNs, fungal contamination, parasitoids or an unknown factor in 16%, 10%, 1% and 73% of samples respectively. Eighty-two EPN isolates were passed through two subsequent inoculations in order to confirm their entomopathogenic nature. A total of 41 EPN isolates were recovered through three rounds of reinoculation. PCR analysis and sequencing was conducted on third generation EPN, targeting the ITS region. Oscheius was recovered from 96% of locations sampled on Hawai’i Island and O’ahu respectively. Sequencing analysis suggested three groups of Oscheius. The Oscheius isolates and an unknown nematode isolate occurred in 76%, 12%, 8% and 4% of positive locations respectively. This survey suggests that Oscheius is a common EPN in Hawai’i.