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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 #415777
Research Project: Crop Health and Genetic Improvement of Sub-Tropical and Tropical Crops in the Pacific

Location: Tropical Plant Genetic Resources and Disease Research

Title: Management of Cylas formicarius using entomopathogenic nematodes

Author
item WONG, LANDON - University Of Hawaii
item WANG, KOON-HUI - University Of Hawaii
item Myers, Roxana
item SIPES, BRENT - University Of Hawaii

Submitted to: Nematropica
Publication Type: Abstract Only
Publication Acceptance Date: 6/18/2024
Publication Date: 2/9/2024
Citation: Wong, L.G., Wang, K., Myers, R.Y., Sipes, B.S. 2024. Management of Cylas formicarius using entomopathogenic nematodes. Nematropica. 54:186.

Interpretive Summary: N/A

Technical Abstract: Entomopathogenic nematodes (EPN) have potential to manage Cylas formicarius, the sweetpotato weevil. Larval susceptibility to Steinernema feltiae MG-14, Oscheius tipulae OA-12, and Heterorhabditis indica OM-160 was evaluated. Larvae were exposed to 200 Infective Juveniles (IJs) of S. feltiae or O. tipulae. In other experiments, C. formicarius was exposed to H. indica or S. feltiae at 11, 42, and 105 IJ/larvae. Subsequently, efficacy of S. feltiae was tested at 0, 0.5, 1.0, and 2.5 billion IJ/ha in a sweetpotato field. Monthly applications of O. tipulae were evaluated in the field. In the laboratory assays, S. feltiae caused an adjusted mortality of 50% to larvae. O. tipulae and H. indica caused an adjusted mortality of 30% and 25% to the larvae, respectively. In the field experiment with S. feltiae, C. formicarius was damage minimal and populations low (< 1 weevil/kg swollen root). The EPN population increased between planting and harvest, but EPN population density was not affected by EPN application rate (P>0.05). A field experiment with O. tipulae experienced high weevil populations and subsequent damage. Sweetpotato treated with O. tipulae suffered less damage and had lower weevil populations than plots not treated with EPN (P<0.05). All three EPN species showed promise in the laboratory. S. feltiae and O. tipulae both demonstrated an ability to control SPW in the field.