Author
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Pair, Sammy |
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Submitted to: Proceedings Oklahoma Pecan Growers Annual Meeting
Publication Type: Proceedings Publication Acceptance Date: 6/30/1996 Publication Date: N/A Citation: N/A Interpretive Summary: Laboratory and field studies were conducted at Lane, OK to evaluate the potential of Steinernema riobravis nematodes (RB) as a biocontrol agent of two important insect pests of pecan, pecan weevil (PW), Curculio caryae, and hickory shuckworm (HSW), Cydia caryana. Results of standard bioassays revealed that RB nematodes can attack and reproduce in PW larvae and adults, and in HSW larvae. Initial studies during 1995 indicated that an application of 400 nematodes per adult PW resulted in 57 % confirmed infection; sufficient numbers of weevil adults were not available to test higher nematode concentrations. However, PW larvae exhibited some resistance to nematode attack as rates of 1000 nematodes per PW larvae were required to achieve 32 % infection. Concentrations of 50 and 200 nematodes, respectively, killed 85 and 100% of exposed HSW larvae. Applications of RB nematodes against HSW larvae tunneled within pecan husks sresulted in 78 and 83 % infection, respectively, when sprayed at the rate of 1 or 2 billion/acre. Similar studies conducted under field conditions yielded a 20 % infection of HSW larvae when the nuts were dry, and 30% infection when nuts were pre-sprayed with water prior to nematode application. Additional field studies are needed to evaluate the potential of RB nematodes for control of adult PW and HSW larvae. Technical Abstract: |
