Progress 09/15/03 to 09/14/05
Outputs
In New Jersey, the May/June beetle, Phyllophaga georgiana,, is a common white grub pest in cranberries. In laboratory experiments, P. georgiana 3rd instars were highly susceptible to Steinernema scarabaei but not to Heterorhabditis bacteriophora. 2nd instar P. georgiana were somewhat less susceptible to S. scarabaei. In a greenhouse experiment, S. scarabaei (2 billion / acre [b/A]) provided 80% control and imidacloprid (0.125-0.5 lb ai/A) provided 42-44% control of a mixture of 1st and 2nd instars. In a 2nd greenhouse experiment, S. scarabaei, H. bacteriophora, and H. zealandica (each at 2 b/A), provided 100, 70, and 96% control, respectively, of 2nd instar Ph. georgiana. Against 3rd instars, S. scarabaei provided 100% control at 2 and 1 b/A, H. bacteriophora 63% at 2 b/A, H. zealandica 67% at 2 b/A, imidacloprid 81% at 0.5 lb ai/A, and clothianidin 81% at 0.5 lb ai/A and 98% at 0.25 lb ai/A. In a 3rd greenhouse experiment, S. scarabaei provided 52-76% control at
0.125-1.0 b/A, H. bacteriophora 24% at 2 b/A, H. zealandica 26 and 67% at 1 and 2 b/A, and imidacloprid and clothianidin both 21% at 0.5 lb ai/A. S. scarabaei is the most effective control agent for Ph. georgiana. Against 2nd instars, H. zealandica and the neonicotinoids warrant some further investigation. In Massachusetts, clear differences in susceptibility to S. scarabaei were observed in the various species tested. Against Hoplia equina, a dose-response assay using 0, 50, 150 and 300 infective juveniles (IJ) showed 85-100% mortality at the highest rate for 3rd instars. 1st, 2nd, and 3rd instar cranberry root grub, Lichnanthe vulpina, were assayed at 0, 600, and 1200 IJ. Only 50-60 % mortality was observed in 1st instars at the highest rate; larger instars were more susceptible, with 80% mortality. Mortality of 1st and 3rd-instar Ph. anxia was assayed at 0, 50, 100, 200, and 400 IJ. Smaller larvae were generally less susceptible than large, with 55 and 85% mortality observed,
respectively, at the 200 IJ rate. At 400 IJ, 89% of larvae of both sizes died. In Massachusetts, field trials with grower cooperators using imidacloprid (Admire 2F) were carried out against 3 soil insects. Against Colaspis costipennis (Chrysomelidae) Admire applied in 2 infested sites in 2004 via chemigation (32 oz/A) provided up to 100% control in 2005. For example, at Site 1, pre-treatment means were 23 larvae/pupae per m2 and 49 adults/sweep set; post-treatment means (2005) were 0 larvae/pupae per m2 and 1.1 adults/sweep set. In 2004, a 2-year program of Admire treatments was established at 5 sites heavily infested with oriental beetle. Soil will be sampled again in spring 2006 (following 2 years of Admire treatments). Pheromone trapping was also carried out in 2004 and 2005; while visual inspection of the beds in 2005 revealed significant recovery, adult numbers increased from 2004-2005. In 2004, a similar program was set up at 2 sites infested with L. vulpina; visual inspections
showed substantial recovery in the dieback area following the 1st year of treatment. Admire treatments were applied just prior to peak egg hatch.
Impacts
Our studies have shown that the neonicotinoid imidacloprid (Admire) can provide effective preventive control of several important soil-dwelling insect pests in NJ and MA cranberry production. The nematode Steinernema scarabaei can provide effective control of existing white grub populations and the nematode Heterorhabditis zealandica may be effective if applied early early-stage white grubs. Imidacloprid and the two nematode species (should they become commercially available) will give cranberry growers a preventive tool and a curative control for the management of soil-dwelling pest and will lead to increased production.
Publications
- No publications reported this period
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Progress 01/01/04 to 12/31/04
Outputs
Objective 1. Evaluate the potential of novel neonicotinoid insecticides and entomopathogenic nematodes against major soil pests of cranberries in New Jersey and Massachusetts: In New Jersey, the May/June beetle, Phyllophaga georgiana,, is a common white grub pest in cranberries. In laboratory experiments, we found that P. georgiana third instars were highly susceptible to Steinernema scarabaei but not to Heterorhabditis bacteriophora. Second instar Ph. georgiana were less susceptible to S. scarabaei than the third stage. In a first greenhouse experiments, S. scarabaei (2 billion / acre [b/A]) provided 80% control and imidacloprid (0.125 to 0.5 lb ai/A) provided 42-44% control of a mixture of first and second instars. In a second greenhouse experiment, the nematodes S. scarabaei, H. bacteriophora, and H. zealandica, each at 2 b/A), provided 100, 70, and 96% control, respectively, of second instar Ph. georgiana. Against third instars, S. scarabaei provide 100% control
at 2 and 1 b/A, H. bacteriophora 63% at 2 b/A, H. zealandica 67% at 2 b/A, imidacloprid 81% at 0.5 lb ai/A, and clothianidin 81% at 0.5 lb ai/A and 98% at 0.25 lb ai/A. In Massachusetts, three trials evaluating S. scarabaei were completed in the lab. Clear differences in susceptibility were observed in the various species tested. Against Hoplia equina, a dose-response assay using 0, 50, 150 and 300 infective juveniles (IJ) showed 85-100% mortality at the highest rate for third instars. Based on trials done earlier in the season, a higher rate of IJ was used for Lichnanthe vulpina. First, second, and third instars were assayed at 0, 600, and 1200 IJ. Only 50 to 60 % mortality was observed in first instars at the highest rate; larger instars were more susceptible, with 80% mortality. Mortality of first and third Ph. anxia was assayed at 0, 50, 100, 200, and 400 IJ. Smaller larvae were generally less susceptible than large, with 55 and 85% mortality observed, respectively, at the 200 IJ
rate. At 400 IJ, ca 89% of larvae of both sizes died. Objective 2. Conduct large-scale field evaluations of imidacloprid targeting major soil insect pests: In Massachusetts, field trials with grower cooperators using the imidacloprid formulation, Admire 2F, were carried out against 3 species of soil insects. Two of the species have not previously been assessed for susceptibility to imidacloprid. Adults of the chrysomelid Colaspis costipennis were quantified by sweep-net sampling at three highly infested sites. Admire 2F was then applied at two of the sites. Through the entire flight season, pheromone trap counts for Exomala orientalis adults were assessed at two sites and for the cranberry specialist, Lichnanthe vulpina prior to Admire 2F treatment. Follow-up assessments of populations will be made in 2005 (growers are unwilling to allow destructive sampling of the cranberry vine in order to quantify larval numbers). Objective 3. Develop and deliver a comprehensive educational program
targeting core clientele on the effective use of novel chemical and biological strategies in cranberries: Too early to report results.
Impacts
By studying new compounds that effectively kill these species of soil-dwelling pests, cranberry producers will have new pest management tools that will lead to increased production.
Publications
- No publications reported this period
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