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Dusky Slug in Field Corn and Soybean

dark brown slug on a green leaf

June 2, 2021

Ambient moisture causes methomyl residues on corn plants to rapidly lose toxicity to the pest slug, Arion subfuscus, Müller
(Gastropoda, Stylommatophora)

The carbamate insecticide methomyl is sometimes used to control slugs in field corn and soybean by foliar applications, but control outcomes in research trials and commercial operations have been mixed. In this study,
laboratory bioassays were conducted on dusky slug, Arion subfuscus Müller, a common pest of corn and soybean in the Mid-Atlantic United States, to evaluate residual toxicity of Lannate LV (methomyl) at low and high
concentrations corresponding to label recommended field rates, and if toxicity may be affected by ambient moisture or repellency to treated plants. Without wetting events, methomyl residues on corn plants caused 90–100% mortality of A. subfuscus for two days and 70–90% mortality for six days. When corn plants were briefly misted with ca. 0.3 cm of water 6 h after methomyl application, mortality was 36% 12 h after treatment, and 0 to 5% 24 h after treatment for both low and high rates. Repellency of A. subfuscus to corn plants treated with the high rate of methomyl was narrowly significant (P = 0.04) and low rate was not significant. These results suggest that high ambient moisture needed to elicit slug activity in the field also abates toxicity of methomyl residues, explaining why field control is usually poor despite high mortality in the lab.

Evaluation of IPM for central WA pear orchards

article title and abstract in the journal biological control

February 9, 2021

IPM for Central WA Pear Orchards

Pear psylla and honeydew marking to fruit cause significant economic damage to pears in Washington, a key pear growing region of the United States. The goal of this project is to compare an integrated pest management (IPM) program using materials which selectively target pests and relies on large natural enemy populations to grower standard conventional and organic pear pest management.

Dupont, T., C. Strohm, L. B. Nottingham and D. Rendon. 2021. Evaluation of an integrated pest management program for central Washington pear orchards. Biol. Control. 152: 104390.

Reflective mulch for pear psylla

two people working in a pear orchard with reflective mulch

November 19, 2020

New Publication!

Pear psylla, Cacopsylla pyricola (Förster), has remained the most challenging pest of commercial pears in Washington and Oregon, the top producers of pears in the United States. The lack of effective integrated pest management tactics for this pest has been a major barrier to effective management. In this study, we examined the potential for reflective plastic mulch affixed beneath pear trees to suppress pear psylla. In 2017 and 2018, single pear tree (cv. Bartlett) plots of reflective plastic mulch, black plastic mulch, and no mulch (check) were established in a research orchard to compare their effects on pear psylla.

Nottingham, L. B. and E. H. Beers 2020. Management of pear psylla (Hemiptera: Psyllidae), using reflective plastic mulch. J. Econ. Entomol. 113:2840-2849.

screenshot of publication in the journal of economic entomology