Impact of cover cropping on non-target arthropod pests of red maple trees in nursery production

Cropping practices can affect the complement of arthropod pests present in production. The impact of cover cropping on key red maple (Acer rubrum [L.]) (Sapindaceae) nursery pests was evaluated. Cover cropping has been identified as a sustainable management method for a key maple pest, flatheaded appletree borer (Chrysobothris femorata [Olivier]) (Buprestidae), but the impact of the cover crop on other non-target arthropod pests in maple production also must be taken into account when determining the usefulness of cover cropping as a pest management tool. In addition to flatheaded appletree borer, other important arthropod pests of red maple in the southeastern United States include maple shoot borer (Proteoteras aesculana [Riley]) (Tortricidae), maple leaftier (Episimus tyrius [Henrich]) (Tortricidae), potato leafhopper (Empoasca fabae [Harris]) (Cicadellidae), ambrosia beetles (e.g., Xylosandrus crassiusculus [Motschulsky]) (Curculionidae), and spider mites (Oligonychus aceris [Shimer] and Tetranychus urticae [Koch]) (Tetranychidae). In the fall of 2015, 400 red maple trees were transplanted into a cover cropped field of crimson clover (Trifolium incarnatum [L.]) (Fabaceae) and winter wheat (Triticum aestivum [L.]) (Poaceae). Four nursery tree row management treatments were evaluated: (1) cover crop, (2) cover crop + insecticide, (3) no cover crop, and (4) no cover crop + insecticide. Treatment plots consisting of 25 trees were replicated 4 times in a 2 × 2 factorial design. All trees were evaluated annually in 2016 and 2017 for damage by the previously mentioned arthropod pests. Overall, the cover crop did not increase damage by the common suite of red maple pests. However, the cover crop did compete with trees for nutrients, water, and space, thereby reducing tree growth and the formation of new maple shoots. The low number of new shoots on maple trees in the cover crop rows, and subsequent availability and suitability of host material was the main driver of pest damage differences among treatments.