Pest Status of Invasive Crane Flies in New York Turfgrass and the Repercussions for Regional Plant Protection

Abstract

Gauging the pest status of invasive insects is a vital element of postestablishment management and response plans. After their 2004 detection in New York, diverse field observations were summarized to appraise the pest status of Tipula oleracea L. and T. paludosa Meigen in turfgrass of the Northeast United States. In residential lawns, impacts included nuisance swarms of adults and accumulations of larvae, and stand loss because of thinning and die-back, mostly attributed to T. paludosa. No damage was attributed to early instars in fall despite densities of 123–544 larvae/m2. For late instars in spring, nondamaging and damaging densities were 123–142 and 753–829 larvae/m2, respectively. In golf courses, impacts included chewing damage on putting greens, nuisance accumulations of larvae on playing surfaces, die-back of rough-mown turf, and disruption resulting from vertebrate predation. Damage to putting greens was attributed to T. oleracea at densities of 140–318 larvae/m2. Abrupt appearance of injury and decline in abundance toward the center of infested greens was evidence for immigration from surrounding turf. Insecticidal control disrupted play because of the abundance of larval cadavers on the surface. On roughs, T. paludosa caused die-back as a consequence of root pruning. For early instars in fall and late instars in spring, nondamaging densities were 136–375 and 77–115 larvae/m2, respectively. In sod farms, impact included presence of larvae in production fields and the first confirmation that harvesting, shipping, and installing infested sod can lead to establishments at sites remote to field of origin. The categories and magnitude of damage observed in New York, the new insecticide burden this engenders, and the likelihood of spread to new regions and agroecosystems, indicate that continued range expansion will have serious repercussions for regional plant protection.