The extremely wet conditions of 2011 may have encouraged a new invasive insect to the turf grasses of Connecticut. Although not confirmed, a few golf courses in the state reported that crane fly larvae were actively feeding in the turf. Tipula oleracea which is sometimes referred to as the marsh or giant common crane fly is the suspected invasive (distinguishing species of crane flies is difficult, a confirmation of the larval species is usually made by an entomologist.) Dr. Pat Vittum turf entomologist for the UMass turf program reported in her early December turf newsletter that several golf course superintendents on the eastern end of Cape Cod, found invasive cranefly larvae Tipula oleraceae, active on many parts of the golf courses. She also reports that this invasive species has probably has been present in the southeastern part of Massachusetts for several years. In 2005, New York State reported that two exotic species, the European crane fly (Tipula paludosa) and the marsh cranefly (T. oleracea), invaded New York State.
The crane fly larvae can severely damage all types of turfgrass and forage grass species. In addition they have been known to attack nursery seedlings as well as many small fruit and vegetable crops.
Dr Vittum’s report states that “The “common” cranefly often experiences two generations per year, with the first generation laying eggs in late April or early May, and larvae (large olive green, legless maggots with some noticeable projections on the tip of the abdomen) feed through the summer months. Adults fly in late August or early September, lay eggs, and the emerging larvae (of the second generation) feed through the fall.”
Craneflies thrive when soil moisture levels are very high, especially during egg-laying. Last year was one of the wettest in New England, providing the right conditions for large numbers of larvae to survive. Fall also brought unseasonably mild temperatures that probably enhanced the larvae’s’ opportunity to forage.
Entomologists from the west coast report that the larvae can be active any time the ground is not frozen, they resume active feeding as the frost leaves the ground in late winter and can cause additional damage before pupating in the spring.
The adults emerge in the early fall, however it is the larvae in the early spring, and late fall, that devour roots and cause yellow spots and bare patches in grass.
The adults are poor fliers and have a short lifespan, therefore do not travel very far on their own. It is thought that introduction of theses invasives may be due to movement of infested soil.
Dr vittum’s turf newsletter: