DAMAGE DESCRIPTION:

Turf unthrifty, slow growing; youngest leaves turn yellow and die; stem apex may be damaged; individual plants turn brown and die; small black flies may be seen; examination of stems near soil surface reveals larvae tunneling; crown rasping insect; larvae inhabits grass stems, crowns, and leaves; occurs in cool climatic regions, with most turf damage in summer and early fall; fly mature larvae 3 mm long, yellow, with black mouth hooks; adults shiny black with small yellow markings on legs; yellowing may occur in just the central leaf of the plant; adults 1/16 inch; attracted to color white-use white handkerchief or tissue to attract them.

HOST GRASSES:

Cool season turfgrasses, especially: Bentgrass, Bluegrasses and Fine fescues

LIFE CYCLE:

Yellowish larvae, overwinter in stems; has 3 instars; pupation occurs n spring followed by emergence of adults; eggs laid on leaves; larvae hatch and feed by tunneling in stems to crown near soil surface; 20 to 60 day life cycle; 3 to 4 generations.

FACTORS THAT MAY PROMOTE INSECT DAMAGE:

Flies attracted to white color; turf damage most severe on closely mowed, irrigated turf; frit also infects oats, wheat rye in which larvae consume developing grains and leave empty kernel or “frit”; cooler climate.

CULTURAL CONTROL:

Monitor sites for flies using white objects, especially close mowed sites.

CHEMICAL CONTROL:

Use pesticides as needed.

REFERENCES:

Beard, J. B. 2002. Turfgrass Management for Golf Courses. Second Edition. Ann Harbor Press. Chelsea, Michigan..

Decker, H. F., Decker, J. M. 1988. Lawn Care-A Handbook for Professionals. Prentice Hall. Englewood Cliffs, New Jersey.

Liskey, E., “Turfgrass Insecticides”, Grounds Maintenance, Volume 37, Number 2, February 2002, pp. 8-10.

Turgeon, A. J. 2002. Turfgrass Management. Sixth Edition. Prentice Hall. Upper Saddle River, New Jersey.