Hi C.J.,

My question likely is too long and detailed for inclusion on your website and also not of interest to most readers. If you think

differently, feel free to use it.

I almost could have written Missy’s Nov. 3 letter (“Grubs on an NY Lawn”), but I don’t know if I’d have been very happy with your answer.

Late this summer, my long-established Minneapolis lawn, a mixture of

Kentucky bluegrass, fescue and perennial ryegrass, took on the patchy,

irregular and thinned-out look so symptomatic of grub infestation. But the foot-square sampling tests that I performed on various parts of the lawn this fall revealed no grubs; in fact, the sod in even the deadest spots was resistant to rolling back.

On Nov. 1, while de-thatching the patchy areas with a multi-tined hand tool and wondering if a winter overseeding would be the way to go, I scraped out of the grass a couple of fat larvae that were not grubs but looked like caterpillars. They were so glutted from eating grass that when squished they shot out fluid so green it seemed to be pure chlorophyll. I’ve scoured internet sites to do a photo ID. No luck there, but I did happen upon a way to force larvae to the surface, i.e., the detergent-in-water treatment.

Fully realizing that grubs and other larvae would be deep in the ground this late in the year, I nonetheless today poured eight gallons of a detergent-water mixture on four areas of the lawn. Wow, did I get results! Out struggled a single larva, ONE! It was neither a grub nor any other beetle larva or worm that I can find via the internet.

I photographed the specimen, but my camera’s lens is not macro enough to show its details. The best I can do is this description:

Overall color: Dark brown to black, with a grey underside

Dimensions: 1 3/16 long. Body is 1/4 in diameter.

Head: Lighter in color than the body, coppery

Number of legs: 6

Segment characteristics: Plain (unmarked) raised bands alternating with unraised bands marked with short black and yellow lines on either side of the segment; the lines (think inverted hyphens) are perpendicular to the body. Proceeding upward from the tail, I can count seven lines on each side of the larva’s back; they seem to fade in the segments closest to the head. Black slash marks in a pattern resembling that of oars on a galley ship, i.e., coordinated, as one might see them from a point alongside the ship (think “Spartacus”), run along the sides of the body.

Tail: No separate tail. There’s a black V on the rump.

I’ve spent hours looking for a photo or matching description of this

creature on the internet, to no avail. But perhaps identifying it isn’t necessary if the treatment is the same as it would be for grubs

(imidacloprid, trichlorfon). What say you?

I realize nothing can be done insofar as chemical treatment until next year. I also know I should find more than one larva to justify applying chemicals, but if the lawn’s slow destruction isn’t caused by grubs, worms or caterpillars, what else is there? Could it be fungus (misnomer: summer patch) even though the problem did not appear in the spring?

It's been unseasonably warm here, with temps as high as 70 degrees the past week. The ground is still too warm to do a dormant overseed but should be cold enough in a couple of weeks or so. Think it might be worth it?

Thanks for any help you can give,

Joan