View Full Version : whats the latest to treat grubs?

07-21-2002, 12:34 PM
we generally put down grub treatments in early july(merit) this year we r way behind schedule, any opinions on how late is too late? thanx

07-22-2002, 12:29 AM
A Merit application now (if immediate irrigation follows) will get moderate results.

Jap beetle grubs can be found now, while European chafers may be much later.

Wai much longer, and you may have to use a quick kill product such as Dylox.

07-22-2002, 12:53 AM
here goes the grub life cycle:
Jan.-Feb. - Grub in winter cell
March- grubs start to come up towards the surface to feed, about 4-8" from surface
April- grubs continue to surface to feed, 1-2" from the surface
May- grubs form cell and prepare to pupate
June- grub changes to pupa and then to adult. which emerges from the ground
July- bettles lay eggs in the ground, mostly in grass
Aug.- eggs hatch. young feed on living roots of plants
Sept. & Oct.- grubs continue to feed and grow rapidly. injury to roots of plants is most common at this time
Nov.& Dec.- grubs mostly full grownand go to depths of 4-8" to to pass winter in earthen cell

you're still fine to put down any type of grub control, i wouldn't worry at all

Kent Lawns
07-22-2002, 09:57 PM
you've gotta know your gdd.

07-22-2002, 10:10 PM
Joshua-- Just remember, going by a monthly 'schedule' is very risky. Follow Kent Lawns advice.....its foolproof.

get rich
07-23-2002, 12:06 AM
:cry: yes i would never put a calendar date on any insect.the weather conditions have a great deal to do with the bugs life cycle.last year we had kinda mild winter in northern IL and i think (my oppinion) the grubs didn't go that deep,and we had a week of 90's in early april and i think it really moved their cycle up a notch early. they came out of the ground here two or three weeks earlier than they did last year.and in that case i'd say the only constant is that the eggs the females lay need only two weeks of warm, moist soil to hatch and get growing.so if they were mating and laying eggs when they arrived two or three weeks earlier then maybe we will start to see damage earlier too, eh?well i just hope that my mach will work.better i pay good money for it.but i think some say you have until the first week of august,so better hurry huh!or check with yor local dealer and see what they say,good luck!

07-23-2002, 12:34 AM
yes it is the 1st week of august.
ppl talk and jump to conclusions.
its amazing somethings ppl say

07-23-2002, 07:08 PM
Mach2 is now labled for 2#ai/A to control the harder Chafers that the old (1.5#ai/A) rate missed.

It's also much better at controlling webworms & other lepodoptera that laugh at Merit.

Mach2 is effective at controlling even 1st instar grubs. Merit is a very good insecticide & has revolutionized grub control as we all know it. But to kill first instar grubs, you must dig them up. Then beat them over their heads with the Merit bag.

Both are pretty weak on Chinch bugs.

Sevin, Diazinon, & Dylox are still around (for now) & are all effective (snicker snicker) at controlling grubs after the fact.