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Alfalfa weevilBy David G. Hallauer Meadowlark District Extension Agent, crops and soils/horticulture Kansas The end of March signaled the first 'report' of alfalfa weevil, but its likely you haven't seen much damage--until now. Alfalfa weevil development and feeding occur at temperatures above 48 degrees F. That said, recent cooler temperatures have probably held damage back just a little. Reports earlier this week, in fact, show weevil larvae still in the first instar of development--little or no change over mid-March reports. As temperatures begin to increase, however, damage is most definitely expected. You'll find the black headed larvae in the terminal and upper leaves of the plant in early spring. Damage from 'inside out' occurs as they emerge from the stem portion of the plant to feed on foliage. Reports of foliar damage at this point have been limited to pin prick sized leaf holes in most cases, but as larvae develop (they'll reach a quarter inch in length in about three weeks), more significant feeding will start to completely defoliate plants. Sample for alfalfa weevil using the stem count method, breaking off 30 to 50 stems at random and shaking them in to a deep sided bucket. Be aware that at cooler temperatures, weevil may well be in the tissue at crown level or wrapped tightly in leaves. Checking plants for those hidden larvae is important from time to time as well. Insecticide applications are based on hay value, but larvae per stem for at current hay prices may warrant chemical control. Insecticides work best at temperatures above 50 degrees F if its necessary they be applied. A number of different insecticides with varying degrees of protection are effective. A list is included in Alfalfa Insect Management 2009 (MF-809). The return of the mole My moles are back with a vengeance. I expected to see them again--but not this bad. Moles like insects and worms. That and soils that allow them to burrow easily. Should be pretty easy to eradicate, right? Not so much. For starters, moles seem to possess a natural shrewdness and ability to sense danger. That makes them hard to trap, even though trapping is the best method to get rid of them. Packing soil with a roller or reducing soil moisture may make the habitat more desirable. Getting rid of insects does the same. The problem with those methods is that before they leave, the moles tend to really get after the digging process in search of food, resulting in more damage. The repellant Thiram is federally registered for protecting bulbs from mole damage. Mothballs or flakes are occasionally suggested as repellants. Others are as well. Unfortunately, little evidence is available to substantiate such claims. Poisoning is difficult at best. Moles don't consume grain, so grain based baits are largely ineffective. Zinc phosphide is a mole poison--but its availability on a grain based bait reduces its effectiveness. Most fumigants are restricted use and thus unavailable. Your best bet for getting rid of moles is still trapping. Some have indicated they can catch them moving early in the morning and oust them from their run. Still others claim their family pet is a good 'moler'. It if works for you, use it. Just be aware that expensive control options may not get you much further than frustrated.
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