ISSUE 2 May 11, 2000ENTOMOLOGY WEB SITES
Here are some web addresses that should be useful sites for obtaining insect management information for around the region. More web addresses will be added through the year.
North Dakota Entomology Updates:
North Dakota Insect Management Guide, 2000
High Plains Integrated Pest Management Guide for Colorado_Western Nebraska
Kansas Dept of Agriculture
Iowa State University
Crop Net Crop Production Website
Colorado State University
CANOLA: CAPTURE 2EC REDUCED RATE
A reduced rate label for Capture 2EC for use in canola to control flea beetles and grasshoppers was issued for North Dakota, Minnesota, and Montana as a 2(ee) recommendation from FMC Corp..
The rates are: 1.3 to 2.1 fl. oz. per acre (reduced from 2.1 to 2.6 fl. oz. per acre).
Apply in a minimum of 2 gallons of finished spray per acre by air or in a minimum of 10 gallons per acre by ground. When applying by air, 1 to 2 quarts of emulsified oil may be substituted for 1 to 2 quarts of water in the finished spray.
Everyone wants to know about residual control of these products. At the high end of these rates, flea beetles should be controlled for up to 5 days. At the low end, expect 3 days of control, perhaps more. Also keep in mind that the canola being treated is small with very little leaf area. Small plants should be treated adequately but new foliage after treatment will not. Continue to scout fields if treatments are made in order to assess effectiveness and whether additional beetles migrate into fields later.
FIRST CUTWORM REPORTS
Reports of dingy cutworm feeding on seedling crops have been received. The first calls have come from Bottineau Co in north central ND. In late April, army cutworm were reported in southwest ND, but this activity has declined.
Dingy cutworms overwinter as partially grown larvae and are the first cutworms to cause problems. The redbacked and related cutworms overwinter as eggs which are hatching now. If you try to starve young cutworms, a delay of 10 to 14 days between cultivation and seeding can help reduce populations. Larvae that have already fed will die if deprived of food for several days.
Action Thresholds for Cutworms by Crop:
|Canola||1 per square foot|
|Small grain||4 to 5 cutworms per square foot|
|Corn||3 to 6% of plants cut and small larvae less than 3/4 inch present|
|Sugarbeets||4 to 5% of plants cut|
|Soybean/||1 or more larvae per three feet|
|Drybean||row or 20% of plants cut|
|Sunflower||1 per square foot or 25 to 30% of plants cut|
|Forage||5 or more per square foot|
Insecticides labeled for treating the above crops for cutworm control include:
Canola Capture. Wheat Warrior and Lorsban 4E-SG. Corn permethrin (Ambush, Pounce), Asana, Lorsban, Sevin, and Warrior. Sugarbeets Asana, Lorsban, and Sevin. Soybean Asana, Lorsban, Pounce, Scout X-tra, Sevin and Warrior. Dry Bean Asana, Sevin, and Orthene. Sunflower Asana, Baythroid, Lorsban, Sevin, and Warrior. Forage permethrin (Ambush, Pounce), Baythroid, Lannate, Lorsban, Sevin, and Warrior
WATCHING FOR A NEW CEREAL GRAIN INSECT PEST
NDSU and the ND Department of Agriculture will be watching western
ND counties closely this season for the presence of Cereal Leaf Beetle. This beetle
feeds on the foliage of cereal grains (oats, wheat, barley, corn and rye; oats are the
preferred host). Though there are no confirmed reports of this insect in our state, it
is established in Richland County, Montana neighboring Williams and McKenzie counties in
northwest ND. The insect is expanding its range eastward, following the
Missouri River. Southwestern ND counties are also at some risk since the beetle has at least been detected in adjacent Montana counties.
Cereal leaf beetle adults are 3/16 inch long. The adult beetles are brightly colored, which aids in identification and detection. The first pair of wings (the elytra) are hard and are metallic blue-black. The legs of adults and the prothorax (first segment behind the head) are red. The brown-to-black larvae are often covered with black, shiny mucus. Fully grown larvae are 1/4 inch long.
The larvae feed on leaves by eating streaks of tissue from the upper surface of the leaf. Larvae-damaged leaves have long, narrow feeding strips between the veins. When adults are feeding in the early season, they chew holes completely through the leaf.
For more information visit the web site: http://scarab.msu.montana.edu/ipm/clb.html