ISSUE 5 May 30, 2002
WARM WEATHER WAKES UP THE INSECTS
The 75+E air and 55+E soil temperatures from Sunday through Wednesday increased activity by a number of insects in the region.
Perhaps the most significant is the flea beetle feeding on canola. Beetles moved rapidly from overwintering sites and started feeding on canola seedlings. Reports from Langdon, ND area and north central counties indicate that feeding injury is exceeding the 25% defoliation in cotyledon stage plants. Foliar treatments have begun to protect young plants. Seed treatments were reported to be holding up in the presence of feeding. However, seed treatments are not a guarantee of protection, in particular where seed has sat in moist soil for extended periods.
Photo: Crucifer flea beetle - feeding injury on canola
In the southwestern counties, the warm soils have stimulated feeding activity in cutworms, probably army cutworm. Cutworms ranging from 3/4 to 1 inch are being found. Check all crops. Eggs were laid last fall where soils are moist, often soils freshly tilled in September. Whatever crop was planted will be at risk.
In the east, the dingy cutworm is now making itís presence known. Reports of problems in the Crookston area came from Ian MacRae, U of MN entomologist. Feeding in sugarbeets and other crops will show up as crops emerge or fail to emerge due to below ground feeding.
It is time to be annoyed by ticks, again. Here is some advice that should be useful in dealing with these bothersome pests.
The American dog tick, or wood tick, is the most common one found in ND. In Minnesota, the blacklegged tick, formerly know as the deer tick, and the American dog tick, are both found. They can be found in grassy fields and in the undergrowth of hardwood forests. All ticks go through an egg, larva, nymph, and adult stage during their development. While they may be found throughout the year, dog tick adults are most active during late April through May. Blacklegged tick adults are most active in late summer and fall.
The larva, nymph, and adult stages must each have a blood meal before they can develop to the next stage. Adult female American dog ticks are reddish brown with whitish markings. The dog tick has a fairly wide host range. Adults commonly infest both large and medium sized mammals such as dogs, cattle, deer, raccoons, and opossum. The immature stages may feed on these same hosts but prefer to infest smaller mammals such as meadow mice, squirrels, and chipmunks. All stages of the dog tick will feed on humans if given the opportunity. Although they are abundant, the American dog tick is not considered to be a serious human health threat in ND. Specifically, they do not transmit Lyme disease. Although dog ticks do not carry Lyme disease, they are the main carrier of Rocky Mountain Spotted Fever in the midwestern states. Fortunately, this disease is relatively rare in ND.
Blacklegged ticks are generally smaller than American dog ticks. Adult female ticks are brownish-orange with black legs. They feed most commonly on white-footed mice and whitetailed deer, although other mammals, including humans can also be bitten. Blacklegged ticks are important because they can be carriers of Lyme disease. Symptoms of Lyme disease can include a red ring, fatigue, chills, fever, headache, muscle pain, sore throat, nausea, and vomiting. See a doctor right away if you believe you have been infected with Lyme disease.
Control of ticks in outdoor areas is difficult. While several insecticides are labeled for outdoor tick control, they are usually not effective in eliminating large numbers of ticks in brushy, wooded areas. There are, however, some management techniques that can discourage a buildup of ticks in these areas. Habitat modification is considered to be the most permanent approach to tick management. Ticks must be in areas of high humidity to survive. They are most commonly found in grassy, brushy, wooded, and shaded areas. Reduce the humidity in these areas by keeping grass well-clipped, removing brush, and pruning trees to allow more sunlight to penetrate to the soil surface will discourage ticks from becoming established in these areas.
Insecticide sprays approved for application in ornamental and turf areas for tick control include diazinon, bifenthrin, cyfluthrin, permethrin, tralomethrin or Sevin. Limit applications to the edges of lawns or along paths or trails to minimize tick movement into higher traffic areas.
The best approach when working or recreating in tick infested areas is to use personal protection in the form of repellents, wear protective clothing, and carefully inspect for and promptly and safely remove any attached ticks.