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*This is an excerpt from Scouting Techniques for Soil Insect Pests of Peanuts, ANR-1364

The lesser cornstalk borer (LCB), Elasmopalpus lignosellus, is one of the major insect pests of peanuts in some parts of Alabama. Overwintering stage: Larvae overwinter in soil and crop debris.

Behavioral clues: Research indicates that LCB is better able to survive dry soil conditions in which its natural predators cannot thrive. This anomaly results in a greater incidence of LCB in the soil. Larvae of this insect are highly attracted to carbon dioxide and heat released by belowground plant parts of peanuts.

Scouting Techniques

• Scouting maps. It is very important to detect this insect early in the season so that control measures can be undertaken in a timely manner. Scouting maps are available for LCB through the AWIS Weather Services Web site. Based on calculation of borer days (BD), there will be a need to scout if the model has values within a 0 to 5 range. BD values over 5 indicate unusually high larval populations.

• Pheromone traps. These are highly effective in detection and monitoring of flight activity of adults. Preliminary data from the 2009 IPM pheromone trapping project in Alabama indicate that moth flight initiate in June followed by several weeks of intense mating activity in July and August. High and dry areas in sandy fields should be monitored closely for crop injury because LCB larvae survive well under xeric conditions.

• Look for webbing. Pull some pods out of the ground and look for webbing  attached to damaged pods. Larvae make feeding tubes that can be easily detected. Action threshold: Presence of larvae in 30 percent of sampling sites suggests economically injurious populations.

Read here to learn more about Scouting Techniques for Soil Insect Pests of Peanuts.

 

 

 

*This is an excerpt from Scouting Techniques for Soil Insect Pests of Peanuts, ANR-1364

The southern corn rootworm (SCRW), Diabrotica undecimpunctata howardi, is the immature form of the spotted cucumber beetle. Overwintering stage: Beetles diapause in November, but the diapause is short and they could emerge quickly the following season. Research indicates that most overwintering populations consist of female beetles that oviposit the following year.

Behavioral clues: Larvae do not make webs, so feeding injury from smaller instars may not be evident on the pods. The adult beetle is highly migratory and a strong flyer.

Scouting Techniques

• Larval infestations. Infestations in the soil should be thoroughly scouted close to the pegging stage. Remember that high soil moisture and poorly drained soils are favorable for the buildup of this insect. Initiate control measures when rootworm larvae are found in 30 percent of sample locations.

• Pheromone traps. These can be used to monitor beetle activity. Pheromone traps for this insect are available commercially as easy assembly kits. According to industry sources, trap catches of over 100 beetles per trap per week is indicative of high insect activity that should be investigated further by direct crop scouting and soil sampling for active larvae to estimate pod damage. Note that larval activity in soil may lag behind adult emergence and mating period.

• Sweep netting. This is a reliable sampling method for SCRW beetles. Collect a sample by making ten sweeps over the crop canopy in ten paces, and repeat this step from five locations per acre (collect representative samples from several random locations). Sweep net sampling should be done mid-morning because afternoon heat could move the insects deep into the crop canopy, thereby reducing sampling accuracy. If feasible, check the plant canopy for the actual number of adult beetles present on entire plants and compare the accuracy of sweep net samples.

• Check for holes. Check the pods for small to mediumsized circular holes at one end of the pod. In some instances, larvae make a series of entry holes all in one area of the pod.

• Risk index. Although SCRW infestations are sporadic, peanut producers may use the “risk index” developed by North Carolina State and Virginia Cooperative Extension to gain more experience about risk factors. SCRW risk index incorporates factors such as cultivar resistance, soil texture, soil moisture, field history, and planting date. Action threshold: Presence of adult or larvae or fresh damage in one-third of sampling sites indicates need for treatment.

Read here to learn more about Scouting Techniques for Soil Insect Pests of Peanuts.

 

 

*This is an excerpt from Citrus Pest Identification and Management Guide, ANR- 2270.

The most characteristic symptom of HLB is blotchy mottling that appears asymmetrically on the leaf blade. Green islands may also occur; these are small, circular, dark green dots that contrast with the light yellow/green background. Foliar symptoms that resemble nutrient deficiencies may be present. A tree may exhibit yellow shoots or other nutrient deficiency symptoms on one or more branches randomly in the canopy. Fruit may be small and lopsided or ripen backward, with the stylar end remaining green as the fruit colors.

Management tips: Citrus greening has not been found in Alabama to date. If citrus greening is suspected, contact your local diagnostic lab.

 

Read more about Citrus Pest Identification and Management Guide.

Download a PDF of Citrus Pest Identification and Management Guide, ANR- 2270.

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