Greenbug numbers usually decline naturally during December and January, and treatment is rarely necessary during this period unless the weather is unusually mild.

In southern parts of the state, overwintering greenbugs can rapidly develop into damaging infestations during warm periods in February and March, and close surveillance of fields is necessary if greenbugs are present. Beneficial insects such as ladybeetles and parasitic wasps become increasingly effective in reducing greenbug populations around mid-April. Once 10 to 15 percent of greenbugs are parasitized, populations usually decline fairly rapidly.

Greenbug control on small grains is occasionally needed during periods of relatively cool weather (below 60°F, but above freezing). This can occur when a sudden cold snap in spring negatively impacts natural enemy populations. Although most recommended insecticides should be effective under these conditions, dimethoate may not give acceptable control at temperatures below 60°F.

Nonchemical management options have likely contributed to reducing greenbug populations and damage potential in High Plains wheat. A number of Kansas wheat varieties still express resistance to greenbugs, although this has receded in importance as a wheat breeding objective, so consult with seed suppliers about currently available cultivars. Avoid unusually early or late planting dates. Planting wheat no-till lowers the risk of infestation, because more crop residue on the soil surface reduces the rate at which winged aphids land on the plants. Avoid pesticide applications when beneficial insects such as lady beetles and parasitic wasps are numerous, as these are effective in preventing greenbugs from reaching economic threshold under most conditions. Augmenting greenbug predators such as ladybeetles or lacewings by purchasing and releasing them is not advisable. These lab-grown insects are likely not adapted to survive in Kansas conditions, and their wild relatives will arrive naturally provided insecticide use is not excessive. Seed treatments containing imidacloprid or thiamethoxam offer seedling protection in the fall and may be appropriate in parts of southern Kansas where the risk of infestation is greater. Thiamethoxam (Cruiser) is commercially applied to seed at 0.75 to 1.33 fl. oz. per 100 pounds of seed, often combined with a fungicide treatment.

Reference labels for information on how these products should be applied. Some products indicate that they are to be commercially applied and others allow end-use seed treatment on agricultural establishments in liquid or slurry treaters at or immediately before planting. Some carry the warning to not graze or feed livestock in treated areas for up to 45 days after planting.