Euonymus scale is in the crawler stage in northern Illinois and is susceptible to sprays of acephate (Orthene), bifenthrin (Onyx, Talstar), cyfluthrin (Tempo), insecticidal soap, and summer spray oil. If the lemon yellow crawlers are no longer present on the foliage, such as in southern and central Illinois, acephate would be most likely to still provide effective control, due to its translaminar systemic action.
Mimosa webworm is present as first-generation larvae. Looking closely at the foliage will reveal two to three leaflets of honey locust or silk tree (mimosa) webbed together with a green or brownish caterpillar feeding between them. Apply acephate (Orthene), Bacillus thuringiensis kurstaki (Dipel, Thuricide), carbaryl (Sevin), spinosad (Conserve), or a labeled pyrethroid to obtain control. Control at this time prevents much more severe damage from occurring by the second generation because first-generation adult moths tend to lay their eggs for the second generation into first-generation larval damage. This insect is most numerous in southern Illinois and is found in northern Illinois primarily on trees growing near buildings. Mimosa webworm larvae migrate to overwinter, and they survive in colder climates under the siding of heated buildings.
Japanese beetle adults should emerge during the next week in southern Illinois, with emergence occurring during the last week of June in central and northern Illinois. Linden, crabapple, rose, and other favored hosts can be protected with sprays of carbaryl (Sevin), clothiandin (Arena), cyfluthrin (Tempo), or dinotefuran (Safari). Early control is important, as the beetles migrate to new hosts every 3 days. They will tend to migrate to hosts that already have Japanese beetle feeding damage. Handpicking of the beetles is also effective but time-consuming.
Emerald ash borer has been found in Naperville, Illinois. This represents the first find in Will County. It is within the previously quarantined northeastern Illinois area.