Insect experts are urging Nebraska farmers to keep watch for soybean aphids.

University of Nebraska-Lincoln entomologist Tom Hunt says the weather's been right for aphid buildup.

The extra July rain and lower temperatures have helped the aphids.

Hunt says aphids start dying when it gets into the 90s day after dry day.

Soybean aphids use their piercing, sucking mouthparts to feed on new tissue near the top of soybean plants or on the undersides of mature leaves.