Illinois Field Crop Applicators Practice Test

What pest causes heavy infestations that led to a reduction in soybean pod counts while excreting honeydew?

1. Spider mites

2. Bean leaf beetles

3. Soybean aphids

4. Alfalfa weevil

The correct answer is: Soybean aphids

The correct answer is soybean aphids, a pest known for causing significant damage to soybean plants. Soybean aphids feed on the sap of the plant, which can lead to a reduction in the number of pods that develop on the soybean plants. This feeding behavior weakens the plant, making it less vigorous and reducing its yield. In addition to the damage caused by their feeding, soybean aphids excrete a sugary substance known as honeydew. This excretion can create a sticky residue on the leaves and surrounding areas, leading to the growth of sooty mold, which further impairs the plant's ability to photosynthesize effectively and can lead to additional stresses on the crop. This combination of direct feeding damage and the negative effects of honeydew makes soybean aphids particularly troublesome for soybean producers. While spider mites, bean leaf beetles, and alfalfa weevils can also impact crops, they do not create the same level of infestation or directly excrete honeydew like soybean aphids do. Spider mites cause damage through feeding but are not known for excreting honeydew; bean leaf beetles primarily affect soybean seedling and can damage foliage but not to the extent of reducing pod counts through honeydew secretion; alfalfa weevils