Ecology and Management ofPemphigus betae(Hemiptera: Aphididae) in Sugar Beet

Abstract

Pemphigus betae Doane (Hemiptera: Aphididae), is a sporadic pest of sugar beet ( Beta vulgaris L. var. vulgaris ) in all major sugar beet production regions of North America. These oval-shaped, pale-yellowish insects, with a body length ranging from 1.9–2.4 mm, secrete a waxy material, giving their subterranean colonies a moldy appearance. Poplars in the genus Populus L. are the preferred primary hosts, while sugar beet and certain weed species, such as common lambsquarters ( Chenopodium album L.) and kochia ( Kochia scoparia (L.)), are among the secondary hosts. Pemphigus betae has a complex and varied life cycle and is usually heteroecious and holocyclic, although anholocyclic apterae are known to overwinter in the soil. Heavy infestations of this aphid can induce significant reductions in yield, sugar content, and recoverable sugar. Under conditions of extreme stress and heavy infestations, the alienicolae can induce stunting, chlorosis, wilting, and even death of sugar beet plants. Accurately establishing population densities for sugarbeet root aphids presents a challenge, because the economic important stage of this insect is subterranean. However, use of a fall root rating index aids in estimating relative population densities. Furthermore, root aphids are especially difficult to control by means of conventional insecticides. For this reason, integrated pest management tactics, including the use of host plant resistance, cultural control techniques, and the use of natural enemies, should take precedence.