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Alydus eurinus (Broad-headed Bug)

Order: Hemiptera
Family: Alydidae
Genus: Alydus

Alydus eurinus`, in the family Alydidae commonly known as broad-headed bugs, belongs to the Order Hemiptera (true bugs, hoppers)(1).  The Order Hemiptera comes from hemi for half and ptera for wings which describes that the anterior portion of the front wings are often thickened and the distal portions membranous (1).  The most unifying defining character of Hemiptera is the presence of sucking-piercing mouthparts (1).  In Hemiptera the mandibles and maxillae are modified into four piercing stylets and are contained in a long, slender, flexible, often segmented sheath derived from the labium (1).  In most Hemiptera these sucking-piercing mouthparts are used to consume plant sap (1). A. eurinus belongs to the Suborder Heteroptera (true bugs) which are defined by the mouth being attached to the front of the head (1).  A. eurinus is further classified into the Infraorder Pentatomomorpha which are distinct from related taxa because they have conspicuous antennae and often specialized setae called trichobothria (1). A. eurinus belongs to the family Alydidae (broad-headed bugs) in reference to the fact that their head is as broad as and nearly as long as the pronotum, the top of the first segment of the thorax behind the head (1).  Alydidae contains 42 genera and about 250 species (2).  Alydidae, like the related Family Pentatomidae (stink bugs), release strong odors when handled, from a pair of scent glands between the middle and hind coxae, where the middle and hind legs attach to the abdomen (1).  These odors are defensive pheromones and are present in both the adult and larval stage (3).  Alydidae inhabit woody areas and edge habitats such as near roadsides where there is weed foliage to feed on (1).  A. eurinus is in the Subfamily Alydinae which are distinct for having swollen hind femora that have ventral spines (2). This specimen of Alydus eurinus was collected on the gravel path near the pond behind the Washington Duke Golf Course

Alydus eurinus - Broad-headed Bug

Alydus eurinus – Broad-headed Bug

Alydus eurinus - Close up of head and sucking mouthparts

Alydus eurinus – Close up of head and mouthparts

Alydus eurinus - Side view of thorax and scent gland

Alydus eurinus – Side view of thorax and scent gland



Alydus eurinus on
Alydus eurinus on ITIS Database




(1) Triplehorn, C.A. and N.F. Johnson, Borror and Delong’s Introduction to the Study of Insects, 7th ed., (2005), Thomson Brooks/Cole, pp. 268, 293, 301.
(2) Schuh, R. T. and J.A. Slater, True Bugs of the World (Hemiptera: Heteroptera): Classification and Natural History, (1995), Ithaca, NY, Cornell University Press, pp. 271-274.
(3) Aldrich, J.R. Chemical Ecology of the Heteroptera, Annual Review of Entomology vol. 33, (1998), pp. 211-238.