Hemlock-conservation
Guides
Adelges tsugae
Hemlock Woolly Adelgid, HWA
Adelges tsugae, the hemlock woolly adelgid, is a small invasive sap-sucking insect native to East Asia. In eastern North America, it is a destructive pest of eastern hemlock (Tsuga canadensis) and Carolina hemlock (Tsuga caroliniana), causing extensive tree mortality and threatening forest ecosystems. The insect is named for the white, woolly wax coating that covers its egg sacs and protects the insects beneath. It reproduces asexually via parthenogenesis in North America, producing two generations per year.
Derodontidae
tooth-necked fungus beetles
Derodontidae is a small family of beetles comprising 42 species in 4 genera and 3 subfamilies. Members are commonly known as tooth-necked fungus beetles due to the spiny pronotal margins found in most genera, though the genus Laricobius lacks these spines. The family is notable for possessing two ocelli on the head, an unusual trait among beetles. The genus Laricobius has gained significant attention as a biological control agent for invasive adelgids threatening hemlock forests in North America.
Laricobius
Laricobius is a Holarctic genus of small predatory beetles in the family Derodontidae, comprising approximately 23 described species. Unlike other Derodontidae genera that feed on fungi, Laricobius species are specialized predators of adelgids (Adelgidae), aphid-like insects that infest conifers. Several species, notably L. nigrinus from western North America and L. osakensis from Japan, have been released as biological control agents against the invasive hemlock woolly adelgid (Adelges tsugae) in eastern North America. The genus exhibits two distinct morphological groups: a southeastern Asian/Himalayan group with shortened bodies and narrow pronota lacking explanate margins, and a more widespread Holarctic group with elongate bodies and transverse, fully explanate pronota.