Megacyllene robiniae

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Megacyllene robiniae
M robiniae.jpg
Adult locust borer
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Coleoptera
Suborder: Polyphaga
Superfamily: Chrysomeloidea
Family: Cerambycidae
Subfamily: Cerambycinae
Tribe: Clytini
Genus: Megacyllene
Species: M. robiniae
Binomial name
Megacyllene robiniae
(Forster, 1771)
  • Megacyllene flexuosum (Fabricius, 1775)
  • Megacyllene pictus (Drury, 1773)

Megacyllene robiniae, commonly known as the locust borer, is a species of longhorn beetle endemic to eastern North America. It is a serious pest to Robinia pseudacacia, the black locust tree, with which it is sympatric.


The specific name, robiniae, is derived from the New Latin name, Robinia, which is the generic name of the black locust tree, Robinia pseudoacacia, on which the larvae feed. The name, Robinia, was coined by Linnaeus to honor the royal French gardeners Jean Robin (father) and Vespasien Robin (son).


From a distance, M. robiniae can easily be mistaken for a wasp or bee. Even at a closer look, it is often mistaken for M. caryae or M. decora. The adult beetle grows between 12 and 20 mm (0.47 and 0.79 in) long and has a W-shaped third stripe on the elytra. The antennae of both sexes are dark brown. The male's antennae are two-thirds its body length, and the female's are one-half. The legs are reddish-brown.

Geographic range and habitat[edit]

Its geographic range has grown over the years following the expanding range of R. pseudoacacia. As more and more people use the black locust tree as an ornamental, the range of M. robiniae grows. It can be found almost anywhere unprotected black locust trees grow, and is often more abundant when Solidago, commonly called goldenrod, is also present. The females are often found running up and down black locust trunks in search of wounds in which to lay their eggs. Both sexes are most common from late day to dusk. Because of the adults' primary food, they tend to stay in uncultivated fields and meadows.


Adult on Solidago

Adults lay their eggs in locust trees in the fall. Later, the larvae hatch and spend the winter hibernating within the bark. Once winter ends, the larvae burrow into the tree trunk and start to tunnel. These tunnels are around 10 cm (3.9 in) long by 7 mm (0.28 in) wide. The larvae then pupate in late July and early August. The adults start to emerge in late August and throughout September. The tunnels serve as a primary infection site for wind-borne spores of the fungus Phellinus robiniae, which causes a damaging heart rot disease of Robinia species.


Adults feed on pollen of goldenrods of the genus Solidago. The larvae feed on the wood of Robinia pseudacacia.

Pest management[edit]

Currently, only one registered product, carbaryl, is effective against M. robiniae. It is applied in a single dose when adults are most active (August/September).[1]