Explanation of Names
Megacyllene robiniae (
Forster 1771)
robiniae = 'of Robinia' (refers to a host tree)
Identification
all elytral markings yellow
(1)
metepisternum (region between 2nd & 3rd hind leg) nearly completely covered in yellow pubescence
(2)
Range
widely distributed, wherever people have planted Black Locust (
Robinia pseudoacacia).
(3)(1)Habitat
Adults common on flowers of goldenrod (Solidago) Aug-Oct
Food
Larvae feed on Black Locust (
Robinia pseudoacacia). Honey Locust (
Gleditsia triacanthos) is not affected.
Adults feed on pollen, particularly goldenrod (Solidago spp.).
Life Cycle
Eggs are laid in the fall. Newly emerged larvae hibernate under bark, tunnel in spring, making tunnels about 10 cm long and 6 mm wide, pupate late Jul/early Aug; adults emerge late Aug-Sep.
Larva & pupa
Remarks
Considered a serious pest of Black Locust; previously weakened or damaged trees are often killed by the larvae. Previously confined to the native range of Black Locust in the northeast, it has spread with the trees throughout the US and parts of Canada. Black Locust is used for reclamation and similar projects where trees are likely to be stressed and thus more vulnerable to damage.
See Also
Hickory Borer (
Megacyllene caryae) is active mainly
Mar-May, and its elytral bands typically alternate yellow and white:
Mesquite Borer (
Placosternus difficilis) is confined to southern US, and sutural one-third of elytron has distinct, abrupt depression margined by a slight carina (or ridge)
(2)
