Molorchus

Bohne, Marc F. DiGirolomo Michael J., 2024, First record of Molorchus minor (Linnaeus, 1758) (Coleoptera: Cerambycidae) in North America, Insecta Mundi 2024 (78), pp. 1-7 : 5

Key to North American species of Molorchus (Modified from Linsley 1931, 1963)

1. Pronotum entirely punctate, lacking smooth raised callused areas; elytra without oblique, white, elevated fasciae; antennae with fourth segment as long as third, much shorter than fifth segment........ 2

— Pronotum with lateral and central raised longitudinal callused areas; elytra with oblique, elevated, ivorywhite fasciae; antennae with fourth segment shorter than third, slightly shorter than fifth segment 3

2(1). Elytra concolorous, testaceous or rufotestaceous; pronotum usually distinctly longer than broad with sides much narrower than base of elytra; length, 5–8 mm ................ M. longicollis LeConte

— Elytra rarely black or reddish, usually bicolored with base, apex, and lateral margin black; pronotum usually slightly longer than broad with the sides as wide or nearly as wide as base of elytra; length, 4–11.5 mm M. bimaculatus Say

3(1). Lateral pronotal calluses narrower, sub-parallel ( Fig. 3A ); bands of light-colored setae at anterior and posterior margins of pronotum shorter, finer, more dense and conspicuous; pronotum length to width ratio slightly larger (PL/PW = 1.37); length, 6–16 mm .............. M. minor (Linnaeus)

— Lateral pronotal calluses wider, distinctly arcuate ( Fig. 3B ); bands of light-colored setae at anterior and posterior margins of pronotum sparse, not conspicuous; pronotum length to width ratio slightly smaller (PL/PW = 1.24); length, 8.5– 11 mm ............................. M. eburneus Linsley

Figures

Figure 3. Head and pronotum of Molorchus spp. A) Molorchus minor. B) Molorchus eburneus.