Pachybrachis othonus

Barney, Robert J., 2016, Definition and Revision of theOthonusSpecies-Group of North AmericanPachybrachisChevrolat (Coleoptera: Chrysomelidae: Cryptocephalinae), The Coleopterists Bulletin 70 (3), pp. 569-605 : 569-605

KEY TO MALES OF THE PACHYBRACHIS OTHONUS SPECIES- GROUP

1. Elytral pattern vittate..................................2

1′. Elytral pattern non-vittate...........................4

2. Pronotal M moderate to heavy, black to reddish orange and sharply outlined, finely alutaceous and shiny, punctation sparse and widely separated; aedeagal beards forming long, dense, incurving wisps ( Fig. 2 ); southeastern USA, Alabama to New Jersey .......... 2. P. armbrusti Barney , new species

2′. Pronotal M moderate to heavy, black, punctation often strigose ......................................... 3

3. Elytral vittae usually well-formed, pronotum strongly transverse with black, strigose punctation covering entire area except for margins and narrow median anterior stripe yellow, often reduced to standard pronotal M ( Fig. 6F ) in specimens from west of 100 th meridian; aedeagal beards forming long, dense, incurved wisps, orificial space with 2 sclerotized, triangular plates appearing as incurved lamellae above the lateral basal plates ( Fig. 1 ) .................. 1. P. othonus (Say)

3′. Elytra appearing black with subsutural vitta and margin yellow ( Fig. 6C ) to yellow with each elytron with 2 discal vittae (often reduced or broken) and the suture black ( Fig. 6E ); pronotum yellow with moderate to broad, sharply defined, black M, lateral vittae rarely disconnected from median one; aedeagal beard short and fine, extending from widest point of median lobe to terminus ( Fig. 5 ) ...... ....................... 5. P. nigricornis (Say) (in part)

4. Entirely black, pronotum and elytra may be margined with yellow.................................5

4′. Yellow, pronotal M moderate to heavy, black, punctation often strigose, elytral striae very regular and complete ( Fig. 3 ) ............... .......................... 3. P. pallidipennis Suffrian

5. Robust (3.0 mm), black, moderately shiny, external margins of pronotum and elytra pale yellow ( Fig. 4 ) ...................................... .................................. 4. P. praeclarus Weise

5′. Smaller (2.3 mm), pronotum and elytra ranging from entirely black ( Fig. 6B ) to obscurely margined with rufous ( Fig. 5 ) to appearing black with subsutural vitta and margin yellow ( Fig. 6A, D ) .................................................... ....................... 5. P. nigricornis (Say) (in part)

1. Pachybrachis othonus (Say), 1825 ( Figs. 1 , 6F ; Map 1A, B)

Figures

Fig. 2. Pachybrachis armbrusti, holotype. A) Dorsal habitus, B) Lateral habitus, C) Face, D) Pygidium, E) Median lobe, lateral view, F) Median lobe, en-face view.

Fig. 6. Dorsal views of male types of former subspecies of Pachybrachis. A) P. nigricornis nigricornis, B) P. carbonarius, C) P. autolycus difficilis, D) P. autolycus wahsatchensis Fall, E) P. autolycus, F) P. othonus sioux.

Fig. 1. Pachybrachis othonus. A) Dorsal habitus, B) Lateral habitus, C) Face, D) Pygidium, E) Median lobe, lateral view, F) Median lobe, en-face view showing sclerotized lamellae above the two lateral basal plates.

Fig. 5. Pachybrachis nigricornis. A) Dorsal habitus, B) Lateral habitus, C) Face, D) Pygidium, E) Median lobe, lateral view, F) Median lobe, en-face view.

Fig. 3. Pachybrachis pallidipennis. A) Dorsal habitus, B) Lateral habitus, C) Face, D) Pygidium, E) Median lobe, lateral view, F) Median lobe, en-face view.

Fig. 4. Pachybrachis praeclarus. A) Dorsal habitus, B) Lateral habitus, C) Face, D) Pygidium, E) Median lobe, lateral view, F) Median lobe, en-face view.