Macrohydnobius, Peck & Cook, 2009

Peck, Stewart B. & Cook, Joyce, 2009, Review of the Sogdini of North and Central America (Coleoptera: Leiodidae: Leiodinae) with descriptions of fourteen new species and three new genera, Zootaxa 2102 (1), pp. 1-74 : 37-38

Key to Species of Macrohydnobius

1 Protibial spurs enlarged, elongate (e.g. Figs. 103 , 110 , 118 ). Males .......................................................................... 2

- Protibial spurs not modified. Females (Note: female of M. tibiocalcaris unknown) .................................................. 7

2 Without a tooth on outer margin of left mandible (Figs. 102,109, 117) ..................................................................... 3

- With small tooth on outer margin of left mandible ( Figs. 124 , 133 ) ........................................................................... 5

3 Elongate protibial spur inserted before base ( Fig. 110 ); elytral intervals with minute punctures as well as larger punctures ................................................................................................................................................... M. simulator

- Elongate protibial spur inserted at or near base ( Figs. 103 , 118 ); elytral intervals without minute punctures .......... 4

4 Parameres short, about 1 / 3 length of median lobe, not partially enveloping median lobe ( Fig. 104 )... M. matthewsi

- Parameres longer, partly enveloping sides of broad median lobe ( Fig. 119 )....................................... M. crestonensis

5 Apical 1 / 5 of median lobe tapering sharply to narrow apex ( Fig. 142 ); eastern species................... M. tibiocalcaris

- Median lobe gradually tapering apically ( Figs. 127 , 136 ); western species ............................................................... 6

6 Median lobe narrow, internal sac at middle with two distinct areas of dense scale-like setae ( Figs. 127, 128 ) ............ .................................................................................................................................................................. M. contortus

- Median lobe less narrow, internal sac at middle with a pair of multidentate sclerites ( Fig. 136 , arrow) M. montanus

7 Without a tooth on outer margin of both mandibles ................................................................................................... 8

- With a tooth on outer margin of both mandibles ( Figs. 125 , 134 )............................................................................. 10

8 Coxites of female genitalia broad and flat with narrow apices curved dorsad, styli inserted on ventral face of coxites ( Fig. 121 ) ............................................................................................................................................. M. crestonensis

- Coxites of female genitalia elongate, cylindrical; styli inserted at apices of coxites ( Figs. 106 , 113 )........................ 9

9 Color usually reddish brown; pronotum clearly widest in posterior one-half; antennal club robust ( Fig. 101 ) ............ ................................................................................................................................................................. M. matthewsi

- Color usually dark brown; pronotum longer, narrower, sides weakly rounded; antennal club narrow ( Fig. 108 ) ........ .................................................................................................................................................................. M. simulator

10 Sternite 8 deeply emarginate apically ( Fig. 129 ) ...................................................................................... M. contortus

- Sternite 8 truncate apically ( Fig. 137 ) ..................................................................................................... M. montanus

Figures

FIGURES 101–106. Macrohydnobius matthewsii. 101. Right antenna, dorsal view. 102. Mandibles, dorsal view. 103. Male right protibia. 104. Aedeagus, dorsal view. 105. Female sternite 8, ventral view. 106. Female coxites and styli, ventral view. Scale bar = 0.3 mm (Fig. 106), 0.5 mm (Figs. 104, 105), 0.75 mm (Figs. 101, 102), 1.0 mm (Fig. 103).

FIGURES 108–114. Macrohydnobius simulator. 108. Right antenna, dorsal view. 109. Mandibles, dorsal view. 110. Male right protibia. 111. Aedeagus, dorsal view. 112. Female sternite 8, ventral view. 113. Female coxites and styli, ventral view. 114. Male right metepimeron showing possible stridulatory file, lateral view, elytron removed. Scale bar = 0.3 mm (Fig. 113), 0.4 mm (Fig. 112), 0.5 mm (Figs. 109, 111), 0.75 mm (Fig. 108), 1.0 mm (Figs. 110, 114).

FIGURES 116–121. Macrohydnobius crestonensis. 116. Right antenna, dorsal view. 117. Mandibles, dorsal view. 118. Male right protibia. 119. Aedeagus, dorsal view. 120. Female sternite 8, ventral view. 121. Female coxites and styli, ventral view. Scale bar = 0.3 mm (Fig. 121), 0.5 mm (Fig. 120), 0.75 mm (Figs. 116, 119), 1.0 mm (Figs. 117, 118).

FIGURES 123–130. Macrohydnobius contortus. 123. Right antenna, dorsal view. 124. Male mandibles, dorsal view. 125. Female mandibles, dorsal view. 126. Male right protibia. 127. Aedeagus, dorsal view. 128. Everted internal sac, dorsal view. 129. Female sternite 8, ventral view. 130. Female coxites and styli, ventral view. Scale bar = 0.3 mm (Fig. 130), 0.5 mm (Figs. 127–129), 0.75 mm (Fig. 123), 1.0 mm (Figs. 124–126).

FIGURES 132–138. Macrohydnobius montanus. 132. Right antenna, dorsal view. 133. Male mandibles, dorsal view. 134. Female mandibles, dorsal view. 135. Male right protibia. 136. Aedeagus, dorsal view. 137. Female sternite 8, ventral view. 138. Female coxites and styli, ventral view. Scale bar = 0.3 mm (Fig. 138), 0.5 mm (Figs. 136, 137), 0.75 mm (Fig. 132), 1.0 mm (Figs. 133–135).

FIGURES 140–142. Macrohydnobius tibiocalcaris. 140. Right antenna, dorsal view. 141. Male right protibia. 142. Aedeagus, dorsal view. Scale bar = 0.5 mm (Fig. 142), 0.75 mm (Fig. 140), 1.0 mm (Fig. 141).