Leptipsius Casey, 1916

Bousquet, Yves, 2003, Redescription of Leptipsius Striatus (Le conte) and Description of a New Species of Leptipsius from United States (Coleoptera: Monotomidae), The Coleopterists Bulletin 57 (2), pp. 133-140 : 134

Genus Leptipsius Casey, 1916

Leptipsius Casey 1916:93 . Type species: Monotoma striatum LeConte, 1858 , by original designation. Arnett (1962:768, 769). Sen Gupta (1988:15, 33); Downie & Arnett (1996:985, 988).

Diagnosis. Members of this genus share the following character states: head constricted behind eyes; antennomere 9 only slightly wider than antennomere 8, club 2-segmented (seemingly 1-segmented); head without antennal grooves; pronotal disc not conspicuously depressed, with impunctate median area and with microsculpture, punctures distant (non subcontiguous); elytral disc with punctures arranged in longitudinal rows; inflexed part of elytron with 4 or 5 rows of setigerous punctures; front coxae rounded; coxal bead of first visible abdominal sternite triangularly produced; visible abdominal sternites II–IV with small, more or less irregularly placed punctures.

Relationship. Sen Gupta (1988:33) noted that the genus Leptipsius has ‘‘close similarities and little differences from Bactridium ’’ and that it was ‘‘also related to the Indian new genus Malabica .’’ Members of Leptipsius , Bactridium and Pycnotomina Casey , the last two genera very likely adelphotaxa, share two character states that I believe are apomorphic for the family Monotomidae : the antennal club is 2-segmented (seemingly 1-segmented) and the coxal bead on the first visible abdominal sternite is triangularly produced. However, these character states occur in other monotomid groups. I have not seen any specimen of Malabica . Until a substantial character state analysis for the family at the world level is done, relationship of Leptipsius to other genera is difficult to assess.

Distribution and Diversity. There are only two species currently included in the genus Leptipsius , both from the United States, L. striatus LeConte and L. dilutus Casey. However , there are several species from the West Indies, Mexico and Central America, listed in the genus Bactridium , that probably belong to the genus Leptipsius , based on the original descriptions. This is the case for L. brevicornis (Sharp) , L. crassus (Sharp) , and L. eumorphus (Sharp) [new combinations] of which I have seen the type specimens in the BMNH.

Note. Members of Leptipsius are most similar to those of Bactridium and Pycnotomina but differ in having the head constricted basally (so the temples are distinct) and the visible abdominal sternites II–IV with 1–3 transverse rows of small, round punctures. In Bactridium and Pycnotomina the head is not constricted behind the eyes and the visible abdominal sternites II–IV have one transverse row of large, oblong punctures.