Lathropus Erichson

Thomas, Michael C., 2010, A review of Lathropus Erichson (Coleoptera: Laemophloeidae) in Florida and the West Indies, excluding the Lesser Antilles, Insecta Mundi 2010 (120), pp. 1-21 : 1-3

Lathropus Erichson

Lathropus Erichson 1846: 327 . Type species: Trogosita ? sepicola Müller , by monotypy.

Diagnosis. The members of this genus are easily recognized by the following combination of character states: their minute size (<2mm); short, clubbed antennae; tarsal formula 5-5- 5 in both sexes; lateral lines on head obliterated by coarse surface sculpture ( Fig. 13-18 ); dorsal pubescence composed of bifurcate setae (Fig. 62); apical sensillae on antennomeres IX-X arranged in a complete ring ( Fig. 53 ); pronotum usually with 3-4 lateral denticles and with discal impressions ( Fig. 19-26 ); each elytral cell enclosing two rows of deep punctures and five rows of setae ( Fig. 51 ); anterior coxal cavities posteriorly closed ( Fig. 60 ); and mesocoxal cavities closed laterally by meso- and metasterna ( Fig. 61 ). Mouthparts ( Fig. 47-50 ) and genitalia ( Fig. 41-45 ) are similar to those of other laemophloeid genera.

Distribution. There is one known European species, the type species L. sepicola (Müller) . The remaining species occur in the New World where they range from northeastern North America west to California and south through Central America and throughout the Caribbean. I have also seen undescribed South American species from as far south as Bolivia.

Discussion. The affinities of Lathropus are unclear. Only one other laemophloeid genus, Carinophloeus Lefkovitch , is known to possess closed mesocoxal cavities, but otherwise differs in many ways from Lathropus : anterior coxal cavities open; dorsal setae grooved, not bifurcate ( Fig. 57 ); antennal sensillae arranged in two incomplete arcs ( Fig. 58 ); elytral cells without rows of deep punctures or rows of setae except for the cell margins ( Fig. 57 ).

Members of Rhabdophloeus Sharp resemble those of Lathropus in general body shape and extremely coarse dorsal surface sculpture but have open procoxal and mesocoxal cavities; grooved setae ( Fig. 55 ); elytral cells as in Carinophloeus ; and generally longer antennae with sensillae confined to two welldefined pits ( Fig. 56 ).

An undescribed genus from the Middle East also has extremely coarse surface sculpture which obliterates the sublateral lines of the head and pronotum ( Fig. 59 ) and with two rows of deep punctures and three rows of setae in each cell ( Fig. 52 ) it approaches the elytral cell arrangement of Lathropus . However, it has open procoxal and mesocoxal cavities, grooved setae, and different genitalia. The sensillae are in a complete ring around antennomeres IX-X but differ in that the portion of the antennomere bearing the sensillae protrudes anteriorly ( Fig. 54 ).

The habits and habitats of the New World members of this genus are poorly known, with information limited to an association with scolytine curculionids ( Thomas 1993). Uliana (2003), in a detailed study of the biology of L. sepicola in Italy, found no real association with scolytines beyond the fact both are found in the same habitat. Instead, adults and larvae both fed on fruiting bodies of Diplodia melaena Lév. (Fungi Imperfecti) ( Uliana 2003).

Figures

Figure 13-18. Surface sculpture of head, Lathropus spp. 13) L. jamaicensis Thomas, n. sp. 14) L. rhabdophloeoides Thomas, n. sp. 15) L. pictus Schwarz. 16) L. chickcharnie Thomas, n. sp. 17) L. vernalis Casey. 18) L. robustulus Casey.

Figure 51-56. 51) Lathropus chickcharnie Thomas, n. sp., elytral cell. 52) N. gen, n. sp., elytral cell. 53) Lathropus jamaicensis Thomas, n. sp., antennal club. 54) N. gen, n. sp., antennal club. 55) Rhabdophloeus sp., Brazil, pronotum. 56) Rhabdophloeus sp., Brazil, antennal club.

Figure 19-24. Pronotum, Lathropus spp. 19) L. parvulus Grouvelle (Panama). 20) L. parvulus Grouvelle (Cayman Islands). 21) L. jamaicensis Thomas, n. sp. 22) L. rhabdophloeoides Thomas, n. sp. 23) L. pictus Schwarz. 24) L. chickcharnie Thomas, n. sp.

Figure 25-26. Pronotum, Lathropus spp. 25) L. robustulus Casey. 26) L. vernalis Casey.

Figure 57-61. 57) Carinophloeus raffrayi (Grouvelle), elytral cell. 58) C. raffrayi (Grouvelle), antennal club. 59) N. gen, n. sp., pronotal detail. 60) Lathropus rhabdophloeoides Thomas, n. sp., procoxal cavity. 61) Lathropus rhabdophloeoides Thomas, n. sp., mesocoxa and surrounding sclerites. 62) Lathropus chickcharnie Thomas, n. sp., bifurcate setae of head.

Figure 47-50. Lathropus rhabdophloeoides Thomas, n. sp., mouthparts. 47) Labrum. 48) Maxilla. 49) Labium. 50) Mandible.

Figure 41-45. Lathropus robustulus Casey, male and female genitalia. 41) Aedeagus. 42) Sclerotization of internal sac (enlarged). 43) Tegmen. 44) Female genitalia. 45) Spermatheca (enlarged).