Notes on the Unique-Headed Bugs of New Caledonia (Hemiptera: Enicocephalidae)

Representatives of the family Enicocephalidae are living fossils of the order Heteroptera because of their evolutionarily conserved morphology. Their taxonomy and systematics are mostly problematic due to the high similarity in exoskeletal characters and relatively little data regarding multiple taxa. During the examination of soil and leaf-litter samples collected during a land snail survey in New Caledonia, multiple specimens of enicocephalid true bugs were found. The examination of specimens resulted in the discovery of the first known male representative of the endemic Monteithostolus caledonicus Štys, 1982, along with further records for the species and the second known occurrence of Systelloderes loebli Štys and Baňař, 2007, the only known macropterous, unique-headed bug of the archipelago. Diagnoses, notes, and distribution records for the discussed species are presented along with an updated key to the New Caledonian enicocephalid bug fauna.