Description of the males of Lincus singularis and Lincus incisus (Hemiptera: Pentatomidae: Discocephalinae)

The Neotropical Lincus Stål, 1867 includes 35 species, thirteen of which are known only from females. Several species are vectors of Phytomonas staheli McGhee & McGhee, 1979, a trypanosomatid parasitic in palm-trees in South America that causes hart-rot, sudden and slow wilt diseases. The hitherto unknown males of L. singularis Rolston, 1983 ("swollen head" species group found in the oil palm Elaeis guineensis Jacq.), and L. incisus Rolston, 1983 ("hatchet-lobed" species group; found in the coconut tree Cocos nucifera L.), are described with emphasis on the morphology of the genitalia, and taxonomic remarks are provided. Males of L. singularis can be distinguished from other species included in "swollen head" group by their pronotal lobes with anterior and posterior margins subparallel and projected laterally from the eye margin, while males of L. incisus can be distinguished from the species of the "swollen head" group by an obtuse projection with a deepest incision and several additional diagnostic characters of the genitalia.