Nomenclatural information https://thrips.info/wiki/Arorathrips_crassiscelis
Diagnosis Body dark brown, darker on head and antennal segment I; legs mostly brown, with anterior tibiae, apexes of mid and hind tibiae, and all tarsi yellow or yellowish brown; antennal segments I and IV–VIII dark brown, III light brown and III brown; fore wings with brownish setae. Head without strong sculpture, slightly prolonged in front of eyes; vertex with 10–18 short but robust setae. Antennae 8-segmented, III & IV each with a simple sense cone; antennal segment I enlarged, II asymmetric with external lateral margin strongly produced. Pronotum trapezoidal, with weak transverse lines of sculpture; with two pairs of short and conspicuous posteroangular setae. Meso & metathoracic endofurca weakly developed, without spinula. Fore coxae enlarged, fore tibiae prolonged externally to apex of the first tarsal segment. Metanotum with paired campaniform sensilla; two pairs of conspicuous setae, median pair arising behind anterior margin. Tarsi 2-segmented. Fore wing first and second veins with few and sparse setae. Abdominal tergites with transverse lines of sculpture, anteriorly with many rows of conspicuous tubercles. Ovipositor unusually small. Female macropterous.
Male not studied.
Intraspecific variation The number of anteocellar setae on head vertex varies from 10 to 18, with most of the type series specimens with 14 or 15 setae.
Genus and similar species information The New World genus Arorathrips includes about 15 species, all of them having antennal segment II strongly asymmetric, and segments III & IV with simple sense cones. It is closely related to Chirothrips but differs in having the mesothoracic endofurca reduced. Arorathrips crassiscelis is similar to A. mexicanus in several ways, such as coloration, sculpture, presence of rows of tubercles on abdominal tergites, and fore tibiae with an apical projection as long or longer than the first tarsal segment. Both species can be distinguished by the number of anteocellar setae on vertex (10–18 in A. crassiscelis, about 6 in A. mexicanus) and relative length of both posteroangular setae on pronotum (external pair shorter than internal pair in A. crassiscelis, external pair as long or longer than internal pair in A. mexicanus).
Distribution around the world Described from Argentina and recorded from Brazil.
Life history Specimens from the type series were collected from seeds of Eustachys distichophylla, but there is no further information on the interaction between the thrips and the plant.
