Diagnosis Female macropterous; body color mainly dark brown, with tarsi and antennae slightly paler; wings light brown, without a dark median line. Antennae 8-segmented, antennomeres III and IV long and club-shaped.Head longer than wide, dorsal surface with three pairs of long and thick setae (an ocellar pair, a postocular pair and a pair in the middle of head) and several shorter setae laterally.Pronotum with at least 2 pairs of well-developed setae (epimeral and posteroangular), anteromarginal and anteroangular pairs short, midlateral pair short to medium-sized; prosternal basantra present. Metanotum with a pair of very long and thick median setae; metathorax lateroventral sclerites without microtrichia, sternopleural sutures absent. Abdominal tergites II–VII with 1 pair of wing-retaining setae. Tube about 5.5x as long as basal width, without lateral setae. All legs similar in appearance, fore femora with long setae, fore tarsi without a tooth. Fore wings with around 53 to 58 duplicated cilia.
Male not studied.
Intraspecific variation Unknown.
Genus and similar species information Anactinothrips is a genus with 15 described species, but it is possible some of them are synonymous to others. These thrips are usually dark, medium to large sized, with basantra present, without metathoracic sternopleural sutures, and tube without lateral setae. Males of Anactinothrips and Diceratothrips have a unique adaptation to their fore legs, with a series of ridges on the coxae and a posterior projection on the femora, which seem to work as a stridulatory structure or as a locking mechanism for the fore legs. Despite this unique structure, these genera probably belong to different evolutionary lineages, and Anactinothrips can be distinguished from Diceratothrips for lacking metathoracic sternopleural sutures, having a transverse pelta, and long setae on metanotum and laterals of abdominal segments. Anactinothrips nigricornis is one of the few species in the genus with completely brown antennae, without any yellow segments or pedicels. A key to Anactinothrips species is available in Mound & Marullo (1996).
Distribution around the world Described from Guyana, and recorded from Brazil.
