Bactrothrips Karny

Dang, Lihong & Qiao, Gexia, 2012, The genus Bactrothrips in China (Thysanoptera: Idolothripinae): morphological and molecular data, and a key with two new species, Zootaxa 3449, pp. 47-61 : 48-50

Bactrothrips Karny

Bactrothrips Karny, 1912: 131 . Type-species: Bactrothrips longiventris Karny, 1912 .

Among species of the genus Bactrothrips , some morphological characters are variable. In B. flectoventris the eyes are prolonged on the ventral surface of the head, but in the others the eyes are developed similarly on both sides of head. In two species from Australia, B. aliceae and B. kranzae , the maxillary stylets are retracted almost to the eyes and closer together, but in other members of the genus the maxillary stylets are shorter and far away from each other. Males of some species lack abdominal tubercles, but in other species these lateral tubercles vary in shape from straight, to curved or even bifurcate. So it is difficult to define the genus based on morphological characters.

Diagnosis. Body large. Head much longer than width across eyes, usually prolonged in front of eyes; eyes normal or obviously prolonged on ventral surface; interocellar, postocellar, postocular and mid-dorsal setae usually well developed, but sometimes small; posterior ocelli in contact with eyes. Maxillary stylets short and wide apart, or long and close together. Antennae 8-segmented, slender or stout; segments III and IV with 2 and 4 sense-cones separately. Pronotum usually with five pairs of major setae well developed, sometimes epimeral accessory setae also well developed; epimeral sutures incomplete or complete; basantra and ferna present. Mesopraesternum boatshaped. Metathoracic sternopleural sutures absent. Wings fully developed with numerous duplicated cilia, or apterous. Fore legs not enlarged and tarsi unarmed. Pelta with two lateral lobes never separated; abdominal tergites II–VII each with two pairs of sigmoid wing-retaining setae in species with wings full developed; tergites V–VIII of male with or without lateral tubercles, the tubercles small, long, straight, curved, horn-like or forked; tube much longer or slightly shorter than head, surface with numerous fine setae; anal setae much shorter than tube.