Mesandrothrips Priesner stat. rev.

Mesandrothrips Priesner, 1933: 80 . Type species: Haplothrips inquilinus Priesner, 1921, by monotypy.

This genus is interpreted here as comprising those Haplothrips -like species that have three sense cones on antennal segments III and four on IV. Within the Haplothripini there are six genera in which species have the third antennal segment bearing three sense cones, and a key to distinguish the five that have a centre of diversity in the Oriental Region was provided by Mound and Minaei (2007). Species of the first two, Androthrips and Euoplothrips, are distinguished by the presence of tubercles on the inner margin of the fore femora, and species of the third, Mesothrips, all have the head sharply constricted to a basal neck and with several prominent setae on the genae. Species in these three genera are all associated with leaf galls on their host plants. In contrast, Dolichothrips species are generally leaf- and flower-living, and are known to be pollinators of Macaranga species (Mound & Okajima 2015). Members of this genus have the mouth cone long and pointed, and almost all of them have an additional pair of wing-retaining setae at least on the third abdominal tergite. Species in the final two genera, Mesandrothrips and Neoheegeria, are structurally very similar, although females of species in the first generally have a well-developed fore tarsal tooth, whereas females of the second have a minute, scarcely visible tooth (Minaei et al. 2018). However, the similarity in body form in these two genera is likely to result from convergence to a basic Haplothrips -like body form, because Neoheegeria species are all flower-living and from the western Palaearctic, whereas species of Mesandrothrips are not flower-living and are from Southeast Asia. The form of the mesopresternum, whether complete or reduced to two lateral triangles, has been used in a key to distinguish genera (Mound & Minaei 2007), but this structure is variable between closely related species of Mesandrothrips, including inquilinus and darci .

Mesandrothrips w a s erected casually by Priesner (1933), with neither details nor diagnosis. It was referred to as a genus intermediate between Mesothrips and Androthrips, and included the single species Haplothrips inquilinus . The genus has been listed as a synonym of Xylaplothrips, because inquilinus was treated in that genus by Pitkin (1976), although no comment on the significance of the name Mesandrothrips has ever been published. The genus is here re established with a formal generic diagnosis and list of Haplothripini species that are reputed to share the character states of that diagnosis. A further species from Java, inquinatus, is known from a single small female that is similar to inquilinus but has darker antennae. Little is known about the biology of species in this genus, but several have been taken from galls or from other enclosed spaces. They are usually collected in very low numbers, and this might suggest that some of them are predators on other small arthropods. Intra-specific structural variation, in association both with sex and with body size, combined with lack of population samples, produces complications in distinguishing the species. The genus Senegathrips, that includes a single species from West Africa living as an invader of galls induced by the phlaeothripine Vuilletia houardi (Mound et al. 2014), shares most character states with Mesandrothrips, but has two pairs of pronotal epimeral setae. The list below includes the 20 species now recognized in the genus Mesandrothrips, which is essentially restricted to Australian and Indo-Malaysian regions.

Diagnosis: Macropterous Haplothripini with 8-segmented antennae; three major sense cones on antennal segment III and four major sense cones on segment IV; segment VIII slender and constricted to the base; pronotum often with only four pairs of major setae, anteromarginal setae scarcely longer than discal setae, epimeral sutures complete; metathoracic sternopleural sutures usually not developed; fore wing weakly constricted medially; tergites II–VII each with 2 pairs of sigmoid wing-retaining setae; tube relatively slender.

Species included

(* based on description; see also Pitkin, 1976)

Mesandrothrips austrosteensia sp.n.

* Mesandrothrips caliginosus (zur Strassen) comb.n.

Mesandrothrips clavipes (Karny) comb.n.

Mesandrothrips darci (Girault) comb.n.

* Mesandrothrips dubius (Okajima) comb.n.

* Mesandrothrips emineus (Ananthakrishnan & Jagadish) comb.n.

* Mesandrothrips flavitibia (Ananthakrishnan & Jagadish) comb.n.

* Mesandrothrips flavus (Ananthakrishnan) comb.n.

Mesandrothrips googongi sp.n.

Mesandrothrips inquilinus (Priesner) comb.n.

Mesandrothrips inquinatus (Karny) comb.n.

Mesandrothrips kurandae sp.n.

Mesandrothrips lamingtoni sp.n.

* Mesandrothrips montanus (Ananthakrishnan & Jagadish) comb.n.

Mesandrothrips oleariae sp.n.

Mesandrothrips pictipes (Bagnall) comb.n.

* Mesandrothrips pusillus (Ananthakrishnan & Jagadish) comb.n.

Mesandrothrips reedi (Pitkin) comb.n.

Mesandrothrips subterraneus (Crawford JC) comb.n.

* Mesandrothrips tener (Ananthakrishnan & Jagadish) comb.n.