Thysanoptera (ThripsWiki, 2020)

Minaei, Kambiz & Mound, Laurence, 2020, Thysanoptera host-plant associations, with an account of species living on Tamarix, and a new species of Lissothrips (Phlaeothripidae), Zootaxa 4868 (2), pp. 275-283 : 276

Thysanoptera species on Tamarix

Tamarix is an Old World plant genus that includes about 50 species of trees or shrubs native to the semi-arid areas of the Sahel zone, although with some species introduced to other countries. The eight species considered here are known only from Tamarix plants, there being no available evidence that any of them also live on any other plant. However, this is an assemblage of unrelated genera and does not comprise a single lineage. These thrips are representatives from three different families and eight different genera. Four of the species apparently feed on leaves, one is flower-living, two are probably predatory on other small arthropods, and one is a fungus-feeder. Presumably, this assemblage is ecologically driven with little or no evolutionary significance. Tamarix lives in a dry and hostile environment, where it is often one of the most important plants available providing food and shelter to phytophagous insects. The absence of Thysanoptera radiation among these Tamarix -associated thrips is itself interesting, in that it contrasts with the situation on Geijera ( Mound 1971) . This Australian shrub similarly grows in scattered stands in semi-arid country, but a single lineage of Phlaeothripidae has radiated on it to produce at least 10 host-specific species.

Six of the eight species here considered associated with Tamarix are known to exhibit particularly unusual character states, although it is not known if this is coincidence or induced in some way by this plant. The antennae of Aeolothrips naderi are no more than 7-segmented, instead of the 9-segmented condition found in the other members of Aeolothripidae . In all known species of Eremiothrips antennal segment V bears near its inner apex a sense cone that is longer than the apical width of this segment, but in E. tamaricis this sense cone is much shorter. Similarly, in Haplothrips tamaricinus the inner sense cone on antennal segment III is much smaller than the external sense cone, a condition that is particularly unusual in this genus. Scirtothrips hafezi is almost unique within the genus Scirtothrips in having long setae on the head and pronotum, and Tamaricothrips tamaricis appears to be a typical species of the genus Anaphothrips apart from having one pair of pronotal posteroangular setae slightly elongate. Finally, Liothrips reuteri is exceptional within the species-rich genus Liothrips in producing micropterous adults.