Gynaikothrips microchaetus, Ananthakrishnan and Jagadish, 1969

SHYAM, M., JOHNSON, TH., RACHANA, R. R., VARATHARAJAN, R. & MOUND, L. A., 2019, Redescription and lectotype designation of Gynaikothrips microchaetus Ananthakrishnan & Jagadish (Thysanoptera: Phlaeothripidae), Zootaxa 4701 (6), pp. 588-590 : 590

Distinguishing microchaetus from ficorum and uzeli

Ananthakrishnan and Sen (1980) differentiated microchaetus from uzeli based on lengths of post ocular, prothoracic and epimeral setae in their key to nine species of Gynaikothrips from India. However, our observations indicated that ficorum , microchaetus and uzeli are very similar in structure. Moreover, ficorum and uzeli are both highly variable, both within and particularly among populations around the world (based on series in the Australian National Insect Collection). These three species may be distinguished as follows:

1. Pronotum with pa setae small and acute, only epim setae elongate ( Fig 2 ); four postocular setae all finely pointed and shorter than width of fore tibiae ( Fig. 1 ); fore wing sub-basal setae acute, shorter than half of wing width ( Fig. 5 ); male sternite VIII with large pore plate ( Fig. 9 ) that occupies entire sternite and extends fully across tergite VIII except for a triangular area anteromedially ( Fig. 8 )......................................................................... microchaetus

-. Pronotum with pa setae variable in length, commonly prominent and half as long as epim setae; postocular setae variable but commonly weakly capitate and as long as width of fore tibiae; fore wing sub-basal setae longer than half of wing width and usually capitate or bluntly pointed; male sternite VIII pore plate variable, usually sub-circular medially but sometimes extending onto lateral margins of tergite......................................................................... 2

2. Pronotum with two pairs of prominent setae on posterior angles of pronotum, pa setae at least 70% as long as epim setae uzeli

-. Pronotum with pa setae variable, usually short and acute but never more than 50% as long as epim setae........... ficorum

Comments. The lack of strong character states in the original description, together with the unknown type depository, have necessitated for this species a redescription and Lectotype designation. Gynaikothrips microchaetus is unique among its congeners in having the male pore plate fully occupying both the sternal and tergal surfaces of abdominal segment VIII. Gynaikothrips uzeli seems to be associated with Ficus benjamina , and G. ficorum with both F. microcarpa and F. benjamina ( Tree et al. 2015) . But G. microchaetus was collected and described by Ananthakrishnan and Jagdish (1969) from galls on an unknown Ficus plant. In the present study, this thrips species has been observed thriving beneath spider webbing on the leaf surface of F. curtipes . The leaves of this plant are rather thick and possibly not suitable for gall formation. Thus G. microchaetus , although probably confined to species of the genus Ficus , is apparently not specific to any particular species within that large genus. Based on our observations over the past two years, G. microchaetus has maintained a continuous aggregation on F. curtipes under the abandoned silken webs produced by spiders.

Figures

FIGURES 1–9. Gynaikothrips microchaetus. (1) Head. (2) Pronotum. (3) Antenna & female fore tarsus. (4) Meso & metanota and pelta. (5) Fore wing sub-basal setae. (6) Segments IX–X. (7) Tergites V–VI. (8) Male tergite VIII. (9) Male sternite VIII.