Distinguishing features

Female fully winged or micropterous. Body brown; antennal segment III paler with base yellow; wings shaded with darker longitudinal lines in proximal two-thirds. Head almost as wide as long, with sculpture lines on posterior half; compound eyes as large dorsally as ventrally; ocellar setae about half as long as acute postocular setae; maxillary stylets reaching about halfway to compound eyes. Antennal segments IV–VI with distinct pedicels; segment III with 2 sense cones, IV with 4. Pronotum with anteromarginal, anteroangular, midlateral, and posteroangular setae acute; epimeral setae slightly longer, stouter, and bluntly acute; basantra present. Mesopresternum transverse, sometimes eroded. Metanotum with a few longitudinal lines of sculpture; median setae acute. Metathoracic sternopleural sutures short. Fore wings with 0–11 (usually about 9) duplicated cilia; major sub-basal setae acute, subequal. Pelta with small lateral lobes; tergites II–VII each with one pair of sigmoid wing-retaining setae; tergite IX posteromarginal setae S1 bluntly acute, more than half as long as tube. Microptera with mesonotum and metanotum more transverse; wing lobe bearing 1 or 2 acute setae; tergites II–VII each with 1 pair of short, curved wing retaining setae.
Male micropterous. Similar to female, but pronotum more elongate, with anteromarginal and anteroangular setae shorter; fore tarsal tooth present; wing lobe usually bearing only 1 seta; pelta more transverse; tergites II–VII with posteromarginal S2 setae long, acute; large males with fore tarsi, fore tibiae, and apex of fore femora yellow; foretarsal tooth larger, fore femora swollen, pronotal setae longer, and median longitudinal apodeme longer.

Related species

The genus Nesothrips includes 31 species, of which 6 are endemic to New Zealand, 13 are from Australia, 9 described from various Pacific islands, and 3 from southeast Asia. Nesothrips species usually have a rather short head, with a pair of setae between the hind ocelli, and the maxillary stylets wide apart. N. alexandrae is similar to N. propinquus, but has the eyes equal in size dorsally and ventrally. It is remarkably constant in colour and structure, both within and between populations, despite varying in size and morph.

Biological data

Feeding on fungal spores, on dead branches, particularly of introduced trees (apricot, peach, pear, willow, and pine).

Distribution data

Known only from New Zealand (NC, MK, CO). Found quite commonly in Central Otago between Alexandra and Lindis Pass.

Family name

PHLAEOTHRIPIDAE, IDOLOTHRIPINAE

Species name

Nesothrips alexandrae Mound & Walker

Original name and synonyms

Nesothrips alexandrae Mound & Walker, 1986: 29

References

Mound LA & Walker AK (1986) Tubulifera (Insecta: Thysanoptera). Fauna of New Zealand 10: 1–140.