Mystrothrips reteanum Shin & Woo

(Figs 19–21)

Mystrothrips reteanum Shin & Woo, 1999: 111

Mystrothrips flavidus Okajima, 2006: 485 . Syn.n. This species was described from 20 females and 6 males, all micropterae but lacking ocelli, collected from leaf litter in Sangju, Kyungbuk, South Korea. The holotype and four other females from the original series have been examined in Canberra and compared with two paratypes of flavidus . The latter species was described from almost 200 females and 100 males, all micropterae and similarly lacking ocelli, that were collected on the Ogasawara group of islands (Bonin Islands) in the Pacific Ocean, 1000km south of Tokyo. The original description of flavidus refers to “three previously known species” of Mystrothrips, although by the year of that description, 2006, there were actually four described species. This wording suggests that the author of flavidus was not aware of the 1999 description of reteanum from Korea. The type specimens of reteanum are not as cleanly prepared as the paratypes of flavidus and the specimens from Australia listed below, but no significant differences have been observed between them.

Prosternal basantra are present but weak in all the available specimens listed below, as indicated in the original description of flavidus, and the mesopresternum is represented by two lateral triangles. Neither of these character states occurs in the two new species from Australia discussed here. Moreover, the ferna of reteanum are bluntly triangular toward the mid-line (Fig. 19), in contrast to dammermanni and the two new species described here. Also, in contrast to dammermanni, the pelta of reteanum does not differ greatly in form between macropterae and micropterae (Figs 20, 21). However, the micropterae of reteanum differ from macropterae in having tergal setae S1 elongate (Figs 20, 21), and the micropterae lack ocelli (except for a single microptera from Tidbinbilla).

The distribution of this species as recorded here is remarkable. Described originally in Korea from well North of the Tropic of Cancer, and then from islands just north of that Tropic, it has also been found widely just south of Cancer in sub-tropical southern China, Guangdong Province (Wang et al. 2008). Moreover, a specimen is listed below that was taken on Fiji, a tropical island in the Pacific Ocean. More surprisingly, breeding populations have been found far south of the Tropic of Capricorn in southern Australia, around Canberra, in an area that experiences light snow falls in winter. Although collected in Canberra by extracting arthropods from leaf-litter using Berlese funnels, it is possible that the species was actually feeding on fungi living at the base of grasses.

Specimens examined (micropterae except where stated). Korea, Kyungbuk, Sangju, 5 females (including holotype), 8.vi.1998 . Japan, Ogasawara Islands, Haha-jima Is., Nakanotaira, 1 female, 1 male from grass (paratypes), 7.iii.1988 , in coll. Masumoto, Japan. Fiji, Viti Levu, near Sigatoka, 1 female from dead grass, 15.iv.1982 . Australia, Australian Capital Territory: Canberra, National Botanic Gardens, in leaf litter, 1 female, 16.x.2011, 1 male, 19.v.2016; Tidbinbilla, 6 females, 4 males, 1 female macroptera in Leptospermum leaf litter, 26.iii.2017 , 3 females, 6 males in Eucalyptus leaf litter, 24.iv.2017; in ANIC.