Scirtothrips mugambii, Mound, Laurence A., 2010

Mound, Laurence A., 2010, A second Scirtothrips species with a hind-femoral comb in males (Thysanoptera, Thripidae), Zootaxa 2643, pp. 66-68 : 66-67

Scirtothrips mugambii sp. n.

Female macroptera. Body mainly brown, abdomen darkest, tergites II–VIII and sternites III–VII with dark brown antecostal ridge; forewings brown; antennal segment I pale, II–VIII dark.

Head about twice as wide as long, postocular and ocellar region closely striate ( Fig. 3 ); ocellar setae pair III arise within ocellar triangle on or close to tangent between anterior margins of posterior ocelli, distance between their bases about equal to their length; compound eyes with no ommatidia strongly pigmented; two pairs of post-ocular setae longer than ocellar setae pair III. Antennae 8-segmented, with many microtrichia ( Fig. 2 ).

Pronotum closely striate ( Fig. 3 ), with 4 pairs of posteromarginal setae, pair S2 scarcely longer than S3. Metanotum reticulate, anterior reticles transverse ( Fig. 4 ); median pair of setae close to anterior margin. Forewing clavus with 4 marginal setae and one discal seta ( Fig. 4 ); second vein with 3 setae, first vein with 3 setae on distal half; posteromarginal fringe cilia wavy.

Tergites II–V with median setae small and close together; tergal microtrichial fields with 2–3 discal setae; VIII usually with one row of discal microtrichia anteromedially, posteromarginal comb complete ( Fig. 1 ); tergite IX with no discal microtrichia, X with band of microtrichia near posterior margin. Sternites with microtrichia extending mesad almost to level of setae S1; marginal setae arising at margin.

Measurements of holotype female in microns. Body length 930. Head, length 60; width 135. pronotum, length 85; width 160; posteromarginal setae 18, 35, 25, 8. Forewing length 630. Antennal segments III–VIII length 45, 42, 40, 40, 7, 15.

Male macroptera. Similar to female in sculpture, but smaller and paler; hind femur with row of 5–7 stout dark setae on distal posterior margin ( Fig. 5 ); tergite IX with pair of upwardly curving dark drepanae.

Specimens studied. Holotype female, KENYA, Meru, Maua, from Cedrus , 17.v.2009 (J. Mugambi ), in the Natural History Museum, London.

Paratypes, 2 males, 10 females, in the National Museum of Kenya, Nairobi, the Natural History Museum, London, and the Australian National Insect Collection, Canberra.

Comments. The only available keys to the species of Scirtothrips from Africa ( Faure, 1925; Bailey, 1964) are based largely on colour and silhouette characters such as setal lengths. Subsequent studies have emphasised the importance of surface structure in the recognition of species in this genus ( Mound, 1968; Mound & Palmer, 1981; Hoddle & Mound, 2003). Despite the lack of detailed information in the descriptions of the African species it is clear that this new species can be distinguished from the previously named species; from spinosus Faure by the shorter pronotal setae; from zuluensis Faure by the few setae on the forewing second vein; from fulleri Faure by the fewer setae on the tergal microtrichial fields; from combreti Faure by the uniformly coloured forewings; from africanus Faure and aurantii Faure by the dark tergites; and from kenyensis Mound by the forewing wavy marginal cilia and the shorter pronotal setae. Only two species, aurantii and mugambii , are known to have the remarkable comb of stout setae on the hind femora of males, but in aurantii the microtrichia extend fully across the sternites and this suggests that these two are not closely related. The reticulate sculpture on the metanotum and the lack of microtrichia medially on the sternites might indicate that mugambii is more closely related to kenyensis but, judging from available fragmentary material, the African fauna of Scirtothrips is probably more extensive than the described species indicate.

Figures

FIGURES 1 – 5. Scirtothrips mugambi sp. n. (1) Tergites VI – X. (2) Antenna. (3) Head and pronotum. (4) Mesonotum and metanotum. (5) Male hind femora.