[Figs 18, 49, 62]
Labiothrips tenor Bhatti & Mound, 1994: 163.
This species was described from specimens collected in a water trap at Port Moresby, Papua New Guinea, but has been found commonly in the Northern Territory around Darwin and on Bathurst Island breeding on the young flush leaves of Cycas armstrongi [Cycadaceae] as well as on cultivated specimens of Cycas revoluta at Darwin and at Burpengary in Queensland. Although described as the type species of the monotypic genus Labiothrips, the species fits within the pattern of variation of Australian Scirtothrips discussed here. The mouth cone is unusually elongate, and in life it is directed posteriorly rather than ventrally as in other Scirtothrips species. However, its length is no greater than that of S. drepanofortis described above, nor of S. muscoaffinis Johansen and Mojica described from Mexico, and it is not a great deal longer than found in S. litotes and S. pilbara described above. Presumably associated in some way with the orientation of the mouth cone, the vertex of the females of S. tenor is exceptionally short, with the posterior margin of the head almost confluent with the posterior margin of the eyes. However, in males the length of the vertex is at least equal to the width of one ommatidium. The pronotum has four pairs of posteromarginal setae, none longer than 15 microns, but several of the new species described here have similar short setae. However, the striae on the head and pronotum are weaker than on typical Scirtothrips species, and the postocular region of the head in females is exceptionally short. As in S. moneres, the microtrichia are reduced on the anterior lines of sculpture on each tergite, and the sternal microtrichial fields are much reduced scarcely extending mesad of setae S 3. The number of sternal posteromarginal setae is not constant, several specimens having been examined with four instead of three setae on more than one sternite. The males have a pair of curved drepanae on the ninth tergite, but the aedeagus does not have an array of spines. The second instar larvae have broadly capitate setae on the pronotum (Fig. 62).