摘要
拱颏瓢虫属Stethorus Weise为小型瓢虫。目前该属已有记录最小的种为Stethoruskeralicus Kapur(Kapur 1961),体长仅0.85毫米,最大的种为Stethorus cruralis Sicard,体长亦仅达1.75毫米。主要以叶螨为食,是叶螨Tetranychus,Paratetranychus等的重要天敌。该属昆虫分布甚广,遍及古北区、东洋区、澳洲区、新北区,Kapur(1948)
In the present paper, three new species of Stethorus Weise (Coccinellidae) fromCanton are described: Stethorus cantonensis, Stethorus longisiphonulus and Stethorusparapauperculus. Stethorus cantonensis, sp. nov. Length: 1.37-1.46 mm; width: 1.0-1.02 mm. Shortly oval, widest in the middle, convex. Head black except clypeus, antennaeand mouth-parts; pronotum, scutellum, elytra and the underside black; tarsi, tibiae, apicalpart of femora yellowish, basal portion of the femera castaneous and trochanter testace-ous. Dorsal surface with greyish, long (about 0.08 mm), sparse, semi-erect pubescence.Head finely and sparsely punctate, antennae rather short, eleven-segmented, with the ter-minal four wider, together forming the club (Fig. Ⅲ-6). Pronotum and elytra with punc-tures moderately coarse. Underside with greyish, moderately long pubescence. Femorallines (Fig. Ⅲ-1) wide, evenly arched, and extending to just about the middle of the seg-ment and ending near the anterior angle. The sixth abdominal sternite in the male(Fig. Ⅲ-5) with a wide and distinct emargination at the apex. Male genitalia: Sclerotised parts of male genitalia similar to those of the type re-presented by Stethorus punctillum Weise. Sipho long, thin, narrow, with a distinct, stronglysclerotised siphonal capsule, the latter with the inner branch elongate; penis tubular, long,narrow and tapering towards the apex and bent towards the paramera in the apical two-thirds; paramera narrow and nearly two-thirds the length of penis, each bearing a seta atthe apex and a short seta at the side near the apex. Holotype ? Canton (1964, Ⅲ); Allotype ? Canton (1964, Ⅲ); Paratype 2 ? ? Canton (1964, Ⅲ), 5 ? ? Canton (1964, Ⅲ, Ⅳ.) Stethorus longisiphonulus, sp. nov. Length: 0.95-1.1 mm; width: 0.7-0.8 mm. Shortly oval, widest in the middle, convex. Black, excepting the tactaceous clypeus;antennae and mouth-parts and tarsi, tibiae, apical part of femora, basal part of the femoracastaneous and the trochanter testaceous. Dorsal surface with greyish, long (about0.07 mm) pubescence. Head finely and sparsely punctate, pronotum with almost uni-formly fine punctures, elytral punctures slightly coarser. Underside with shorter pubes-cence and coarse punctures on poststernum. Femoral lines (Fig. Ⅳ-1) simicircular, andextending beyond the middle to nearly two-thirds the length of the segment. Last abdo- minal sternite in the male (Fig. Ⅳ-5) devoid of any emargination. Male genitalia: Sclerotised parts of male genitalia similar to those of the type re-presented by Stethorus punctillum Weise. Sipho very long, narrow, tapering towards theapex, siphonal capsule with the inner branch elongate; penis thick, narrow and taperingtowards the apex and bent towards the paramera in the apical one-third; paramera slightlynarrow, and nearly three-fifths the length of penis, with five short setae at the apicalone-third and a long stout seta at the extreme apex, with apical branches. Holotype ? Hainan (Haikow 1964, Ⅴ); Allotype ? Hainan (Haikow 1964, Ⅴ); Paratypes 2 ? ? Hainan (Haikow 1964, Ⅴ), Canton (1964, Ⅲ), 3 ? ? Hainan(Haikow, Haga 1964, Ⅴ). Stethorus parapauperculus, sp. nov. Length: 0.98-1.2; width 0.7-0.9 mm. Shortly oval, widest in the middle, convex. Black, except the testaceous clypeus,antennae, mouth-parts, tarsi, tibiae, femora and trochanter. Dorsal surface with greyishpubescence. Head finely and sparsely punctate, pronotum with almost uniformly finepunctures, elytra punctures slightly coarser, poststernum with almost slightly coarser punc-tures. Femoral lines wide and extending beyond the middle to nearly two-thirds of thelength of the segment (Fig. Ⅴ-5), devoid of distinct emargination. Male genitalis: Sclerotised parts of male genitalia similar to those of the type re-presented by Stethorus pauperculus Weise. Sipho short, stout, moderately curved near thebase and recurved in the apical one-sixth; siphonal capsule with inner and outer branches.Trabes dark, longer than twice the length of penis. Penis elongate, sub-triangular, nar-rowed towards the apex. Paramera short, nearl
