TWO NEW SPECIES OF GENUS SIOBLA CAMERON ( HYMENOPTERA : TENTHREDINIDAE ) FROM INDIA AND A REVISED KEY TO THE INDIAN SPECIES

Genus Siobla was erected by Cameron (1877) t.aking S.mooreana as its type species. Later, in 1934 Malaise added another species i.e. S. turneri to this genus. However, while reviewi~g this genus from South East Asia in 1945, .he, in addition to· lowering species status of S. punctata Cameron 1899 to sub species level i. ·e. S. mooreana punctata Cameron 1899, raised another sub species S. mooreat:'a melaena from Myanmar. Five new species were added to this genus by Saini et al., 1985, thus raising the total to seven. In the present text, two new species are described and S. mooreana punctata malaise has been raised to species level after taking some morphological and external genitalia differences into consideration. ·The types of new species are presently with the authors, but wi)) be submitted to IARI, PUSA, National Collections, New Delhi.

Antenna longer than head and thorax combined; 1 sl and, 2nd antennal segments each longer than broad; 3nJ and 4lh as 4 : 3 ; 4 to 9 slightly decreasing in length; frontal area raised' almost to level of eyes ; s~praantennal tubercles moderately raised and confluent with frontal ridges; median fovea broad and shallow with uneven bottom ; circum, inter and postoce~lar furrows sharp, lateral ones sunken, almost reaching hypothetical hind margin of head; postocellar area as long as broad.Head carinated and converging behind eyes.Scutellum roundly raised with blunt apex.IA TS : MB : OATS = 2.0 : 3.8 : 1..1.
Head on and around frontal area with dense minute but distinct punctures, surface between punctures less than the diameter of each puncture.Hind orbits covered with very fine and scattered punctures, area subshining.Mesonotum with minute, shallow and scattered punctures.Anterior slope of scutellum almost impunctate, smooth and shining, posterior slope with dense and 'deep punctures.Appendage impunctate.Mesepisternum densely rugosely punctured.Mesosternum covered with very fine, ~inute and shallow punctures.Metepisternum finely pun~tured along dorsolateral aspect.Abdomen impunctate shining.Body covered with silvery pubescence.
'33mm Discussion: S. punctata Cameron 1899 was given the status of subspecies by Malaise, 1945 as S. mooreana punctata on basis of some male specimens only.Its female has been recorded for the first time a.nd studies of its female and male external genitalia revel considerable differences from the same of s. mooreana Cameron (1877).So its specie"s status has again bee~ restored.
Antenna slightly longer than head and thorax combined; I sl and 2 nd antennal segments each longer than broad; length of 3nJ an4 4th as 2 : ~.I, 4 to 9 gradually decreasing in length.frontal area slightly above level of eyes; supra antennal tubercles moderately elevated and confluent with low frontal ridges; median fovea broad, distinct with uneven bottom and divided into two parts by weak horizontal ridge; circum, inter and postocellar furrows sharp; lateral furrows distinct and outwardly curved, not reac~ing hypothetical hind margi.n of head; postocellar area convex, broader than long as 2: 1.2.Head carinated and converging behind eyes.Scutellum convex.
Head densely and minutely punctured.Mesonotum .minutely,shallowly and sparsely punctured.Few large punctures on anterior slope of scutellum, its posterior slope and appendage impunctate.Mesepimeron and mesepisternum covered with large, shallow and almost confluent punctures.Propodeum and I sl two tergites punctured on lateral aspects, rest of the abdomen impunctate.Body covered with silvery pubescence.
Male: Average length-9.5mm.Similar to female except following differences: meso and Inetascutellar appendages, 2 nd and 3nJ tergites except a median dirty patch, crescent shaped extreme anterior margin of 4lh tergite, all legs except for coxae, metafemur and apical 1/3nJ of metatib~a, whitish.Head and thorax covered with comparatively minute and dense punctures.Population Variation: In some specimens black colour on abdomen covering more or less.basal tergites.Discussion: S. harpeata sp.nov.runs in Malaise's key of S .E.Asia (1945) upto c.ouplet 13, but does not tally with S. turner; Malaise (1932), keyed out there.This species goes close to S. bengalensis Saini et al., 1985, S. darjeelingia Saini et al., 1985, but can be easily distinguished from them on the basis of puncturation of head and thorax.

Gonoforceps -
Etymology: The species name S. harpeata is based on harpe (Gonoforceps), which has a strikingly different, light yellowish colour as compared to other known species of Siobla,.which have dark brown colour.
Hcad covered with dense, minute, distinct, but shallow punctures.Mesonotum uniformly punctured.Scutellum with scattered and distinct punctures on its anterior slope, whereas its postcrior slope with minute and dense punctures.Appendage almost impunctate.Mesepisternum and Illcsosternunl with .ninuteand shallow punctures.Propodeum with few punctures on its lateral aspects.renlaining tergites almost impunctate shining.Body covered with silvery to golden pubescence.
Paratypes nov.antenna as long as head and thora"x combined (in S. harpeata sp.nov.antenna longer than head and thorax combined).