Revision of Stauronematus BENSON , 1953 and additions to the sawfly fauna of Corsica and Sardinia ( Hymenoptera , Tenthredinidae ) With 17 figures

Cladius pallipes SERVILLE, 1823 is a new synonym of Tenthredo compressicornis FABRICIUS, 1804. The valid name of the species formerly known as Stauronematus compressicornis (F.) is Stauronematus platycerus (HARTIG, 1840) comb. nov. Valid name of Cladius (Priophorus) pallipes SERVILLE is Cladius (Priophorus) compressicornis (F.) comb. nov. Type species of Stauronema BENSON, 1948 (preoccupied) and its replacement name Stauronematus BENSON, 1953 is here fixed as Nematus platycerus HARTIG, 1840. Stauronematus saliciphilus sp. n. is described from Corsica and Sardinia. Hostplant is Salix atrocinerea. Stauronematus saliciphilus is compared with its only other known congener S. platycerus, larval hosts Populus spp. Lectotypes are designated for Tenthredo compressicornis, Nematus platycerus and Nematus callicerus THOMSON, 1863. Previous statements that Stauronematus BENSON, 1953 has a Holarctic distribution are mistaken. At present, definite records are only from the Palaearctic. Three species of Tenthredinidae are recorded for the first time in Corsica and six in Sardinia. The important role of Salix species for the diversity of the sawfly fauna of Corsica and Sardinia is highlighted.


Description
Mouth-parts normal; maxillary palp longer than cardo with stipes, and articles 3 and 5 the longest.Labial palps about twice as long as ligula.Clypeus subtruncate in front, very narrow.Malar space only about half as long as distance between antennal sockets.Inter-antennal crest very prominent, medially carinate.Antenna in female subcylindrical and about as long as costa and stigma of forewing; in male laterally compressed (so that third segment is scarcely four times longer than broad) with each segment produced at the apex beneath, as long as body with head.Wing venation as in Pristiphora LATREILLE, 1810: costa strongly swollen at the apex so that at the point of origin of cubital vein from subcosta the intercostal area is only about as wide as medial width of costa, radial cell without cross-vein, intercostal vein received on the subcosta before the origin of cubital, and anal cell without basal loop.Claws with swollen basal lobe and an inner tooth, well separated from end tooth and longer than it.Sawsheath rounded behind in dorsal aspect, (Fig. 1), basally constricted; male with procidentia of eighth tergite not extending beyond slightly excised apex of segment, reaching maximally one half of the length of the tergite, triangular in form, medially elevated but not clearly carinate, delimited by two obtusely angled furrows converging forwards.Penisvalve (Fig. 2): valvispina long and straight, arising from dorsal margin of paravalva.

Diagnosis
Adult morphology resembles Pristiphora LATREILLE, 1810.Stauronematus can be recognised by Stauronematus can be recognised by Stauronematus the combination of long inner tooth and presence of a basal lobe on the tarsal claws, and the form of the sawsheath: in dorsal view basally constricted, apically tapering, subtriangular.Claws of Pristiphora simple or with a small basal tooth, rarely bifid and never with a basal lobe.In most Pristiphora simple or with a small basal tooth, rarely bifid and never with a basal lobe.In most Pristiphora Pristiphora species sawsheath is apically subtruncate or excised on either side of the middle, often Pristiphora species sawsheath is apically subtruncate or excised on either side of the middle, often Pristiphora with a pronounced scopa, and not basally constricted.1819) gives the body length of a male specimen under this name in the FABRICIUS Collection as "2 Linien", which equates to approximately 4 mm.However, some larger males of H. minuta in the DEI collection are 5 mm long.Typical H. minuta in the DEI collection are 5 mm long.Typical H. minuta male specimens of Cladius compressicornis are not less than 5 mm long, but the original length Cladius compressicornis are not less than 5 mm long, but the original length Cladius compressicornis of the lectotype is not clear, because the abdomen is missing.In all other respects, the lectotype agrees with FABRICIUS's description.Although the sex of the specimen(s) which he described as T. compressicornis is not explicitly mentioned, the very long, compressed antennae are found in T. compressicornis is not explicitly mentioned, the very long, compressed antennae are found in T. compressicornis European Nematinae only in the males of a few species.Those of females of the same species are shorter and subcylindrical.The description does almost also fit the male of Stauronematus platycerus ( cerus ( cerus HARTIG, 1840), except that the tegulae are invariably conspicuously pale in the latter, a character which FABRICIUS would surely not have overlooked.Note that DUSMET (1949: 457) used the name compressicornis FABRICIUS in combination with Cladius while referring to a male specimen.He gives no explanation for this usage.It seems unlikely that he examined FABRICIUS's material.Possibly he was led to place S. platycerus in S. platycerus in S. platycerus Cladius because of the form of its antennae, but in the same paper (p.459) he refers separately to Lygaeonematus compressicornis (F.), so that the first name combination might also be considered the result of a mistake.

Species identification of Stauronematus
A.
Pronotum completely black, or only extreme upper and rear edges brown (Figs 6, 7).Female head in dorsal view subparallel behind eyes, male only slightly contracted (Figs 6, 7).Abdomen entirely black.Mesepisternum more densely pubescent above than below but usually without entirely glabrous area on lower half (Fig. 3).Rear coxa with at least basal half black.Wing membrane hyaline.Lancet with 19 annulets (Fig. 8).Penisvalve with ventral margin of paravalva not emarginate (Fig. 2).Body length 5.0-6.5 mm.Nematus callicerus in the Nematus callicerus THOMSON collection were examined.Only the second specimen in the series can be regarded as a syntype.The small green label indicates that this was collected at the type locality Ringsjön (R. DANIELSSON, pers. comm.).A second male specimen with a similar green label can not be regarded as a syntype, because THOMSON only described the female sex.Nematus cebrionicornis COSTA was not available for examination.CAMERON's synonymy of this taxon with Nematus compressicornis seems justified.The description of the thorax as completely Nematus compressicornis seems justified.The description of the thorax as completely Nematus compressicornis black except for the pale tegulae corresponds with S. platycerus, but not with S. saliciphilus sp.n.GHIGI (1905) in a revision of material including COSTA (1905) in a revision of material including COSTA (1905) in a revision of material including 's types held by the Naples Museum, did COSTA's types held by the Naples Museum, did COSTA not mention cebrionicornis by name, but lists a male or males which he identified as cebrionicornis by name, but lists a male or males which he identified as cebrionicornis Lygaeonematus compressicornis (F.) from Camaldoli (the type locality for compressicornis (F.) from Camaldoli (the type locality for compressicornis N. cebrionicornis as given by N. cebrionicornis as given by N. cebrionicornis COSTA).

Diagnostic combination (see also key, above):
Most valuable single external character for separating S. platycerus from S. platycerus from S. platycerus S. saliciphilus, in both sexes, is the colour of the pronotum.This is black in platycerus, at most edged with a dull brown tint, and clear white or yellow in saliciphilus.Shape of the head behind the eyes, although slightly variable in both species, is much more sharply contracted in the female of saliciphilus.This difference is not so pronounced in the males.The entirely glabrous patch on the lower part of the mesepisternum typical of saliciphilus is not completely constant: one female from Sardinia has no such patch.Conversely, S. platycerus normally has the mesepisternum entirely pubescent although two female specimens of a total of 47 examined possess a non-pubescent area.The slightly darker wing membrane of saliciphilus appears to be a constant character, but is difficult to appreciate unless specimens can be compared directly.The gross morphology of the lamnium of the female lancet appears to be constant in both species (3 specimens of saliciphilus and 9 saliciphilus and 9 saliciphilus platycerus examined).platycerus examined).platycerus Stauronematus saliciphilus has 16 serrulae, S. platycerus 19.The reduced number in S. saliciphilus is compensated by an increase in their size, so that the length of the spaces between the serrulae relative to the length of a serrula is similar in both species.The penisvalve of S. saliciphilus is very similar to that of S. saliciphilus is very similar to that of S. saliciphilus S. platycerus.Further males of saliciphilus will have to be obtained in order to reveal whether the apparent difference in the outline of the ventral edge of the paravalva is a useful character for distinction of the species.

Variability:
In all German specimens examined, the pronotum is completely black.BENSON (1958) and ZHELOCHOVTSEV (1988) state that the corners of pronotum are yellow.ZHELOCHOVTSEV (1988) state that the corners of pronotum are yellow.ZHELOCHOVTSEV MUCHE (1974) noted this discrepancy, stating that in the material which he had seen, the pronotum is all black.According to CAMERON (1885: 48, key) the pronotum is entirely black.About half of the specimens examined from Sweden and the Netherlands have brown upper and rear edges of the pronotum, in the others the pronotum is completely black.V. VIKBERG (pers.comm.)noticed a similar testaceous colouration in all of ten specimens reared in Helsinki from Populus tremula and one captured male Populus tremula and one captured male Populus tremula and female from Slovakia.The mesepisternum is usually slightly pubescent on lower half, rarely with glabrous patch.Rear femur usually entirely pale, occasionally with a dorso-apical black spot.The labrum may be black or brownish.
Distribution: Apparently widespread in the Palaearctic ( Apparently widespread in the Palaearctic ( A TAEGER et al. 2006;TAEGER et al. 2006;TAEGER VERZHUTSKII 1981;XIAO et al. 1992).Material from the following countries has been examined: Norway, Sweden, the Netherlands, Germany, France, Turkey and China.
Diagnostic combination: see key and under S. platycerus (above).

Variability:
One of the Corsican females has the abdominal terga posterior to tergum 2 dark brown, but the Corsican specimens all have a very much darker abdomen than the two females from Sardinia.
All the pale body parts in the Sardinian specimens are a more reddish-yellow (orange) than the pale yellow of those from Corsica.Although the glabrous patch on the lower half of the mesepisternum seems to be a useful character for distinguishing the two species, one of the Sardinian S. saliciphilus lacks this, as in most specimens of S. saliciphilus lacks this, as in most specimens of S. saliciphilus S. platycerus.The colouration of the Sardinian specimens of S. saliciphilus is so strikingly different from those from Corsica, that it seems pos-S.saliciphilus is so strikingly different from those from Corsica, that it seems pos-S.saliciphilus sible that they might represent a distinct geographical race, but they are considered to be conspecific, because their morphology is very similar.More material and biological information for the Sardinian population should be sought.imagines (Corsican syntypes) shortly after collection of the larvae, indicates that S. saliciphilus, like S. platycerus, has more than one generation per year.
Distribution: Corsica and Sardinia.BENSON (1962), in a review of Holarctic Symphyta, makes no mention of Stauronematus, so at present it seems best to regard his earlier mention of a Holarctic distribution as mistaken.

Records of other species from Corsica and Sardinia
Hymenoptera Symphyta are generally rather poorly represented on the islands of the Mediterranean, but the numbers of species known from the West Mediterranean islands of Sicily (ca.100), Sardinia (74), and Corsica (77) greatly exceed those from Crete (28) and Cyprus (34) in the East Mediterranean (TAEGER et al. 2006).The reasons for this are certainly complex, but TAEGER et al. 2006).The reasons for this are certainly complex, but TAEGER one of the factors contributing to the difference is likely to be the absence of Salix purpurea and Salix purpurea and Salix purpurea S. atrocinerea on Crete and Cyprus.These two willow species contribute significantly to the compar-atrocinerea on Crete and Cyprus.These two willow species contribute significantly to the compar-atrocinerea ative richness of the Corsosardinian tenthredinid fauna (LISTON & SPÄ SPÄ SP TH ÄTH Ä 2005, LISTON 2005 and below), supporting seven or eight nematine species which probably do not feed on Salix alba (the Salix alba (the Salix alba only widespread willow species on the East Mediterranean Islands).In total, the combined species list of Symphyta for Corsica and Sardinia includes approximately 120 species.Many of these are recorded from a single or very few specimens.It might therefore be supposed that numerous additional species remain undetected.This is not so in Crete and Cyprus, where relatively many individuals of most species are recorded.Noteworthy in comparison with the fauna of Crete and Cyprus is also the markedly lower proportion of Corsosardinian species with a eumediterranean, or mainly South European distribution.It is not yet possible to state which of the taxa at present known only from Mediterranean islands might represent endemic forms.Particularly with respect to Nematinae, the fauna of mainland Mediterranean countries is still too poorly known.Species are listed below in alphabetical order of the initial letter of the genus name.

Revision of Stauronematus BENSON, 1953 and additions to the sawfly fauna of Corsica and Sardinia (Hymenoptera, Tenthredinidae)
Cladius pallipe(LISTON & SPÄ SPÄ SP TH ÄTH Ä 2005)f Tenthredo compressicornis FABRICIUS, 1804.The valid name of the species formerly known as Stauronematus compressicornis (F.) is Stauronematus compressicornis (F.) is Stauronematus compressicornis Stauronematus platycerus (HARTIG, 1840) comb.nov.Valid name of Cladius ( Cladius ( Cladius Priophorus) Priophorus) Priophorus pallipes SERVILLE is Cladius (Priophorus) Priophorus) Priophorus compressicornis (F.) comb.nov.Type species of compressicornis (F.) comb.nov.Type species of compressicornis Stauronema BENSON, 1948 (preoccupied) and its replacement name Stauronematus BENSON, 1953 is here fixed as Nematus platycerus HARTIG, 1840.Stauronematus saliciphilus sp.n. is described from Corsica and Sardinia.Hostplant is saliciphilus sp.n. is described from Corsica and Sardinia.Hostplant is saliciphilus Salix atrocinerea.Stauronematus saliciphilus is compared with its only other known congener iciphilus is compared with its only other known congener iciphilus S. platycerus, larval hosts Populus spp.Stauronematus BENSON, 1953 has a Holarctic distribution are mistaken.At present, definite records are only from the Palaearctic.Three species of Tenthredinidae are recorded for the first time in Corsica and six in Sardinia.The important role of Salix species for the diversity of the sawfly fauna of Salix species for the diversity of the sawfly fauna of Salix Corsica and Sardinia is highlighted.Cladius pallipes SERVILLE, 1823 ist ein neues Synonym von Tenthredo compressicornis FABRICIUS, 1804.Der gültige Name für die Art, die bisher als Stauronematus compressicornis (F.) bekannt war, ist Tenthredo compressicornis FABRICIUS, Nematus platycerus HARTIG und Nematus callicerus THOMSON, 1863 designiert.Entgegen Literaturangaben, ist Stauronematus nicht holarktisch verbreitet.Stauronematus nicht holarktisch verbreitet.Stauronematus Drei Tenthredinidae-Arten werden erstmalig für Korsika nachgewiesen.Sechs sind neu für Sardinien.Die wichtige Rolle, welche Salix-Arten für die Diversität der Blattwespenfauna in Korsika und Sardinien spielen, Salix-Arten für die Diversität der Blattwespenfauna in Korsika und Sardinien spielen, Salix wird unterstrichen.IntroductionFollowing field excursions inCorsica in 2004(LISTON & SPÄ SPÄ SP TH ÄTH Ä 2005), this island was visited once more by Dr. J. SPÄ SPÄ SP TH ÄTH Ä in April 2005 with the specific objective of collecting sawflies.A few species not previously found there were detected.The author collected in Sardinia in April 2006.Although only 15 sawfly species were found, 6 of these are additions to the known fauna of Sardinia.This contribution presents data mainly on species new to the fauna of these islands, including some older material in the collection of the Deutsches Entomologisches Institut, Müncheberg.The genus Stauronematus BENSON, 1953 is revised, in connection with a previously undescribed species found in Corsica and Sardinia, and brief comments on other species of particular interest presented.

The single existing syntype of Tenthredo compressicornis FABRICIUS was examined, with the following result: Cladius
ZIMSEN (1964)hape of the serrulae of the lancet of Stauronematus does not occur in any species of Stauronematus does not occur in any species of Stauronematus Pristiphora.Penisvalve of Stauronematus with valvispina long and straight, arising dorsally of ventral margin of paravalva.In Pristiphora the valvispina short or long, often curved strongly upwards: where long, it arises from the ventral margin of paravalva.Larva of Stauronematus with 3rd abdominal segment bearing setae on an-Stauronematus with 3rd abdominal segment bearing setae on an-Stauronematus nulets l, 2 and 4. Pristiphora has setae only on annulets 2 and 4. Cladius pallipes SERVILLE, 1823: 78, no. 5,  , type locality: France, Paris.Lectotype designated byBLANK & TAEGER (1998: 166)., des.LISTON 2006", ZMUC.Condition: missing are entire abdomen, rear legs apart from coxae, right forewing, antennomere 9 of left antenna.The second label was evidently not written by FABRICIUS (cf.handwriting samples inHORN et al. 1990).It can no longer be ascertained whether FABRICIUS based his description on one or more specimens.ZIMSEN (1964)records the existence of only one syntype specimen, in the Copenhagen collection.
(Figs 11, 12).Male with subgenital plate and harpes brown.Mesepisternum usually with a sharply defined entirely glabrous area on lower half.Rear coxa with only extreme base black.Wing membrane slightly infuscate.Lancet with 16 annulets (Fig.13).Penisvalve with ventral margin of paravalva emarginate(Figs 14, 15).Body length 5.0-5.5 mm.Larval host: Salix atrocinerea.S. purpurea requires confirmation .... Stauronematus saliciphilus KONOWType material examinedNematus platycerus HARTIG.Lectotype (here designated) : [red, printed] "Cotype", "Nematus platycerus HTG, Th.HARTIG det.", "Lygaeonematus compressicornis F.Lygaeonematus compressicornis F. Lygaeonematus compressicornis , E. CLÉMONT det.", "platycerus m.", [printed] " BENSON (1948ost.The first such mention seems to be by Salix as a host.The first such mention seems to be by SalixBENSON (1948), repeated in BENSON (1958).He does not state the source of his information.Many of the subsequent indications of Salix as a hostplant in the European literature, few of which seem to be Salix as a hostplant in the European literature, few of which seem to be Salix based on original data, probably result from BENSON's publications.The only published primary data known to the present author which indicate Salix as the natural host of Populus alba.PSCHORN-WALCHER & ALTENHOFER (2000) record that larvae of Stauronematus platycerus in Central Europe usually feed on Populus tremula, more rarely P. nigra, but were capable of surviving on Salix purpurea in rearing experiments.In the light of the results presented here, the identity of Stauronematus specimens associ-Stauronematus specimens associ-Stauronematus ated in nature with Salix should be checked.Salix should be checked.Holarctic distribution, probably based on BENSON (1958).GOULET (1992) mentions the occurrence of Stauronematus in Canada, but this is definitely based on Stauronematus in Canada, but this is definitely based on Stauronematus BENSON (1958) (H.GOULET, pers.comm.).Neither H. GOULET nor D. R. SMITH (pers.comm.)knows of any definite Nearctic records.