A fourth contribution to the knowledge of the Hymenoptera of Sarawak
P. Cameron published this taxonomic contribution in 1906 in the Journal of the Straits Branch of the Royal Asiatic Society (Vol. 46, pp. 103–123), describing eighteen new species of Hymenoptera and recording three previously known species from Sarawak, Borneo. Working from material supplied by John Hewitt, curator of the Sarawak Museum, Cameron extended his ongoing series of faunal contributions to the region, covering families from Evaniiidae through Vespidae. The paper is a straightforward species-description exercise typical of early twentieth-century systematic entomology, with each entry providing colouration, morphological diagnostics, measurements, locality, and a brief discussion of affinity to known congeners.
Summary
The article treats twenty-one species across eight families of Hymenoptera, the bulk of which are new to science. Cameron’s heaviest concentration falls on the Braconidae, where he describes six new species of Iphiaulax (tribe Bracoinae) alongside one Spinaria (Exothecinae), one Neotrimerus (Doryctinae), and two Agathinae (Disophrys and Cremnops). The Ichneumonidae yield three new species (Epirhyssa tuberculata, Xanthopimpla lissonota, Xanthopimpla bimaculata, and Polyaenus spiniferus), while the remaining families contribute one each: an Evaniiid (Pristaulacus fasciatipennis), a Sphegid (Sphex (Isodontia) Hewitti), a Pompilid (Salius Ridleyi), and a Vespine (Ischnogaster clypealis). Three previously described species—Habroba petiolata, Vespa annulata, and Vespa bellicosa—are recorded from Sarawak localities, with Cameron offering taxonomic commentary on the status of annulata relative to bellicosa in light of du Buysson’s 1904 monograph.
The localities are overwhelmingly Kuching, with a handful of specimens from Sadong, Matang, Bidi, Santabong, and Pulo Burong. Collection months span the full year (August through March), suggesting year-round sampling by Hewitt and his collectors. Cameron’s diagnostic approach relies heavily on wing venation (particularly the position of the transverse median nervure, the shape of the areola and areolet, and the form of the recurrent nervure), abdominal sculpture (striation, reticulation, keels, and tubercles), and colouration patterns. He provides dichotomous keys or explicit separation notes where new species resemble previously described congeners, as with the Iphiaulax group, the Spinaria complex, and the three Ischnogaster species.
A notable taxonomic act in the paper is Cameron’s formal separation of Epirhyssa from Rhyssa on the basis of the presence or absence of an areolet in the fore wing and the relative length of the first abdominal segment, a distinction he presents as a diagnostic couplet. He also discusses the generic placement of Polyaenus spiniferus, noting its close resemblance to neotropical species while identifying subtle differences in temple shape, scutellar profile, and petiolar proportions.
Key Findings
- Eighteen new species are described: 1 Evaniiid, 7 Braconiids (6 Iphiaulax, 1 Spinaria), 1 Spthiine (record only), 1 Doryctine, 2 Agathines, 4 Ichneumones (1 Epirhyssa, 2 Xanthopimpla, 1 Polyaenus), 1 Sphegid, 1 Pompilid, 1 Vespine (pp. 103–123).
- Epirhyssa tuberculata is the largest species treated, at 28 mm body length, collected at Kuching; Cameron uses it to formally separate Epirhyssa from Rhyssa via the areolet and first-segment length (p. 114–115).
- Sphex (Isodontia) Hewitti is also 28 mm, collected at Kuching in March; its wing neuration is compared to S. umbrosus Kohl (1881) and its abdominal colouration to S. confrater Kohl from New Britain (p. 119–120).
- Salius Ridleyi (Pompilidae) is 21 mm, collected at Matang; the testaceous colouration of the middle hind tarsal joints is noted as possibly a discolouration artifact, with one leg showing clear yellow on the second joint (p. 121).
- Iphiaulax sadongensis is the largest Iphiaulax at 13 mm (terebra 5 mm), collected at Sadong in August; it is separated from I. xanthopsis Cameron (Ceylon) by the extent of the frontal furrow and the orbital mark (pp. 105–106).
- Vespa annulata Smith is recorded from Santabong Matang (December) and Kuching (January); Cameron questions du Buysson’s (1904) synonymy with V. bellicosa, suggesting the male may prove it a distinct species, while V. bellicosa itself is recorded from Pulo Burong (p. 122).
Conclusion
Cameron’s paper is a routine but substantial increment to the known Hymenoptera fauna of Sarawak, adding eighteen new species to the regional list and confirming the presence of several previously known taxa. Its lasting value lies in the detailed morphological descriptions and the diagnostic couplets that remain the primary reference for several of these species, particularly the Iphiaulax group and the Ischnogaster complex, where Cameron’s separation criteria continue to be cited in subsequent revisions.
Context
- Cameron was a metropolitan taxonomist (British Museum, London) describing material collected in the Sarawak protectorate; the specimens were supplied by John Hewitt, curator of the Sarawak Museum, reflecting the standard colonial-era pipeline of field collection feeding metropolitan systematics (p. 103).
- The paper draws on contemporary European taxonomic literature for generic frameworks, citing Bradley’s Deraiodontus, Enderlein’s 1905 revision of Spinaria, Krieger’s 1898 groups of Xanthopimpla, and du Buysson’s 1904 Vespa monograph, situating the work firmly within the international systematic entomology of the period.