A Revision of Oriental Species of Psilocera Walker (Hymenoptera: Chalcidoidea: Pteromalidae) with Descriptions of Two New Species from Namdapha National Park, Arunachal Pradesh, India

The Oriental species of Psilocera Walker (Hymenoptera: Chalcidoidea: Pteromalidae) is revised, and two new species, namely, P. namdaphaensis sp.nov. and P. intermedia sp.nov. are described from Arunachal Pradesh, India. The affinities of the new species with the other known species are discussed. Systematic account of the Oriental species of Psilocera and a key to separate them are also provided. 1. Introduction The genus Psilocera Walker belongs to the subfamily Pteromalinae of Pteromalidae (Hymenoptera: Chalcidoidea) and is known for 28 described species throughout the world with seven species known from the Oriental Region [1–3]. Sureshan [2] synonymised the genus Acanthometopon Ashmead under Psilocera, based on the close resemblance of the two genera except for the characteristic humped scutellum with a stout fingernail like tip in the former. He also described two other species, namely, P. scutellata and P. heydoni with a similar scutellum from India. Narendran and Kumar [3] described the species P. neoclavicornis from West Bengal, India with a humped scutellum. There is a gradation observed in the length of the conical hump and the sharpness of the finger nail tip of scutellum in all these species. It may now be assumed that the genus Psilocera contains two species groups, one with a normal scutellum and the other with the scutellum produced in the form of hump with a distinct finger nail-like tip. Boucek [4] had opined that Acanthometopon may constitute a subgenus of Psilocera. During the faunal exploration surveys undertaken in the Namdapha National Park, Arunachal Pradesh (27°23′ to 27°39′？N Latitudes and 96°15′ and 96°58′？E longitudes) one of the important biodiversity areas in India, interesting specimens of the genus Psilocera Walker were collected. The collections were made from an evergreen forest patch by sweeping over the leaf litter on the forest floor with an insect net. On detailed studies, the specimens were proved to belong to two undescribed species which are described hereunder. Affinities of these species with other known species are discussed. Systematic account of the other species of Psilocera known from the Oriental Region and a key to separate them are also provided (see Table 1). The type specimens are deposited in Zoological Survey of India, Western Ghat Regional Centre, Calicut, Kerala, India (ZSIC). Table 1: Key to the Oriental Species of Psilocera Walker (Based on Females, Modified from Sureshan 2000). The morphological terminology used in this paper follows that of Boucek [4] and the following abbreviations are used in