Taxonomic study of Bornean species of Utivarachna Kishida, 1940 (Araneae: Trachelidae), with the description of a new species.

The genus Utivarachna Kishida, 1940 currently comprises 23 species, with eight described from Borneo. We examined the type materials of the Bornean species, except for U. fukasawana Kishida, 1940, as well as newly collected specimens.

Sibling Cannibalism in Group-Living Larvae of the Solitary Wasp, Isodontia harmandi (Hymenoptera: Sphecidae): Effects of Prey Availability and Size Discrepancy.

Sibling cannibalism has rarely been documented in the resource-based context of sibling rivalry. The solitary wasp Isodontia harmandi (Pérez) (Hymenoptera: Sphecidae) has an exceptional style of nursery 'communal brood cells', in which multiple larvae gregariously develop while relying on maternal prey provisioning. In this species there are several distinct features; e.

Brood reduction caused by sibling cannibalism in Isodontia harmandi (Hymenoptera: Sphecidae), a solitary wasp species building communal brood cells.

Sibling rivalry or brood reduction prevailing within bird nests is effectively avoided in solitary aculeate nests because the larvae of wasps and bees usually develop in each brood cell. However, a solitary wasp species, Isodontia harmandi, allows us to study brood reduction in a communal brood cell, where up to a dozen larvae develop in a group relying on prey provisioned by a female wasp. To demonstrate brood reduction in this species, we collected nests at various developmental brood stages from fields for five years (2010-2015).

Life history and nesting ecology of a Japanese tube-nesting spider wasp Dipogon sperconsus (Hymenoptera: Pompilidae).

To clarify the life history of the Japanese spider wasp Dipogon sperconsus, bionomical studies using bamboo-cane trap nests were carried out in Japan. Based on weekly and consecutive daily surveys of trap nests and rearing of broods from collected nests, we evaluated the production of cells and eggs per day, prey spiders, and seasonal patterns of nesting activities. We found a relatively short critical period of switching from the summer generation into the overwintering generation.

Constraints on the jumping and prey-capture abilities of ant-mimicking spiders (Salticidae, Salticinae, Myrmarachne).

Accurate morphological ant mimicry by Myrmarachne jumping spiders confers strong protective benefits against predators. However, it has been hypothesized that the slender and constricted ant-like appearance imposes costs on the hunting ability because their jumping power to capture prey is obtained from hydraulic pressure in their bodies. This hypothesis remains to be sufficiently investigated.

New species of the ant-mimicking genus Myrmarachne MacLeay, 1839 (Araneae: Salticidae) from Sarawak, Borneo.

The genus Myrmarachne MacLeay, 1839 (Araneae: Salticidae) is one of the most diversified salticid groups in Southeast Asia, with 23 species previously recorded from Borneo. Based on the collections accumulated from 2004 to 2014 in the Lambir Hills National Park, we herein describe six new species: M. amabilis sp.

Revision of the subgenus Stigmatodipogon Ishikawa of the genus Dipogon Fox (Hymenoptera: Pompilidae: Pepsinae).

The systematics of the subgenus Stigmatodipogon Ishikawa of the genus Dipogon Fox is revised. Six species are listed. Two new species, Dipogon (Stigmatodipogon) kurokawai Shimizu, sp.

A new species of the genus Castoponera (Araneae, Corinnidae) from Sarawak, Borneo, with comparison to a related species.

A new species of the genus Castoponera Deeleman-Reinhold, 2001, Castoponera christae sp. n., is described here.