Genus Pseudagrion

NEW RECORD in Borneo
This Pseudagrion sp HILLZONE is a new record for Borneo in 2017 and need scientists further verification. No scientific name yet.

Pseudagrion sp HILLZONE 婆羅洲細蟌 new record in Borneo	Pseudagrion microcephalum 瘦面細蟌	Pseudagrion pilidorsum 弓背細蟌 new record in Borneo
♂47mm 2017-06-26 HILLZONE	2007-02-09 MEROTAI	2007-06-10 BUKIT GEMOK
♂45mm 44mm♀	♂34mm 34mm♀	♂39mm 39mm♀
Pseudagrion sp HILLZONE Male anal appendages	Pseudagrion microcephalum Male anal appendages	Pseudagrion pilidorsum Male anal appendages
Male secondary genitalia on segments 2–3	Male secondary genitalia on segments 2–3	Male secondary genitalia on segments 2–3

Known commonly in North Asia. Pseudagrion pilidorsum is very little know in Borneo Island. So far found only in eastern part of Sabah such as Lahad Datu and Tawau.

Pseudagrion microcephalum is a very common and widespread inhabitant of ponds, lakes and drains. The male is black, strongly marked with bright blue bands. At first it can be confused with many other common coenagrionids, including Archibasis species and Argiocnemis rubescens, all of which fall into the same size range (S hw, 16-24 mm) and have a similar pattern of blue on black. However with experience you will soon find it easy to separate from other genera, especially in life, by its general look or 'jazz'. It is more difficult to separate from other blue Pseudagrion species, but P. microcephalum is by far the commonest and most widespread member of its genus and the only one known from disturbed habitats. The female is light brown with obscure greenish markings. Mating takes place in the mid afternoon and after insemination the pair may remain in tandem for well over an hour, skimming the water surface and resting frequently on lily pads. Females often submerge completely to lay their eggs in the stems of water plants.

Pseudagrion lalakense is similar in its habits but it is known from only a few blackwater lagoons in Brunei and northern Sarawak. It flies together with P. microcephalum and can be recognized in life by the greater area of blue on the thorax and at the base of the abdomen. Identifying dead specimens is generally far more difficult and only a close examination of pattern and terminalia will separate the males, although the females are quite distinct.

Pseudagrion coomansi is also generally similar to these two species but is more lightly built. It is restricted to shady areas in peat swamp forest in south-west Borneo.

Pseudagrion perfuscatum is a distinctive larger species (S hw, 19 mm) found universally in semi-disturbed shaded streams in the lowlands. It is quite different from other members of the genus, being marked in orange-brown, partially obscured by pruinescence in mature specimens. It generally flies in sunny patches but can be overlooked on account of its somber colors.