Ceriagrion chaoi A RARE DAMSELFLY REDISCOVERED. by H.S. Yong and Matti Hamalainen

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2 Ceriagrion chaoi A RARE DAMSELFLY REDISCOVERED by H.S. Yong and Matti Hamalainen After almost a century, the rare damselfly Ceriagrion chaoi has been rediscovered in Malaysia. Only once before has this species been collected in Malaysia on i April igoi in Kuala Kangsar, Perak. The pictures of this damselfly accompanying this article are the first to be published since then. DRAGONFLIES and damsclflies (order Odonata) are primitive insects acclaimed as the world's most spectacular. The adult insects, particularly the dragonflies, are capable of powerful flight, while the larvae are aquatic in habit. Both adults and larvae are predators of other insects. Adult dragonflies and damselflies are most easily encountered near water, such as ponds and streams. They are magnificent subjects for behaviour study and photography. Indeed, dragonflyand damselfly-watching easily rivals bird-watching as a rewarding hobby and scientific pursuit. 100 NATURE MALAYSIANA, DECEMBER I 994

3 Some 200 species of odonates are present in Peninsular Malaysia. At present, over 40 species have been recorded in the University of Malaya campus in Kuala Lumpur. The campus offers many suitable biotypes lakes, ponds, ditches, streams, rivers, gardens, farms, forests, swamps and various water-containers to observe dragonflies and damselflies. (A study on the composition of campus fauna is in progress.) On 25 April 1994 the senior author (YHS) was on his regular lunch-time sojourn to the botanical garden at the University's Faculty of Science. He was there to observe tephritid fruit flies, odonates and other insects, when he chanced upon a mating pair of damselfly. Being new to him, the pair was photographed and collected for identification by the second author (MH), who happened to be in Malaysia studying odonates, particularly at Mt. Kinabalu and Danum Valley in Sabah. Above A breeding site for Ceriagrion chaoi at the Faculty of Science, University of Malaya. Opposite A mating pair of Ceriagrion chaoi in tandem, with the female perching on an aquatic plant. These damselflies turned out to be an exciting find, belonging to Ceriagrion chaoi (Schmidt, 1964) a rare Myanmar (Burma)/Thai species last collected in Malaysia 94 years ago! Observations in May-early July 1994 revealed that mating of this rare damselfly took place regularly. Mating pairs were observed on 26 May, 30 May, 2 June, 6 June, 14 June, 21 June, 4 July and 6 July at the Science Faculty garden. As many as three mating pairs have been observed on two occasions. At times, single male and/or female individuals were also observed. Besides the insects spotted at the Science Faculty garden, a single mating pair was also observed on two occasions (15 June and 25 June) at Rimba Ilmu, a botanical park at the University. The breeding sites at the Science Faculty garden were cement tanks with aquatic plants, while the site at Rimba Ilmu was the edge of a pond. Both mating pairs as well as single individuals of both sexes were wary of approaching humans and other odonates. The female laid its eggs on floating or submerged vegetation. This had been observed both in the morning and early afternoon. Ceriagrion chaoi was described in a paper (Schmidt, 1964) reporting on materials collected by the Swedish entomologist Dr Rene Malaise (designer of the 'Malaise trap', widely used by entomologists worldwide to collect flying insects) from Myanmar in The type series came from two localities in the Southern Shan States. In the same paper, another species, Ceriagrion malaisei, was named after him. Ceriagron chaoi was named after Dr Hsiu-fu Chao (b. 1917), the well-known specialist of the gomphid dragonflies of China. The original description of C. chaoi was exceptionally short. Asahina (1967) provided a more comprehensive description, however, a few years later he (Asahina, 1970) placed C. chaoi under synonymy of an earlier named taxon C. auranticum (Fraser, 1924). However, this decision proved to be incorrect and Hamalainen (1987) showed that auranticum and chaoi were both valid species, and that auranticum was the correct name for a species commonly known as C. latericium (Lieftinck, 1951). NATURE MALAYSIANA, DECEMBER 1994 IOI

4 A mating pair of Ceriagrion chaoi, with the female in the act of laving eggs.

5 Besides the type series, only one further Myanmar record of C. chaoi has been published, a male collected in Maymyo. From Thailand, published and unpublished records show nearly 10 sites in the following five provinces: Chiang Rai, Chiang Mai, Chaiyaphum, Kanchanaburi and Krabi. Only one previous record was known from Malaysia a male specimen collected in Kuala Kangsar (Perak) on i April This is the first specimen of C. chaoi ever collected. The number of specimens collected has always been small; less than 20 specimens are known to us until the present discovery. Although the range of C. chaoi spreads from at least 22 N to 3 N, it seems to be a rather rare species. The known Myanmar sites are at an altitude of 900 m and 1500 m, and those in Thailand are between ca m. The University of Malaya campus in Peninsular Malaysia is not very much higher than sea level. In Thailand, the species seems to prefer ponds in forested areas fed with small brooks or runlets. The present discovery of C. chaoi after a lapse of 90 years shows once again how little we know of our natural heritage. There is certainly a dire need for concerted effort to document the biodiversity of Malaysia. In the case of C. chaoi, a diligent study would certainly reveal the presence of this damselfly in other parts of the country. References Asahina, S. (1967). A revision of the Asiatic species of the damselflies of the genus Ceriagrion (Odonata, Agrionidae). Jap.J. Zool. 15: Asahina, S. (1970). Burmese Odonata collected by Dr Arthur Svihla, with supplementary notes on Asiatic Ceriagrion species. Jap.J. Zool. 16: Hamalainen, M. (1987). Note on synonymy in Asiatic Ceriagrion species (Zygoptera : Coenagrionidae). Odonatologica 16: Schmidt, E. (1964). Libellen aus Burma, gesammelt von Dr. Rene Malaise, Stockholm. Ent. Tidskr. 85: A mating pair of Ceriagrion chaoi in tandem, with the female perching on a cement tank. NATURE MALAYSIANA, DECEMBER I