B A T R E 0 p I L C A A L

L R A I By 0 N F Earl of Cranbrook 0 N R David SEdwards E G~ With other contributions by

George Argent Charles M Francis Penroose Saleha Martin Barker Freddy Gathome-Hardy Axel Dalberg Poulsen Roger A Beaver David T lanes Klaus Riede Peter F Becker Kamariah Abu Salim Gaden S Robinson Peter S Bellwood Chris J Kofron Sheila M Ross Elizabeth L Bennett Ruth Levy David Roubik Webber E Booth A Q Malik Samhan Nyawa Philip E Bragg C1iveF Mann Martin Sands Dielrich Burkhardl Nick Mawdsley Haji Serudin Tinggal­ loe K Charles lason, Lord Medway Gavin C Smith Salish C Choy Tom C Mitchell Rowland Snazell Mark A Cook Jonathan Moran Brian M Spooner Ind rane iI Das D Neil Morgan Mary C Slockdale Martin Drake Ingrid de la Motte Peter Wilkie John Dransfield Mark Mulligan Yanilla Willcox Soejatmi Drullsfield Nico Nieser John TWills Alan P Dykes Alben G Orr Yong Nget Yung Peter P Eaton Colin A Pendry Twenty-nine species of Phasmida have been collected in the Belalong forest: Anarchoides Iyralus (a male) was taken on Bukit Belalong . In the daily cycle of changing sounds in the abdomen, and stabbing or pinching Belalong, many noises are produced by movements of the powerfully spined hind insects, their chief purposes to attract po­ legs. Two species of leaf insects (Phyllium) tential mates and/or advertise territory. recorded from Borneo produce sounds by Orthoptera: Many Orthoptera produce rubbing together the thickened third seg­ noises, using a great variety of sound­ ments of their antennae. producing mechanisms. At Belalong, it is Cicadidae: The calils of cicadas are among the group known as long-horned grass­ the loudest noises of the forest, a variety of hoppers (Ensifera) that produce the major­ buzzing, whining or trumpeting sounds, ity of buzzes and chirps to be heard in the each distinctive to one species. The sound forest at night. Among these, crickets is produced by tymballs situated at both (Gryllidae) and katydids (Tettigoniidae) sides of the f,irst abdominal segments. The employ a mechanism at the underside of stiff cuhcular tymbal membrane is drawn the forewings, consisting of a scraping inward by a strong muscle and flips back by 239 organ (plectrum) which is rubbed against its own elasticity, thus producing a click. a file-like row of cuticular teeth during lin­ The songs consist of a complex sequence ward movements of the wings. Loud, re­ of clicks arranged in a species-specific petitive signals with a narrow-band carrier time sequence, with a characteristic spec­ frequency between 4 and 9 kHz, are gen­ trum of higher harmonics. His amplified by erated by the rhythmic wing movements of an airsac which can occupy a large part of male cr,ickets. Wing movements produce the abdomen. pulses of sound which can be mixed to Lepidoptera: Several butterflies and moths produce more complex sounds, called also produce sounds, although these are 'chirps'. Carrier frequency, pulse rate and less strident. The mechanisms differ from chirp are species-specific, and are impor­ one group to another. For instance, some tant stimuli for the innate behavioural re­ hawk moths (Sphingidae) pass air through sponses of searching con specific females. the mouth region to produce a squeak; an The katydids employ the same sound example of a 'squeaker' in the Brunei fauna producing mechanism but, in general, their is the Death's head hawk-moth (Acherontia songs consist of a broader range of fre­ lachesis). Males of some other hawk moths quencies, reaching up to the ultrasonic. At (e.g. Psilogramma menephron) produce 8elal'ong, however, species of sound by rubbing patches of stiff scales at Tympanophyllum producing narrow car­ the apex of the abdomen and on the geni­ rier frequencies have been observed; these talia to produce a hissing noise. Other belong to the leaf-mimicking tettigoniid sub­ Lepidoptera produce sound by rubbing family Pseudophyllinae. roughened surfaces on opposite pairs of Phasmida: At least six genera are known legs, leg against wing or wing against wing, to have sound-producing organs; in all or by tapping or vibrating specialised struc­ cases the noise appears to be used only tures of the external skeleton (tymbal or­ for defence. Three of these genera occur in gans). In some cases, these noises fulfil Borneo, and one species, Haaniella the general functions of communication echinata, is common in the Belal'ong for­ with mates or territorial rivals but, among est. Haaniella and Heteropteryx (subfamily night-flying moths, the sounds produced Heteropteryginae) both have short wings are of high frequency and evidently de­ which are used to produce a noise (which signed for defensive purposes, to confuse sounds like a combination of rusHing and predatory bats by jamming their sonar clicking) by rubbing the wings together. (echo-detection) system or to tell the bat This stridulation is produced in response to that the moth is distasteful, poisonous and attack and is often combined with raising best avoided. being so numerous, termites are an FOREST SOUNDS important food resource for other ani­ mals. Ants, ambng the invertebrates, The daily cycle of cicada calls dominate the sounds of Belalong forest. Calling and many vertebrates, such as the pan­ begins in the middle of the day, increas­ golin, Malay civet and sun bear, are ing progressivel!y towards dusk. The termite predators. Some species of frogs loudest caller of all has been nick-named and snakes are termite and ant special­ the 'six o'clock' cicada, because it nor­ mally sounds off around the hour of ists, while others, including lizards and dusk. After preliminary clicks and grunts, squirrels, will feed opportunistically one will lead with its sonorous, trumpet­ on termites wherever large numbers ing call, to be followed by others as the concentrate, for example, at feeding chorus moves up or down the valley. 240 Changes in light intensity and in humid­ sites, foraging columns and nest en­ ity of the air evidently affect the timing of trances. When alates emerge to swarm, onset. In the wet weather of October/ they are eagerly hunted by insectivo­ November P991,), on heavily overcast and rainy afternoons, individuals called rous bats. as early as 1630 hours and the chorus could develop locally from 1640 hours ­ often ceasing in subsequent rain; but STICK INSECTS resuming around the expected 1800 hours. As the day finally darkens into night, the cicadas fall silent, and other The stick insects (Order Phasmida) are vocalists take up the task. predominantly tropical in distribution, especially in forest environments. There are over 2,900 named species, worldwide, of which some 300 are re­ corded from Borneo. They feed on soft plant tissue, typically shoots and leaves, and most are nocturnal. By day, rely for concealment largely on stillness and the cryptic col­ ours and outline of their elongated, twig-like bodies. A few are spiny, and some emit strong smelling, irritating Acacus sarawacus - a non-winged member of the liquids when disturbed. Nonetheless, Necrosciinae, a widespread stick insect in all they frequently fall prey to insectivo­ parts of northern Borneo. rous predators. Members of the su bfamily sites, and building nests and galleries, Lonchodinae drop their eggs to the while their subterranean tunnels, af­ ground and, as a result, tend to live fect rates of water infiltration. Thirdly, near the ground and are seen more Dares validispinus - Stick insects of this ground­ Carausius everetti - No formal description of the dwelling genus occur in all parts of Borneo. male shown here has yet been published. 241

2cm

The stick insect (Hoploc/onia cuspidata), male and female, collected at Belalong, rediscovered for the first time since the original description of the species in 1906. STICK INSECTS AT BELALONG

During 12 nights, adults of 30 species were collected; this included representa­ tives of five of the nine subfamilies which occur in Borneo. With the exception of members of Acacus, Dares, Haaniella and Lonchodes (four genera which seem to be found everywhere in Borneo), most species were represented by a single example. Of 26 species identified, one is new (Lonchodes harmant) and eight are species for which either the male or the 242 female is unknown. The subfamily Necrosciinae in­ cludes most of the winged phasmids amounting to about half of all species known to occur in Borneo. Many, per­ haps most, seem to live in the forest canopy and as a result a few are com­ monly found. Many species glue their eggs to the trees or push their eggs into cracks in the trees, and do not need to descend to ground level. The range of sizes was large among the collection: a male Presbistus fulvipennis, at 3 cm long, is one of the smallest in Borneo, and a female Pharnacia saggita, at 28 cm long, is the second longest phasmid ever recorded from Borneo, much longer than previous records of this species, and one of the longest insects in the world!

often. The two most numerous genera of this subfamily in Borneo are Lonchodes and Carausius. Members of the subfamily Heteropteryginae lay their eggs in the soil and many, perhaps all, hide on the ground during the day. They are quite heavily built, more like pieces of tree bark rather than sticks. Three genera, Dares, Hop/oc/onla and Haanlella were found. The long-legged centipede (Scutigera) is a fast moving predator of smaller vertebrates. Trees and Woody Shrubs

Flowers of jarum-jarum, attractive 10 underslorey butterflies.