862 ME. NELSON ANNANDALE ON THE [Dec. 4, 



Earthworm" \ a Gryllotalpid cricket, contributes from its hole in the 

 ground a deep, organ-like note. What is the meaning of all this 

 noise ? " The riang-riang sing," a Malay would say, " because 

 their livers are glad " ; and in many cases we are not in a position 

 to give any better reason. The stridulation of the male Cicada 

 appears to be in the main and primarily a sexual call, but may also 

 be used as a warning or alarming cry. 



Of insects capable of producing a sound, some species stridulate 

 when captured, but all do not. The brilliantly coloured little black 

 and scarlet Huechys sanguinea, which, unlike the majority of 

 Malayan Cicada?, is diurnal and flies about among bushes in the 

 open at midday, is silent when handled. The male of the large 

 dung-beetle Eeliocopris mouhotus, a pair of which was brought to 

 me at Biserat by an elephant mahout, squeaks like a bat when 

 touched, but is silent when lifted from the ground. The female 

 of this species is dumb. On the other hand, many kinds of 

 Orthoptera only stridulate when they are left in peace and quiet. 

 In the Malay Peninsula the majority of stridulating species are 

 nocturnal, or only sing at sunset and just before sunrise. There 

 one does not hear the noise of grasshoppers among long grass at 

 midday as one does in this country, though in the jungle there is 

 a subdued hum of insects continually. At Belimbing in Legeh a 

 man brought me several specimens of the " Belalang Rusa Ijou" 

 or Green Deer Grasshopper (Mecopoda elongata). Each specimen 

 was in a small bamboo-cage, as he said that if two were put together 

 they would fight. He told me that children kept this grasshopper 

 as a pet, feeding it on the young shoots of the pineapple, in order 

 that they might hear it " crow." My specimens were silent all 

 day, and all the evening while the lamp was lit ; but in the middle 

 of the night we were awakened by their stridulations. 



VI. Insect Luminosity. 

 An Aquatic Lampyrid Larva. 



Form and Colour. — The body is elongated and narrow : the head 

 is minute, and can be retracted within the thorax. There are 

 eight abdominal segments, which are little differentiated from those 

 of the thorax superficially. The upper surface is corrugated. The 

 colour is dark brown, minutely marked with dull yellow in some 

 specimens. The luminous organs were situated in two small oval 

 patches on the under surface of the last abdominal segment, just 

 behind the anus. 



Habits. — On March 30th, when catching fire-flies by the side of 

 a marsh at Lampam, the chief town of Patalung, I noticed a 

 number of luminous points on the surface of a small stagnant pool. 

 We had some difficulty in ascertaining the origin of these, for they 

 died away slowly when the water was disturbed ; and it was not 

 until we examined some of the plants floating on the top of the 



1 See ' Oxford Magazine,' Oct. 17th, 1900, p. 9. 



