416 JOURNAL, BOMBAY NATURAL HLST. &OCIETY, Vol. XXIL 



No. XXXIV.— LIFE-HISTORY OF EUMASTAX, sp. 



Dr. David Sharp, in the Cambridge Nat. Hist., Insecta, Pt. 1, p. 301, 

 says of the tribe Mastacides of the Family Acridiidce that nothing seemed 

 to be known at that time (1901) of their habits or development. In 1906-7, 

 therefore, since a sp. of Mastax or JEumasta.r was common near Macao in 

 South China, I worked out the life-history and sent the paper and figures 

 to Dr. Sharp, but unfortunately it was lost. I have recently found some of 

 the principal rough notes from which the paper was written, and send the 

 following brief account, as I believe very little is even yet known of the 

 habits of these insects. 



This species is usually very common but exceedingly local near Macao, and 

 is only abundant in a small patch of wood at Pak-sa-liang village. It is 

 not found except in wooded districts, and appears to browse entirely on 

 shrubs and woody plants ; I have never seen it feed on grasses. One of 

 the favourite food-plants is Pavetta indica, L., N. O. Rubiacece. The males 

 much outnumber the females, and are very brilliantly coloured with vivid 

 yellow-green and two spots of blue-green on one of the abdominal seg- 

 ments. There are a few hyaline spots in the wing and one spot of green. 

 The general ground colour is very dark brown and black, the tegmina 

 being black. The female is larger than the male, and sombrely coloured 

 with various shades of brown and dusky black. The parts left white on 

 the figure of the male are chiefly bright, almost metallic, green. The few 

 spots left white on the figure of the female are dull ochreous. {See Plate C.) 



Eggs were laid on September 14th, 1906. They are slightly curved, 

 smooth, rather shiny and of a darkish yellow.* They are deposited in 

 small batches in the ground in the usual manner, except that very little 

 coUaterial fluid is used, though the eggs are slightly cemented together. 

 One pair of the insects remained in copula about three hours in the early 

 morning, and the eggs were laid in the afternoon. The first nymphs 

 hatched out on the morning of April 8th, 1907. 



Summary of life-history : — 



Eggs laid, September 14, 1906. 



„ hatched, April 8, 1907. 



to adult. 



After the final moult the male takes about five days to arrive at full 

 adult colouring, passing through various brown and ochreous colouring 

 before the green tints become gradually visible. 



From these few notes it will be seen that there is nothing special about 

 the development of this insect, except that the eggs seem to be deposited 

 in a careless and rough manner, with very little protection from collaterial 

 matter, no real covering over the egg-batch being formed. The batches 

 seem to always contain few eggs, and there is but one brood a year ; about 

 the beginning of November all the Mastax seem to have died off. The 

 females appear to live about a month longer than the males. There are 

 periods of really cold weather in S. China from November to March, and 

 this is also the dry season. 



The great difference of colouration between the sexes is unusual in the 

 Acridiidas. 



* The e<?gs are large compared to the size of the insect. 



