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TWO SCOLIID PARASITES ON SCARABAEID 

 LARVAE IN BARBADOS. 



By W. NOWELL, A.R.C.S. 



{Imperial Department of Agriculture for the West Indies.) 



(With Plate XV and 1 Text-figure.) 



As introduction a word should be said regarding the incidence of 

 the rainfall in Barbados and the agricultural operations determined by 

 it, since these have a bearing on the life of the insects to be considered. 

 There is no definite separation into dry and wet seasons, but generally 

 speaking the first five months of the year are characterised by drought, 

 broken now and then by more or less heavy showers ; from late May or 

 early June onwards these are supplemented by the occurrence of very 

 occasional falls of two or three inches of rain, producing what may by 

 contrast be called the rainy season. The canes are planted towards 

 the end of this season, about December, and are reaped in March and 

 April, some sixteen months later. After the reaping season, as showers 

 permit, various other crops — among them sorghum and maize — are 

 planted, and these have often accomplished a fair amount of growth by 

 the time that the heavier rains bring in the period of greatest insect 

 activity. 



Two beetles of the family Scarabaeidae occur in Barbados. Ligyrus 

 tumulosis Burm., a Dynastid, is universally distributed and very abun- 

 dant. Its larvae live in soil rich in decaying vegetable matter. They 

 occur in very large numbers in pen manure and are to be found at the 

 base of the heaps of dead sugar-cane leaves or cane stumps which are 

 made up at the end of the reaping season. They are not known to 

 attack living plants. The beetle has no definite seasonal distribution, 

 but the adults are capable of remaining for a considerable time in the 

 soil, from which they emerge in large numbers after rain. 



Phytalus smithi Arrow, a Melolonthid, though common, is much less 

 noticeable owing to the fact that the adults are very rarely attracted 



