W. Nowell 47 



to light. They emerge in large numbers after the May rains and may be 

 found feeding at night on the foliage of various field and garden plants. 

 At other seasons of the year they are very seldom seen, though there is 

 evidence that they occur in small numbers. The larvae attack the 

 roots of many plants, and in gardens are very destructive to rose bushes, 

 but it is as pests of sugar-cane that they are of special importance. 

 Their occurrence in destructive numbers in the Barbados cane-fields is 

 rare and seems confined to small and shifting areas, but in Mauritius, 

 into which island it seems highly probable that they were introduced 

 in sugar-cane stools from Barbados, great and continuous damage is 

 being caused over an ever-widening area. 



While investigating root grubs of sugar-cane at Spencers Plantation 

 towards the end of the year 1911 the writer noticed in the soil beneath 

 and about the roots of sugar-cane small numbers of brown cocoons. 

 These proved to contain pupae of a black Scoliid wasp, which was 

 bred out. When forwarded later through Mr G. A. K. Marshall, then 

 Secretary of the Entomological Research Committee, it was identified at 

 the British Museum as Tiphia parallela Smith. The specimens then 

 in the British Museum collection, which were females only, had been 

 obtained from Brazil. 



Both sexes are shining black in colour, with greyish pubescence on 

 the legs and grey fringes at the joints of the abdomen. The wings are 

 lightly tinted with brown. There is very considerable variation in 

 size among the females, the range in length (excluding the antennae) 

 in a representative collection being from 15 mm. to 9 mm. The males 

 range from 9 to 6-5 mm., excluding antennae and anal spine. The 

 males are readily distinguished by the presence of this spine, which 

 projects from the tip of the abdomen; its rigidity and stoutness 

 sufficiently prevent confusion with the sting of the female, and it has a 

 marked upward curve. 



By examination of the remains adhering to the cocoons the writer 

 was able to determine that the host was the larva of Phytalus. 



After rain in early June the adult wasps, male and female, were found 

 in large numbers in the same locality feeding on the honeydew on 

 aphis-infested sorghum. They were observed in greatly fluctuating 

 numbers until about the end of September, and it was noticed that 

 towards the end of the period there was a large preponderance of males. 

 In 1913 large numbers again occurred in June, in practically the same 

 place. That their emergence is not confined to the wetter months is 

 proved by the finding at all periods of the year of newly parasitized 



