102 d. d'emmerez de charmoy. 



found in great numbers on trees infested with Icerya seychellarum, Westwood. Now 

 these ants sometimes occur in such large numbers on leaves of Herbe Conde that one 

 might believe this plant to be infested with Aphids, the belief being strengthened by 

 the fact that the ants circle round a central spot, just as if they were surrounding an 

 Aphid or a Coccid. This further tends to prove the similarity that apparently exists 

 between the secretions of the Aphids and the sweetish content of the vesicular hairs 

 of Gordia interrupta. 



It would be premature to conclude from the preceding observations that the 

 quality of the food was chiefly responsible for the attempts at Tiphia importation 

 having been nearly a failure, as there may exist other causes which more systematic 

 searches might bring to light. 



The writer's aim in recording these observations and in trying to interpret them 

 was to point out the difficulties experienced in introducing insects from a long distance 

 and the necessity of a closer study of the food requirements of the economic species 

 utilised by mankind as auxiliaries. 



The importation of Tiphias and their establishment in Mauritius have brought to 

 light several interesting facts which may serve as guides in the future for the intro- 

 duction into other countries of species of the same family. 



It is the pleasant duty of the writer to avail himself of this opportunity for acknow- 

 ledging the valuable assistance received from all those who contributed to this 

 importation. To Mr. John R. Bovell, Superintendent of Agriculture, Barbados, 

 and his assistants, Messrs. W. Nowell and J. Sydney Dash ; to Dr. Guy A. K. 

 Marshall, Director of the Imperial Bureau of Entomology ; to Mr. C. P. Lounsbury, 

 Chief of the Division of Entomology of the Union of South Africa ; and to Mr. C. W. 

 Mally, Entomologist of the Cape Province, are due the grateful thanks of the planters 

 of this Colony for their untiring efforts in securing the importation into Mauritius of 

 this valuable parasite. 



[Since the foregoing paper was received Mr. d'Emmerez has written to say that 

 at that time (5th May 1917) specimens of Tiphia parallela were to be found in 

 thousands on Coriia interrupta all over Esperance Estate and Maison Blanche. 

 He estimated the females on the plants at about 5%, but was not certain whether 

 this was due to the earlier emergence of the males, or to the fact that the majority 

 of the females were engaged in oviposition underground. He states that in his 

 insectary the females have laid fertile eggs on larvae of Adoretus versutus, and on 

 young larvae of Oryctes. — Ed.] 



