THE IMPORTATION OF TIPHIA PARALLELA INTO MAURITIUS. 99 



As already stated, the adult insects were transferred from the cases to the Insectarv 

 as soon as they hatched out ; by 20th November, however, no parasitised larva could 

 be found (so far as could be ascertained without disturbing the insectaries), and it 

 was decided to set free some insects. Two couples were therefore liberated at Mon 

 Rocher to the east of the Botanical Gardens ; two further couples escaped from the 

 Wardian cases on being transferred to the Insectaries and new away to the west of 

 the Gardens. 



(5) The fifth consignment was despatched on 18th June 1915, and reached 

 Mauritius on 25th August ; it consisted of cocoons spun in the case. After the 

 parasitising of the Phytalus larvae had taken place in Barbados, the case, which had 

 been fitted with four small feet, was closed exactly at the level of the contained earth, 

 thus guarding both the earth and cocoons from being moved about. The case travelled 

 via Southampton in the cold storage hold of steamers as far as Durban, but from the 

 latter place to Mauritius it had to be transhipped and was placed directly upon ice 

 blocks, which caused the death of the Phytalus larvae and the Tiphia pupae in the 

 cocoons. On arrival there were found only fifty cocoons that had been spun in s 

 that is to say, a number far inferior to that originally placed in the case. 



The recurrence of the same facts on three different occasions, and the ever-increasing 

 difficulties that were experienced in obtaining new shipments from Barbados, induced 

 the Department of Agriculture to consider the question of obtaining another closely 

 allied species from a nearer source than Barbados. This question was carefully gone 

 into and the Chamber of Agriculture passed a resolution to the effect that steps should 

 be taken for the introduction of Tiphia bisinuata from Madagascar ; and in the 

 meanwhile, in case this attempt should not prove successful, that more effective 

 measures be taken to secure further shipments of Tiphia parallela from Barbados or 

 Brazil under the best possible conditions. 



In view of a great reduction in the number of Phytalus to be found at Mon Rocher, 

 very careful and thorough searches were made amongst the larvae. Not only was a 

 large percentage of larvae found to be affected with bacterial or cryptogamic diseases, 

 but also during this search parasitised larvae came to light. Two parasitised larvae 

 were detected on the 8th and 9th May 1916 in the very field where Tiphias had been 

 liberated in 1915, and by the 26th of the same month 7 other parasitised larvae had 

 been found in various fields that were somewhat distant from each other. The first 

 adult Tiphias were met with on the 23rd of the same month on Herbe Conde {Cordia 

 interrupta) in the immediate vicinity of the field where Tiphia larvae had been found, 

 and some days later 6 females and 10 males were found at Esperance. In the month 

 of July parasitised larvae and adult Tiphias were found in greater numbers, more than 

 40 adults being met with in one instance on a single plant of Herbe Conde\ In the 

 following months they were found less frequently and became scarce in September 

 and October. 



The presence of parasitised larvae in the very field where adult Tiphias had been 

 liberated 6 months previously left no doubt as to their orig n, as well as that of those 

 found elsewhere, i.e., on the leeward side of the Botanical Gardens, in which direction 

 those adults had flown that escaped from the Wardian cases as before stated. 

 (C365) g2 



