56 Two Scoliid Parasites 



firm, is largely used in making up the pen manure, and seems to afford 

 protection to large numbers of the grubs. As described above, 

 when this material is more or less broken up by distribution in the 

 fields, the wasps collect about it in a way that is not seen before it is 

 disturbed. 



In digging up cane stools in the fields an imago or a cocoon of 

 Campsomeris was occasionally met with in the situations usually 

 occupied by Tiphia, and in the extensive digging operations connected 

 with the shipments to Mauritius it was definitely established by the 

 examination of the skins attached to these occasional cocoons that 

 Campsomeris is to a small extent parasitic on Phytalus 1 . The ratio 

 of this parasitism to that due to Tiphia at the same time and place was 

 calculated to be about one hundredth. The writer has never found 

 Tiphia on Ligyrus. 



A Rhipiphorid beetle, identified through the Imperial Bureau of 

 Entomology as Macrosiagon octomaculatus Gerst., has several times been 

 found to emerge from cocoons of Campsomeris, and has been taken on 

 flowers of Antigonon leptopus, which are much frequented by the imagos 

 of that wasp. No direct information has yet been obtained as to its 

 method of parasitism, but it is probably that common to the order, 

 the eggs being laid on or near flowers, the young larva attaching itself 

 to a wasp visiting the flowers, and transferring itself when the egg of 

 the wasp is laid. Numbers of a triungulin whose relations have not 

 been ascertained were recently found on several Ligyrus larvae which 

 bore eggs of Campsomeris. 



So far observations have shown that Tiphia, which does not visit 

 flowers, completely escapes this parasite. 



The investigations described in this paper were carried out in 

 connection with the Barbados Department of Agriculture, and are 

 published by kind permission of Mr J. R. Bovell, I.S.O., F.L.S., F.C.S., 

 Superintendent of Agriculture. The somewhat ragged state in which 

 certain matters have been left is due to my transfer from that Depart- 

 ment and the assumption of duties of a different nature. I am specially 

 indebted to Mr A. A. Evelyn, of Spencers Plantation, without whose 

 interest and co-operation the field work would have been impossible, 

 and my thanks are due to my present colleague, Mr H. A. Ballou, M.Sc, 



1 An earlier record of the parasitism of Campsomeris on Phytalus is contained in a 

 letter from Mr G. A. K. Marshall to the Superintendent of Agriculture in Barbardos, 

 mentioning the finding of one example at Spencers, in February 1912. This is the occur- 

 rence referred to in the Report of the Bureau of Entomology, 1914. 



