GLOSSINA INVESTIGATIONS IN NY AS ALAND. 253 



scratching animals. This supposition has not seemed to me to be tenable, seeing 

 that one never finds such a covering, however carefully one digs up the pupae ; and 

 moreover, though a certain amount of dust does cUng to the pupa, it is invariably 

 in the form of minute particles only in the neighbourhood of the intersegmental 

 rings. 



A more likely supposition has seemed to me that the secretion might have a 

 protective function, the period between the birtn of the larva and its burying itself 

 in the ground, during which it crawls on the surface, being probably the most critical 

 in the life-history of the fly. Ants are invariably found in the breeding places, and 

 as they depend so largely on insect food, a series of experiments have been conducted 

 with a view to finding out the attitude of various species towards the larvae. 

 Those selected first for the experiment were a small black Myrmicine [Pheidole 

 megacephala, F.]. These usually run about singly, and though repeated trials were 

 made, in no single instance did a solitary ant, or even two or three together, attempt 

 to molest the larva, the usual procedure being for an ant, having exammed it with 

 its antennae, to back away and run off on other business. When, however, a larva 

 was placed close to a nest of these ants well stirred up, several invariably attacked 

 it, but in a short time relaxed their hold and cleaned their antennae, though others 

 then seized it. The same results were obtained with another Myrmicine ant 

 Pheidole lieiigmei, For.]. 



In the case of another ant [Cremastogaster chiarini, Emery], a larva was placed 

 close to a large party engaged in the work of dismembering a big cockroach. Two 

 or three having investigated it with their antennae retired, but after a time one 

 large one seized it by the black prominences at the posterior end and held on 

 for some seconds till three or four others came up and gripped it elsewhere. It was 

 obvious that they were by no means happy with their prey, for they let go one after 

 the other, cleaning their mandibles, but by and by again seized it. These ants are 

 not, however, found in the breeding places, as they favour more open situations. 



The only really definite results were obtained with the small Ponerine ants 

 {Euponera senaarensis, Mayr],* one of which on several occasions uncompromisingly 

 seized the larva and ran off with it. 



From these results I think that a reasonable inference may be drawn that the 

 secretion is protective against such ants as are usually found in breeding places. 

 It is probable also that it is of material advantage in protecting the delicate cuticle 

 from injury as the larva makes its way down to its future resting place in the soil. 



Parasites of Glossina morsitans. 



The large number of Mutillid wasps in the Lingadzi district attracted my attention 

 from the first, and I endeavoured during my earlier days here to parasitise tsetse 

 pupae with them, but without success. Long series of the smaller species, which 

 seemed suitable, have been sent home. 



In late May, however, two Mutillids, a male and a female, which I have since learnt 

 from the Bulletin are Mutilla glossinae, Turner, were bred out from pupae found 

 in the vicinity of Monkey Bay, and a good series have now been obtained, 6 males 



* [Mr. W. C. Crawley kindly identified the auts forwarded by Dr. Lambom. — Ed.]. 

 (C205) jD 



