260 MAJOR W. S. PATTON. 



placed separately in a dry tube in order to preserve the first-stage larvae as soon as they 

 hatched, and the remainder of the eggs were placed in the mouth of a dead bird or 

 animal, which was then wrapped up as explained above. Some second-stage larvae 

 were collected about the second or third day, the third-stage larvae later, and finally 

 the flies were bred out of puparia. In this way I was able to obtain the eggs, first, 

 second and third-stage larvae, of a large number of the commoner Indian species; 

 such material is extremely valuable for comparative studies. 



This method of rearing the larvae of the semi-specific myiasis-producing larvae is 

 very satisfactory. In the case of the specific myiasis-producing species, such as 

 Chrysomyia hezziana or Wohlfahrtia magnifica, it is a mere waste of time attempting 

 to rear their larvae in decomposing animal matter. They can only be reared to 

 maturity in living tissues. It is therefore obviously necessary to be able to recognise 

 the second-stage larvae of such a species as Chrysomyia hezziana — the first stage is 

 very seldom found, as it is a very short one. The second-stage larva of Ck. hezziana 

 is fortunately very characteristic, and I am not acquainted with any other species 

 which has a similar larva. The segmental spines are extremely well developed and 

 stand out as dark bands ; the anterior spiracles consist of live finger-like processes ; 

 there is a well developed short accessory belt of spines at the sides of the abdominal 

 segments 1 to 7 in front of the segmental bands, and the spines on the ventral pads 

 consist of two separate rows. All the spines become weaker after the 5th segment, 

 and are poorly developed on the 8th. The posterior stigmata are situated on a well 

 developed plate, and consist of two rather broad straight slits directed backwards 

 and inwarcls ; the tracheae give off many branches after the vestibule, so that the 

 8th segment has a dark colour, owing to these showing through the integument. 



If the case is one of rhinal, oral, aural or vaginal myiasis, the larvae should be 

 removed by spraying the parts with glycerine, or even with a little weak chloroform 

 water ; it may be difficult to dislodge the larvae when they are high up in the accessory 

 nasal sinuses, but it is nearly always possible to get a few. Medical officers in India 

 have always been able to send me a considerable number of larvae from such cases. 

 The mature larvae of Ch. hezziana when removed from the tissues should be placed 

 in some earth in a cigarette tin and allowed to pupate. 



With the help of the above key, medical and veterinary officers should find no 

 difficulty in determining the genera to which the larvae belong, by simply examining 

 the posterior stigmata with the aid of a pocket lens magnifying 15 times. The 

 presence of fleshy processes on the larva points to its being either Fannia, Aphiochaeta 

 or such Calliphokinae as Chrysomyia alhiceps orvaripes, two Oriental and Australian 

 blowflies. If the larva is smooth, note whether the stigmatic slits are curled or 

 straight. If curled it belongs to the Muscinae, if straight, to either Calliphora, 

 Chrysomyia, Lucilia or Sarcophaga. With the aid of the key, and the drawings 

 accompanying these notes, the larva can be accurately placed in any of these genera. 

 If there is any doubt as to whether the chitinous ring is complete or not, shave off 

 the end of the 8th abdominal segment with the stigmata with a razor, and clear it 

 in 10 per cent, caustic potash, and mount, after dehydration, in Canada balsam on 

 a slide. The determination of the species should, in most cases, be left to a specialist. 



All Sarcophaga larvae should be reared to maturity, and the adults hatched out 

 and carefully pinned, especially the males, as there is no means at present of deter- 

 mining the larvae of these flies. Any such material would be most valuable. 



In the case of the Oestridae, all of which are specific myiasis-producing flies, 

 success in hatching out the adults is only possible if the mature larvae, which have of 

 their own accord left their host, can be obtained. Such larvae should be placed in 

 some earth in a cigarette tin and should be handled as little as possible. The mature 

 larvae of the Oestrinae are usually much darker than the immature specimens; 

 in others the skin becomes dark yellow and harder. Mature larvae can sometimes 

 be obtained in places where their hosts are in the habit of lying up during the evening. 



