THE MOUTH-PAKTS OF PANGONIA LOXGIROSTRIS. 257 



shrinking, i.e., its tip had penetrated, but obliquely and so gradually that I had not 

 felt it. So it seems that this species feeds on the wing. I send the specimen. I had 

 always wondered how Pangonia managed its long proboscis." 



A little later in the same year Prof. Poulton exhibited another Pangonia which 

 had been identified by Austen as P. varicolor, Wied., and was captured by 

 W. J. Burchell at Uitenhage on 27th Nov. 1813 (vide Proc. Entom. Soc. 1916, p. xc). 

 Burchell had added in a manuscript catalogue, under the same number which the 

 specimen bears, " The fly that sucks the oxen without settling upon them." 



Prof. H. Maxwell Lefroy (who has kindly allowed me to use the information) has 

 observed Pangonia attacking cattle in India. He says that they make wounds 

 with the mandibles, turning up the proboscis as an elephant does its trunk. They 

 then back a little and suck up the blood by means of the proboscis. They are walking 

 and not hovering at the time. 



This description agrees with one given by Roubaud (15) in an account of an 

 experiment he carried out in Senegal-Niger, West Africa, with a Pangonia ; the species 

 was undetermined, nor does he mention the sex, but I take it to be a female. The 

 insect was confined in a muslin cage and this was placed on the author's bare arm 

 to see if the Pangonia would bite, but beyond the testing of the skin with the 

 labella, there was no result. A piece of sugar soaked in water was placed in the 

 cage, and after leaving the insect feeding on it for a quarter of an hour, the cage 

 was replaced on the author's arm. This time blood-sucking started at once, and 

 continued without a break for 7-8 minutes at a temperature of 23-25° C, when the 

 insect was fully fed. This experiment seems to show that a meal of nectar woulcf 

 precede any blood-sucking. 



M. Roubaud concludes his account thus : — " These observations show the biting 

 role and the manifest blood-sucking habits of Pangonia. There is no doubt that by 

 reason of the large size of the wounding apparatus, tropical pathology and biology 

 must henceforth reckon with these curious Tabanidae." 



From the above descriptions it will be seen that the possible processes of blood- 

 sucking in the species of Pangonia may be classed as follows : — 



1. The insect punctures and sucks up the blood through the proboscis alone, 



while on the wing. 



2. The insect alights and punctures with its proboscis. 



3. The insect alights, punctures with its other trophi, and then sucks up blood 



through its proboscis. 



I shall return again to this subject after giving a description of the mouth-parts 

 in both sexes of Pangonia longirostris. 



I am indebted to Dr. A. D. Imms for supplying me with the two pairs of insects 

 upon which this research was carried out. These were preserved in alcohol and 

 were taken by him at Bhowali, in the Kumaon Himalaya, at an altitude of about 

 five thousand feet, on 7th August 1912. 



(C419) e 



