256 H. TETLEY. 



detaching them from the labium and holding the latter at a wide angle from the 

 other parts of the mouth. Bates found, on a southern tributary of the Amazon, a 

 Pangonia with a proboscis half an inch long and sharper than the finest needle ; 

 this insect settled on the backs of his party and pricked them through their clothing. 

 Sharp (16), speaking of the genus Pangonia, says that " The proboscis in the 

 females of some of the species is three or four times the length of the body, and as 

 it is stiff and needle-like the creature can use it while hovering on the wing, and 

 will pierce the human body even through clothing of considerable thickness." 



I will not comment on this at present except to say that the implied difference 

 in length of proboscis between the male and female is not mentioned, so far as I 

 can find out, in any species of Pangonia, and does not apply to Pangonia longirostris, 

 as will be seen from the table of the lengths of the mouth-parts of the two sexes of 

 this insect. According to Patton and Cragg (13) " there is evidence that some of 

 these flies, notwithstanding the great length of the proboscis, feed on mammalian 

 blood . . . while hovering near by, making sudden darts. . . . Such a 

 habit is apparently exceptional in the genus, as in the majority of cases the mandibles 

 and maxillae are shorter than the labium, and cannot, therefore, be employed in 

 making a wound." Austen (2) considers that the fact that, in such species as 

 P. rostrata and P. gulosa (of Africa) there occurs the great extension of the proboscis 

 beyond the piercing stylets, would obviously offer a mechanical obstacle to the 

 piercing of the skin of a mammal by these flies. He thinks it possible that when 

 such flies appear to be attacking animals, they are merely sucking up the blood 

 flowing from wounds caused by other Tabanidae. 



In two more instances taken from Austen (2), the methods of blood-sucking are 

 given. Pangonia rupelli was seen attacking horses in Northern Nigeria ; it did this 

 by sucking blood on the wing, and darted away after feeding. Dr. Old (12) says of 

 P. oldii that it " hovers for a few seconds, alights, and then deliberately punctures, 

 like a needle, with its extraordinary proboscis." 



Neave (11) also mentions that individuals of this species were inclined to enter 

 tents and the females occasionally attacked the bare skins of the natives. 



Wesche (19), writing in 1904, remarks that " In Pangonia is found an extra- 

 ordinary development in the length of the labium without the geniculation that 

 usually accompanies this character. This enables these insects to pierce through 

 clothing to the skin." 



In 1916 Prof. Poulton exhibited at the Entomological Society of London a 

 specimen of what was probably a form of P. oldii. Aust. (vide Proc. Entom. Soc. 1916, 

 p. lxxii) and read some notes written by Dr. G. D. H. Carpenter, who had conducted 

 some observations in German East Africa. The latter wrote, " I was bitten one day 

 [16th June 1916] in this locality [30° 55' E., 2° 5' S.] by a Pangonia, the first I have 

 met. I heard its hum (an unmistakable Tabanid hum), and looking towards the 

 sound saw what I thought was a fine Bombyliid hovering at my bare forearm 

 sucking up moisture from the skin, as Syrphids often do. The proboscis seemed to 

 me to be laid along the surface. I could not quite reconcile the Tabanid hum with 

 the Bombyliid appearance, and was interested to notice that the proboscis was 



