78 THE EARLY STAGES OF TABANID^E 



SO in Tahanus. The three types of coloration observed are well 

 shown by the three Tahanus larvae figured (Plate 3, Figs. 40, 41, 

 and 42). 



PupcB. — The great difference between the abdominal spiracles and 

 terminal teeth of the lineola group and those of the atralus group is 

 evident from Hart's figures (Plate 13, Figs. 162 and 163). In both, 

 the thoracic spiracles are in a plane nearly parallel to the adjacent 

 surface and the spinous fringes contain long and short spines. The 

 preanal fringe in the lineola group shows more or less of a chitin- 

 ous web, uniting the bases of the spines. 



A pair of short appressed palpal sheaths on the lower surface of the 

 head, resembling the antennal sheaths, differs slightly in position in 

 related species of the atratus group. 



The species of Tahanus have been classified by various authors, 

 but for convenience, I have listed them here "n alphabetical order. 



We possess data on early stages of fifty-five determined, and four- 

 teen undetermined species of Tahanus. Those of some of the worst 

 stock pests still await description. 



Tahanus alhimedius Walker, — This is one of the commonest Indian 

 species of Tahanus, according to Patton and Cragg, and occurs almost 

 all the year round in Madras. 



Observations on the life history and early stages have been made 

 by Patton and Cragg (1913). The species oviposits in a variety of 

 situations, but most frequently on the leaves of some plant over- 

 hanging deep water. The egg masses have also been found on small 

 rocks in the bed of a stream, and on pieces of string hanging over 

 house drains; on one occasion a mass was found on a papaya tree, at 

 the foot of which water was occasionally allowed to flow. The num- 

 ber of eggs laid is between 500 and 600. The eggs, as in all the 

 larger Indian species mentioned by Patton and Cragg {Tahanus 

 striatus, alhimedius, and speciosus) are subcylindric with tapering 

 ends. The eggs of Tahanus alhimedius measure 1.9 to 2 mm. in 

 length and -4 mm. in breadth. The eggs are brownish white when 

 deposited A chalcid parasite, which was not identified by Patton 

 and Cragg, regularly destroys large numbers of egg masses of this 

 species, and of striatus. This species, as the larger species of India in 



