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ON THE UTILISATION OF AN INDIGENOUS AFRICAN SILK- 

 WORM (ANAPHE INFR ACTA, WLSM.) IN UGANDA. 



By C, C. Gowdey, B.Sc, F.Z.S., F.E.S., 



Government Entomologist of Uganda. 



The silkworms which are found in the largest quantities in Uganda belong to 

 the genus Anaphe (family Eupterotid^e), of which we have three species, 

 Anaphe infracta, Wlsm., A. venata, But!., and A. moloneyi, Drucc. The other 

 species of silkworms which have so far been observed in the Protectorate are 

 Mimopacha gerstaeckeri, Dew., and Hypsoides milled, de Juan, but these are com- 

 paratively rare. This paper deals only with Anaphe infracta. 



Description of Adult. 



The wings of the moth are of a creamy white colour ; the anterior wings have 

 broad bands of dark brown — two broad bands in the middle of the wing 

 joining at the posterior margin to form a V? an( ^ two sub-parallel bands of the 

 same colour join the outer arm of the V to the lateral margin ; the lateral 

 margins of both the anterior and posterior wings are also bordered with dark 

 brown, but the border of the latter is not so pronounced. The segments of the 

 abdomen are marked with rings of golden-brown hairs. The female differs from 

 the male in being larger and having the tip of the abdomen covered with golden- 

 brown hairs. 



Life-history and Habits. 



There are two broods in a year, and, as the life-cycle of each brood takes 

 about a year to complete, the broods overlap each other. The adults of one 

 brood emerge from the cocoon-mass, or nest, in September and of the other in 

 January. The only marked difference in the duration of the metamorphoses of 

 the two broods is in the chrysalis stage ; in the September brood the length 

 of this stage is about thirteen weeks, whereas in the January brood it is about 

 six weeks. Below is given the duration of the stages of the two broods in 

 tabular form for comparison : — 



Stage of Insect. 



Length of Stage 

 (in days). 



January Brood. 



September Brood. 



From 



To 



From 



To 



Egg 



Larval 



Spinning of Cocoon 



Chrysalis... 



Life of Adult 



45 

 107 to 150 



120 



45 to 92 



5 to 6 



Dec. 15 

 Feb. 1 

 July 1 

 Nov. 1 

 Dec. 16 



Jan. 31 

 June 30 

 Oct. 31 

 Dec. 15 

 Dec. 21 



Aug. 1 

 Sept. 15 

 Jan . 1 

 May 1 

 Aug. 1 



Sept. 15 

 Dec. 31 

 April 30 

 Aug. 1 



Aug. 7 



The table shows that the life-cycle occupies from 322 to 413 days, the longer 

 period being for the September brood, which appears also to be rather smaller 

 than the earlier brood. The dates are, of course, only approximate. 



The eggs are laid on the under-side of the leaf of the food- plant in large clusters. 

 These clusters, which contain from 200 to 300 eggs, are covered with the silky 



