166 



W. M. GRAHAM — 



It is further worthy of remark that the flies of both these species issue 

 from the pupa-cases with unmarked wings, and that the brown banding only 

 gradually appears during the expanding and drying of these organs. 



List of West African Species of Dacus. 



Species. 

 1. '^ D. armatus,V.,l^Oo 



Habitat. 



Fruit Infested. 



Guinea. 



■ 



'2. S 2 I^. testaceus, Maeq., 1835 ... 



Senegal. 





3. 5 D. hkittatus, Bigot, 1858 .... 



Gaboon. 





4. c^ $ Z). ciliat^is, Loew, 1862 



Guinea. 





5. cj" 5 i). 2Mnct2difro7is, Karscli, 1887. 



Pungo-Adongo. 





6. (S I). inor7iatm, Bezzi, 1908 



Congo. 





7. r? $ i>. vertehratus, Bezzi, 1908 .... 



Eritrea, Lagos. 



\ Musk and Blenheim orange- 1 

 \ melons. 



8. c? I), mesomelas, Bezzi, 1908 .... 



Congo, Lagos. 



( Musk and Blenheim oran^e- 



9« 5 D, bqmrtitus, Graliam, sp. n. . . 



Ashanti, Lagos. 



< melons, vegetable mar- 

 rows, cucumbers. 



10. 2 D.Jlavicnis, Graham, sp. n. . . 



Lagos. 





11. $ D.fuscovittatus, Graham, sp. n. 



Lagos. 





It will be seen that in more than half of the species one sex only is known, 

 and that the habits of but two species have been recorded. As in the case 

 of Ceratitis, the species of this genus are known to attack a great variety of 

 cultivated fruits and vegetables in other parts of the world, as the following 

 list will show : — peach, orange, mango, guava, banana, pineapple, granadilla, 

 olive, tomato, cucumber, melon, marrow and string beans. 



In both Ashanti and Lagos the attacks of Dacus render it impossible to 

 rear melons or allied vegetables in the open during the rainy season. They 

 can only be grown by protecting the plant with a frame covered with 

 mosquito-netting, or by enclosing the fruit in oiled paper bags. At Yaba 

 (Lagos) Blenheim orange-melons planted in April (beginning of rains) pro- 

 duced uninfected fruit, but of the same kind of melons planted in August 

 not a single one escaped infection. 



Months of prevalence for Dacus in West Africa (so far as at 

 present known). 

 1). hipartitiis — August to November. 

 D.flavicans — March. 

 IJ, fuscovittatiis — September. 

 D. mesomelas —March. 

 7>. vertehratus — September, October. 



