FRUIT FLIES OF THE GENUS DACUS. 101 



i. Dacus, F. 



1. Dacus (Leptoxyda) longistyius, Wied. (1838). 



Bezzi, Bull. Ent. Kes., v, 1914, p. 154, and vi, 1915, p. 99. 



Some specimens of both sexes in the Indian Museum from Balighai, near Puri, Orissa, 

 16-20. viii. 1911 {N. Annandale andi^. H. Gravely), and some others from Coimbatore, 

 vi.x.l913, on Calotropis {T. B. Fletcher) ; Nagpur, 9.iv.l914, on Calotropis. 



No doubt this is the same as the African species which lives on the same plant 

 (Calotropis procera), and which was doubtfully recorded by me in 1913 from Karachi. 

 The Indian specimens before me are very hke those from Eg}'pt and equally small, 

 while the specimens from Abyssinia and Senegal are more robust and of much larger 

 size. The ovipositor is also proportionally shorter in the smaller Egyptian and Indian 

 form. 



2. Dacus brevistylus, Bezzi (1908). 



Bezzi, Bull. Ent. Res., v, 1914, p. 154, and vi, 1915, p. 100. 



Some specimens of both sexes from Hagari, v. 1908, in watermelon (E. Ballard); 

 Siddhout, Cuddappale, Madras, iv. 1910, in melon; Coimbatore, 26. iv. 1912, 

 in melon (T. B. Fletcher). 



This is the well-known Ethiopian species that attacks melons and other cultivated 

 Cucurbitaceae. Some specimens have the thoracic markings and the scutellum of a 

 reddish instead of a yellow colour ; a single specimen shows a double h}^opleural 

 spot, thus forming a link with D. vertebratus, Bezzi. 



Note. — Of other Oriental or Australian species belonging to the genus Dacus {s. str.), 

 I know only D. cucumis, French (1907), from Queensland, which has, however, four 

 scutellar bristles, a thing which has never been observed in any Ethiopian species of 

 the genus. 



ii. Bactrocera, Guer. (1832). 



No species of this genus is at present known from the Indian fauna ; besides the 

 typical species umhrosa, F., it seems th.a,t frauenfeldi, Schiner, /renc/ii, Froggattj_and 

 albistrigata, Meij., also belong here. 



iii. Chaetodacus, Bezzi. (1913). 



In my paper of 1913 nine forms of this group were distinguished, but the distinctions 

 were based on very scanty material ; at present I have before me many hundreds of 

 specimens, and I am able to give a better revision. Some species seem to be very 

 variable in the colouring of the body and wings, as is shown by the bred material of 

 ferrugineus and cucurbitae ; the fuscous punctuation of the frons and the black 

 pattern on the thorax and abdomen seem to be chiefly subject to variation. The 

 studies of Prof. Berlese on D. oleae {Redia, iv, 1906, pp. 5-7, fig. 4) also confirm the 

 great variability of the thoracic and abdominal markings in the present genus. I 

 think therefore that Prof. Hendel* has described some forms which must be considered 

 only as varieties, and I have made here an attempt to difterentiate the various forms 

 into which the typical D. ferrugineus may be divided. 



*F. Hondel. Genus Dacus, Fabricius (1805) (Dipt.). Supplem. Entomolog., No. 1, 

 August 1912, pp. 13-24, pi. 1. 

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