THE BLOOD-SUCKING DIPTERA OF PALESTINE. 117 



with a dark brown or blackish spot or streak on posterior surface ; middle femora 

 with extreme tips light mummy-brown on upper surface ; hind legs clothed with 

 fine yellowish hair (tips of tarsi with brownish hair) ; hind tibiae strongly expanded 

 towards chstal extremities ; last four joints of front tarsi together approximately 

 equal in length to, or slightly longer than first joint ; first joint of hind tarsi somewhat 

 lighter towards base, second joint short but without any noticeable dorsal excision, 

 combined length of last four joints of hind tarsi equal to slightly more than half 

 length of first joint. 



Wadi el Kelt, Jordan Valley, near Jericho : type and three para-types, l.vi.l918, 

 forming part of a number of SS '^^ same species, dancing in small swarms in dry 

 portion of Wadi bed, 5.30-6.30 p.m. At the same time $$ of Simulium equinum. L. 

 (see below), were abundant in the ears of horses picketed close by, on top of the 

 Wadi bank. 



The species just described is alhed to the Algerian Simulium beckeri. Roubaud 

 (Bull. Mus. d'Hist. Nat., xii, p. 520, 1906), but is apparently distinguishable, inter 

 alia, by its somewhat larger size, and by the leg markings, e.g., by the presence of 

 dark brown or brownish tips to the front and middle tibiae, and by the proximal 

 extremity of the hind tibiae being entirely yellowish {i.e., without a blackish ring 

 at the base). Simulium jlavipes is also closely allied to an undetermined Ethiopian 

 species (represented in the National Collection by five specimens from Zomba, 

 Nyasaland Protectorate), in which, however, the dark markings of the femora and 

 tibiae are more strongly developed. 



Simulium equinum, L.* 



Seven ^^, Tel Abu Zeitun, near Jerisheh, 5 miles N.-E. of Jaffa, 2.V.1918 — 

 part of small swarm dancing at foot of the Tel, near the marsh, 6.15 p.m. ; 3 $$, 

 Jericho Plain, 15.iv.l918, " biting horses' ears in morning and evening, all over 

 the Plain " {Captain Kendle, Australian Veterinary Corps) ; 12 $$, Jericho 

 Plain, 19.iv.l918, "in large numbers, attacking insides of horses' ears " ; 1 $, 

 Hadrah Dam, R. Auja, 29.iv.1918, " flying low over the water, apparently ovipositing 

 on green slime close to the water's edge, 6.15 p.m." ; 1 $ (pale-legged variety), 

 Jericho Plain, near Wadi el Kelt, 31. v. 1918, " in horse's ear in evening." 



In the Wadi Hamis, near Ain Kanieh (about 11 miles N.N.-W. of Jerusalem), 

 on 8.iii.l918, at a spot where the shallow water was flowing very swiftly, a greenish 

 Simulium larva was present in myriads on the stones in the bed of the stream. No 

 adults were seen, and under the circumstances it was impossible to attempt to breed 

 out any of the larvae. Close to the spot referred to, a number of Simulium larvae, 

 apparently belonging to three different species, were also found on the leaves of a 

 submerged piece of reed. Some of these latter larvae were collected and taken back 

 to quarters, and although the majority of those brought back died within two days, 

 two were observed on 10.iii.l918 to have pupated. One of the pupae (examined 

 and sketched as well as possible with the aid of an ordinary platyscopic lens) was found 

 to have on each side six slender respiratory filaments, apparently arising separately 

 from what looked like a long, narrow, whitish pad, the whole arrangement, except 

 as regards the thinness and length of the filaments, being similar to that of the pupal 

 respiratory organs of 5. equinum, L., as recently figured by Edwards.j 



On 19.iv.l918 in the Wadi el Aujah (6| miles N. of Jericho), a rushing stream 

 of about five yards in width, Simulium larvae were abundant on the stones. In 

 fact, just as in the Wadi Hamis six weeks earlier, so numerous were the larvae on 

 some of the stones that the latter looked as though they were hair}^ 



* For the definite determination of this species, the writer is indebted to Mr. F. W. Edwards. 

 t F. W. Edwards, BuU. Ent. Res., xi, pt. 3, p. 236, fig. 6 (December 1920). 



