A Monograph of Egyptian Diplera. 55 



more longitudinal lines. The pupa (puparium) is elcngately ovate, 

 arched above, somewhat flat below, broad and rounded in front, 

 mure or less tapering behind; it is sometimes longer and more 

 drop-like (in the narrow bodied species); it has, of course, the 

 same dermal structure as the larva, only it is generally less pro- 

 nounced, and the larger warts, when such are present, are smal- 

 ler and more contracted. The anterior larval spiracles are general- 

 ly not to be seen, but the posterior process is present as in the 

 larva. The colour is similar to that of the larva, but it is often 

 altered as the development of the imago proceeds, because the 

 colour of the imago shine through the puparium." 



The larvae are all aphidiphagous and are found on the leaves 

 and stalks of various plants among Aphids infesting these. 



Further the same author gives a most vivid and interesting 

 account of the feeding process of these predacious larva?, which I 

 feel it would be of great interest to give here: "...; the larvae are 

 very voracious; I once had a larva, of S. nitens which in six days 

 devoured so many Aphids that the white, empty skins of these 

 latter formed a thick layer on the bottom of the bottle ; the larva 

 had during that period grown double the size. It is interesting 

 to examine the larva when feeding ; it is generally sitting amongst 

 a colony of Aphids and it stretches and raises the fore-parts of 

 its body and bends it down to different sides until an Aphid is 

 touched; it then pierces it with its mouth-hooks, detaches it with 

 a jerk, and with the fore-parts of the body in a raised position it 

 sucks it out with a pumping action ; the Aphid is seen to become 

 white, and is quite sucked in one minute or in a few minutes ; it 

 is then thrown off by a small jerk and the action is repeated. 

 Sometimes larvae have been observed to attack and suck other larvae 

 of their own kind, such as is also the case with Lasiophthicus. The 

 pupa is generally found on leaves or stalks attached by some glue 

 with the hind part... According to Buckton (Mon. of Brit. Aphid. 

 II, Roy. Soc. 119. 1879.), the egg-shell is ornamented with bifurcate 

 papillae ; the eggs are deposited singly and may often be seen on 

 leaves of oak, fir etc., where they are placed in the midst of 

 Aphids." 



It is surprising that this genus should be so poorly represented 

 in Egypt ; of the genus over 60 species are known from the 

 Palaearctic region and strictly speaking only one species, S. corol- 

 Ice seems to occur commonly in this country. 



The species of Syrphus are beautiful flies and exquisite 

 hoverers in the sunshine and our common species seems to occur 

 every-where near plants and flowers in the desert as well as 

 throughout the Nile valley. Verrall states that species of Syrphus 



