,4 Monograpli of Egypliaii Dïplera. 29 



that of .S'///7>A//.valthougli a dil't'crciico may he det'octfd hy n (raiii- 

 ed eye iii the niorc proiiouiurd iiiidulat imi of the turne-d iij) iiorlion 

 of M 1+2. 



This gcmis shows a disliiirt cDniicc'.ioii witli our Xa-nllio- 

 (jratiuna a'(jiij)tiiim, althoui;h in I'"-un)ii;^ it se?nis lo ho wtMl sej)ar- 

 Mtcd hy its distinct slijui',' ;iiid markini^s. 



S/i//<rro/}/ioi ia. as a l'cst rictcd i^immis, cccufs in North Africa, 

 India, Cévlon, Aust i';ili;i, danaii, N.Mth and South Aiiifricn, Si- 

 hcria, (uvonhuid, Madcira. ('anary Ishinds, Asia Minor, dava,, 

 Sninatia, iXoiih America, Maïqncsas and Tahiti Islands, ami 

 throughout Europe. 



Tlic métamorphoses oi' a fcw s|KU'i;s arc known. 'l'h'- Lirva 

 aiid pnpa of S.scri/)fu, wliich were fourni amon;^' Aphids in .\])i-il 

 and Mav, hâve heen deserihed hy R(i\scl (Ins. Belust. Il, 1749 Muse. 

 31 T. VI.), Bouché (Naturo-. d. Ins. 1834, 51, T.V. f. 4-(i) dcs- 

 crihcs the devclopniental statues of S. iinnthiisfii (hicii'riln) and 

 States that the larvae were found ainoni^- Aphids on Coinposila'. 

 Zettersted (Dipt. Scand., II. 1843, 7()())' savs thaï he found larva' 

 and pupge of S.scri'pta as well as thosc of S.iNrnthn^Iri, the larva; 

 of the latter feeding on Aphids on Vicia faha. Lundbcek (Dipt. 

 Dannica, V. 340. 1916) has aiso found the larva of S. scripfa feed- 

 ing on Aphids and I hâve mvself found the larvœ of X. f/dvirai/fiff, 

 feeding on an Ai^his on Ccnt'^nirci <vr,}i i-.tvict . 



Lundheek describes the larva of N. incnthnslri as heing "of the 

 "usual shape of a Syrphus larva ; it is corrugated ahove, thcdermis 

 "is finely shagreened and there are very small bristles on the 

 "dorsum and at the sides, arranged quite as in Si/rp/ni'< : on th(> 

 ■'ventral side there are slight transverse swellings ; the pns^erior 

 '"spiraeular process is not quite short, blaek, with a longitudinal 

 "dividing furrow above and l)clo\v and the apical cicft with the 

 "points a little diverging. The larva is liglit grcen with two 

 "whitish longitudinal dorsal stripes. Length fi'om 7 to 10 mm. The 

 ■pnpa is hroad and rounded in front and attenuatcd h-ehind and 

 '"thus dropdike; the spiraeular process is as in the larva; it is green 

 "during the first part of the development, later the imago shines 

 "through and the empty puparium is whitish. Length about 7 mm." 



The larvse are aphidiphagous. Verrall states that ,S'. fluricni'l'i 

 is in some way associated with the garden Asparagus and that 

 an allied genus Mrsorfrnpta {M. polifa. Pav) has heen pniVL^d to eat 

 pollen in the larval stage. 



At the period of pnpation tlie larva attaches itself by its 

 posterior extremity to a leaf or stalk. 



SYNONYMY:—! agrée with what Vei-rall savs as regards the 

 synonymy of this genus, and entirely support bis statement that 



