INSEeXS PREYING ON THE ORANGE APHIS. 



183 



THE I'on: SPOTTED AIMIIS-FL'S'/ 



{Bacclta Ixtbisln Walker.) 

 [Figs. 81, 82 and 83.] 



This is a rather sleuder fly, with a large, well-rounded head, and a 

 club shaped hind body, supported ou a slender stalk or peduncle; the 

 eyes, which cover the greater part 

 of the head, are mahogany -brown; 

 the thorax black, with a metallic 

 luster, and with a golden-yellow 

 shield ; the wings are tiansparent; 

 the club of the abdomen brown, 

 marked with four i)ale triangular 

 spots. (Fig. 81.) Length, 10-""' 

 (/^r inch). 





Fig. 82. — Baccha babisla, larva. 

 (Original.) 



Fig. 81 — Baccha babista, adult. (Original.) 



The larva (Fig. 82) has a cylindrical body, greenish, with a longitud 

 iual band of dull red on the back; the joints about equal in size, ex 

 cept the first three, which are tapered, and form a re- 

 tractile neck ; the surface is covered with very short, 

 stifl" hairs, giving it a velvety appearance ; each joint 

 of the body is armed with a row of soft si)ines above 

 and a pair of fleshy prop legs below.Length, when at 

 rest, 7.5""" (^^ inch). 



The puparium, or chrysalis (Fig. 83), has the form 

 ofa cone, with one side flattened and fastened to the 

 surface of the leaf; the large end is broadly rounded, 

 convex ; the color varies from dirty white to dull yel- 

 low, and there are more or less distinct cross-shaped 

 markings ui)on the back ; the spines of the larva shrink 

 to minute prickles on the pupariuin. 



The eggs are elongate-oval, brilliant white, the surface marked 

 with diamonds by obliquely intersecting engraved lines. They are 

 deposited by the parent fly singly upon the leaves among Plant-lice. 



FaruHitcH. — 3Iinute Chalcid parasites prey upon the Syrphus larva, 



Fig. m.— Baccha 6a- 

 bUta, ])iipariuiu: 



a, (loisal view; 



b, hilonil view. 

 (Oiigiual.) 



* This vt^ry common species has been described by Mr. Ashmead under the name 



Conopnf quadrimaculata. (Orange Insects, page 69.) 



