142 



THE AMERICAN ENTOMOLOGIST. 



rapidlj'. Down the stems aud jar they would 

 come, and wander about over the paper on 

 which the jar stood. I then consulted the books, 

 and found that " the insect attaches itself by a 

 glutinous secretion to the leaves and stems of 

 plants ; its body then contracts and hardens, and 

 the insect assumes the pupa state within the 

 larva skin." So I returned them to the plants ; 

 I wished them to be scientific larvffi, and did n't 

 the books say they assumed the pupa state on 

 the leaves aud stems? But it was of no use, as 

 fast as I returned them, down they would come. 

 They were determined not to be scientific. So 

 I gave them a little box of earth into which 

 they immediately disappeared, where they as- 

 sumed the pupa state; and in about a week 

 thereafter, the perfect insects — the beautiful 

 Syrphus-flies — made their appearance.* 



[»The great bulk of the HyriAua larva; with which we are 

 acquainted fasten themselves to the leaves and stems of 

 plants, before contracting to pupse, but some have long been 

 known to transform in the ground. According to Westwood, 

 the pupa of Cheilosia ruficornis has been found at the root of 

 a tree by Fallen, while the Eoot-louse Syrphus-fly {Pipiza 

 radicum W. & R., see A. E. Vol. 1, p. S3) not only trans- 

 forms under ground, but lives there in the larva state. In a 

 recent letter, touching on this subject, Dr. Wm Le Baron, 

 of Geneva, Ills. , says: 'The pupa; of S. ribesii have been 

 found under stones, and Mr. Say discovered the pupa; of his 

 S. concava attached by their ventral surface to rails From 

 this it would seem that those larva; which live upon leaA'es, 

 desert these unreliable organs when about to pupate, and 

 attach themselves to more pennanent objects. Zetterstedt 

 found the pupa; of Aphritis, Latr. {Microdon, Meig.)botli 

 under the baric of a tree and also attached to the stems of 

 grass The larva; of Milesia, Criorhina and Xylota are found 

 in rotten wood , and probably they pupate in the same, or in the 

 ground beneath . The same remarii may be made of the genera 

 Syritta and Rhingia, whose larvffi inhabit the dung of horses 

 and cows . The laiwa; ofEristalis and Helophilus are aquatic, 

 and their larvse are known to burrow in the ground, in order 

 to undergo their transformations ." At our request Mrs . 

 Treat has sent us some of the bred flies which are mentioned 

 in this article, and among them are three species of the genus 

 Syrpkus and one of Hclojitiilus . Tlie latter is the H. latifrom 



[Big. !I4 : 



of Loew. (I<'ig. 91.) Of the thi 

 Syrph-us Jlics two are undetermined 

 in our cabinet and the other one wc 

 illustrate herewith (Fig. 05.) It is a 

 quite common species , aud we take 

 it to.be the rhiladelphia Syrphns- 

 fly (Scoiva [Syrphus] jihiladclphicus , 

 Macq.); but as there are at least 

 three described S . A. species which 

 bear a very close resemblance to each 

 Color-Biaek and j'cJIow other. We forwarded a specimen to 

 Dr. Le Baron for his opinion, and fpig. Oj.] 



here subjoin his reply : ' 'This is a 

 common species, and seems to be 

 the American representative of the 

 equally common SccRva i-ibcsii of Eu- 

 rope. Tile term Seccva is discarded 

 by the German end French ento- 

 mologists, being merged in tlie older 

 genus Syrphtis. The Swedish anil 

 English entomologists, however, 

 retain it. The principal distiuc- CoIm— Black aud yellow. 

 tions seem to be as follows: lu Syrphus tire abdomen is 

 broader, being more oval than elliptical; the seta is some- 

 times plumose, but never so in Sceeoa; in Syrphus the epis- 

 toma descends more decidedly below the eyes; but the mo.st 

 conspicuous character is the painting of the abdomen, which 

 in Scava always consists of transverse yellowish bauds, 

 rarely interrupted in the middle, whilst in Syrphus it is either 

 wholly wanting or reduced to a few triangular spots. If we 

 consider the genera distinct, the present species will evi- 

 dently come into the genus Sceeva. This species comes very 

 near Philadelphicus , but in those points in which Macquart 

 distinguishes his Philadelphicus from the ribesii of Europe, it 

 is curious that our species actually resembles the latter, vi/.., 

 in the brown upper margin of the antenna; (which, in Phila- 

 dclphiciis, are wholly fulvous), and in_ the presence of a 

 blackish spot just above the base of the antenna;; Our spe- 

 cies also^comes near the S. concava of Say, but the antennie 



In two or three instances the rightful tenant 

 did not come forth from the Syrphus pupa; 

 but an entirely difierent four-winged, sprightly 

 busy-body had killed the owner and taken pos- 

 session of its house. This was all plain to me, 

 for I had caught the busy Ichneumon in the act 

 of depositing her eggs in Syrphus larvre while 

 the latter were engaged in feeding upon the 

 plant-lice. 



There is another enemy of the plant-lice, a 

 minute Ichneumon [doubtless some species of 

 Ajyhidius — Ed.] which causes greater conster- 

 nation among them than all of their other foes. 

 The Syrphus picked his victim off so quietly 

 that it never seemed to dream that danger was 

 near, until it was kicking on the end of his pro- 

 boscis. But this very tiny Ichneumon, even 

 smaller than its victim, would set a whole colony 

 of plant-lice on a stem in commotion. Bringing 

 my lens to bear upon such a stem, I invariably 

 found the author of the mischief peixhed upon 

 the back of an unlucky plant-louse, which was 

 vainly endeavoring to dislodge her by kicking 

 and throwing back its antennre. But she was 

 usually too firmly seated to be unhorsed, and 

 patiently waited until quiet was restored, when 

 she would introduce her ovipositor in the back 

 of the plant-louse and leave an egg to hatch into a 

 tiny larva wliich should finally eat into the vitals, 

 causing a slow aud lingering death. After the 

 Ichneumon had deposited her egg, she quietly 

 dismounted and proceeded to another plant- 

 louse, which Avould in the same manner become 

 restive, and again the alarm would be commu- 

 nicated to all on the stem. They would hold 

 on to the stem by their beaks, and kick, and 



in that species are described as pale testaceous I should 

 remark here that I ha\eiii my possession only jMaciiuart's 

 and say's and Wiedemann's descriptions. Jlr. Walker has 

 de.scribed about twenty X . A. species, but the works which 

 contain them, 1 believe, are not very eiisily accessible." 



In July, ISliT, wc bred this tly from larva; which were 

 feeding on a large red plant-louse (Aphis rudbeckia, Fitch) 

 which congregates in immense numbers, head downwards, 

 on the stalks of the Ooldeurod. When full grown this Syr- 

 phus larva measures 0.30 inch; the general color is pale- 

 yellow, incliuing lo sulphur-yellow, audit is variegated on 

 ry ,.,. ., the back i^'ith black, brown, 



^ "' ' "■' and brick-red, us in Kigure 96, 



b. Thtse larv:e contracted to 

 ]jui):c upon the stems of the 

 plant, aud iii)on the sides of the 

 vessel in which they were con- 

 lined. We also know that the 

 closely allied Syrphus ribesii 

 pupates sometimes upon stents, 

 and Curtis (Farm Insects, p. 

 SO) lignres the pupa oiS.pyras- 

 iyi, I. inn., likewise upon a 

 stem. Thus it results (since 

 this same sjiecies was also bred 

 by iVIrs. Treat from pupie that form under ground) that the 

 same species sometimes pupates above, and at other times 

 below ground. May it not be, that those larvic hatched 

 during the summer months and which are destined to pro- 

 duce Hies soon after they become lull grown, invariably 

 transibrm on the plants where they reside; while those 

 which are hatched later in the season, and which may have 

 to pass the winter in the pupa state, prefer to enter the ground 

 to transform?— Ed.] 



Culois— (aaud li) Sulplnir-vclIoM-, 

 bliii'k, aud hi-iuk-n ' 



