TEPHRITIS (oXYNa) FLAVIPENNIS, LW. 57 



Variation in the wing=niarkings of Tephritis (Oxyna) flavipennis, Lw. 



(IVitk plate.) 

 By J. E. COLLIN, F.Z.S., F.E.S. 



The Dipterous family Tri/petidae, to which the above species belongs, 

 is composed of Acalyptrate Muscids with, in the majority of cases, 

 prettily mottled or banded wings ; the shape and disposition of these 

 wing-markings constituting specific, and to a certain extent, generic 

 characters. Many of the species live in the larval stages intheliower- 

 heads, or stems, or in galls on the stems or roots of 'Jumiumtae. : others 

 live in the seeds, or fruit, or mine the leaves, of various plants. The 

 ■imagines in many cases are never found far away from their food-plant, 

 and are often sporadic in their appearance, so that a species which for 

 man^^ years may have been considered a great rarity suddenly turns up 

 in considerable numbers ; this has been the case so far as ni}' experience 

 goes with the species under discussion, T. jiavipenim : over forty years 

 collecting by the late Mr. Verrall produced only two specimens, but in 

 June and July, 1904 and 1911, Mr. C. G. Lamb of Cambridge found 

 the species in a very limited area in the parish of St. Merryn (Corn- 

 wall) and could have taken any number of specimens ; he called my 

 attention to the great variation displayed in the wing-markings of his 

 long series, and very kindly placed the specimens unreservedly at my 

 disposal for purposes of study. Owing to the great use made of 

 characters in the wing-markings for distinguishing species, the publi- 

 cation of a few photographs taken by my friend Mr. Hugh Main, 

 showing, to a certain extent, the amount of variation in Mr. Lamb's 

 specimens, may not be without scientific interest. 



T. jiai-ipennis, Lw., so closely resembles two other British species, 

 parietina, Lw., and proboscidea, Lw., that Loew in his monumental 

 work Die Eio-opaischeii Bohrjiieifen (1862) expressed a doubt as to 

 whether they were not really all varieties of one species ; he, however, 

 overlooked the important character of an extra pair of dorso-central 

 bristles on the thorax oijiavii)eiuiis, making three pairs in all, while 

 parietina and' probuscidea have only two pairs of such bristles. The 

 larva of T. jkicipennis lives in galls on the root-stock of Acliillea iiiille- 

 foliniii. 



T. parietina, L., has rather smaller eyes and consequently larger 

 cheeks ihena jlaripennis, and the proportion of depth to length of head 

 is more equal, while the proboscis is not quite so long. On the wings 

 the crossveins are rather closer, and the triangle of hyaline spots having 

 its base on the costa is not so directly over the crossveiu closing 

 the discal cell, but slightly beyond it. I have not yet seen a British 

 specimen, but as the larvie live in the stems of Artemisia rnli/aris, a 

 common British plant, ; the record as British is probably correct. 



1 . proboscidea, Lw., has more the wings of parietina and the head 

 of llaripennis, but in addition to the one pair of black incurved lower 

 fronto-orbital bristles, there are 1-2 pairs of quite small, whitish, 

 incurved bristles that are absent in the other two species ; moreover 

 proboHciilea normally has only two pairs of scutellar bristles, while the 

 other two species normally have four. The larv;e live singly in galls 

 on the root-stock of Chri/sant/iemKni le>icanthetintni. 



The Plate is self-explanatory, the top left hand figure showing a 

 specimen with the pale markings abnormally extensive, those below 

 this and on the right showing a gradual restriction of these pale 



