253 



THE STRUCTURE OF THE MOUTH-PARTS OF PANGONIA LONGIROSTRIS 

 IN RELATION TO THE PROBABLE FEEDING-HABITS OF THE SPECIES. 



By H. Tetley, B.Sc. (Leeds). 

 (From the Dept. of Agricultural Entomology, Manchester University.) 



(Plate VI.) 



« 



CONTENTS. 



I. Habits and Economic Significance of the Genus Pangonia 



II. Mouth-parts of the Female 



III. Mouth-parts of the Male 



IV. Measurements in Millimetres of the Mouth-parts of both Sexes 

 V. Conclusions as to the Feeding Habits of the Species 



VI. Comparison of the Mouth-parts with those of other Tabanidae 



PAGE. 



253 

 258 

 262 

 264 

 264 

 265 



The present research was carried out in the Department of Agricultural 

 Entomology at Manchester University, under the direction of Dr. A. D. Imms. I 

 am greatly indebted to him both for giving me the insects upon which this research 

 was prosecuted, and also for much help at the University, and afterwards in 

 looking over my paper and aiding its publication. 



I. Habits and Economic Significance of the Genus Pangonia. 



Pangonia longirostris is one of the Orthorrhapha Brachycera, of the family 

 Tabanidae and sub-family Pangoniinae. This fly was first described by 

 Hardwicke in the Transactions of the Linnaean Society of 1825 from specimens taken 

 in Nepal. His description is as follows : — 



" P. villosa flava, thorace ferrugineo, abdomine nigro-brunneo : segmentorum 

 marginibus flavis, alis immaculatis. 



" Rostrum about twelve times longer than the head. Antennae approximated 

 at the base, short, consisting of three pieces, the two lowest of which are very 

 small, the upper one long, tapering to a point, and composed of eight small articula- 

 tions. Eyes large, very prominent. Head and thorax very hairy both above and 

 beneath, longer under the throat ; of a bright yellow beneath, brownish above. 

 Wings longer than the body, hyaline ; costal nervures brown. Body black ; the 

 margins of each segment shining, the sides hairy. Halteres short, having the shafts 

 yellow and the knobs ovate, black. 



