349 



tinct species we have in North America. In this branch of the work 

 there is a splendid opening for original and valuable investigation. 



Agromyza pruni Grossenbacher 



Agromysa pruni Grossenbaclier, Bull. Torrey Bot. Club, Vol. 42, 1915, p. 235. 



Larva, full-grown (PI. LXXXIV, Fig. 8). — Length, 11-13 mm. 

 White, semitransparent, mouth hooks black. Prothoracic segment 

 longer than succeeding one, head parts retracted within prothorax ( PI. 

 LXXXIV, Fig. 9), prothoracic respiratory organs indistinguishable 

 except in one larva which had evidently been near the point of pupat- 

 ing. First abdominal segment longer than the two preceding thoracic 

 segments together and shorter than second abdominal ; segments 2 to 5 

 subequal in length; 6 shorter than 5; 7 and 8 together about equal to 

 6; integument of thoracic segments with numerous microscopic puncti- 

 form marks which are only visible under a very high magnification; 

 abdominal segments with microscopic setulae at the incisions, on their 

 anterior margins, those on segments i to 5 consisting of one or two 

 series which, like those of the apical segments, do not extend entirely 

 round the body ; segment 6 with 3 or 4 series, segment 7 with 6 or 7, 

 apical segment with 8—9 ; anal respiratory organs rather conspicuous, 

 ending in 3 short branches. 



Puparium (PI. LXXXIV, Fig. 10). — Length, 5 mm. Testaceous, 

 slightly shining. Anterior respiratory organs very small. Abdominal 

 segmentation not deep ; segments with weak transverse rugae ; anal ven- 

 tral orifice marked by a black spot ; anal respiratory organs small, but 

 slightly protruded. 



Imago: male and female. — Black. Head black, anterior portion of 

 frons, the antennae, and palpi brown. Legs black, fore tibiae and tarsi 

 and apices of mid and hind tarsi yellowish (alcoholic specimens). 



Frons over one third the head-width; orbits differentiated, each 

 about one fourth the width of center stripe; 5 pairs of orbital bristles 

 present, their length decreasing anteriorly; antennae of moderate size, 

 third joint rounded apically, pilosity short, arista slender, almost bare, 

 the entire length about equal to that of frons ; face concave ; cheek nar- 

 row, about one sixth as high as eye, marginal bristles of moderate 

 strength, not numerous, vibrissa well differentiated ; eye nearly twice as 

 high as long; palpi of moderate size. Mesonotum with 4 pairs of 

 dorso-central bristles, the two anterior pairs reduced in size, the fore- 

 Tiost pair well in front of suture; the pair of bristles between the pos- 

 ;erior pair of dorso-centrals half as long as the latter; disc with numer- 

 )us short setulae. Abdomen stout ; male hypopygium small, very much 



