Report of the State Entomologist. 



197 



and too costly an operation. When the plant is seen to be so badly 

 attacked that the removal of the infested leaves would almost involve 

 its defoliation, then the plant should be burned at once. By such 

 stringent measures there is but little doubt that an attack taken at, 

 or soon after, its commencement would be arrested. 



Identified with the European Form. 



As the insect and its attack seemed to be unknown in this country, 

 examples of the fly, together with its pupae and mines, were for- 

 warded to Baron Osten Sacken, who readily identified it as the 

 ■Phytomyza lateralis Fallen, of Europe, and cited the following litera- 

 ture upon it: 



" It is figured in Curtis' British Entomology, vol. viii., Diptera, plate 

 393. The description is incorrect and misleading ; a better one 

 may be found in Schiner's Fauna. 



"According to Kaltenbach, loc. cit., the fly has been found in the 

 heads of Gompositce {Anthemis, Pyrethrum, and Chrysanthemum) and also 

 in the stems of Centaurea (of the Gompositce), Verbena, and Urtica dioica. 



" Schiner quotes from Ann. Soc. Ent. Er., ii., 9, 156, to the effect that 

 Goureau had found the larva mining in Sonchus oleraceus, or sow- 

 thistle. It is nowhere else recorded as a leaf-miner." 



Description of the Fly. 



Curtis' description above cited, is as follows : Silky cinereous. Head 

 and antennae black; lip 

 and face yellow : eyes 

 with a reddish tinge 

 when alive, entirely 

 black when dead; 

 several black bristles 

 on the crown of the 

 head and a row down 

 each side of the face. 

 Thorax with the 

 pleurae yellow, six 

 longitudinal rows of 

 strong black bristles 

 and several of smaller 

 ones between them. 

 Abdomen black, shin- 

 ing, and pilose, a-broad 

 margin on each side 

 beneath and the an- 

 terior edges of the 

 segments yellow, that 



of the sixth being the Fig. 32. — The Marguerite fly, Phytomyza lateealis, 

 broadest. Wings yel- enlarged ; with still greater enlargement of wing and head, 

 low at the base, nerv- the latter in different views. 



ures brown, the central one very faint. Halteres yellow. Legs black, 

 tips of the thighs yellow. 



