22 MASS. EXPERIMENT STATION BULLETIN 157. 



The methods and appUances used in connection with the work are all 

 very simple. The methods are described in the various sections which 

 follow. The habits of the adults were studied very largely with the aid 

 of an ordinary pocket lens while the flies were at large upon the host plants 

 in the insectary. In the study of the other phenomena relating to the 

 adults, cheesecloth bags possessing a certain degree of stiffness were found 

 very useful. In the laboratory, for the study of the various stages, habits 

 of the larva, etc., an ordinary compound microscope and a Zeiss-Greenough 

 binocular were found indispensable. 



The outlines of the drawings, except that of the adult, were all made 

 by means of the camera lucida. The photographs were taken by T. W. 

 Nicolet under the direction of the writer. 



HISTORY AND DISTRIBUTION. 



The Chrysanthemum Leaf Miner, Chrysanthemum Fly, Marguerite 

 Leaf Miner, Marguerite Daisy Fly, or the Marguerite Fly, as the insect is 

 variously called, was first detected in this country, according to Dr. 

 Lintner (Fourth Report on the Injurious and Other Insects of the State 

 of New York, 1888, p. 73) in October, 1886, in the greenhouse of Mr. 

 Chas. A. Dana, near Glen Cove, N. Y. Dr. Lintner writes: "The leaves 

 of some daisies (marguerites) were seen to show some wart-like specks 

 and irregular, whitish, Unear markings, and soon afterward to shrivel up 

 and die. Examination for the cause disclosed very small 'worms' work- 

 ing within channels in the interior of the leaves." Some of the infested 

 foliage was sent to Dr. Lintner in Albany the foUov/ing February. The 

 operations of the insect were first noticed by Mr. Wm. Falconer, head 

 gardener at "Dosoris." 



Mr. Falconer reported this discovery independent!}^ in the "American 

 Florist," March 15, 1887 (Vol. II., p. 297). "This little pest," writes 

 Mr. Falconer, "made its first appearance here last November." (There 

 is a shght discrepancy between the statements of Dr. Lintner and Mr. 

 Falconer regarding the first appearance of the fly in the greenhouse; 

 according to Dr. Lintner it was October.) "Before then I was not aware 

 of its presence in this country, but since then I find it as abundant in green- 

 houses at Glen Cove Landing and at Hinsdale as it is here." (Mr. 

 Falconer, like some others at the time, thought the insect a European 

 species.) "I first observed its presence by noticing little wart-hke specks 

 and irregular, whitish, line-hke markings on the leaves of some of the 

 marguerites, and these traces soon multiphed exceedingly and the much- 

 affected leaves wdthered up and died. The fly is a small insect and might 

 readily be mistaken for one of the little flies so abundant about fermenting 

 horse manure. When disturbed it ' hops ' about rather lazily or flies from 

 one branch to another, but seldom flies away more than a few feet. It 

 lays its eggs singly under the skin of the leaf, the wart-like specks forming^ 

 over the eggs. In a few days' time the little white grubs are hatched; 

 these are the evil workers. Thev devour the fleshv substance between 



