202 REPORT OF THE COMMISSIONER OF AGRICULTURE. 



color. The anterior end of the body is nearly pointed and the posterior 

 end is truncate. At the juncture of the segments is a somewhat cleyateil , 

 broad ridge, which carries several rows of minute, backward-directed 

 teeth. Tlie last segment has its spiracles mounted upon a ])air of quite 

 long, slender tubercles, directed backward and curved inward, and the 

 prothoracic spiracles are also mounted on similar, though smaller, pro- 

 jections. 



The puparia are LS""'"* (.07 inch) in length, dark-brown in color, and 

 oval in shape. From each end of the body projects a pair of slender, 

 diverging, conical tubercles, which are the prothoracic and anal spirac- 

 ular tubercles mentioned in the description of the larva. There are only 

 ten segments of the body distinguishable, each well marked and rounded. 



The mines of this insect -were not noticed until October 23, although 

 there probably was one if not more earlier broods. The flies from the 

 mines, collected on the date mentioned, began to issue November 14. 

 They were stout, active, hairy, little black tlies, resembling the clover 

 Oscinis in general form, dilfering, however, in color and in being some- 

 what larger. Specimens were forwarded to Mr. Burgess, who deemed it 

 necessary to found a new species for them, and sent the following de- 

 8crix3tion for publication : 



OscE>a8 MALVAE, Burg., ep. nov. 



Black; face, lateral stripes on tliorax, and halteres briglit yellow. Scutellum with 

 six bristles. Front yellow, borders on eacli side, above, dnsky; occllar triangle and 

 antennae black; bristle with fine pubescence; face and cheeks yellow. Thorax black, 

 a broad, bright-yellow, longitudinal stripe on either side, which includes the base of 

 the -wings. Scutellum black, with six long bristles. Abdomen bristly, black. Wings 

 elightly clouded, roots yellow, Teins, except the costal, pale, darker towards the tips. 

 Third and fourtli longitudinals nearly parallel. Halteres bright yellow. Legs brown- 

 ish-black, knees of the first pair paler. Length of body, Uj''-'^ ; of wing, less than 2""". 



Habitat, District of Columbia; larva mines leaves of Malva rqtundifoJia. — [Prof. J. 



H. COMSTOCK. 



INSECTS INJUEIOUS TO ORANGE TREES. 



The production of oranges has become a very important industry in 

 the more southern parts of the United States, especially in Florida, Lou- 

 isiana, and California, and the number of orange groves under cultiva- 

 tion is increasing with marvelous rapidity. It seems probable that in the 

 near future a very large proi)ortion of the oranges consumed in this coun- 

 try will be produced from our own soil. The fact that imported oranges 

 cannot compete in delicacy of flavor with those grown in some parts of 

 the United States renders this more certain, provided the trees can be 

 kept free from the various diseases to which they are subject. 



The importance of guarding against the ravages of insects seems to be 

 appreciated by many orange-growers. Excepting cotton, there is no 

 crop respecting the insect enemies of which we have received more in- 

 quiries during the past year than that of oranges. And so little has the 

 subject been studied by entomologists that in many cases we have been 

 obliged to answer the inquiries by a confession of ignorance. Finally, 

 it was concluded to undertake a thorough investigation of the insect 

 enemies of the citrus fruits grown in the United States. To this end a 

 trfi> was made through the State of Florida during the months of Janu- 

 ary and February, 1S80. The object of this jouriicy was simply to make 

 a reconuoissance, so that the investigation could be conducted intelli- 

 gently and economically. During the trip, however, we carefully col- 

 lected specimens of all the insects found infesting trees of the genus 

 Citrus, and as full notes made upon their habits as was possible in the 

 limited time at our disposal. Living specimens were forwarded to Wash- 



