98 FIFTH REPORT OF THE ENTOMOLOGICAL COMMISSION. 



44. The white-lined thee hopper. 

 Thelia univittata Harris. 

 Order Hemiptera; family Membracid^. 

 Common upon oak limbs and twigs, puncturing them and sucking their juices. 



This tree hopper is found on the oak iu July. It is about four-tenths 

 of an inch in length ; the thorax is brown, has a short, obtuse horn ex- 

 tending obliquely upwards from in front, and there is a white line on 

 the back extending from the top of the horn to the hinder extremity* 



(Harris.) 



45. The oak blight. 



Eriosoma querci Fitch. 



Order Hemiptera ; family Aphidid^, 



A species of blight, or a woolly aphis upon oak limbs, puucturing them and exhaust- 

 ing them of their sap. 



This blight is very like a similar insect upon the basswood. The 

 winged individuals are black throughout, and slightly dusted over with 

 an ash-gray powder resembling mold. The fore wings are clear and 

 glassy, with their stigma-spot dusky and feebly transparent, their rib- 

 vein black, and their third oblique vein abortive nearly or quite to the 

 fork. It is .16 long to the tips of its wings. (Fitch.) 



46. The white oak scale-insect. 



Lecanium quercifex Fitch. 



Order Hemiptera ; family Coccid^e. 



Adhering to the smooth bark of the limbs of the white oak, in June, an oval, con- 

 vex, brownish-black scale, about .30 inch long and .18 wide, its margin paler and 

 dull yellowish, (Fitch.) 



47. The quercitron scale-insect. 



Lecanium quercitronis Fitch. 



Order Hemiptera ; family CocciD^. 



On the small limbs of the black oak; a scale like the preceding but smaller, and of 

 a nearly hemispherical form; its color varying from brownish-black to dull reddish 

 and pale, dull yellow, with a more or less distinct stripe of paler yellow along the 

 middle of its back, and the paler individuals usually mottled with black spots or 

 stripes. Length, .20; width, .16 inch. (Fitch.) 



These scales are parasitized by Platygaster lecanii (Fitch) 



48. The black scale of California. 

 Lecanium oJea' Bernard. 



The black scale is stated by Signoret to be properly iu France an 

 olive scale, sometimes, however, becoming so common as to occur on all 

 neighboring ])lants also. In California we tind it infesting the greatest 

 variety of plants and becoming a very serious enemy to orange and 

 other citrus trees. I have found it at Los Angeles on orange and all 



