554 FIFTH REPORT OF THE ENTOMOLOGICAL COMMISSION. 



There are two plates caudad of each incision ; these plates are usually simple, but 

 are sometimes toothed ; occasionally there is a third plate in one or more of these 

 places. There are three to four irregular slender plates between the third and fourth 

 pairs of spines. The first, second, and third pairs of spines are situated as in allied 

 species; the fourth pair is at two-thirds the distance from the lobes to the penulti- 

 mate segment. Described from five specimens from maple, two from peach, seven 

 from osage orange, twelve from hackberry, fifteen from ash, and eleven from Staphyllea 

 trifoliata. 



Variety. — A form oi Aspidiotus was found, the scales of which I am unable to dis- 

 tinguish from those of A. ancylus; but the last segment of the female presents the 

 following difference from the typical form of this species: There are no plates be- 

 tween the third and fourth pairs of spines ; and the vaginal opening is mesad the 

 anterior spinnerets of the posterior lateral groups, instead of the posterior members 

 of the same groups. The variation in the number of the spinnerets is greater in my 

 specimens of the variety than in those of the typical form, there being in some cases 

 seventeen on the anterior laterals, and nine in the posterior laterals. Described 

 from twenty-one specimens from linden, eleven from beech, eighteen from oak, and 

 four from water-locust. 



Scale of male. — The scale of the male resembles that of the female in color, but is 

 smaller and more elongated. Length 1.2""", width 0.6""". 



Male. — The male is easily distinguished from all other species known to us by the 

 small size of its wings. We have bred numerous specimens from seven species of 

 plants : Maple, Staphyllea, hackberry, ash, osage orange, peach, and water-locust. 

 These males show considerable variation, and for a time I believed that I had two 

 species. In each the color of the body is orange yellow ; in the former, which was 

 bred from peach, the thoracic band is dark brown, and the distal joints of the antennae 

 are not enlarged ; in the latter, which was bred from ash, the thoracic band is of the 

 same color as the remainder of the body, and the distal joints of the antennte are con- 

 spicuously enlarged. These two forms shade into each other, and each was bred 

 from plants which were infested by the typical females only. 



Habitat. — Davenport, Iowa (Putnam), Washington, and western New York, Dis- 

 trict of Columbia. (Comstock.) 



26. The ash gall-mite. 



Phytoptus fraxini Garman. 



Class Arachnida ; order Acarina. 



In Mr. S. A. Forbes' twelfth report as State Entomologist of Illinois, 

 Mr. H. Garman describes two gall mites found on the asb, the first of 

 which produces galls on the leaves of the green ash, Fraxinus viridis, 

 Michx. 



The light-green color of these galls so strongly contrasts with the dark leaves that 

 the latter appear at a little distance to be spotted with light. It is a depressed wart- 

 like gall. The center of its cavity is about in the 

 plane of the leaf, as the projection above and be- 

 low is nearly equal. The outer surface is vari- 

 ously indented, in some cases as if with the finger- 

 nail. The outline seen from above is elongate, 

 circular, or quite irregular. The opening beneath 



_ ,o„ TT X- 1 x- ^ T^^ is a slit, surrounded by a raised lip clothed with 

 Fig. 186.— Vertical section of a Phy- ' ' ' 



toptus gall from a leaf of the green ash ^l^it® ^^^rs. One or more folds with many- 

 {Fraxinus vii-idis). AfterGaiman. celled hairs at their free edges project into the 



interior, dividing it into more or less perfect com- 

 partments. The median of these folds is usually largest, and sometimes reaches the 



