THE THYSANOPTERA OF CALIFORNTA. 59 



(18) Thrips tabaci Lindenian. 



For description see Hinds's Mouograpli, page 179. 



Thrijps tabaci is common eveiy where in wild and cultivated flowers, 

 but its principal food plant is the onion. It has been very destructive 

 on several large seed farms where onions are grown for seed pur- 

 poses. It is commonly known as the onion thrips. 



(19) Thrips bremnerii, new species. (PI. V, tigs. 37-89.) 

 Meas\irements\ Head, length 0.1 mm., width O.lo mm.; prothorax, 



length 0.12 mm., width 0.14 mm.; mesothorax, width 0.18 mm.; al)- 

 domen, width 0.21 nun. ; total body, length 1.08 mm. Antenni«: 1, 21//; 

 2, 33/<; 3, 42//; -1, 86/^; 5, 33//; <^, 39/^; 7, 15//; total, 0.21 mm. Color 

 uniform light lemon-yellow, shading to light brown; abdominal seg- 

 ments often shaded brown on dorsal side. Body long and slender. 



Head about as long as wide, angular in front, Ijasal segments of 

 antenna? received in concave depressions on upper front side, back of 

 head faintly cross-striate; cheeks arched but little. A spine on either 

 side of anterior ocellus and one immediately behind each posterior 

 ocellus, the spines light, concolorous with head and not conspicuous. 

 Eyes prominent, protruding, pilose, black or deep purple by trans- 

 mitted light, red by reflected light. Ocelli subapproximate, veiy 

 light and margined inwardly with light-brown crescents. M<mth cone 

 shading dark brown toward the end and tipped with black; maxillar^^ 

 palpi three-segmented, labial palpi two-segmented, terminal one very 

 long. Antenna quite uniform light brown, basal segment often 

 lighter or second segment darker. 



Prothorax but little larger than the head; all angles rounded, and 

 if the body is distended, together with the light colored interseg- 

 mental membrane, the prothorax is quite round; two large brown 

 spines on each posterior angle, with a row of three on each side along 

 the hind margiti, the inner one being the larger. PteiiJiora.r some- 

 what darker than prothorax; sides of mesothorax rounded, sides of 

 metathorax narrowed in front, forming a (juite noticeable concave 

 depression on either side. Legs medium, concc^lorous with or some- 

 what lighter than body, hind tibia^ alone armed with spines, a dark 

 brown spot on the tip of each tarsus. Wings fully developed, though 

 not reaching to tip of abdomen, lu'oad at base; unifoi-m white with 

 brown spines. Veins are either very rudimentary or, as in some 

 specimens, highh^ developed. In these latter the two longitudinal 

 veins may be seen extending to and joining the margin on either side 

 of the tip; also there are two cross veins, one at about one-third, and 

 a second at about two-thirds the wing's length from the base; they 

 connect costa and foi'e longitudinal vein. Costa with twenty-tive 

 spines; fore vein with twelve, arranged as follows: Two groups of 

 four and three, respectively, on basal half of wing, and Ave others 

 regulai'ly placed on distal half; twelve on hind vein. 



