THE THYSANOPTEKA OF CALIFOKNIA. 65 



JJescr'ihcd from one nuile. 



Food plant : Gvitss. 



Habitat: Alum Hock Cunyoii, Cal. 



10. Genus MEGALOTHRIPS Heeger. 



(25) Megalothrips hesperus, new species. (PI. VI, tigs. ,53-5«!.) 



Jlea-sur&inents: Head, length 0.58 mm., width 0.26 iimi. ; prothorax, 

 length 0.25 mm., width 0.46 mm.; metathorax, width 0,83 mm.; abdo- 

 men, width 1 mm. ; tube, leng-th 0.83 mm., width 0.11 mm. ; total bod}", 

 length -1:.66 mm. Antennas: 1, 75/^; 2, 81//; 3, 315/i; 1, 234yu; 5, 195yu; 

 6, 102//; 7, 75//; 8, 90/^; total, 1.17 mm. ^^W/w dark brown, with orange 

 or red pigment; all tibife and tarsi shaded to yellow; bases of antennal 

 segments 3, 4, 5, and 6 are lemon-yellow. 



Head more than twice as long as wide, greatest width across eyes; 

 cheeks roughened, almost parallel, slightly concave close behind eyes, 

 constricted at union with prothorax; Irons elevated between bases of 

 tirst segments of antennas; back of head transversely striate and with 

 a few short spines set on very small tubercles. Hyts large, with con- 

 spicuous light-A^ellow outer borders; with small facets and ver}' faintly 

 pilose. Ocelli present, anterior one on apex of head, posterior ones 

 contiguous, with indistinct, light inner margins of eyes. Moutl^ cone 

 ))road and short, with blunt tip, and reaching hardly halfway across 

 prosternum. Maxillary palpi two-segmented, basal segment very 

 short; labial palpi very small. Antenyise, eight-segmented, about twice 

 as long as head; segments 1, 2, 7, and 8, and tips of 4, 5, and 6 brown; 

 tip of 3 light-brown; segment 3 with along, narrow stalk; segments 4 

 and 5 similar, but with shorter stalks. Darkened sense area on seg- 

 ment 2; one sense cone on segment 6, two on segments 3 and 5, four 

 on 4, and a row of sense hairs on segment 8. 



Prothorax about one-half wider than long, transverselv. striate; it 

 bears six prominent spines, two on anterior margin, a pair on anterior 

 angles, and a larger pair on the posterior angles. Memthorax with 

 prominent, square, anterior angles; sides almost straight and parallel, 

 with edges roughened, united evenl}" with metathorax. Metothirdx 

 with posterior angles broadly rounded. Leg^ long and slender; all 

 femora dark-brown; tibire yellow, shaded with brown near the middle; 

 tarsi yellow tipped with brown; trochanters with red pigment. All 

 legs armed with long, stout, j^ellow spines; these are especially prom- 

 inent on femora; fore coxte protruding, forming the prominent angles 

 of the prothorax. Wings present, reaching to tip of fourth abdominal 

 segment; membrane white; both pairs with long, simple anterior and 

 posterior fringes of closely arranged hairs; anterior wings double 

 fringed along their posterior distal margin for about half their length; 

 each wing with a single rudimentary vein. 



