142 PROCEEDINGS ENTOMOLOGICAL SOCIETY 



the loose scales of bark on living trees, and the peculiar mouth- 

 parts appear to be an adaptation to such a life. 



Rhynchothrips pruni, new species. (PI. vi, fig. 4.) 



Female (for ma brachyptera). Length about 1.5mm. Color nearly black, 

 thorax paler; tarsi, articulations of legs, and at least the basal portions of 

 antennal segments 1-6, ochreous. 



Head as wide as long, broadest somewhat behind eyes; cheeks slightly 

 converging posteriorly, rounded rather abruptly to eyes and gently to base 

 of head; lateral and dorsal surf aces noticeably transversely striate, sparsely, 

 briefly, and scarcely visibly spinose; vertex slightly rounded in front; 

 postocular bristles pointed, equal in length to eyes. Eyes one-fourth as 

 long as head, subcircular as seen from above. Ocelli small, situated far 

 forward; anterior ocellus well down on vertex, overhanging; posterior 

 ocelli situated near anterior angles of eyes. Antennae stout, slightly more 

 than twice as long as head, faintly subreticulate; segment 1 slightly broader 

 than long; 2 swollen, 1.5 times as long as wide; 3 swollen, clavate, scarcely 

 twice as long as wide, pedicel one-fourth of greatest w r idth; 4-6 subglo- 

 bose, pedicellate, less than 1.5 times as long as wide, 4 broadest, 6 with 

 sides less rounded apically ; 7 oblong, pedicellate, truncate at apex and broad- 

 ly united to 8, which is conical, not narrowed at base, and twice as long 

 as wide; antennae bright ochre in first two segments, becoming gradually 

 darker toward apex, 7 and 8 being concolorous with body. Sense cones of 

 moderate length, slender; formula: 3, 0-1; 4, 1-1; 5, 1-1+'; 6, 1-1+ 1 ; 7 

 with one on dorsum near apex. Mouth cone very long, slender, fully as 

 long as dorsum of head, surpassing base of prosternum; labrum surpassing 

 labium. 



Prothorax slightly longer than head and (inclusive of coxae) only 1.7 times 

 as wide as long; pronotum with short, median thickening; all spines pres- 

 ent, pointed, only the pair at posterior angles long. Pterothorax slightly 

 wider than prothorax, sides straight, slightly diverging posteriorly. Legs 

 short and stout, the fore femora shorter than head; fore tarsi unarmed. 



Abdomen large, broad, about 1.4 times as wide as prothorax, narrowing 

 roundly from about segment 4 to base of tube. Tube about 0.9 as long as 

 head, less than twice as long as basal width, and fully twice as wide at 

 base as at apex, sides straight. Bristles pointed, brown; lateral bristles on 

 segment 9 subequal to terminal bristles, equal in length to tube. 



Measurements of holotype: Length 1.55 mm.; head, length 0.162 mm., 

 width 0.163 mm.; prothorax, length 0.175 mm., width (inclusive of coxse) 

 0.296 mm.; pterothorax, width 0.318 mm.; abdomen, width 0.426 mm.; 

 tube, length 0.148 mm., width at base 0.081 mm., at apex 0.035 mm. An- 

 tennal segments: 1, 27 /*; 2, 50 n; 3, 54 M; 4, 46 M; 5, 48 n; 6, 48 n; 7, 49 M; 

 8, 32 n; total length of antenna, 0.36 mm., width at segment 4, 0.033mm. 



Male. Slightly smaller than female, with more slender abdomen; fore 

 tarsi unarmed. 



