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Indiana University Studies 



basally; with 14 segments, the first not twice the length of the second, 

 the second somewhat elongate but short, the third only slightly longer 

 than the fourth, the last only one third longer than the preceding. 

 THORAX: Broad, brownish rufous to very dark brown, sometimes in 

 part blackish, scatteringly hairy, most densely hairy on the sides; 

 mesonotum finely, closely puncto-rugose, shagreened in places; parap- 

 sidal grooves fairly deep, more or less rugose at bottom, convergent 

 posteriorly, moderately close together at the scutellum, not extending to 

 the pronotum; median groove distinct and shortened, or lacking; an- 

 terior parallel lines rather fine to scarcely evident, extending more than 

 half way to the scutellum; lateral lines distinct, long, almost parallel 

 to the parapsides, somewhat curved inward anteriorly; scutellum rugose, 

 the basal depression broad, deep, smooth and more or less rugose at 

 bottom, separated by a very fine ridge into two, large foveas; pronotum 

 laterally rugoso-punctate, rather dense with long hairs; mesopleurse 

 densely, closely, irregularly aciculate, naked over most of the area. 

 ABDOMEN: Darker or lighter rufous; smooth, very microscopically 

 punctate on the ventral margins of the segments; naked except for a 

 very few hairs latero-basally, on the edges of the posterior segments, 

 on the ventral spine and valves; somewhat longer than wide, produced 

 only slightly dorsally, the second segment covering most of the ab- 

 domen; posterior edges of segments at a 75° angle, the ventral edges 

 only slightly rounded; ventral spine rather long, slender. LEGS: Al- 

 most wholly yellow rufous, tips of tarsi darker, the tarsal claws mod- 

 erately strong, simple. WINGS : Clear, faintly hairy, edges hardly 

 ciliate, veins brownish; areolet closed to large, cubitus very faint, not 

 reaching the basalis; radial cell open, neither vein reaching the margin, 

 second abscissa of the radius distinctly curved, first abscissa of the 

 radius arcuate to distinctly angulate. LENGTH: 1.7-3.7 mm. These 

 characters are common to all of the following species and varieties. 



GALL. — Monothalamous bud gall, cylindrical, more or less elongate, 

 two-parted in one species; slender tipped, the tip more or less curved; 

 smooth, with or without scurf or wool covering. Internally with an 

 elongate cavity usually extending most of the length of the gall, the 

 larval cell usually nearer the apical end of the cavity; the adults emerge 

 from near the base of the gall. Sessil, laterally, or terminally, on twigs 

 of Qitercus chri/solepis. 



RANGE.— California, (Arizona?). 



TYPE. — Andricus dasydactyli Ashmead. 



The species included in this genus are remarkably similar 

 in the morphology of the insects ; the large amount of detail in 

 the description of the genus applies to all species, emphasizing 

 their close relationships. More distinct differences in insect 

 structure are shown between the varieties of many species 

 than between the species of the genus. That the differences 

 between the insects of two species are nevertheless real enough 

 was evidenced when one of my freshman students, without 



