iii6 
Journal of Agricultural Research 
Vol. V, No. a 3 
This much remains: Fitch was not sure that he was not dealing with a 
compound species in his apple-root form and his winged forms. This is 
shown by the following note: “Amyot describes Eriosoma lanigerum as 
producing excrescences. Can these small lice be that species, and the 
winged ones another species accidentally present with them?” 
What Fitch suspected is, the writer believes, true, and Fitch described 
the winged form of one species and the work of wingless lanigerum . 
In the United States National Museum collection there is some material 
labeled “P. pyri Fitch, Type,” and mounted by Pergande from the Fitch 
collection. This proves to agree in every detail with the different descrip¬ 
tions of the winged forms given by Fitch. There seems good reason to 
believe that the material represents the specimens from which Fitch 
drew up his diagnosis. This is strengthened by the fact that the species 
occurs in the vicinity of Washington, D. C., and Vienna, Va., upon apple 
and upon pear ( Pyrus spp.) roots. It is particularly common upon pear 
roots, and it occurs also upon Crataegus spp. and ash ( Fraxinus spp.). 
Since this material seems to settle finally the standing of pyri , a descrip¬ 
tion is here given of the form based upon this material and- upon other 
specimens collected mostly from pear roots. The form proves to belong 
to the genus Prociphilus, and in order to separate it from other species of 
the genus, descriptive notes and figures are given of the other species 
known to the writer. Particular stress is laid in these notes on the dorsal 
wax plates of the thorax, since these seem to prove good diagnostic 
characters. 
The writer has never seen specimens of Prociphilus crataegi Tullgren, 
and it may be possible that pyri and crataegi are the same, since the 
sensory characters are similar. There seems, however, to be considerable 
difference in measurements. The question as to their distinctness or 
identity can only be determined by a careful comparison of the two. 
It is possible, also, that venafuscus Patch may prove to be pyri. But 
in the specimens studied by the writer the sensoria are much more even, 
and pyri seems to lack the small, pointed projection near the base of the 
third segment of the antennae. 
The following description will, however, serve to place pyri: 
Prociphilus pyri (Fitch) 
Fall migrant (fig. 1, E, Q).—Morphological characters: Antennal segments as fol¬ 
lows: I, 0,064 mm.; II, 0.096 mm.; Ill, 0.544 mm.; IV, 0.224 mm.; V, 0.24 mm.; 
VI, base 0.192 mm., unguis 0.064 mm.; segments III to VI with transverse sensoria, 
usually very irregular in disposition and giving the segments, particularly segment 
III, a gnarled appearance; segment III with 28 to 35 sensoria, segment IV with 8 or 9, 
segment V with about the same number, and segment VI with 3 to 6. These sensoria 
are on the underside of the antennae, the upper surface being armed with a few hairs 
situated on tubercles. Head above with two oval or almost circular transparent wax 
plates. Dorsum of thorax with a pair of rather small, somewhat triangular wax plates. 
Forewings 4.38 mm, long and 1.43 mm. wide at their greatest width. Hind tibiae 
1.2 mm. long. Length from vertex to tip of cauda, 2.48 mm. 
