20 
Journal of Agricultural Research 
Vol. II, No. t 
Mr. J. R. Malloch, formerly of the Bureau of Entomology, has kindly 
consented to draw up descriptions of the larva and pupa. He has rede¬ 
scribed the adults also. His descriptions follow. 
THE LARVA (FIGS. 3 AND 4) 
Fig. 3. —Agromyza parvicornis , the corn-leaf 
blotch miner: Full-grown larva; a. sp., anterior 
spiracles; p. sp., posterior spiracles. Much 
enlarged. (Original.) 
In color the larva is pale greenish white, becoming, as it nears maturity, more 
yellowish white. The average length when mature is about 3 mm. and the breadth 
about 1 mm. The segments are but poorly defined and under a strong magnification 
show on the surfaces shallow, closely placed 
punctures, in each of which is situated a 
very minute hair. The mouth parts are 
heavily chitinized, deep black, and, while 
capable of being entirely retracted, are 
always visible, as they show clearly through 
the semitransparent larval skin. The spir¬ 
acles of the anterior pair are small and 
slightly darker than the general color of the larva; the posterior pair, which are more 
or less embedded in the body, are closely approximated and placed at the extreme 
end of the body. On the ventral surface close to the anal extremity there is a vestigial 
sucker-like foot. 
THE PUPARIUM (FIG. 5) 
In color the puparium is reddish brown. The length averages about 3 mm. and the 
breadth slightly over 1 mm. The segments are well differentiated, without any 
ornamentation or punctation. The spiracles of the anterior pair are prominent and 
protruding, those of the posterior pair (fig. 5, c) much more closely placed and less 
distinct. In shape the puparium is as represented in figure 5, a and 6. 
THE ADULT (PL. Ill, FIG. i) 
Agromyza parvicornis Loew, 1869, in Berlin. Ent. Ztschr., Jahrg. 13, No. 92, p. 49. 
Male and Female —Frons black or black brown, opaque; orbits slightly shining 
black, four orbital bristles present; orbits differentiated from center stripe, bristles 
situated nearer inner than outer margin of orbits, a few 
weak hairs in an irregular row laterally beyond them. 
Antennae brown or brownish black, rather below the 
normal size; third joint short, rounded in front, 
thickly covered with short, soft, whitish pilosity; 
arista brown, generally yellowish near base, except 
on the short thickened portion, which is glossy black; 
pubescence very close, generally distinct; length of 
arista equal to the distance from its base to the upper 
orbital bristle. Face brown, nearly perpendicular in 
profile, the central keel slight; cheeks brown or yellowish brown, very much higher 
posteriorly than anteriorly, at highest part one-third as high as eye; marginal bristles 
numerous; vibrissa differentiated but not very strong; proboscis brown; palpi black, 
very slightly dilated, weakly bristled. Mesonotum glossy black; disk thickly 
covered with short setulae; two pairs of dorso-centrals present; the bristles between 
the posterior pair distinct; pleurae, scutellum, and postnotum concolorous with 
disk of mesonotum, pleural sutures rarely, and beneath wing bases generally 
yellowish; squamae whitish yellow, fringes brown. Abdomen colored as the 
thorax; ovipositor of female as in Plate III, figure 1, E; hypopygium of male as in 
Plate III, figure 1, D. Legs black, the tibiae and tarsi sometimes paler, brownish 
Fig. 4. —Agromyza parvicornis , the 
corn-leaf blotch miner: Mouth 
hooks of larva. Greatly enlarged. 
(Original.) 
