September, 1941 
sprays or dusts. It is an insect that should 
be looked for every year. 
The hickory plant bug, Neolygus caryae 
Knight, may migrate from its natural host 
to peach trees, where the adults puncture 
and suck sap from the young fruit. It 
causes some injury to peaches, which is simi- 
lar to that of the tarnished plant bug. Seri- 
ous damage by this insect has been reported 
from New York and Ohio. 
In several western states the legume bug, 
Lygus hesperus Knight, causes considerable 
loss in alfalfa seed due to puncturing and 
feeding by the bugs on the flower buds. The 
pale legume bug, L. elisus Van Duzee, does 
similar damage, but in most localities this 
KNIGHT: PLANT Buss, or MirIpDAE, oF ILLINOIS 1 
species is outnumbered by L. hesperus. In 
the upper Mississippi River valley the 
alfalfa plant bug, Adelphocoris lineolatus 
(Goeze), is extremely abundant on alfalfa 
and sweet clover and may prove to be a pest 
where these crops are grown for seed pro- 
duction. 
Other species of Miridae that are from 
time to time reported as pests are hop plant 
bug, Paracalocoris hawleyi Knight, on hops; 
hollyhock plant bug, Melanotrichus althaeae 
(Hussey), fig. 16; meadow plant bug, Miris 
dolabratus (Linnaeus), on timothy and 
other grasses; and the rapid plant bug, 
Adelphocoris rapidus (Say), on cotton in the 
South. 
Taxonomy 
The Miridae are distinguished by four- 
segmented antennae, a four-segmented ros- 
trum of which the first segment is as long as 
or longer than the head, three-segmented 
tarsi (except Peritropis in which they are 
two-segmented), wing membrane with only 
two cells or areoles, one longitudinal vein 
(anal vein), a well-developed cuneus on the 
wing, and by absence of ocelli, fig. 17. The 
four-segmented antennae are usually slen- 
der, nearly linear or the second segment 
only slightly thickened apically, but in a few 
genera strongly thickened as in Capsus, 
Atractotomus and Teleorhinus; third and 
fourth segments usually slender but in some 
forms distinctly thickened as in Ceratocap- 
sus. The hemelytra are typically separated 
into clavus, corium, cuneus and membrane, 
the embolium usually not clearly separated 
from corium; veins of membrane forming 
two cells, a small and larger areole; how- 
ever, in a number of species the hemelytra 
may be abbreviated (brachypterous), the 
membrane almost absent or reduced to a 
narrow band with veins poorly indicated. 
Modifications of the arolia, the pulvillaelike 
structures between the tarsal claws, furnish 
the most reliable characters for separating 
the subfamilies. 
In general, the Miridae are small to 
medium in size, from 2.0 to 9.5 mm. in 
length, usually rather fragile, broader than 
high and longer than broad; as viewed from 
above, ovate to oblong, but in a few genera 
rather slender, as in T'rigonotylus. The 
male is usually more slender than the fe- 
male. The body is variously clothed with 
fine hairs or pubescence, sometimes modified 
to form sericeous or scalelike hairs, which 
are easily shed; frequently the dorsum is 
practically glabrous and strongly shining. 
The numerous species exhibit the greatest 
variety of color patterns, ranging from the 
most obscure to forms that are vivid red. 
Color varieties within the species are fre- 
quent, and the two sexes are more often 
differently colored, the male usually darker 
colored than the female. 
Brachypterous and apterous forms occur 
throughout the family, and individuals of a 
single species may exhibit variation in this 
respect, as in Halticus bracteatus (Say) and 
Miris dolabratus (Linnaeus). Usually the 
male is macropterous even when the female 
is apterous, but in rare cases the male may 
be apterous. Ant mimic forms are rather 
numerous among the Miridae, especially in 
species of Coquillettia, Sericophanes and 
Pilophorus. In such forms the abdomen is 
constricted at the base while the head and 
thorax are so modified the resemblance to 
ants is unmistakable. The species of Seri- 
cophanes and Cogquillettia are generally 
found upon the ground running about among 
ants, but the biological relationship, if any, 
has not been determined. In Iowa the writer 
has found Sericophanes heidemanni Poppius 
rather abundant on the ground among short 
grasses and weeds of closely cropped pasture 
land; the bugs running about where the little 
brown ants, Lasius niger alienus var. amert- 
canus Emory, were very abundant. At Fort 
Snelling, Minnesota, in an area of little 
disturbed, high, prairie vegetation, particu- 
larly among the shorter grasses, the writer 
found and collected a large series of Coquil- 
