12 IOWA STUDIES IN NATURAL HISTORY 
are beneficial, others are harmful although in our own state 
damage of a serious nature has not yet been reported. 
Most of these bugs are mainly or wholly plant feeders and dur- 
ing both the adult and nymphal stages feed by inserting their 
beaks into the plant tissues and extracting the juices therefrom. 
Important vegetable and truck crops are often subject to injury. 
Growing shoots of plants and developed fruit are usually chosen 
for points of attack and they may be retarded in growth or killed 
if the infestation be severe. In addition to this damage from the 
punctures themselves, recent investigations have shown that 
some of the pentatomids at least are distributors of certain fun- 
gous diseases in plants. In the Southern States the Harlequin 
Cabbage Bug, Murgantia histrionica (Hahn), and the Southern 
Green Plant Bug, Nezara viridula Linn., are two of the most 
serious pests with which the truck farmer and fruit grower have 
to contend. 
The genus Huschistus which contains one of our most widely 
distributed and abundant species, E. variolarius (P. B.), includes 
other species which are mainly plant feeders, although a few are 
more or less predaceous and destroy noxious insects. Huschistus 
variolarius is known to feed on Carduus, Thermopsis, maize, as- 
paragus, broom corn, oats, rye, red clover, tomatoes, raspberry, 
mullein, tobacco, grasses and peaches. It is also said to feed on 
some lepidopterous larve. Of course it is only when the number 
of such insects increases greatly above normal that marked dam- 
age is done. 
The members of the subfamily Asopinae may be, on the whole, 
classed among our beneficial bugs for they feed, in part at least, 
on noxious insects. In the nymphal stages many of these bugs 
are plant feeders while in the adult stage some are predaceous 
and others are both predaceous and plant feeders. Members of 
the genera Apateticus and Podisus are included here and among 
the insects attacked by the Iowa representatives may be men- 
tioned several species of leaf beetles of the family Chrysomelidae. 
The negro bugs of the genus Thyreocoris often attack eulti- 
vated plants and although no serious outbreak has occurred in 
Iowa, some damage has been noted on potatoes, wheat, tomatoes 
and other garden truck. In the South, tobacco is often injured 
