NATURE OF INJURY. 15 
correspondent that the discoloration appears as soon as the boll 
opens. 
Following the foregoing accounts the next reference to the nature 
of plant-bug damage, so far as known to the writer, is a brief descrip- 
tion of damage to cotton in Egypt by a Lygseid, Oxycaremis hyalini- 
pennis Costa, published in 1890. a This description, which is cred- 
ited to Dr. E. Sickenberger, states that these insects "suck the sap 
from the base of the young pods and from the blossoms and thus 
prevent their development; they attack also the seeds when they are 
tender, which results in a diminution of the germinative strength and 
consequently a diminution in the product of the plant." A staining of 
the lint is also mentioned but the exact method by which this injury 
is brought about is unexplained. 
The cotton leaf-bug (Calocoris rapidus Say) and the bordered plant- 
bug (Largus succinctus L.) are reported by Mr. F. W. Mally 6 to 
damage cotton bolls, leaving a small, round, black dot at the point 
of the puncture. He says: "The injury nearly always has the effect 
of causing the boll to 'flare' and drop, or if not, then the tuft of 
cotton in that section of the boll becomes stained." The first 
accounts of damage to cotton bolls, with Heteropterous insects deter- 
mined as the cause by definite experimental work, were published in 
1905, Prof. E. D. Sanderson describing the injury caused by Calocoris 
rapidus, and the present writer the injury by the conchuela, Pentatoma 
ligata Say. Concerning the former Professor Sanderson says: "It 
punctured the squares and young bolls, either causing them to drop 
or making the bolls shrivel or decay where punctured. The punctures 
in the boll are indicated by small round black spots resembling dis- 
eased places, which gradually become larger and sunken.'' The 
fullest consideration heretofore published of the nature of the injury 
caused by the cotton stainers is found in the recent paper by Mr. 
H. A. Ballou, previously referred to. This author reports no per- 
sonal observations concerning the staining of cotton lint by the 
excrement of the bugs but mentions the probability of injury through 
the feeding of tin 1 insects on immature bolls and. Later, on the seed at 
time of the opening of the bolls. 
EXTERNAL EVIDENCE OF PLANT-BUG INJURY. 
As the Leaf-bug {('<il<>c<>ris rapidus) is sometimes present in con- 
siderable numbers in cotton fields where no external evidence <)( 
injury such as described by Professor Sanderson can he found, it 
seems likely that the sunken spots on the outside of the boll, resem- 
bling some diseased condition, are not a necessary accompaniment oi 
a Insect Life, Vol. III. v . 68, L890. 
6 Bui. 20. o. s.. Div. Km.. I'. s. Dept. Agr., j>. 31, 1893, 
c Farmers' Bulletin 223, p. '-'it. L905, 
