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sweet clover (Melilotus alba), pink fleabane (Erigeron philadelphi- 
cus), daisy fleabane (E. ramosus), mare's tail (E. canadensis), rag- 
weed (Ambrosia trifida), coneflower (Rudbeckia laciniaia), yarrow 
(Achillea millefolium), oxeye daisy (Chrysanthemum leucanthe- 
mum), thistle (Cnicus altissimus) , wild lettuce (Lactuca canadensis 
and L. floridana), bellflower (Campanula americana), nettle (Urtica 
gracilis and U. dioica) and timothy (Phleum pratense). Most of 
these are Compositcu, it will be noticed, and nearly all are weeds. 
Injury. — The beetles do not lay their eggs in seedling clover, but 
find clover that is more than one year old and select only the larger 
stems of that. 
By autumn, red clover sown in spring has developed stems of con- 
siderable size, and the beetles are present — but they do not lay eggs in 
autumn, in my experience. 
The larva, by eating the pith, hollows out the clover stem, making 
a long burrow, the walls of which turn brown. By cutting stems 
across, beginning near the ground, and looking at the cut ends, one 
can see whether the pith is white and solid or whether it has been 
eaten out by this borer. The larvae eat usually nothing but the pith, 
which happens to be the part that the plant can best afford to lose. 
Comstock wrote, "While they do not kill the stem outright, they 
gradually weaken it and eventually cause its destruction, having also, 
of course, a very injurious eft'ect upon the maturing of the seed." Un- 
doubtedly the insect is injurious, but it is not so injurious as might be 
supposed. The loss of the pith may affect the nutrition of the plant 
to some extent, since the pith contains reserve food-material in the 
form of starch. The chief effect of the stem-borer is, however, a 
mechanical one. The stems that are hollowed out fall to the ground 
prematurely, tho not until they have attained a considerable size. One 
can find the borers most abundantly in the large prostrate stems rather 
than in the stems that remain erect. The plants that lodge carry 
their flowers to the ground, become soiled with dirt, and are not easy 
to mow. Mammoth clover, running far into the season, lodges badly 
from the work of the borer; while medium red clover, if cut when it 
should be, escapes practically all injury from this insect. 
Rarely the borer occurs in a small soft stem and causes it to wilt ; 
for in such a stem the larva eats not only the pith, but also some of 
the adjacent ducts, thru which water is conveyed up the stem to the 
leaves. In old stems these ducts are too tough to be eaten by the 
larva. 
Were this insect more numerous it might gradually develop into 
a pest of considerable importance. It is most common on clover, but 
has to its credit the fact that it affects also a considerable number of 
weeds. 
July 6 we found 41 percent of the old stems to be infested by 
this borer. This was in the hay crop — as yet uncut. On the same 
day we examined 61 new stems — the second growth after cutting — 
and found two egg pits as the only signs of the borer. The beetles 
