131 
divided within by a notch intermediate in form between a V and 
a U. Apical part of each prong acute, curved ventrally upward 
and a trifle forward at tip. 
Described from three examples in alcohol. 
Protkctivk Mi;asures. 
The fact that the elm twig-girdler is deficient in the instinct of 
dispersal, and hence remains to breed in the twigs of the tree in 
which it originated, makes it a dangerous insect, but at the same 
time exposes it to wholesale destruction by artificial measures easily 
applied to the small number of trees which it is likely to infest to a 
dangerous degree. Its feeding habits and its life history suggest 
two practicable methods of destroying it. Since the beetle feeds on 
the leaves of the elm, it may be poisoned by arsenical insecticides 
sprayed on the leaves during the last week in May ; or, since it 
completes its transformations in its burrow, it may be killed in the 
larval or pupal stage by trimming off and burning the infested twigs 
in spring at any time preceding the middle of May. A combina- 
tion of these operations, first cutting off the visibly infested tvvigs 
and then spraying the tree to destroy any beetles coming in from 
outside or emerging from twigs overlooked, would be a doubly ef- 
fective safeguard against further injury. Both these methods were 
tested at Decatur with encouraging results. 
Infested twigs are easily recognized in spring by their stubbed 
ends, left by the breaking off of the twig at the place where the 
outer girdle has been made by the female before depositing hei 
eggs. Twigs containing the insects are commonly a fourth of an 
inch or less in diameter, and the pupa is formed almost invariably 
within two inches of the end of the stub. By a practical test of the 
trimming method, made in Decatur May 5, it was found that badly 
injured trees were easily cleared of infested twigs, which were 
readily seen among the scanty foliage, but that it was more difficult 
to make sure of a thorough operation where the injury was less and 
the foliage more abundant. Eighteen trees ten to thirty feet high 
were pruned by Mr. Taylor, with one assistant, in an average time 
of half an hour to the tree, using- a 14-foot step-ladder, a pruning- 
saw, and a pair of pruning-shears with handles eight and twelve 
feet long. No way was found, however, to clear by this means 
trees more than thirty feet in height, and for these the spraying 
method must be the main dependence. 
In Mr. Taylor's report of an extensive spraying experiment 
made at Decatur May 23, fifteen trees averaging about twenty-one 
