424 
The Ohio Naturalist. 
[Vol. IX, No. 3, 
species, in only one or two instances has anything like a definite 
life history been worked out and then not very completely. 
Reports of their occurrence, the extent of injury and occasionally 
a description of egg, larva or pupa, with a few recommendations 
for treatment make up the bulk of the limited amount of liter¬ 
ature available. Mr. F. H. Chittenden 1 of the Bureau of Ento¬ 
mology has worked out the life history of Disonycha xanthome- 
laena at Washington, D. C. Miss M. E. Murtfeldt 5 reported the 
same species as doing considerable damage to spinach beds in 
Missouri in 1899. Mr. L. Bruner 6 has reported D. quinquevittata 
and D. pensvlvanica as injurious to young trees in Nebraska, 
early in the spring when the buds begin to open. Mr. H. 
Garman 7 has reported D. glabrata from Lexington, Ky. where 
the larvae strip the leaves from pigweed, Amarantus retroflexus. 
D. triangularis and D. xanthomelaena also do a considerable 
amount of injury to beet leaves in Illinois, although the natural 
host plant is the lambs-quarter. Brief mention of some of the 
other species has been made at various times, a list of which 
literature is found in the appended bibliography. 
Of the 18 species in the genus, 11 are found in Ohio, the list 
of which is as follows: 
1. Disonycha pensvlvanica. 7. 
2. “ discoidea. 8. 
3. “ quinquevittata. 9. 
4. “ crenicollis. 
5. “ caroliniana. 10. 
6. “ glabrata. 11. 
Disonycha abbreviata. 
“ triangularis. 
“ xanthomelaena. 
(collaris.) 
“ mellicollis. 
“ collata. 
A complete kev and quite elaborate descriptions of all the 18 
species of the genus has been worked out by Mr. Geo. H. Horn, 
M. D., and included in his paper on “A Synopsis of the Halticini 
of Boreal America” and since no key for the distinctly Ohio 
species is in print, the following key, adapted in great part from 
Horn, is presented with brief descriptions and notes on the 
distribution of the several Ohio species. 
Ivey to the Ohio Species of Disonycha. 
After Geo. H. Horn, M. D. 
1. Form elongate, parallel, elytra subsuleate, thorax rather irregularly 
convex; elytra yellow, with black vittae.pensylvanica. 
Varieties: 
Thorax with spots confluent in a large discal black space, having 
a comparatively narrow yellow border. Body beneath and legs 
black . limbicollis. 
Head in part yellow. Thorax beneath entirely yellow. Body 
beneath black, abdomen paler at sides and apex., pensylvanica 
Head in part yellow. Thorax beneath entirely yellow. Body 
beneath black. Abdomen paler at sides and apex. Legs are 
reddish yellow, tibia darker, tarsi piceous.pallipes. 
Black of the surface replaced by a rufous; legs even to tarsi, 
reddish yellow . conjugata. 
Form more or less oval, elytra even; thorax regularly convex.2 
