20 
that the great abundance of these insects in Michigan during the past 
summer was probably due to the large number present last vear. - 
While examining the orchards for the San José seale last winter his 
attention was attracted by the remarkable quantities of plant-lice eggs 
deposited on young nursery stock and on orchard trees. So numer- 
ous were these eggs in some cases that the trees had the appearance of 
being varnished. His experience agreed with that of Dr. Howard, that 
hot weather was a most important factor in controlling the increase of 
plant-lice. Referring to Mr. Howard’s first paper, Mr. Barrows spoke 
of the general lack of appreciation of the value of such experiments 
as those described and the lack of careful observations concerning the 
relation of temperature effects to the increase or decrease of injurious 
insects in connection with the abundance or absence of their natural 
enemies. A man might have observed a decrease or increase over the 
normal of the temperature for the winter of 1895-96 and arrived at the 
conclusion that this had been the chief factor in checking the outbreak 
of the Orgyia caterpillar, thus neglecting to take into account the 
action of the parasites. There was great need for careful and exhaus- 
tive observations whenever temperature effects are associated with the 
abundance or scarcity of any insect. 
Mr. Webster called attention to the fact that the great numbers of 
aphides in Ohio nurseries this year had seriously injured a large quan. 
tity of young, rapidly growing stock. 
In the absence of Mr. Chittenden, the secretary pro tempore read 
the following paper: 
NOTES ON CERTAIN SPECIES OF COLEOPTERA THAT ATTACK 
USEFUL PLANTS. 
By F. H. CHITTENDEN, Washington, D. C. 
The following notes are selected from a number of observations that 
have been made during the past year or two upon certain species of 
Coleoptera, most of which attack rather exceptionally cultivated or other 
useful plants: 
ORSODACHNA ATRA AHR. ON PEAR AND CHERRY.—In the Proceed- 
ings of the Entomological Society of Washington, published in June, 
1892 (Vol. II, p. 262), I mentioned the occurrence of this chrysomelid 
on the willow when in bloom. A year or two later it made its appear- 
ance as usual with the willow blossoms early in April, and a few days 
afterward when the fruit trees blossomed it was found also on pear and 
cherry, feeding upon the anthers of the flowers. 
In the National Museum collection is a specimen from Mr. J. G. Bar- 
low, collected in Missouri in March, 1883, and presumably at Cadet, 
labeled “ Feeding on catkins of hazel and alder.” 
This chrysomelid was not known as an injurious species until 1891, 
when Miss M. E. Murtfeldt observed it destroying the anthers of peach 
