502 
ECONOMIC RELATIONS OF OUR BIRDS. 
follow, however, that the bird should be exterminated. I am confident that the 
service which this species renders in Wisconsin alone, during its hurried transits 
in the fall and spring, more than compensates for what injury it may do to 
grapes. It is unfortunate that the grajie-gi'ower should be obliged to sustain 
the whole injury of this species while the state at large shares its benefits, but 
such conditions are common, and, so far as I can see, to be endured. Should it 
be proved that the injury which the state sustains from this Warbler is greater 
than the service it receives, it would not then follow, as was stated in the “In¬ 
troduction,” that it should be exterminated. We are not the only people whose 
interests are affected by this bird. What the extent of its services during its 
five months’ stay in the south is, we do not knovv^ Until we do, we should be 
cautious how we destroy it for any trivial injury which it may do. 
Food: Of thirty-three specimens examined, two had eaten two very small 
hymenoptera (probably parasitic); seven, thirteen catei'pillars; three, fifteen diji- 
tera; six, thirteen beetles; three, forty-two plant-lice, among which were two 
specimens of the corn plant-louse Aphis maidis f?); three, thirty-five small 
heteroptera, .09 of an inch long; and one, eleven insect eggs. 
33. Dendrceca ^tiva (Gm.). Bd. BLUE-EYED YELLOW WARBLER; 
GOLDEN WARBLER; SUMMER YELLOWBIRD. Group I. Class b. 
This elegant little species and common summer resident frequents most com¬ 
monly the willow clumps of alluvial meadows, but is also to be seen in gi’oves, 
along wooded water-courses, and in vihages, orchards and gardens. In the 
Eastern and Middle States it is much more familiar and abundant than with us. 
At Ithaca, N. Y., it nests very commonly in the city, building in the shade and 
fruit trees, sometimes so close to the windows of the dwellings that its nest can 
almost be reached from them. It only requires suitable breeding places to be¬ 
come, in time, exti’emely serviceable as a destroyer of garden and orchard in¬ 
sects. It loves to search for insects in rosaries and among berry bushes. 
Food: Of five specimens examined, two had eaten four small larvae; two, two 
beetles. 
Small green caterpillars (Wils.). Said to feed on juicy fmits in autumn 
(Cooper). Canker-worm (Maynard). HymenoiDtera, moths and caterpillare, among 
them canker-worms, beetles, diptera, hemiptera, spidere and myriapods (Forbes). 
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34. Dbndrgeca VIRENS (Gm.), Bd. BLACK-THROATED GREEN WARBLER. 
Group 1. Class a. 
Migrant. Common during the middle of May, and again during nearly the 
whole of September; a few are said to breed in the state. Much of its food is 
taken upon the wing among the branches of trees. During its migrations it 
may usually be seen darting among the uppermost branches of high oj^en 
woods, but tamai’ack swamps, gi’oves, and orchards ai'e also visited by it. 
Food; Of twelve specimens examined, one had eaten a moth; three, seven 
caterpillars; one, two diptera; one, six larvae — probably caterpillars; three, 
eleven beetles; and one, a heteroptera. 
The smaller winged insects, caterpillars and other larvae (Brewer). Larvae of 
insects that prey upon opening buds (Wilson). Hymenoptera, caterpillars and 
curculios (Forbes). 
