XEliiOW-BELLIED WOODPECKER OR SAPSUCKER. 29 



purpose of feeding on the inner bark. Thus, instead of destroying 

 insects, it made the conditions favorable for the attack of bark beetles 

 and other insects which had bred in the bark and wood in considerable 

 numbers. To anticipate the possible conclusion that the woodpecker 

 intended to thus trap the insects and return to eat them. Dr. Hopkins 

 added that at the time the observations were made, the insects had 

 not been molested.* 



This investigation of the food- of the yellow-bellied sapsucker is 

 based upon examination of the contents of 313 stomachs, collected in 

 24 States, Canada, and the District of Columbia, and distributed over 

 12 months of the year. Of this food 49.31 per cent is animal matter 

 and 50.69 vegetable. This is the first species discussed in which the 

 vegetable part of the diet is greater than the animal. This is true 

 of 5 of the 1 6 species under consideration. 



Animalfood. — Useful beetles, i. e., predaceous ground beetles and 

 ladybirds (CoccinellidEe), are eaten by the sapsucker to the extent of 

 only 0.91 per cent of the whole food. Other beetles amount to 4.54 

 per cent, and are made up of weevils, dung beetles (Aphodius), and 

 click beetles, with a few cerambycid larvse. Ants amount to 34.31 

 per cent of the whole food, or 69 per cent of the animal part. They 

 are evidently favorite food, being eaten quite regularly through the 

 year, although the months from May to August, inclusive, show the 

 highest percentages, averaging over 68 per cent. Other Hymenoptera 

 amount to 2.64 per cent, and are very irregularly taken. October 

 appears to be the month of greatest consumption, with 15.07 per cent. 

 Hemiptera are eaten very sparingly. Scales (Coccidse) were found in 

 two stomachs, and in one were identified as the plum scale (Eulecan- 

 ium cerasifex) ; these, with a few stink bugs, amount to a little less 

 than 1 per cent for the year. A few miscellaneous insects and spiders 

 aggregate 5.44 per cent. The insects consist of May fhes, stone fhes, 

 grasshoppers, crickets, tree hoppers, caterpillars and moths, and 

 flies (Diptera). A few eggs were found, probably those of the tent 

 caterpillars (Malacosoma). 



The following is a list of insects identified in the stomachs : 



COLBOPTERA. 



Coccinella 9^notata. Aphodius inquinatus. 



Cocemella sanguinea. Dichelonycha sp. 



Adalia bipunctata. Xanthonia 10-notata. 



Anatis sp. Diahrotica 12-punctata. 



Lxmophlxus biguttatus. Canifa pallipes. 



Onthophagus sp. Pandeletejus hilaris. 



Aphodius fi/metarms. Balanirms ep. 



HYMBNOPTEKA. 



Vespa maculata. Pimpla sp. 



Vespa arenaria. 



1 Hopkins, A. D., Bull. 56, West Virginia Agric. Exper. Sta., p. 355, 1890. 



