INSECT FOOD. 25 



White potatoes. — The potato beetle {Doryjyhora 10-lineata) caused 

 every year considerable injury to white potatoes. During May, 1899, 

 it had destroyed at least half of the foliage of several acres of potatoes 

 about 6 inches high in lot 3. The field was watched for an hour or 

 two each day for several days, but only three birds were seen in the 

 patch^ — a pair of bobwhites, which are noted potato-beetle eaters, 

 sometimes consuming from 50 to 100 at a single meal, and a cardinal, 

 which is a near relative of the rose-breasted grosbeak, probably the 

 the most valuable destroyer of the pest. Unfortunately neither spe- 

 cies could be either observed feeding in the patch or subsequently col- 

 lected. Other birds were very abundant along Persimmon Branch 

 and the river front, but appeared to manifest no interest in potato 

 beetles. From May 28 to May 30, 1896, the potatoes in the kitchen 

 garden, though in fair foliage, had from several to a dozen beetles on 

 each plant. Birds were about the garden all the time. Forty of 

 them, principalh^ catbirds, vireos, house wrens, chipping sparrows, 

 summer warblers, orchard orioles, and flycatchers were collected, but 

 none had eaten the beetles. On the 16th of June, 1901, a large patch 

 of potatoes by the negro cabin in lot 2 was infested. Above it circled 

 a score of swifts and swallows, mainly barn and bank swallows, with a 

 few purple martins. They did not touch the beetles, but caught caddis- 

 flies, which were numerous over the patch. 



The caddis-fly, very abundant and regarded by birds as a choice mor- 

 sel, may, like the May-fly, distract their attention from other insects. 

 It usually appears about the last of May or the first of June, and it is 

 greedily eaten by many species, especially by arboreal and aerial 

 feeders. It is a harmless insect, whose larvse lead an aquatic exist- 

 ence. It, top, like the May-fl}^, would be excessively abundant only 

 near large rivers or lakes. 



String beans. — At a time when potatoes were suffering in the 

 kitchen garden (May 28-30, 1896), a dozen rows of string beans beside 

 them were ravaged by thousands of bean flea-beetles ( Cerotoma tri- 

 furcata)^ but none of the 40 birds collected had preyed on them, a fact 

 po.«sibly due to the presence of caddis-flies. Another uprising of 

 these beetles was observed May 17-20, 1899, but then May-flies were 

 abundant enough to engross the birds' attention. This beetle is sim- 

 ilar, however, to species that are eaten by many kinds of birds, and, 

 under other circumstances, might perhaps have been destroyed in 

 large numbers. 



Sweet potatoes. — Two tortoise beetles injure sweet potatoes (PI. V^lII, 

 fig 2) at Marshall Hall. The more common one ( Cojptocycla hicolor) 

 has the power to change its color, and at its brightest looks like a 

 drop of molten gold, from which it is generally known as the 'gold 

 bug.' During June, 1899, it was especially abundant. On the Mar- 

 shall Hall farm, near a small plot of sweet potatoes that it was injur- 



