FOOD PLANTS. 



317 



still fresh they were placed in eight-ounce glass jars, and four 

 caterpillars, in the fourth or fifth molt, were placed upon them. 

 This number was about all that could feed without crowd- 

 ing, and at the same time give appreciable results before the 

 plants wilted. The jars were covered at the top with thin 

 cloth, to prevent the escape of the caterpillars and at the 

 same time to allow ventilation. They were numbered, and 

 the numbers, with the names of the plants, were booked at 

 the time the caterpillars were placed on the food, the jars 

 being kept in a place sufficiently cool to prevent undue evap- 

 oration, but at a temperature at which the caterpillars fed 

 readily. Observations were made every twenty- four hours, 

 and, if at the end of three days the caterpillars showed an 

 unwillingness to feed on the plant, the experiment was re- 

 peated with a fresh stock of caterpillars on a fresh supply of 

 the same food. If they did not attack it at the second trial, 

 in view of their accustomed readiness to feed on nearly all 

 plants, it was assumed that they would not feed on the plant 

 in question. The flora of the region about Maiden is mari- 

 time rather than inland, and some of the common plants 

 of the central and western parts of the State do not occur 

 there. 



Attention is called to the fact that the caterpillars of 

 the gypsy moth feed readily on common water plants, 

 such as jSfymphoea odorata, Pontederia cordata and Alisma 

 plantago. Experiments performed this year proved that 

 some of the caterpillars will live for several days floating 

 on the water and without food. These two facts in connec- 

 tion may help to explain the distribution of this insect along 

 streams. 



In the following lists both the common and scientific 

 names are given, as far as possible. The nomenclature is 

 that of Gray's "Manual of Botany," 1889, for the wild 

 plants, and Wood's *' Botany" of 1889, for the cultivated 

 plants. An asterisk before a name denotes that the cater- 

 pillars fed on the plant only when forced to do so by 

 starvation. It will be noticed that about twenty-one per 

 cent, of the plants in the following list are of economic 

 value. 



