APPLE TWIGS, LOCUST FOOD OF THE LARVA. 43 



sects, but the past year they came from the ground among such 

 trees as abundantly as in the original timber lands. It has been 

 commonly supposed heretofore that the larva?, derive their nou- 

 rishment from the roots of the trees upon which the eggs were 

 deposited, puncturing the bark with their beaks and extracting 

 the juices, and in this way it has been supposed that much greater 

 injury was done to the trees than by the wounds made upon the 

 twigs by the perfect insects. This view has been sustained by 

 Miss Margaretta H. Morris, in an interesting communication to 

 the Philadelphia Academy of Natural Sciences, and published 

 also in Downing's Horticulturist (vol. ii. p. 1G), in which she 

 attributes the failure of pear and other fruit trees, in many cases, 

 to the exhaustion of the sap, produced by these larvse fixing them- 

 selves upon the foots. On examining a pear tree which had ceased 

 to thrive, she found that all those roots which were six inches 

 or more beneath the surface were thronged with countless num- 

 bers of the larvae, clinging to them by means of their beaks in- 

 serted in the bark. From one root, a yard in length and about 

 an inch in diameter, she gathered twenty- three larvse, varying in 

 length from a quarter of an inch to an inch — a much greater dis- 

 parity in size than could have been anticipated in larvse which 

 were all of the same age. 



The habits and nourishment of these larvse is a topic which 

 needs further investigation. Mr. R. W. Kennicott, of West 

 Northfield, Illinois, writes me that in the month of November in 

 following down the roots of several trees and shrubs, the twigs of 

 which were badly cut to pieces by the locusts last year, to the 

 distance of a foot or more, he Avas unable to find a single one of 

 these grubs, a strong indication that when young they descend 

 deeper than Miss Morris supposes. And a more important fact 

 is, that they subsist upon the roots of grass and herbs as well as 

 those of trees. I learn from j)r. J. W. Moody, that at Spring 

 Arbor, Jackson county, Michigan, in fields which had been 

 cleared of their timber some sixteen years, and which have been 

 under cultivation most of the time since, the locusts came forth 

 last June as plentifully as in the timber land; and these seemed 

 to have been equally as well nourished, f-jr they were of the same 



