

THE TIMOTHY STEM-BORER. 7 



as feet; the body is then braced by fixing the spines of the anal seg- 

 ment against the opposite wall of the stem ; the maxillae and true feet 

 then advance the thorax and head. By executing these movements 

 almost simultaneously the larvae can move quite rapidly. In going- 

 backward the movements are reversed. The dorsal feet or tubercles 

 and the anal spines enable the larva to support itself in the stem. 



THE MOVEMENTS OF THE LARVA OUTSIDE THE STEM. 



Naturally enough, as the larva seems peculiarly adapted for move- 

 ment in a small hollow stem, when it is placed on a flat surface it 

 appears wholly at a loss how to proceed. It arches its body and 

 turns on its side, going through the same movements as though it 

 were in a stem, but it moves very slowly. It then turns on its back 

 and tries to walk on its dorsal feet. By bringing all of its knowledge 

 of the different ways of walking to bear on the problem, it moves 

 slowly, in a drunken way, to a protecting object, if any be near. 



THE PUPA. 



When ready to pupate, the larva (Plate I, a) reverses its position 

 in the stem and ascends to a point anywhere between the first joint 

 from the root and the first or second joint from the top, depending 

 upon whether the timothy has been cut or not. Plate I, b, shows 

 a larva ready to pupate, just below the second joint from the root. 

 It probably locates most often just above the first or second joint 

 from the root. It then seals up the stem above and below with 

 detritus, making a cell of from 1 to 2 inches in length. It will reseal 

 a stem if interfered with, but if its burrow be molested many times 

 it will live for weeks and not pupate, finally dying. 



After inclosing itself within this cell the larva becomes sluggish, 

 contracts slightly, and thickens perceptibly in the thoracic region. 

 It soon casts its larval skin and becomes a fully developed pupa. 

 In Plate I, c, is seen a pupa hi its cell just above the second joint 

 from the root. After pupation it is a pale cream color, gradually 

 changing to a brownish tint. 



THE MOVEMENTS OF THE PUPA IN THE STEM. 



The movements of the pupa in ascending and descending the 

 stem are fully as complicated and interesting as in the case of the 

 larva. In moving up the stem, the spurs of the last segment are 

 planted firmly in the wall; the body is then bowed ventrally and 

 the spines of the dorsal tubercles are brought forward and fixed 

 in the wall; then by quickly releasing the anal spines, with the 

 long pointed pygidium of the eighth segment, they and the dorsal 

 tubercles act as levers and thus propel it up the stem. By executing 

 these evolutions quickly they can move with considerable rapidity. 



