RILEY NOTES ON THE YUCCA BORER. 



3 2 7 



States to sometimes be found in every third plant over extended 

 regions, its work renders the Yucca worthless as a hedge plant, 

 for which it has been tried. 



[Fig. 27.] 



'^V i^PIr 



Megathymus vucCiE: a, egg, side view, enlarged; b, egg from which the larva has 

 hatched; bb, bbb, unhatched eggs, nat. size; c. newly-hatched larva, enlarged; cc, full- 

 grown larva, nat. size; d, underside of head of same, enlarged to show the trophi. 



In the months of April and May, in South Carolina, but earlier 

 in more southern latitudes, the parent Megathymus may be 

 observed, where the Yuccas abound, passing, with very rapid, 

 darting flight, from plant to plant, remaining but a few seconds 

 at one place, during which she fastens an egg (Fig. 27, bb) to 

 some portion of a leaf. She is generally seen at this work in the 

 morning hours. The eggs, which are well-developed when she 

 issues from the pupa, are laid singly, though several are often 

 attached to the same leaf, generally near its tip and on the upper 

 or under side indifferently. In the course of about ten days the 

 young, reddish-brown larva (Fig. 27, c) gnaws its way out through 

 the crown of the egg and conceals itself in a web between some 

 of the more tender terminal leaves. Generally it will be found at 

 first near the tip of a leaf where the sides naturally roll up and 

 afford a safe retreat. It then gradually works to the base, feed- 

 ing the while and rolling and shriveling the blade as it descends. 

 Other blades are often joined, and, in fact, the insect lives 

 among the blades till it is about one-fourth grown, and seldom 

 enters the trunk before that time. How soon, in the larval 

 development, the white, powdery secretion, already spoken of, 

 appears, or how many larval molts occur, has not been ascer- 

 tained ; but the more mature larva is alwavs more or less covered 



