﻿OF THE STATE ENTOMOLOGIST. 



171 



These thoughts naturally present themselves in considenng so osculant a species 

 jis the Yucca Borer. 



BIOLOGICAL. 



The reader of these Reports is aware that the queenly Yuccas cradle and nourish 

 a, very curious and anomalous Lepidopteron — the Pronuba yuccasclla {cf. Rep. V, pp. 

 150-60 ; Rep. VI, pp. 131-5). The orenus is further interesting, from the entomological 

 side, as giving us the insect under consideration. 



In the home of the Yuccas, and more particularly in tlie home of the caulescent 

 species, like T. uloifolia and Y. glonosa* persons who have occasion to dig up the 

 roots, or subterranean trunks, often notice that these are bored and hollowed out along 

 the axis (Fig. 49, b), the burrow cylindrical, and lined at its upper end with silk, which 

 is generally intermixed with a white glistening, soapy powder. These tunnelings are 

 made by our Yucca Borer, which dwells therein ; and their presence may generally be 

 detected by masses of excrement observable among the leaves, and by certain chimney- 

 like projections made by the twisting and webbing together of the more tender heart- 

 leaves, or even of the flower-stalk, after they have been partly devoured, into a sort of 

 funnel, from which the excrement is expelled (Fig. 49, «, o). The tunnelings weaken 

 the trunk and induce rot, so that the plant is not unfrequentiy prostrated thereby; and 

 as the insect is sufficiently common in the Gulf 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. 50.] 



Megathymus yucc-e : — Female. 



In the months of April and May, in South Carolina, but earlier i;i 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 eo^g (Fig. 51, hb) 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 cnurse of about ten days the young, reddish-brown larva (Fig. 51, 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 



*Though I huve positive proof of its working in aloifolia, gloriosa and filamcntosa, its range does 

 rot seem to be co-extensive with tliis last species, as I believe the insect has not yet been reported north 

 of latitude 36 degrees. 



