58 



PAPERS OX INSECTS AFFECTING VEGETABLES. 



Fig. 9. — The sugar-beet webworm 

 (Loxostege sticticalis) : Moth. 

 Twice natural size. (Reengraved 

 after Insect Life.) 



GENERAL APPEARANCE OF THE SUGAR-BEET WEBWORM AND 



NATURE OF ATTACK. 



The parent of this webworm (fig. 9) belongs to the lepidopterous 

 family Pyralida?, and is a tawny-brown, active moth, or ** miller.** 

 with a wing expanse of about 1 inch. 



It is larger and more conspicuously colored than the garden web- 

 worm which is shown in figure 10. 



The moths deposit their pearly-white 

 eggs singly or in rows of from two to 

 five or more, usually on the under side 

 of the leaf. TYlien deposited in rows 

 they overlap more or less. Each female 

 moth is capable, under normal condi- 

 tions, of depositing at least 200 eggs. 

 From these eggs hatch the small larvae, 

 or "worms." When first hatched the 

 "worms'* are whitish, with black heads, 

 but as they feed and increase in size 

 they become green, with dark markings. 

 The very young larvae eat small holes in the under side of the leaves 

 without, however, cutting through the upper epidermis, but as they 

 increase in size they consume almost the entire leaf, with the excep- 

 tion of the larger veins and the petioles. The "worms " prefer the 

 older leaves, and unless the food supply is nearly exhausted do not 

 eat the voiing leaves at the 

 center of the plant. "When 

 full grown the " worms," ; 

 which are slender and 

 about an inch in length, 

 leave the beets and burrow 

 in the soil, usually close 

 about the infested plants, 

 and spin tubelike cases in 

 which they later pupate. 

 The pupa? are slender, 

 yellow-brown, inactive ob- 

 ject^, from which during 

 the summer months the 



moths issue within a few days. The moths, after issuing, feed on 

 the nectar in alfalfa or other blossoms and within a few days mate 

 and are ready to commence depositing eggs for another generation 

 or brood of " worms." 



c 



Fig. 10. — The garden webworm (Loxostege simi- 

 lalis i : Oj Male moth ; l>. larva, lateral view ; c, 

 larva, dorsal view ; d, anal segment ; e, abdominal 

 segment, lateral view ; f, pupa : </, eremaster. 

 Oj> fr> Cj fj somewhat enlarged ; (7, e, <j, more en- 

 larged. (After Riley, except c, from Chittenden.) 



