438 INSECT PESTS OF FARM, GARDEN AND ORCHARD 



are considerably smaller than the females. The moths fly during 

 the day and are readily mistaken for wasps of the genus Polistes. 

 The males fly in a quick, wasp-like manner, and when they rest 

 on a leaf will occasionally flutter the wings like an angry wasp, 

 which is accompanied by a low buzzing sound, which makes the 

 mimicry very effective. 



Life History. The eggs are laid singly on weeds, grasses or 

 other vegetation in the vineyard or on the bark or leaves of the 

 vines, a single female laying some 400 eggs. 

 The egg is oval, one-twenty-fifth inch long, 

 of chocolate-brown color, and finely pitted 

 and sculptured. They are very readily washed 

 off by the rain and drop to the soil, where 

 they hatch in about three weeks. The little 

 Iarva3 bore directly into the soil, wherever 



they may be ' m searcn of grape roots, and 

 may survive for several days without any 



f d ' Up n reachin S a root the larva bores 

 through the outer bark and then makes an 



irregular burrow in the softer parts of the bark, which may 

 encircle the root several times. As the burrows grow larger 

 they run with the grain of the wood, and as they are enlarg- 

 ed with the growth of the larva, only the outer bark is left 

 on roots one-half inch or less in diameter, the interior being 

 tunnelled out and filled with the castings of the larva. Most 

 of the larva? feed a foot or so from the base of the vine, though one 

 was found on a root nine feet from the base. The larvae bore in 

 the roots until the second fall, when they are about full grown and 

 make cells or hibernacula, thinly lined with silk, in which they 

 hibernate in the root. The larva becomes full grown the next 

 spring and is then 1J to If inches long, of the general shape 

 shown in Fig. 368, yellowish-white, with a small brown head, three 

 pairs of brown thoracic legs, and five pairs of abdominal prolegs. 

 When ready to pupate the larva comes near the surface of the 

 soil and there makes a tough cocoon an inch or so long, composed 

 of earth and excrement and lined with silk, and in it transforms 

 to a brown pupa with yellow bands around the abdomen. In 

 about four or five weeks the pupa wriggles half way out of the 

 cocoon and the moth emerges, leaving the empty pupal skin 



