570 INSECT PESTS OF FARM, GARDEN AND ORCHARD 



furnished with a strong ovipositor with saw-like teeth at the 

 tip, with which she cuts a little blister-like cell beneath the upper 

 surface of the leaf, in which the egg is deposited, as shown in Fig. 

 505. The egg hatches in about two weeks and the little larva 

 makes its way out of the cell through a crescent-shaped cut. 



The young larva is at first nearly white, except the yellowish- 

 brown head, but very soon a slimy or gluey olive-colored liquid 



exudes from over the 

 entire body, giving it 

 the appearance of a min- 

 ute slug, from which it 

 gets its name. The head 

 is now dark brown, ap- 

 pearing almost black 

 under the slime, and 

 the body is also darker. 

 The anterior segments 

 are much swollen, con- 

 cealing the head and the 

 thoracic legs. The ab- 

 domen is furnished with 

 seven pairs of prolegs, 

 FIG. 504. The pear slug (Caliroa cerasi Lin- the usual pair on the 

 naeus.): a, adult female saw-fly; 6, larva with j ^ segment beine 

 slime removed ; c, same in norma state ; d, leaves ^ 



with larvae natural size; a, 6, c, much enlarged, wanting so that the tip 

 (After Marlatt, U. S. Dept. Agr.)- of the abdomen is 



slightly elevated. The little slugs commence eating out small bits 

 of the upper surface of the leaf, which they gradually enlarge un- 

 til nearly the whole upper surface is denuded, leaving merely a 

 net work of veins, held together by the brown epidermis of the 

 lower surface, which is nearly intact. Leaves thus injured turn 

 brown, die and drop, so that a tree will sometimes be nearly def- 

 oliated, except for the new growth which starts out. The larvae 

 grow rapidly, becoming full grown in about twenty-five days, when 

 they are about one-half inch long. When full grown the larva 

 molts for the fifth time and loses its olive-green slimy appearance, 

 becoming a light orange-yellow color, clean and dry, with a light- 

 colored head marked by only the small circular black eye-spots 

 on the sides. 



