Bulletin 151, Truck and Garden Insects due to the insect sucking the sap, brown spots are produced where the punctures are made. These greatly reduce the at- tractiveness of the produce on the market. The adult bug is only about 2/5 of an inch long. The male is dark reddish-brown and the female light brown with light yellow markings. They breed rapidly. The young - (fig. 78) are greenish in " color. These bugs are rather restless and are quick in / their movements. For this G. 78.-Tarnished plant-bug: Immature reason they are most easily stages. Four times natural size. (From U. S. Bur. of Ent.) captured or killed in the early morning when they are relatively sluggish. A strong tobacco extract with plenty of soap will kill the young and most of the adults but kerosene emulsion is better. A number of other bugs, such as False Chinch-bug (Nysius angustatus), frequently attack celery. The character of the injury is similar to that of the tarnished plant-bug and the control measures identical. CELERY CATERPILLAR (Papilio polyxenes) This caterpillar sometimes strips the leaves from celery and, as the caterpillar is rather large, a single one can inflict much damage. It is con- V V spicuously colored in green and black. It is a close 1 relative to the common Si "orange dog" (Papilio cresphontes) and, like that species, when disturbed, it Sthrusts out a yellow horn- like process from the head FIG. 79.-Tarnished plant-bug: Adult and young. About four times natural size. accompanied by a strong (From U. S. Bur. of Ent.) pungent odor. This seems to protect the insect from birds and possibly other foes. It grows to a length of 2 inches. The pupa is fastened to a sup- port partly by a silken thread about its middle. In from 12 to 15 days, in summer, there issues from it a swallow-tailed but- terfly. This is smaller than the adult of the orange dog and much darker in color. It is called the black swallow-tail. Both the caterpillar and its work are so conspicuous that hand-picking will usually be the most economical means of