EXPERIMENT STATION BULLETINS. 343 



other infection the followinji- season. Where conditions will permit, ro- 

 tation of crops will prove very desirable, devoting the land to cabbages, 

 onions, peppermint or some other suitable crop for two or more years 

 until the land is free of these spores. 



INSECTS AFFECTING THE CELERY PLANT.* 



The Celery plant is by no means immune to insect attack. It is preyed 

 on by many of the garden pests, array-worms, cut-worms, the zebra- 

 caterpillar, the celery-looper and by a number of other caterpillars. Be- 

 sides these are several sucking insects, plant-lice, leaf-hoppers, a negro- 

 bug and a thrips. Most conspicuous of all is the parsley-caterpillar, 

 which works also on carrots, caroway, fennel and other plants of the 

 same family, — a naked caterpillar nearly two inches long, green or yel- 

 low in color, with transverse black bands, and spotted with yellow. Wlien 

 disturbed, the larva protrudes a Y-shaped yellow horn, from which 

 emanates a sickening odor, presumably distasteful to birds and other 

 enemies. The adult is the common black, parsley swallow-tail butterfly, 

 a beautiful velvet black butterfly having long swallow-tails, and marked 

 by rows of yellow spots. 



Control of these insects will depend on their feeding habits. Grass- 

 hoppers should be killed by Criddle mixture, which is poisoned and 

 slightly salted horse-manure. Flea-beetles may be driven away or killed 

 by arsenate of lead, while the plants are small, that being the time when 

 most injury is done. Cut-worms like poisoned bran, made by mixing 

 thoroughly, one pound of Paris green with fifty pounds of dry bran and 

 then moistening it with a little molasses and water. The zebra caterpil- 

 lar can be usually hand-picked profitably, as well as the parsley caterpil- 

 lar. The plant-lice and negro-bugs should respond to a spraying with 

 strong tobacco tea or with one of the nicotine extracts. This is true also 

 of the thrips. 



The leaf-hoppers will be driven away by such a spray, but they will 

 return after it evaporates. For the latter, a regular practice of clean 

 culture, and the burning of all rubbish, after cold weather has set in. 

 will gradually get rid of them, especially if this treatment be extended 

 over a wide area. Many noxious insects winter in rubbish, fallen leaves, 

 along hedges, etc. 



Details concerning the life-histories of some of these pests, and direc- 

 tions for the preparation of insecticides may be found in Bulletin 233 

 of this Station, being a bulletin on Insects of the Garden. 



•R. H. PETTIT, 

 T^ntomologist of Experiment Station. 



VARIETIES. 

 WHITE PLUME. 



A self blanching variety that is grown almost exclusively in this state 

 for the earliest crop. The stalks are tall and the leaves a rich dark 

 green, turning light colored and sometimes nearly pure white when the 

 plants are mature. It matures earlier than the Golden Self Blanching 

 but is not considered to be quite as good in quality. Its stalks blanch 

 a pure clean white, making it superior to all others as a table decoration. 



