EXPERIMENT STATION BULLETINS. 403 



OTHER CATERPILLARS ON CELERY. 



One of our common leaf rollers and one that we might expect to find on 

 celery, as it is such a general feeder, is the oblique banded leaf roller 



{Cacoecia rosaceana^avr.). The pale 

 green caterpillar is one of our largest, 

 plumpest leaf rollers. 



Very similar in shape but of a uni- 

 form buff color is another moth ( Tor- 

 trix pallorana Rob.) that was bred on 

 the leaves of celery, August 17. It is a 

 leaf roller with habits similar to the 

 others, and is also quite a general feeder. 

 Only one specimen of each of the above 



Fig. 20— The obliqne banded leaf roller, Caccecia • i a 4-1.^^ ^^i-^^^iU^^ 



rosaceana, a, moth; b, caterpillar; c, pupa specics was reared. Another Caterpillar 

 -(afterc. F.Baker). ^jj^t destroyed at least two rather small 



plants by eating stems and leaves was the large hairy red and black 

 one (Pyrrharctia Isabella S. & A.) that is so common everywhere in the 

 autumn. It is probable that this one specimen was rather partial to celery 

 as others of the same species were found around celery that did not seem 

 to feed on it at all. In confinement they eat it readily. 



There were several other caterpillars (at least four species) that were 

 taken feeding on celery but they did not reach maturity. One of these 

 was a dark, dingy specimen, about half an inch long, that bored in the 

 hearts of very young plants. It possibly was a cut-worm but looked more 

 like the larva of a butterfly. Only the one was found and by an accident 

 it escaped from confinement before reaching maturity. Another partly 

 grown specimen was determined at Washington, D. C, as probably 

 Leucarctia acrea. 



"RED SPIDER" {Tetranychus telarius, Linn). 

 Obdee ACAKINA. Family TROMBIDID^. 



Our common little greenhouse mite, commonly known as " red spider," 

 has taken a liking to celery this season and enrolls itself along with the 

 celery insects. The latter part of the season was extremely dry, and favor- 

 able for its increase and, before the drought was broken, little blotches 

 made by the mite began to appear in places quite thickly over the under 

 side of the leaves. By raising the leaf the yellowish mites about the size 

 of a pin head, will be seen through a slight web in which they live. They 

 thrive only in a dry, hot atmosphere, and plenty of water is equivalent to 

 poison for them. 



Quite a number of other insects of various orders were collected on 

 celery and although suspicion brands many of them as celery insects, they 

 are not mentioned, as they were seen neither feeding nor breeding on the 

 plant. Being in the fields only at intervals has interfered somewhat with 

 extended observations that are so essential to the best work. Enough has^ 

 probably been given to show the number of insects the celery-grower must 

 compete with in raising his crop. 



