INSECTS INJURIOUS TO CELERY, PARSNIPS, ETC. 183 



brown, the darker shades velvety brown. The larva is similar 

 to the cabhai^e loopcr and similar remedies are applicable. 



The Little Negro Bug {Corimclccna pulicaria Germ.). — This 

 minute black bug sometimes does considerable damage to 

 celery, as happened in 1893. when attack was quite general 

 throughout the celery-growing portions of Michigan. The 

 insects collect in clusters around the nodes where the three 

 top leaflets meet. Here they suck the sap until the leaflets 

 wilt and droop, after which they go to the joint below and 

 repeat the operation till the leaf is drained of sap. 



The mature negro bug measures only about an eighth of an 

 inch, and is glossy black, the scutellum occupying over half of 

 the upper surface and being surrounded by a white margin. This 

 insect is common and well distributed. It prefers old celery 

 when about ready for blanching and plants are retarded in 

 growth from two to three weeks, recovering with large numbers 

 of small curling, gnarly stalks of little or no market value. 

 In such cases the crop is practically an entire loss. This 

 species is a general feeder attacking numerous garden plants, 

 among which are strawberry and blackberry, and it is due in 

 part to this insect that these berries sometimes have such a 

 disgustingly sour taste, and "buggy" odor, particularly when 

 picked in the field. 



Remedies. — Carbolic or kerosene emulsion sa'q useful both 

 as destroyers and repellents. In experiments conducted by Mr. 

 G. C. Davis, the bugs were readily killed with hot water at a 

 temperature of 155° F., a«nd the celery plants were found to 

 endure a stream heated to 175°. This remedy is most effective 

 when the insects first appear and when applied on the plants 

 where they are most numerous. It necessitates the use of a 

 thermometer that the temperature may not go above 175°. 

 Celery should not be planted in the vicinity of weedy fields, 

 especially those containing umbellifers, as these harbor the 

 insects sometimes in enermous numbers. 



