180 



STATE BOARD OF AGRICULTURE. 



orange spot with a black center. There are many irridescent blue scales 

 near the outer margins of the hind-wings. 



REMEDIES. 



Hand-picking usually will suffice if the ^^worms" are on celery, but 

 one of the emulsions should work to perfection, in case they ever become 

 numerous. 



Celery Flea-beetles (Longitarsus melanurus, Crepidodera cucumeris 



Cliaetocnevia parcipunctata) . 



Several species of flea-beetles are 

 known to be partial to celery, the 

 three mentioned by Mr. Davis, are 

 given above. These little creatures 

 do the most harm when the plants 

 are very young. At such times, a 

 spray of bordeaux should act as a 

 repellant if we may judge from its 

 effects in the case of the flea-beetle 

 on potato and others. A spray of 

 tobacco decoction is said to be 

 efficient. Tobacco dust should also 

 „ ^ , ^ ^ ., ,, ., T prove of some use. 



Fig. 30. — Celery flea-beetle (Langitarsus melan- ^ 

 uTus), enlarged. (After G. C. Davis.) 



INSECTS AFFECTING THE CUCUMBER. 



INSECTS WORKING ON THE FOLIAGE. 

 Melon-louse on Cucumber {ApMs gossipii). 



At all times after cucumbers commence to "run" they are subject to 

 attack by a plant-louse. The insect is blackish-green in color and both 

 winged and wingless forms occur. They multiply so rapidly as almost 

 to cover the under sides of the leaves in a short time. Ordinarily in 

 large fields, the attack commences in certain small, well-defined areas, 

 from which the trouble spreads rapidly in ever widening circles rendered 

 conspicuous by the curled and discolored leaves. The source of the pests 

 was for some' time a mystery, but Mr. Theodore Pergande, of our Na- 

 tional Bureau of Entomology, throws a great deal of light on the subject* 

 when he explains that the same insect feeds also on cotton, orange, 

 melons, strawberry as well as on a long list of our common weeds. In 

 the light of this information, it is easy to see how the pest is kept 

 alive until opportunity to attack melons and cucumbers offers itself. 



TREATMENT. 



The fact that the pests work almost entirely on the undersides of the 

 leaves, where it is difficult to apply sprays, makes them very serious 



* "Insect Life," vol. VII, p. 309. 



