Ninth Report of the State Entomologist 375 



largely to the number of its attacking insects, and at present the list of 

 its known depredators embraces sixty-four different species. 



The beet plants submitted for examination, show the operations of 

 several distinct species. The principal of these seems to be a plant-bug 

 which punctures with its beak the leaf or stem for sucking its juices,* 

 and leaves an unsightly deadened spot and scar. On one of the leaves 

 a hundred of these spots may be counted. Many of these are probably 

 caused by that great pest of our gardens and orchards, the tarnished 

 plant-bug, Lygits pratensls (Linn.). A number of these operating 

 together upon the plant would not only mar the leaves in this manner^ 

 and render them undesirable for " greens," but would also tend to arrest 

 the growth and development of the beet icself. 



In some of the plants, irregular holes have been eaten in the leaves, 

 which may have been by one of the several species of iiea-beetles which 

 are known to operate upon the beet in this manner. One of the most 

 injurious of these is the "pale-colored flea-beetle," Systena blanda 

 (Melsh.), while another is the very common "striped flea-beetle," Phyl- 

 loir eta vittata (Fabr.), sometimes known as the turnip flea-beetle from 

 its special fondness for this plant, although almost equally injurious to 

 the radish and other of the Cruel ferm. 



On a few of ihe leaves transparent spots were observed, which are 

 probably the c ,mmencement of the attack of one of the beet-leaf mining- 

 flies. This ordinirily commences about the middle of June, and it soon 

 increases to such an extent that the leaves can no longer be used on the 

 table for " greens." On holding them up to the light — within large semi- 

 transpar -nt blotches, a goodly-sized larva or "maggot," as commonly 

 termed, may be seen industriously cutting out and feeding upon the 

 inner material (parenchyma) of the leaf. The growth of these larvae is 

 completed during the latter part of July, when they creep out from the 

 leaves and enter the ground for pupation. Early in August the pupae 

 give out the perfect insect, which is a fly, somewhat resembling the 

 common house-fly, but of a smaller size, and quite nearly allied to the 

 onion-fly. For an account of these beet-leaf miners, of which three dis- 

 tinct species are known to me, my First Report on the Insects of New 

 York, 1883, pp. 205-211, may be referred to. 



The best protection from the injuries of the insects above noticed is 

 probably to be found in the application to the plants at the proper time 

 of kerosene emulsion. The proper time would be when the insects first 

 make their appearance, as the emulsion does not drive away, but kills 

 by contact. If made of the usual strength recommended — one part of 

 kerosene to fifteen of water — it would not interfere with the use of the 



*See G. C. Davis, in Bulletin 102, of the Michigan Agricultural Experiment Station, 1893, p. 6. 



