THE EGGPLANT LACE-BUG. 



NATURAL ENEMIES. 



Several predaceous insects were observed feeding on the nymphs 

 and adults of the eggplant lace-bug. The species of ladybeetles 

 common in this section, Hippodamia convergens Guer. and Megilla 

 maculata De Geer, in both the larval and adult forms feed on the 

 nymphs and adults of this lace-bug, usually turning them over on 

 their backs before feeding. A common soldier-bug, Podisus macu- 

 liventris Say, feeds on the nymphs. Another common hemipteron 

 found feeding on the nymphs is TripMeps insidiosus Say. Three 

 species of spiders, Epeira domiciliorum Hentz, Plectana stellata Hentz, 

 and ChiracantMum inclusum Hentz, identified by Mr. Nathan Banks, 

 of the Bureau of Entomology, were observed feeding on all stages of 

 the lace-bugs. It was not uncommon to find many lace-bugs with the 

 head severed and the body mutilated. A very few specimens of a 

 hymenopterous parasite were reared with the adult lace-bugs; this 

 was identified as Microdus sp. 1 but it was not positively proved to 

 attack the lace-bug. 



METHODS OF CONTROL. 



June 17 and 18, 1914, a series of spraying experiments against this 

 lace-bug was undertaken in which the comparative values of fish-oil 

 soap and various strengths of a standard blackleaf tobacco extract 

 containing 40 per cent active nicotine sulphate were tested. (See Plate 

 IV.) The results were quite satisfactory. 



Table IV. — Spraying experiments against the eggplant lace-bug, Norfolk, Va., 1914. 



No. 



Fish-oil soap. 



Nicotine sul- 

 phate. 



Nymphs 



killed (per 



cent). 



Adults 



killed (per 



cent). 



1 pound to 50 gallons of water . . . 



do 



do 



2 J pounds to 50 gallons of water. 

 3 pounds to 50 gallons of water . . 



5 pounds to 50 gallons of water . . 



6 pounds to 50 gallons of water . . 



7 pounds to 50 gallons of water. . 



8 pounds to 50 gallons of water. . 



1 to 1, 066 

 1 to 800 

 1 to 640 



SO to 85 

 90 

 85 to 90 

 80 to 85 

 90 

 95 

 100 

 100 

 100 



None. 



None, 



None. 



None. 



None. 



None. 



40 to 50 



90 to 95 



95 



From the above table it will be readily seen that the percentage of 

 nymphs killed was but slightly affected by the increase in the amount 

 of the nicotine sulphate, and that the latter had no effect whatever on 

 the adults; whereas with each increase in the amount of fish-oil soap 

 there was a corresponding increase in the percentage of nymphs killed, 

 until finally we arrive at a strength which will affect the adults. 

 Above that strength we may then get perfect control of both the 

 nymphs and adults. 



Too much emphasis can not be laid on the thoroughness with 

 which the spraying should be performed. It is particularly essential 

 that the underside of the leaves be thoroughly covered by the spray. 



i Chttn. No. 137301. 



WASHINGTON : GOVERNMENT PRINTING OFFICE : 1915 



