24 BULLETIN 689, U. 5. DEPARTMENT OF AGRICULTURE. 



day following the treatment over 50 per cent were active, and even 

 in the case of nymphs in the third instar at least 50 per cent survived. 



SPRAYING WITH KEROSENE EMULSION. 



Experiments with strong mixtures of kerosene-soap emulsion also 

 gave unsatisfactory results. One part of stock solution, made up of f 

 kerosene and yellow laundry soap, to two parts of water did not 

 kill all nymphs that were drenched with it. Undiluted kerosene. 

 as would be expected, quickly killed individuals in both the nymphal 

 and adult stages. 



In the experiments it was noted that nymphs which, immediately 

 after being drenched with a contact insecticide, apparently showed 

 signs of approaching death, recovered later. 



HAND PICKING. 



Hand picking can be done profitably where valuable vegetable 

 crops are being attacked. The bugs may be collected in a receptacle 

 containing a little water coated with a film of kerosene, or some 

 other collecting device may be used. Where the bugs occur on other 

 than low-growing plants the receptacle may be a pan or wide- 

 mouthed dish and the bugs may be brushed or knocked from the 

 plants into it. Collecting can be done best hi the early morning, or 

 during cool weather, when the bugs are sluggish. In addition to 

 collecting and destroying the adults and nymphs, the destruction of 

 egg clusters is recommended. 



In order to secure a maximum reduction in the amount of damage 

 done to the plants, hand picking not only should be carefully done, 

 but should be put into practice when the attack begins. 



USE OF TRAP CROPS. 



The adults are attracted to mustard and turnips during the fall, 

 as indicated by the collections referred to below. These were mad? 

 from a few plants in a garden at Baton Rouge where serious injury 

 by the species is seldom noted. About 15 minutes a day were 

 spent hi the work, all collections being made from the same plants. 

 It would appear that after the first coUection the succeeding adults 

 were individuals that came to the plants from the time of one coUec- 

 tion to the next, it being unlikely that many adults escaped at the 

 time each coUection was made. 



On October 24. 47 adults were collected: on October 25, 81; on 

 October 2S. 79: and on October 31, 42. In addition to the fore- 

 going 249 adults. 14S nymphs were collected. 



The fact that nymphs and adults are often very abundant in the 

 late fall on turnip and mustard suggests that a few of these plants, 

 or others on which the southern green plant-bug is found to congre- 

 gate, might be grown as trap crops in sections where serious injury 

 occurs. The bugs might be hand picked or. killed by spraying with a 



