EXPERIMENT STATION BULLETINS. 289 



ROSE CHAFER. 



( Macrodactylus suhspinosus. ) 



Our hereditary enemy, the rose-chafer, or rose beetle, has of late been 

 making such bold invasions into the grape territory that any measures 

 which promise even partial success are welcome to the vineyard OT\Tiers. 



The life history of this awkward creature is known pretty well by 

 those interested; the eggs are laid usually in sod land and in well- 

 drained, sandy sod by preference, just such land as abounds in the fruit 

 belt. The larvae are white grubs, resembling, in minature, the grubs 

 of the ordinary white grub of the June-beetle. Like their larger rela- 

 tives, they feed on the roots of vegetation. They attain their full size 

 in the fall, and at that time hollow out small cells in the soil, where 

 they pass the winter. In the spring the larvae change to pupae and, 

 later in June, the adult beetles, with tlieir long awkward legs, come out 

 and spread over the country-side, collecting in regions where their food 

 plants are to be found, new legions appearing from day to day as earlier 

 ones die or are killed off, sometimes collecting in almost unbelievable 

 numbers. 



Grapes suffer most of all the fruits. The beetles seem to come out 

 just in time to feast on the flowers and young sets, and a single beetle 

 can account for many bunches of grapes at such a time. 



On just such an occasion, the writer, in company with his assistant, 

 Mr. E. J. Kraus, visited a vineyard at Decatur, a well-known gi^ape 

 region. Here a pan 7 ft. G in. long, 22 in. wide and 1 in. deep was made 

 from a sheet of galvanized iron. To one side of this was fastened a light 

 frame 3 ft. high and running the entire length of the frame, being 

 securely braced to the frame of the pan. The pan was prepared by 

 placing a number of old pieces of cloth, soaked in water, in the bottom 

 and over this pouring about a quart of kerosene. When the pan had 

 been made ready, it was placed alongside of a vine and the beetles 

 beaten into it by means of switches made of broom corn. After collect- 

 ing the beetles from one vine the pan was moved along to the next and 

 the beating repeated. Some of the beetles fell short of the pan, some 

 struck the shield and bounded back, but most of them stayed in and 

 died. It is likely that a deep notch in the side of the pan, which would 

 admit of placing the pan closer to the vines, would make it possible to 

 catch more of the beetles. Of course, all the beetles that touched the 

 oil died. 



Quite a large number of beetles were collected in (his^way, but on 

 the day of the trial the beetles were not so plentiful as the writer has 

 seen them at other times. It is likely that when the beetles are not 

 numerous, two men with ordinary milk pans, with oil rags in the bottom 

 and with switches would do about as well. When very numerous the 

 large pan should be efficient. It requires hard work to carry such a 

 pan over the hills, such as are ordinarily used for grape growing. Fig. 

 11 shows such a pan in use. 

 37 



