THE EUROPEAN EARWIG AND ITS CONTROL. 11 



flowerpot, with excelsior in the bottom, inverted over a 9-inch stick 

 set in the ground close to plants or vines where earwigs are most 

 numerous. The earwigs hide in the excelsior and should be shaken 

 into a pail of water which has a thin film of kerosene oil on its sur- 

 face. Pieces of bamboo, piles of straw, strawberry boxes, and in 

 fact anything that offers shelter may be used ; but these substitutes 

 are either less effective or less easily handled than flowerpot traps. 



MISCELLANEOUS. 



In cases of extreme abundance earwigs may be kept from a porch 

 by surrounding the porch completely with a 1-inch band of a suit- 

 able sticky substance. This sticky material prevents the invasion 

 of earwigs unless 'some crevice exists under the band or some vine 

 furnishes a bridge over it. To be effective this material should be 

 applied by June 15, and its surface must be brushed over with a 

 wire brush by July 15, and possibly once more during the season. 



EFFICIENCY OF CONTROL MEASURES. 



Experiments in the field with poisoned-bread bait in May were 

 on a rather small scale. Several flower beds and small isolated lawns 

 which were literally swarming with young earwigs were treated 

 with this bait. The results were surprising. Very nearly 100 per 

 cent of the larva? were killed with one application of bait in each 

 case. 



Five estates were partially treated with this bait on June 22, 1916, 

 and again three days later. The young earwigs at that time were 

 passing rapidly into the fourth stage. As has been stated, the habits 

 rapidly become similar to those of the adult. At this late date 

 flowers such as sweet William and roses furnished food, and many 

 of the earwigs had left their nests in the ground. Thus they were 

 harder to reach with the poisoned-bread bait. It is estimated that 

 over 75 per cent of the larvae on these five estates were killed by 

 these two late applications of bait. Far better results could be ex- 

 pected earlier in the season on favorable nights. 



Spraying with contact sprays at night was done on a large scale 

 after July 1. Mr. Simmons and an assistant used a barrel pump 

 for this work, equipped with a Bordeaux nozzle. They planned to 

 spray every three nights the same area, namely, the vines near the 

 houses, and a 10- foot circle of lawn around each house. In this 

 way the houses were kept free from the insect. This spraying was 

 continued for over a month, although far less than 1 per cent of 

 the usual number of earwigs could be found on these estates after 

 July 20. A few continued to crawl in from surrounding estates, 

 especially late in the fall. 



