THE EUROPEAN EARWIG AND ITS CONTROL. 7 



about 6| miles northeast of this infested area, on the estate of the 

 late Alfred Gwynn Vanderbilt, of Portsmouth. 



1916. — About 10 square miles were heavily infested in 1916 and 

 many new small colonies were found outside of this area. The small 

 colonies of the previous year showed considerable growth. In some 

 cases hundreds of earwigs were present on estates where only a few 

 were found the year before. 



METHODS OF DISPERSION. 



This species rarety if ever spreads by flight; in fact, experi- 

 mental efforts to induce these insects to use their delicate and com- 

 plex wings were unsuccessful. 



Many cases have been noticed where adult earwigs have been 

 carried long distances in folds of clothing. Visitors to Newport 

 may spread the insect to near-by cities in this way. Several 

 isolated colonies located at a distance from the main infestation 

 are at points where automobiles frequently stop while their owners 

 walk about the extensive grounds. 



These insects may be spread while hiding in the packing mate- 

 rial or the soil of shipments of plants and general nursery stock. 

 One dead specimen was found by J. J. Pillsbury, assistant State 

 entomologist of Rhode Island, in a shipment of plants from Holland. 

 The writer has noted these insects in the fall between the toes of 

 dahlia bulbs. 



NATURAL ENEMIES. 



A parasitic, threadlike worm has caused the death of approxi- 

 mately 10 per cent of the earwig larvae under close observation in 

 the laboratory. This worm 1 lives free in the body cavity of full- 

 grown larval and adult earwigs. The average measurements of five 

 of these parasites was 3| inches by -£% inch. 



Various other parasites are reported as having been reared from 

 this species of earwig in Europe, but at Newport those so far dis- 

 sected have been free from parasites except in the case of one small 

 unidentified larva and the worm just referred to. 



Toads eat earwig larvae readily, but are not common at Newport. 



Hens devour adult earwigs ravenously. One hen ate 10 of these 

 insects thrown to her in as many seconds. Under natural conditions 

 these insects are hidden away so carefully through the day that 

 fowls can hardly be considered as economically important in the 

 sense of controlling the insect. 



1 Filar la locustae. 



