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in a controlled experiment.

Like other insects, the European earwig has its host of parasites and predators. The two common parasites are tachinids, Bigonicheta setipennis (Fall.) and Rhacodineura antiqua Meig. These were studied in Portland, Oregon by Atwell and Stearns in 1926 and were found to be quite effective in killing their host. A roundworm, Mermis nigrescens Dujardin or M. subnigrescens Cobb, was found in the abdominal and thoracic portions of the insect by G. Steiner (Guppy, 1941). A gregarine, Clepsidrina ovata (Dufour, 1828) is said to occur in earwigs in Europe by Crumb (1941); and H. E. Ewing of the Bureau of Entomology and Plant Quarantine, tells of the nymphs of a mite species belonging to the family Tyroglyphidae that, although not parasitic, annoy the earwigs to such an extent that death ensues. Crumb (1941) has observed the fungus Entomophthora forficulae among earwig nymphs and a muscardine fungus, Metarrhizium anisophilae Sorokin, infesting earwigs on some occasions. The green muscardine fungus, Oospora destructor (Metschni). Delacroix on European earwig and other insects in Oregon was reportedly first studied by Barss and Stearns in 1925.

Among important predators of the European earwig, the ground beetle Pterostichus vulgaris in a controlled experiment by Crumb (1941) was reported to have eaten on the average one earwig every two days. However, Ormerod (1898) Walton and Kearns (1931) report that P. vulgaris is a voracious feeder on strawberries in England. Pterostichusalgidus Lec. is a native predatory beetle common to western Washington, which in confinement ate an average of one earwig every five to seven days in an experiment by Crumb, Eide and Bonn (1941). In another experiment, performed by the same persons, Carabus nemoralis