170 Mr Brindley, Notes on certain parasites, food, and capture 



Among fungoid parasites, EntomopMhora forficulae diminishes 

 the number of earwigs (Picard, Bidl. Soc. Etude Vulg. Zool. Agric. 

 Bordeaux, Jan. — April, 1914, pp. 1, 25, 37, 62). It is possibly this 

 species which has caused heavy mortality among the earwigs which 

 I have kept in captivity in the Zoological Laboratory during 

 recent years. Infection by the above or other fungus is a very 

 frequent result of damp in the soil or in the plaster of Paris cells 

 bedded with coco fibre which I have employed. The most effective 

 preventive of fungus has so far been keeping the earwigs in 

 roomy glass dishes lined with virtuall}^ dry sand and supplj^ing 

 water only by wetting the vegetable food given. 



(6) Food. 



In " The Wild Fauna and Flora of the Royal Botanic Gardens, 

 Kew," 1906 {Kew Bull. Add. Series V), Lucas writes (p. 23) of the 

 Common Earwig, " It is an animal feeder. Does it do. as much 

 damage as is supposed ? " And Ealand in " Insects and Man," 

 1915, p. 266, states "most gardeners would assert that the insect 

 is destructive to cultivated plants. Careful observation and 

 experiment, however, show that it is carnivorous and that it 

 devours caterpillars, snails, slugs, etc.... its habit of hiding in such 

 flowers as the sunflower and dahlia have earned it an undeserved 

 reputation for evil." 



I find that seven out of nine recent and more or less compre- 

 hensive manuals of Economic Entomology do not mention earwigs 

 at all, which is fair evidence for considerable doubt as to their 

 being harmful insects. Of the two works in which earwigs are 

 mentioned one speaks of them as destructive to mangolds, turnips, 

 cabbage crops, and plant blossoms, while the other states dahlias 

 as attacked, " but nearly all plants suffer." Virtually every fruit 

 grower and horticulturist of whom we make enquiry assures us 

 that earwigs are most destructive pests, but is the general belief 

 thus expressed really well founded ? 



Recent literature leaves the impression that in certain localities 

 earwigs may be specially harmful to plants of economic value, 

 though an explanation of this capriciousness is wanting. Theobald 

 (Rep. on Econ. Zool., South-Eastern Agric. Coll., Wye, April 1914) 

 gives hops as attacked by F. auricidaria. Lind and others in a 

 summary of the diseases of agricultural plants in 1918 (79 Be- 

 retning fra Staiens Forsogsvirksamded i Plantekidtur, no. 30, 

 Copenhagen, 1914) state that in one locality in Denmark cauli- 

 flowers were completely destroyed by the Common Earwig, which 

 seems a very exceptional event. Sch^^iyen in Beretning om skadein- 

 sekter og plantesygdommer i land og havchruket 1915 (Report on the 

 injurious insects and fungi of the field and the orchard in 1916), 



