54 Mr BrincUey, Further Notes on the Food Plants 



23-30 Oct. '18. Sow thistle [Sonchus oleaceus): leaves holed slightly; flower 



huds not attacked. 

 3-17 Nov. '18. Strawberry (Fragaria vesca) W: leaves holed a little. 

 31 Aug.-6 Sept. '18. Tomato (Lycopersicum esculentum): leaves and vipe fruit 



gnawed thoroughly. 

 14-15 Sept. '18. Valerian, Red Garden ( Valeriana sp. ) : edges of leaves gnawed 



moderately ; petals entirely devoured. 

 21-24 Aug. '18. Vervain, Blue (Verbena sp.): leaves nibbled slightly, haiiy 



undersides used for assembhng; petals entirely devoured. 

 24-31 Aug. '18. Vetch, Mauve and White garden varieties (Vicia sp.): leaves 



attacked very slightly, if at all; petals entirely devoured. 

 23 Oct.-3 Nov. '18. Violet, Single and Double garden varieties {Viola sp.): 



leaves holed and edges gnawed moderately. 

 3-17 Nov. '19. Wartweed (Euphorbia helioscopia) T^: edges of leaves gnawed 



very shghtly. 

 15-18 Sept. '18. Wormwood (Artemisia sp ): leaves not attacked. 



These observations are of course subject to tbe drawback that 

 in captivity animals which normally feed daily may take unusual 

 food with apparent eagerness because no other is available; but 

 the above record probably indicates normal preferences over a 

 certain range of common plants, and also that some are disliked 

 by earwigs; thus Wartweed was left entirely untouched for many 

 days in the absence of any other food, the animals attacking potato 

 tuber ravenously as soon as this was substituted. It seems natural 

 that such stiff and dry foliage leaves as those of Raspberry, Haw- 

 thorn, and Cherry, should escape attack, and there is no doubt that 

 the more succulent leaves are preferred. The list of plants affords 

 some information which may facilitate the destruction of earwigs 

 when they become a pest by the indications obtained as to plants 

 which are popular as refuges, and also by the mode in which the 

 attack on leaves is made; thus, some leaves seem to be attacked 

 by holing as well as by gnawing along the edges, and others only 

 by the latter method. There is no doubt that earwigs have pre- 

 ferences among the common plants of a flower or vegetable garden, 

 and that if numerous they are likely to become a pest. In certain 

 cases, as for instance, chrysanthemums, the actual damage done 

 seems to be exaggerated by common report. 



Since the epitome of recent literature on the subject in my 

 previous paper {Proc. Camb. Phil. Sac, xix, Part 4, 1918, p. 170) 

 was written. The Review of Applied Entomology has recorded 

 attacks on beets and sugar-beets in Denmark sufficiently serious 

 to obtain mention by Lind and others in their Report on Agri- 

 cultural Pests in 1915 {Beretning fra Statens Forsogsvirksomhed i 

 Plantekultur, Copenhagen, 1916, pp. 397-423). 



As regards the carnivorous habit of F. auricularia, lean roast 

 mutton without other food was given for several days to the ear- 

 wigs under observation in 1918 and was gnawed sparingly, while 



