of the Common Earwig (Forficula auricularia) 51 



immigrant from warmer countries of the East. The earwigs under 

 observation during the past three summers had no animal food save 

 that afforded by those which died. In order to obtain information 

 as to preference for one kind of plant above another they were 

 usually given three different species, taken haphazard, at a time, 

 for a period of two or more days. 



In the following summary the observations of 1917 and 1918, 

 with a few made in 1919, are combined. The dates when the different 

 foods were given are noted, as in the latter part of September, when 

 the animals tend to become lethargic, and in the succeeding two 

 months the desire for food is much lessened, even in the artificial 

 temperature of a laboratory. The capital letters after the names of 

 the plants indicate those which were given at the same time, and 

 the numbers appended indicate the preference exhibited by the 

 earwigs: e.g. in food group M, M^ was attacked more than M^, M^ 

 more than M^; in group F, F^ after two plants indicates that they 

 seemed to be attacked equally, and more readily than F^: while 

 in group Q, Q*' indicates that the plant offered was not attacked at 

 all. Similarly for the other groups. 



24-26 Aug. '17. Alkanet, Blue {AncJmsa sp.) C-: leaves not attacked; petals 



gnawed considerably. 

 27-29 Aug. '17. Anemone, White Japanese {Anemone japonica) D^: leaves 



not attacked ; petals eaten moderately. 

 1-23 Sept. '17. Apple {Pyrus Mains) F^: rather unripe fruit with skin whole 



was not attacked; but when cut across was gnawed moderately: 24-28 



Sept. '18, leaves holed. 

 24-28 Sept. '18. Ai-tichoke, Jerusalem {Helianthus tuberosus) W: leaves holed 



and edges gnawed down to midrib; tuber, cross sUce attacked vigorously 



and its buds also devoured. 

 20 Sept.-5 Oct., 3-17 Nov. '18. Asparagus {Asparagus officmalis) OS T": leaves 



gnawed a little ; fruit not attacked. 

 26-31 Aug. '18. Aster, Mauve China {Callistephics chinensis) K-: leaves not 



attacked ; petals and flower buds much eaten. 

 6-11 Sept. '18. Aster, Pink China {Callistephus chinensis): leaves shghtly 



nibbled; petals much eaten ; ^OM;ers used as a refuge. 

 15-20 Sept. '18. Balm, Pale Mauve {Melissa officinalis) J^ : leaves not attacked : 



petals of buds devoured. 

 22-23 Aug. '17. Bean, Dwarf {Phaseolus vulgaris) B^: leaves nibbled ver;^ 



shghtly. 

 30-31 Aug. '17. Bean, Scarlet Runner {Phaseolus multiflorus) E^: leaves, 



floivers and pods apparently neglected: 16-18 Oct. '18, leaves holed a good 



deal and edges gnawed down to veins. 

 20-28 Oct. '18. Beard Tongue, Scarlet {Pentstemon sp.) R": leaves and flowers 



not attacked. 

 22-23 Aug. '17. Beet {Beta vulgaris) B^: leaves much attacked, especially the 



petioles, which were opened out and their pith devoured. 

 20-24 Sept. '18. Bell Flower, White {Campanula sp.) K^: leaves not touched; 



petals completely devoured. 

 31 Aug.-6 Sept. '18. Bindweed, Common {Convolvulus sp.): leaves much holed. 

 11-13 Sept. '18. Blackberry {Rubus fruticosus): vipe fruit well gnawed. 



4—2 



