474 



from the adult beetles, and single Hymenopterous larvae have been 

 found on several occasions in the bodies of adults. Gregarines have been 

 frequently observed in the alimentary canal of adults of S. hispidula and 

 also of S. ptmcticollis ; but the fungus, Botrytis bassiana, seems to be 

 the most serious natural enemy of both adults and larvae of S. hispidula. 



S. sulcifrons, Thun., has been recorded throughout Europe and in 

 the Caucasus, and damage by it to leguminous crops has been observed 

 in France, Germany and Russia. In the British Isles it is widely 

 distributed and is common on red clover, especially in the north of 

 Scotland. Other species of clover and bird's-foot trefoil {Lotus 

 cornicidatus) are also infested ; in Europe it has been recorded damaging 

 peas, clover, lucerne and buckwheat. The damage done by the adults 

 is very similar to that by S. hispidula, except that the shape of the 

 eaten-out areas is more regular ; the larvae feed principally on the root 

 nodules of clover or the small fibrous roots, but never seem to attack 

 the main root. The stages of this species are described, as well as the 

 characters distinguishing it from other species. The life-history, which 

 is given in detail, closely resembles that of 5. hispidula. Insect 

 parasites appear to be rare ; the Braconids, Perilitus cerealium, Hal., 

 and a species of Liophron have been bred from the adults, and single 

 Hymenopterous larvae have occasionally been found in the bodies of 

 the beetles. The fungus, B. bassiana, also attacks this species. 



5. crinita has been recorded as an important pest of peas and beans 

 in England, and has therefore been included in the present research, 

 though the author has never found it seriously abundant. In Kent it 

 frequented the same food-plants as S. lineata [R.A.E., A, ix, 170], 

 but was always greatly outnumbered by the latter. The weevils eat 

 semi-circular patches in the leaves ; the larvae feed upon the root 

 nodules and occasionally tunnel in the main root. The adult is 

 described and compared with species likely to be confused with it. 

 The life-history is very similar to that of 5. lineata [loc. cit.]. A 

 Braconid {Perilitus sp.) has been bred from an adult of 5. crinita, 

 and single Hymenopterous larvae have been found within the bodies 

 of the beetles ; the fungus, B. bassiana, also attacks the adults. 



Davidson (J.). Biological Studies of Aphis rumicis, Linn. Repro- 

 duction on Varieties oJ Viciafaha. 



Fisher (R. A.). A Statistical Appendix. — Ann. App. Biol., Cambridge, 

 ix, no. 2, June 1922, pp. 135-145, 1 fig. 



In continuation of previous work [R.A.E., A, ix, 404] the varying 

 reproductive capacity of Aphis rumicis on 18 different varieties of 

 field beans was tested. The methods employed are described. The 

 Aphids used in the experiments were the offspring of one fundatrix, 

 and all were kept under similar conditions. Five plants of each variety 

 were used, and the total number of Aphids produced on each plant 

 from one apterous viviparous female in 14 days was counted. Tables 

 show the results obtained and are compared with those observed for 

 prolific longpod beans, which are taken as the standard (100 per cent.) 

 for fixing the relative values of susceptibility of other varieties. The 

 average number of Aphids produced on the different varieties, including 

 the standard, ranged from 37 to 1,037. On these infestation figures 

 the varieties are grouped into six classes, representing various grades of 

 susceptibility ranging from 98 to 3 per cent. None among the classes 

 tested showed complete immunity from attack, but the Aphids were 

 compelled to stay on the plants, and probably in nature winged 



