1 12 The Larval aial Pupal Stages 0/ Agriotes obscurus 



the value of moles from the economic point of view. Digestion in the 

 stomach of the mole is apparently very rapid, thus rendering identifi- 

 cation of the stomach contents difficult. It is, at any rate, certain 

 that the animal is a very voracious feeder as SchefEer(i5) found that 

 Scalops aquaticus, a mole distributed over the eastern region of the 

 United States, will consume more than its own weight of suitable food 

 in a day. In the stomachs of nine moles which I examined it was 

 found that three stomachs contained remains of Elaterid larvae (the 

 remainder of the food was mainly various insect larvae, earthworms 

 and slugs). It is interesting to note that in the districts where these 

 nine moles were trapped, one farmer would not allow moles to be trapped, 

 save when they were becoming too plentiful ; on all the surrounding 

 farms the moles were trapped regularly. The district has been examined 

 for wireworms, and it was found that on the farm where the moles 

 were protected, wireworms were very scarce, and then could only be 

 found in small numbers in a very old pasture. On the surrounding 

 farms, where moles were trapped, wireworms were taken in numbers. 

 The animal is often a nuisance in grassland and cornfields, but it should 

 be remembered that the mole is burrowing after food, and not for 

 amusement. Again, as its food consists principally of insect larvae, 

 and, as Adams (i) remarks, the mole does not hibernate, but continue? 

 active all the year round, it can w^ell be seen how useful the animal is. 

 These facts together with its voracity, and its need for meals at frequent 

 intervals (Adams, loc. cit.), show the utility of the animal. It certainly 

 destroys large numbers of wireworms, and should therefore be merely 

 prevented from becoming too abundant. According to Graf (7), an 

 important enemy of adult Elaterids is to be found in the Carabidae, 

 species of Calosoma being particularly important in the control of 

 Limonius californicus (sugar beet wireworm). Curtis (loc. cit.) mentions 

 that the Carabs Pterostichus madidus and Nebria hrevicollis are enemies 

 of the wireworm. While collecting between 1914 and 1915, Carabid 

 larvae and small adults {Nebria, sp.) were commonly found in potato 

 drills, where wireworms were attacking the tubers. The adult Carabs 

 most commonly found were Pterostichus madidus and Nebria brevicolUs. 

 It was found, as the result of carrying away two wireworms and a 

 Nebria brericollis in a tin box containing earth, that the Carab attacked 

 the wireworms. On examination, after the day's work, the Nebria 

 was alive, and the two wireworms dead and mutilated. Under natural 

 conditions, no Carabs were seen attacking wireworms, though injured 

 larvae were seen. 



I 



I 



