292 



Insect and other Invertebrate Fauna 



The numbers per acre of the more abundant groups were as follows: 

 Oligochaeta {Limicolae), etc., 3,609,424; Formicidae 2,946,125; Collembola 

 2,390,570; Diplopoda 1,367,002; Oligochaeta {Terncolae) 1,010,101; 

 Acarina 531,986; Chironomidae (larvae) 515,151. The numbers of insects 

 belonging to groups which are recognised as pests were: Elateridae 



No. of 

 species 



No. of 

 species 



I, Collembola ; 2, Thysanura ; 3. Orthoptnra ; i, Tkysanoptera ; 5, Hemiptera : &, Lepidoptera ; 7 , Coleopfera ; 

 8, Diptera; 9, Hymcnoptera ; 10, Diplopoda ; 11, Chilopoda ; 12, Areinida; 13, Acarina. 



Fig. 6. Number of species in the different orders in the manured and control plots. 



(larvae) 198,653; Tipulidae (larvae) 16,835; Hepialidae (larvae) 23,569. 

 The numbers per acre in the different orders are shown in Fig. 5. The 

 "probable error" in the total population per acre is ± 1,700,000, and in 

 the number of Elateridae larvae per acre ± 22,000. 



The number of species of insects which occurred in the samples was 

 about 72 but the number may have been slightly higher, as all the larvae 



