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CHAPTER V. 



INSECTS USEFUL TO FOBESTS. 



IT is most essential that in combating the attacks of 

 injurious forest insects the forester should be able to distinguish 

 insect friends from foes, and unimportant species from 

 hurtful ones. 



The following is therefore a short account of the most 

 useful families of insects, which are found chiefly in the 

 orders of Coleoptera and Hymenoptcra. 



ORDER I. COLEOPTERA. 



1. Cicindelidae (Tiger Beetles). 



Perfect insects of moderate size, slender ; mandibles power- 

 ful, with three teeth; antennae filiform, with eleven joints. 

 Legs long and slender, with five tarsal joints. Abdomen 

 of six segments, the three first fused. Larvae long, some- 

 what flattened and humped in the middle, with a broad 

 head and six feet. 



The larvae dig vertical holes as thick as a quill in the 

 sand, and remain at the entrance with projecting head, in 

 wait for any passing insects or worms, which they seize, and 

 suck dry. The beetles prefer sandy and sunny localities, 

 especially white sandy roads, are very active, alternately 

 running and flying over short distances, and greedily devour 

 other insects. 



One genus, Cicindela, with a few British species ; of these, 

 C. campestris, L., is the only one with an extended distribution 

 in suitable woodland localities. 



2. Carabidae (Ground-Beetles). 



Perfect insects variable in size, but often large ; mandibles 

 smooth or with only one tooth ; antennae filiform, with 

 eleven joints. 



