INSECTS 



pletely described as it might have been had there been more opportunity for 

 collating the material in the different collections. 



For the past seven years considerable attention has been given in the 

 Agricultural Department of the Technical School to the injurious pests of the 

 county, and in connexion with the County Council agricultural work, farmers 

 and market-gardeners have been encouraged by gratuitous advice or treatment 

 to report on damage done, and to send in specimens for identification. In each 

 of the orders throughout this article special reference is made to the extent of 

 the injury caused by different species in the county since systematic observations 

 began, but the limited space prevents more than occasional reference to pre- 

 ventative and remedial methods of treatment. 



The following table shows at a glance the number of Cornish insects in 

 each order that, so far as the writer is aware, have been identified up to 

 31 March, 1906. It is more than probable -that the numbers given are in 

 some cases slightly understated, as it has been impossible for the author at 

 Truro to gain access to all the monographs on British insects or to ransack all 

 the entomological periodicals for records : 



Aptera . 



Orthoptera (including introductions) 



Neuroptera . 



Dragon-flies. 



Pseudo-neuroptera 



Neuroptera-planipennia 



Trichoptera . 

 Hymenoptcra 



Phytophaga . 



Entomophaga 



Aculeata, &c. 

 Coleoptera . 

 Lepidoptera. 



Rhopalocera 



Heterocera . 

 Diptera 

 Hemiptera . 



Heteroptera . 



Homoptera . 

 Aphides 



24 

 66 

 34 



218 



53i 



263 



48 



1,065 



218 

 101 



48 



36 

 222 



1,012 



I,73 



722 



98 



Total 



5,273 



These numbers, of course, are approximately true only up to the date 

 specified, as several of them will be considerably increased when the Lizard 

 peninsula and the north coast receive systematic and continuous attention. 

 Unfortunately, too, our knowledge of the insects of the entire eastern half of 

 the county, except the Whitsand Bay and Plymouth district, is still in a frag- 

 mentary condition because of the dearth of resident entomologists. Among 

 the Diptera and the Entomophagous Hymenoptera there must be many 

 hundreds of county specimens waiting identification, and in every order, save 

 the Aptera and the Orthoptera, there is a residue of doubtful and unidentified 

 species, several of which may prove new to the British Isles. 



In addition to the help from so many ' brethren of the net ' acknowledged 

 in almost every section of the work, the writer wishes to express his great 



165 



