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HARDWICKE'S SCIENCE-GOSSIP. 



investigate and report on the ravages committed by 

 injurious insects, and the best means for preventing 

 their attacks. Also to give lectures to agricultural 

 societies, and otherwise assist in disseminating useful 

 information among those who are more particularly 

 in need of it. 



Now, in order to supply, as far as possible, by 

 other means, this public desideratum, many sugges- 

 tions have been made at various times ; but the one 

 which has probably met with most favour, is the 

 establishment and exhibition of educational collections 

 of insects in our various museums, colleges, public 

 schools, and in other suitable places. 



It is with the intention of briefly relating the best 

 means of forming such a collection that the present 

 article has been written. 



Owing to our comparative ignorance of the 

 economy of the great majority of insect forms which 

 inhabit these islands, we are often at a loss to determine 

 whether a certain insect is to be classed as injurious 

 or beneficial. 



There are many species which appear to be 

 decidedly either one way or the other ; while, on the 

 other hand, there are many kinds which are really 

 both injurious and beneficial, in which case it is a 

 question whether the good outweighs the evil, or vice 

 versa. 



Then there are many insects which are beneficial 

 when in limited numbers, but which are injurious 

 when abundant. It will be seen therefore that there 

 is sometimes a great difficulty in discriminating 

 between our insect friends and enemies, and the 

 only philosophical conclusion is that a good know- 

 ledge of entomology is highly essential to the agri- 

 culturist for his advancement and prosperity. 



In the arrangement of the insects in the proposed 

 collection, no scientific order can with convenience 

 be followed, so that it will be found preferable to 

 adopt the alphabetical as far as practicable. 



The following are the headings under which all 

 insects injurious in a particular sphere may be 

 brought together : — 



1. Insects injurious to man personally, such as 

 cause him personal injury and annoyance. 



2. Insects injurious to stores, provisions, clothes, 

 furniture, and household goods. 



3. Insects injurious to domestic animals, cattle, 

 sheep, and poultry. 



4. Insects injurious to vegetable crops. 



5. Insects injurious to cereal and grain crops. 



6. Insects injurious to fruit crops. 



7. Insects injurious to forest trees. 



8. Insects injurious to garden and greenhouse 

 plants. 



Under the above primary headings subsidiary 

 headings might be arranged in alphabetical order, 

 the following of which is an example : — 



Insects Injurious to Vegetable Crops. 



Asparagus — Bean — Beet — Cabbages — Carrots — 

 Celery — Herbs — Hops — ■ Lettuce — Onions — 

 Parsnips — Peas — Potatoes — Turnips, &c. 



Then under each of these sub-headings would be 

 arranged alphabetically the various insects which 

 attack them ; for instance : — 



Cabbages. 

 Cabbage aphis — Cabbage butterflies — Cabbage-fly — 

 Cabbage gall weevil — Cabbage moths — Cabbage 

 powdered wing — Cabbage root-eating fly, &c. 



Many insects are injurious to several crops, and 

 specimens of these should be placed under each crop 

 which they attack; thus, for instance, the carrot- 

 blossom moths {Depressaria daucella and Depressaria 

 depressella) are injurious to parsnips as well as carrots 

 /under both of which headings specimens should be 

 exhibited). 



Under the heading of " Beneficial Insects," all the 

 insects which are more or less beneficial should be 

 arranged according to their various uses, of which the 

 following are the principal : — 



1. Insects beneficial to man in a commercial point 

 of view. 



2. Insects beneficial in consuming offal and de- 

 cayed vegetable substances, thereby preventing the 

 spread of malaria, &c. 



3. Insects beneficial in keeping within proper 

 bounds the undue multiplication of insect pests. 



4. Insects beneficial in keeping within proper 

 limits the growth of vegetation (in this country such 

 as feed on weeds). 



5. Insects beneficial in keeping the air in a state of 

 continual motion, thereby sustaining it in equal pro- 

 portions. 



6. Insects beneficial in adding to the beauties of 

 nature. 



Then there are many insects which are both 

 injurious and beneficial (as we mentioned before), 

 and for these the most philosophical plan, it would 

 seem, is to include them under both of the headings 

 of injurious and beneficial insects. 



It will probably be found most convenient and 

 preferable to devote separate cases for the primary 

 headings — some of them indeed will probably require 

 two or three apiece. 



Under each specimen should be given the English 

 and Latin names with a brief description (in the case 

 of an injurious insect) of the particular mode of injury 

 caused, and the best known remedies for preventing its 

 attacks, and in the case of a beneficial insect a note 

 explaining its particular uses. The above may be 

 printed, or else legibly written, on a square of white 

 cardboard. 



The following are two examples of what we 

 mean : — 

 Asparagus beetle {Crioceris asparagi). The larvce 



