182 BRITISH APHIDES. 



Legs short ; tarsi long, single-jointed, and furnished 

 with a single claw and bristles. Rostrum short and 

 extending to the second coxae. 



Habitat. — North-west Provinces of India. 



Thus the known area now covered by these interest- 

 ing insects is a very large one, extending from 

 Northern Siberia to the Brazils in the southern hemi- 

 sphere ; from Colorado in the far west to New York ; 

 from Britain to Croatia ; and from the Himalaya to 

 China in the east. 



No notices yet have been published as to the 

 occurrence of the family in Southern Africa, or in the 

 temperate parts of Australia. Considerable interest 

 will attach to any indigenous forms which may here- 

 after be shown to exist in these parts of the world. 



7.— OBSERVATIONS ON THE NATURAL AND ARTIFICIAL 

 CHECKS TO THE INCREASE OF APHIDES. 



Although the primary aim of science is discovery, 

 and the knowledge of laws which govern the universe, 

 in a secondary manner we may well study phenomena 

 in connection with our own economy, and their bear- 

 ings on our material well-being and comfort. Some 

 information may therefore be here expected, as to the 

 methods, natural or artificial, which are of avail in 

 controlling the spread of insect pests in general, and 

 of Aphis in particular. 



As to the former subject, several notices will be found 

 scattered throughout my previous volumes relating to 

 the parasitic insects winch prey on Aphides ; and these 

 parasites will be found the most powerful checks to 

 Aphis increase, if perhaps we except all electrical 

 storms, rains, and winds. As to the artificial methods, 

 it must be confessed that, the numerous nostrums 

 advocated ami published through various journals, both 

 home and foreign, only prove how little we can do where 



