404 



Observations on the various Insects 



Power who created them. These are profound and mysterious 

 subjects which we cannot fathom, yet the divine book of nature 

 is open to all ; but it will only prove profitable to those who 

 have a thirst for knowledge, and who delight in contemplating 

 the wonderful works of the Creator. 



During the past summer the prodigious swarms of Aphides* 

 which suddenly covered the young shoots and under sides of the 

 leaves of almost every plant, so that the surface was blackened by 

 them, was unprecedented, as far as can be ascertained, and it 

 excited the attention of the public generally. The migratory 

 locust,t which is an awful visitation on the Continent.^ has this 

 year also reached our island. I have had several transmitted to 

 me from various counties ; and during a short stay on the 

 eastern coast last August, I saw six specimens which had been 

 ca})tured in a wheat-field by the gleaners, yet in all probability 

 neither the aphides nor the locusts will be present next year; 

 indeed, the former died in closely-packed groups, with their 

 beaks thrust into the leaves, and their wings erect ; and possibly 

 were either poisoned by feeding upon juices not adapted to their 

 constitutions, or they might have been held fast by the drying of 

 the leaves in which their rostrums were imbedded. A still 

 more remarkable instance of the sudden appearance of insects, 

 and the destruction of crops hitherto free from such depredations, 

 we shall give in the development of the economy of those species 

 which affect the mangold- wurzel. 



SiLPHA OPACA. The Beet Carrion-beetle. 



Dickson § says, that mangold-wurzel is not injured by insects 

 or drought ; and such appeared to be the case until the last two 

 or three years, when in France and Ireland the larva of a beetle 

 made its appearance in sufficient numbers to carry off entire 

 crops, and I find it now has several insect enemies to contend 

 with. 



There is a carrion-beetle called Silpha opaca, which was 

 known to Linnaeus, and is common enough in dead animals in 

 April: it has also been found in February at the roots of trees, 

 where, probably, it had wintered. In May I have detected it 

 under stones in sandy warrens, and also on the flowers of the 



* From a careful examination of these insects, I consider them to be 

 identical with the bean-plant louse, Aphis fohce ; and Mr. Francis Walker 

 entertains the same opinion. Vide Royal Agric. Jour., vol. vii. p. 416, 

 pi. R, figs. 20-23. 



f The history of this insect will be given when we come to the pasture- 

 land. 



% Vide Kirby and Spence's Introd. to Ent., Oth ed., vol. i. p. 185. 

 § Practical Agriculture, vol. ii. p. 723, 



