378 OBSERVATIONS 



they would produce ; but instead of a butterfly, 

 one of them produced a number of small ichneumon 

 flies. 



There are many instances of the great service 

 these little insects are to mankind in reducing the 

 number of noxious insects, by depositing their eggs 

 in the soft bodies of their larvae ; but none more re- 

 markable than that of the ichneumon tipula, which 

 pierces the tender body and deposits its eggs in the 

 larva of the tipula tritici, an insect which, when it 

 abounds greatly, is very prejudicial to the grains of 

 wheat. This operation I have frequently seen it 

 perform with wonder and delight. MARK WICK. 



BOMBYLIUS MEDIUS. The bombylius medius is 

 much about in March and the beginning of April, 

 and soon seems to retire. It is a hairy insect, like 

 a humble-bee, but with only two wings, and a long 

 straight beak, with which it sucks the early flowers. 

 The female seems to lay its eggs as it poises on its 

 wings, by striking its tail on the ground, and against 

 the grass that stands in its way, in a quick manner, 

 for several times together. WHITE. 



I have often seen this insect fly with great velocity, 

 stop on a sudden, hang in the air in a stationary 

 position for some time, and then fly off again ; but 

 do not recollect having ever seen it strike its tail 

 against the ground, or any other substance. 



MARKWICK. 



MUSCLE, (FLIES.) In the decline of the year, when 

 the mornings and evenings become chilly, many spe- 

 cies of flies (muscce) retire into houses, and swarm 

 in the windows. 



At first they are very brisk and alert; but, as 

 they grow more torpid, one cannot help observing 



