7720 Insects. 



ness of this, but have never observed it myself; I am only aware that 

 they emit a greenish fluid from the month, with which they stick 

 together grains of earth, and so make an oval cocoon in which to 

 undergo their metamorphosis. This commonly takes place in Septem- 

 ber, in favourable seasons during the second week ; if the weather is 

 unfavourable at the end of that month, sometimes even in October. 



The larva remains in the cocoon during the winter ; it then gradu- 

 ally becomes shorter and thicker, the head sinking more between the 

 six fore legs, which increase in length, the remaining legs gradually 

 disappearing. The last moult does not take place until the beginning 

 of June, when a red-coloured shining pupa is produced, in which the 

 colours of the perfect insect are gradually developed. De Geer's 

 observations concerning this pupa are very noteworthy, as also the 

 manner in which he observed its passage from the larval state, and his 

 remarks upon the subject. 



The imago appears in the month of June of the following year. It 

 is by no means a scarce insect with us, and has been observed in many 

 different parts of the kingdom. On warm days and in the bright sun- 

 shine it appears very quick in its movements, but like most of the other 

 Tenthredinidaj it is by no means shy. 



The males occur less frequently than the females. The former are 

 11 mm. long from the head to the anus, the latter 14 or 15 mm., and 

 expand 28 mm. The head is black, granular, punctate and covered 

 with short hairs ; eyes black ; ocelli ruby-coloured. The first joint of 

 the antennae is testaceous or yellow, the remaining joints black ; the 

 antennae themselves are shorter than the head and thorax ; the third 

 joint is the longest, the sixth the thickest. A milk-white, somewhat 

 curved transverse line runs across the clypeus ; the mandibles are light 

 brown with black tips. The thorax is coarsely punclulate, pubescent, 

 black ; two yellow stripes run from the middle of the protliorax to the 

 insertion of the wings, which is covered on either side with a brown 

 tegula. Just above the coxae of the third pair of legs is a round ivory- 

 white spot. The scutellum is perceptibly raised. The abdomen is 

 shining bluish black. The first, fourth and fifth segments have a yel- 

 low border. In some specimens small yellow spots are found on the 

 sides of the third segment, and in some females on the sides of 

 the sixth also. In the middle of the hind margin of the seventh 

 segment is a semilunar spot ; the eighth segment in the male 

 is black, with a yellow spot in the middle ; in the female the 

 eighth and ninth are yellow. The wings have a pale brown costal 

 nervure and stigma ; a brownish blue-black spot extends over the 



