BEETLES. 



347 



egg-mass of the locust, this larva forms a cavity in the ground, partially moults, and 

 enters the pseudo-pupal (sometimes termed coarctate larval) stage. Usually hil>erna- 

 tion takes place in this stage. The third larva is revealed in the spring by a shedding 

 of the pseudo-pupal skin. The third larva burrows about the ground, without feed- 

 ing, soon pupates, and the imago emerges shortly after. The stages of the Meloidu' 

 parasitic upon bees, and of those which are devourers of locust eggs, can be more 

 easily understood and compared with the ordinary metamorphoses of Coleoptera by a 

 glance at the following tabular arrangement : - 



BEE-PARASITES. 



Egg. 



Triungulin (1st larva): Active, often a plant- 

 climber; bee-parasite, and egg-eater. 



Second larva: Sluggish, and a honey-eater; 

 usually with two moults. 



Pseudo-pupa : Coarctate larva, is a resting 



stage. 



Third larva : Again active, but does not feed. 

 Pupa. 

 Imago. 



DEVOURING EGGS OF ORTUOPTERA. 



Egg. 



Triungulin (1st larva): Active, running about 

 the ground ; an egg-eater. 



Second larva: An f carabidoid stage, 

 egg-eater. 1 scarabreidoid stage. 



I ultimate stage. 



Pseudo-pupa : Coarctate larva, is a resting 



stage. 



Third larva : Again active, but does not feed. 

 Pupa. 

 Imago. 



Lytta vesicatoria, the Spanish fly, is a bronze green species, about 0.75 of an inch 

 long, and is found in middle and southern Europe and in southwestern Asia, where it 

 feeds upon ash (Fraxinus excelsior), lilac, and other trees. Curiously enough, the 





FIG. 389. Lytta vesicatoria, Spanish tiy. 



life history of this insect, which was so long used for medicinal purposes, remained 

 almost unknown until 1879, when J. Lichtenstein published an account of rearing 

 the imago from the triungulin, which latter fed upon eggs of Ceratina chalcites, a 

 hymenopteron. The triungulin, which is, of course, very small, has strongly protu- 

 berant eyes, and two long caudal appendages. In five or six days the triungulin 

 changes to the second larva, a little white grub, with six feet. The mandibles, sharp 

 in the triungulin, are short and blunt in the second larva, which feeds on honey. 

 After five days the second larva moults, the mandibles are still more blunt, and the 

 eyes less prominent. At the end of a second five days' period another moulting takes 

 place, the eyes entirely disappear, and the larva becomes scarabasidoid. The larva 

 now descends into the ground, where, in a small cavity, it pupates in about five days. 

 The pseudo-pupa is similar to the well-known pupre of Muscidae, but has four little 

 protuberances or Avarts upon the head and three pair of warts in place of feet. The 

 color is yellowish white ; and from time to time a clear fluid is exuded from pores of 



