XIII 



LOCUSTIDAE 



313 



of the rings covered by it being indicated by the letters m, mt, 

 aV . These changes are very similar to those we have described 

 in Acridiidae, the chief difference being the greater development 

 of the dependent wing-pads previous to the fourth instar. 



The ocelli in Locust idae are much more imperfect than they 

 are in Acridiidae, and are frequently rudimentary or nearly totally 

 absent, or there may be but one in- 

 stead of three. They are, however, 

 present in a fairly well-developed state 

 in some species, and this is the case 

 with the one whose face we portray 

 in rig. 189, where the anterior of the 

 three ocelli is quite conspicuous, the 

 other two being placed one on each 

 side of the curious frontal cone near 

 its base. The peculiar head ornament 

 shown in this figure exists in both 

 sexes, and something similar occurs in 

 a large number of Conocephalides. We 

 have not the slightest idea of its im- 

 port. Individuals of one or more 

 species of this curious South American 

 genus are occasionally met with alive 

 in gardens near London. They are, no 

 doubt, imported as eggs, for they are 

 sometimes met with in the juvenile 

 state, but in what way they are intro- 

 duced is not known. 



The ovipositor frequently attains a 

 great length in these Insects, so as to exceed that of the body. It is 

 used in different ways, some of the family depositing their eggs in 

 the earth, perhaps in vegetable matter under the surface ; but other 

 species place the ova in twigs or stems of plants, arranging them 

 in a very neat and compact manner in two series, as depicted by 

 Eiley^ in the case of Microcentrum retinerve (Fig. 190). These 

 eggs are laid in the autumn, and in the following spring become 

 more swollen before hatching. The Insect undergoes a moult 

 during the process of emerging from the Qgg. By the time the 

 emergence is completed the Microcentrum has expanded so much 

 ^ Ann. Rep. Insects Missouri, vi. 1874, p. 155. 



Fig. 189. Front of head of 

 Copiophora cornuta, female. 

 Demerara. 



