FAM. MEMBRACIDiE 37 



the final molt, and the old exuviae may be found in this position several days after the process has been 

 completed. In some cases only the first pair of legs :ire thus attached; in others all six legs. Some 

 species do not attach themselves and the old skin falls to the ground as soon as ecdysis is complete; in 

 other species the old nymphal skin hangs to the end of the abdomen of the adult and is carried about 

 for some time after molting. Just before the last molt, the skin dries out and becomes more or less 

 transparent and scaly. Under the micioscope it is possible to distinguish regioiis in which the 

 integument has pulled away from the new skin even before splitting begins. The splitting occurs 

 down the dorsal line but does not always start in the same place. In most cases the splitting occurs 

 lirst along the dorsal line of the head; in a considerable number it begins near the thorax, and in 

 a few over the abdomen. The various segments gradually enlarge as they are freed, and become 

 decidedly swollen within a few minutes following ecdysis. The exuviae, if perfect, ma}' be used for 

 diagnosis and correctly represent the last nymphal stage. 



The nymphs are active but they do not jump as do the adults. They are prone to hide them- 

 selves in crevices in the bark and in the axils of leaves, where their coloration renders them very 

 inconspicuous. If disturbed they often creep around to the opposite side of the twig and are able to 

 run fairly rapidly when in the later instars. They often have the habit of flattening themselves close to 

 the twig if molested and remain without movement even when touched. During ecdysis they are of 

 course comparatively helpless and may be studied with great ease. 



The newly emerged adults are lighter in color than the normal hue of the species, and are very 

 soft-bodied. The exoskeleton becomes hardened, however, within a couple of hours and the normal 

 colors appear in twenty-four hours. In the insects ave injured during this period the injury becomes 

 permanent and the mutilation may appear as a grotesque twist or bend in the hardened pronotum. 

 We suspect that such injured specimens have given rise to certain so-called new species and varieties, 

 the descriptions of which have beenbased on single specimens with apparently new pronotal characters. 

 After reaching the adult stage the insect often moves to a different host from that on which the eggs 

 were laid. In fact such migration may take place during the last or the next to the last nymphal instar. 

 In some cases a clear distinction can be made between the host used for oviposition and that used 

 as a food plant; in other cases the insect spends its entire life on one plant which serves both as food 

 and as an egg host. In the latter case both nymphs and adults may be taken together, and apparently 

 they lead a more or less gregarious existence. 



The foregoing life history notes apply in a general way to the family as a whole as the activities 

 of the insects have been observed in many parts of the world. In the matters of numbers of broods 

 and of methods of wintering over, however, no general statement can be made, since these aspects of 

 the life histories of the insects show great variation according to the regions concerned. In the temperate 

 zone and in all regions where the vegetation is retarded by winter conditions for a long or short penod, 

 the insects usually winter over in the egg stage with an occasional species surviving as adults hibernating 

 in leaves and debris around the plants. In such regions the number of broods per year seems to vary 

 with the length of the summer and ranges from one to five. In the tropics, however, membracids may 

 be found as adults and in all the nymphal stages at practically all times of the year, and apparently 

 mating, oviposition, development and maturation are continuous [jrocesses. In fact our collection of 

 tropical membracids shows specimens collected in every month of the year and curiously enough no 

 one month seems to be favored over the others .so that we are forced to conclude that there is no break 

 in the life histories unless it be due to purely local seasonal conditions. 



