8 HOMOPTERA 



Since the membracids have large, povverful, well-developed wings, there seems to be no reason why they 

 should not be capable of long, sustained flight unless they are handicapped by the weight and size of the 

 over-developed pronotum. Buckton (igoS) claims that the Memhracida, in spite of their abnormal pro- 

 notal structures, have no difficulty in locomotion, and states on the authority of Mickeljohn that even the 

 species Bocydium globtdare, which is one of the most bizarre of the tropical forms, « flitted from one shrub 

 to another without difificulty or apparent laboured flight h . The writer cannot agree at all with this 

 conclusion. Our observations on exotic forms indicate that they are seldom abie to handle themselves 

 in creditable fashion even though the mechanism and development of their wings are excellent. It 

 seems very reasonable to conclude, therefore, that the shape, size and weight of the enormous pronotum 

 proves more of a handicap to the insects than has been supposed. Certainly the Membracida are far 

 inferior to the closely related families of Cicadidce, Fulgorida, Cicadellidce and Cercopida in the matter 

 of flight. 



In the matter of jumping, the Membracida seem to use this method of locomotion only when 

 leaving the twig for flight. The insect leaves its support with a quick snap, which is apparently accom- 

 pHshed by means of the powerful hind legs though the movement is entirely too rapid to be diagnosed 

 l)y observation. The spring from the support on which the insect has rested seems to carry it for some 

 little distance before the wings are spread. There is, however, no true leaping or hopping from twig 

 to twig or from leaf to leaf in any species that has been studied in the field. 



The commonest method of locomotion is merely walking about over the hosl. In this process 

 all three pairs of legs seem to be equally functional. The movement is generally slow and deliberate, 

 but when disturbed the insect is able to scramble rapidly around the twig in a rather awkward and 

 amusing fashion. Both nymphs and adults adopt this method as the ordinary means of progress. 

 The nymphs, of course, are unable to fly and in no case has a nymph been seen to attempt anything 

 resembling a leap. 



At this point in the discussion of habits it may be well to mention the subject of care of the 

 young, or « maternal affection », which has been given rather general circulation in connection with 

 the Membracida. The theory apparently originated in a report by Miss Murtfeldt (1887) which has 

 been given wide credence and has often been quoted («. g. Kirkaldy 1906). Miss Murtfeldt describes 

 the finding of an egg cluster of Entylia sinuata, with a female on the leaf, and expresses surprise that 

 the insect did not fly away when touched but remained on the leaf while the latter was carried to the 

 house and later after the eggs had hatched. The significant statement is made, however, that 

 « although I would not assert that she made an}' demonstrations of affection, she certainly seemed to 

 enjoy having them (the nymphs) around her». This appears to be the total evidence for belief in 

 the maternal solicitude which is attributed to the Membracida. The truth is that the species in question 

 is one of the most sluggish of all of the membracids, and the most persistent in clinging to the host 

 plant. The writer has often carried a thistle covered with Entylias for several miles along a country 

 road without dislodging the specimens. Moreover, when an attempt is made to take the insect from 

 the leaf, the insect not only does not spring off, but actually seems to cHng more tightly to the hairy 

 surface of the leaf to escape being captured. The experience of Miss Murtfeldt is therefore not un- 

 usual, nor is the behavior of the membracid in the case at all unnatural, and it is unlikely that the theory 

 of maternal affection as based on her report can be proved. Efforts to substantiate such a theory by 

 observation of a large number of species in many parts of the world have yielded no evidence in its 

 favor. Many forms have the habit of clinging closely to their host plant if disturbed, and this is true 

 whether or not there are eggs or nymphs on the plant with them. 



On the whole, the Membracida must be considered as rather sluggish insects, content to Hve a 

 quiet Ufe and showing much less general activity than most of their near relatives. 



