No. 34-] HEMIPTERA OF CONNECTICUT: MEMBRACIDAE. 167 



About six weeks are required in development of which in most 

 cases the first four instars consume approximately a week each and 

 the last instar two weeks. 



A few species (e.g., Vanduzea arquata and Entylia bactriana) 

 have two or more broods a year depending on seasonal conditions. 

 In such cases there is much variation in the time required for the 

 various periods of development and it often happens that nymphs 

 of all stages and adults of different ages may be collected practi- 

 cally throughout the entire Summer. In such cases, also, the 

 individuals of the last brood often fail to reach maturity before 

 they are killed by cold weather. 



Very few of the species of Connecticut winter over in the adult 

 stage but it is possible that Entylia bactriana, Campylenchia latipes 

 and Publilia concava may show such hibernation, as adults are 

 often taken suspiciously early in the Spring. 



Hosts. 



The various species of Membracidae usually confine themselves 

 to very definite host plants and are excellent botanists. In many 

 cases the association between the insect and its host is so character- 

 istic that a knowledge of the one is sufficient for the recognition 

 of the other. Several of the species change their host plants 

 during their life cycle, the nymphs feeding on one plant, usually 

 some succulent weed; the adults ovipositing on another, usually 

 a tree. A wide variety of hosts have been recorded for the family, 

 about fifty plants common to Connecticut being known as favor- 

 ites, most of which are either nutbearing trees, legumes, Rosa- 

 ceae or composites. The specific hosts are here recorded, when 

 known, under the discussion of the various species. 



Economic Importance. 



As a family the Membracidae are not to be considered as of 

 any great economic importance and very few of the species found 

 in Connecticut have ever been accused of causing any considerable 

 damage to host plants. Careful field notes, extending over a 

 number of years, would indicate that the amount of sap consumed 

 by the insects in feeding is negligible since no detrimental effect 

 has been observed from this cause. The damage done in opposi- 

 tion is very slight since the egg-slits are superficial, in woody 

 plants seldom extending to the cambium, and usually healing over 

 without leaving a scar. 



A few exceptions, however, may be noted. Ceresa bubalus 

 makes a peculiar curving egg-slit and several slits are often made 

 so close together that a definite area is cut out of the bark which 

 leaves a characteristic line of scars on young twigs. Ceresa 

 borealis likewise makes rather deep wounds which sometimes fail 

 to heal and may become infected with fungi. Three species, 



