Biology of the Membracidae of the Cayuga Lake Basin 425 



on other hosts in which to lay the winter eggs, and if such hosts were not 

 available they would probably not be able to winter over. In such 

 cases, also, the membracids would probably yield as readily to the various 

 types of hopperdozers as do most of the other grass- and grain-inhabiting 

 insects. 



The suggestions, then, for the control of the species of this family if 

 they should become numerous enough and destructive enough to be con- 

 sidered as pests, would be, first, clean cultivation. In this work particular 

 attention should be paid to leguminous weeds, such as sweet clover and 

 alfalfa, in fence corners and around orchards. Secondly, careful pruning 

 should destroy most of the egg masses. Thirdly, the use of contact sprays 

 should kill the insects in the nymphal stages. 



It is admitted that in the course of this study the main idea has been to 

 preserve the membracids of the basin rather than to destroy them, and 

 the above suggestions are entirely theoretical. 



BREEDING EXPERIMENTS 



Breeding experiments have l^een carried on both in the field and in the 

 insectaiy. , 



In the field the most satisfactory method has been to cover an egg mass 

 with fine netting and make regular observations during the period of 

 development, taking such specimens from time to time as were necessary 

 to show each of the instars. The eggs were usually located in the winter 

 or early in the spring, and a large piece of the branch or twig was covered 

 with netting — generally bolting cloth, but in some cases cheesecloth — 

 in such a fashion as to prevent the escape of any of the insects and at the 

 same time allow them a wide range of movement in their natural environ- 

 ment with natural sap conditions. The method had the additional 

 advantage of preventing other insects, and particularly other specimens 

 of membracids from neighboring colonies, from mingling with the brood 

 studied. Practically all the species in the basin whose life histories have 

 been worked out were reared in this manner. From such experiments 

 valuable data have been obtained regarding the variation in nymphal 

 periods of individuals from the same egg mass, as recorded in preceding 

 paragraphs for a number of the species. 



In a number of cases the host plants, with egg masses or colonies of 

 nymphs, have been transplanted to the writer's garden for more con- 



