42 HOMOPTERA 



deeply inserted that the buds have been deformed. In the case of a fruit bud this would of course 

 result in an economic loss, but the chances are so largely in favor of the choice of large buds, or of 

 leaf buds which can be replaced without serious results, that the relative injury done is small. 



The fact that Membracida are found in many parts of the world on host plants of great economic 

 value, such as fruit trees in North America, teak in the Dutch Indies, sandal in India, and forage crops 

 in various countries, and that so few reports on economic loss due to these insects have ever been made, 

 would indicate that the membracids as a group should not be considered as pests. 



Even if certain species should prove to be destructive, the problem of control should not be 

 difficult. Very few if any of the Homoptera are so poorly adapted by habits and Hke factors to resist 

 the ordinary control measures of the entomologist, as are the tree-inhabiting speciesof the Membracida, 

 and it seems hardly likely that in orchards or forests in which the simplest kind of preventative work 

 is done they will ever become serious pests. The nymphs of all species are very soft-bodied and habitu- 

 ally rest in the crotches of twigs and the axils of leaves, where they can easily be reached by contact 

 sprays. Liquid sprays of the miscible oil or nicotine type will run down the twig and collect in such 

 places, even if applied in a very careless and superficial manner to the tree. Egg masses are easily 

 found, are usually on comparatively young stems, and can be removed by intelligent pruning. Clean 

 cultivation and the removal of the weeds which furnish the food or of the secondary hosts on which the 

 eggs are laid will control those forms which feed on one host and oviposit on another. On the whole 

 the Membracida seem to be of little concern to the agriculturist or forester. 



TERMINOLOGY 



The peculiar pronotal structures of the Membracida have been largely responsible for the 

 development of a terminology for this family which is in many cases quite different from that used for 

 other insects. Certain descriptive terms have been proposed and adopted which are in some instances 

 unique in entomology. Many of these names were first used by early writers but have found favor by 

 later entomologists since they were well suited for descriptive purposes and they have now become well 

 established. 



Since these terms are used throughout the foUowing descriptions of genera and in the taxonomic 

 keys, a few of the most important should be mentioned. 



Pronotum . Applies to any part of the notum of the prothorax whether visible or hidden. It is often 

 greatly exaggerated in the Membracida. 



Anterior process. Any projection arising from the front of the pronotum. 



Dorsal crest. A protuberance or hump at or near the center of the pronotum. 



Posterior process. Any extension of the pronotum behind the scutellum. 



Scutellum. The posterior dorsal sclerite of the mesonotum. 



Humeral angles. The lateral protuberances on either side of the front of the pronotum above 

 the eyes. 



Suprahumeral horns. Projections often cornute or auriculate on either side of the front of the 

 pronotum above the humeral angles. Generally spoken of simply as « suprahumerals ». 



Metopidium. The decHvous part of the pronotum from the base of the head to the front of the 

 dorsum. 



