FAM. MEMBRACIDiE 33 



opens into the swollen rectum, which connects by a smaller rectal tube to the opening in the abdomen. 

 At the point where the mid-intestine ends and the small intestine begins, both these organs are 

 somewhat looped and give rise to the urinary tubules. This part of the intestine has been called 

 the filter chamber, and has been described in the Cercopida by Licent (igi i); but in the type of chamber 

 shown by that family the mid-intestine and the urinary tubules are twisted many times around one 

 another in an enclosed part of the canal. A similar filter chamber, though not so eloborate, is de- 

 scribed by Berlese (1909) for certain Coccida. Apparently such an arrangement of twisted intestine 

 and nephridial organs is not uncommon in the Homoptera. 



The respiratory system shows no peculiarities so far as has been observed. The spiracles have 

 been discussed under the description of the external anatomy. 



In the reproductive system the only points noted as applied particularly to the Membracida are the 

 number of eggs found in various species in life-history studies. It may be noted in this respect that 

 the eggs are very large in proportion to the size of the insect, and are usually all matured at about 

 the same time. 



LIFE HISTORIES 



The complete hfe histories of very few species of Membracidce have ever been reported. The 

 writer has published (1915-20) descriptions of the life historiesofa number of North American forms 

 but no similar studies have been made of tropical species so far as the literature of the family would 

 indicate. However, from field observations in many parts of the world, we believe that the life histories 

 of these insects are much the same, wherever they are found, except in the matters of number of broods 

 per year and hibernation. 



In the United States most species of Membracida spend the winter in the egg stage and the first 

 evidence of the family in the spring is the appearance of the nymphs from the winter eggs. These 

 usually appear in the south in late March and early April while in the north some species do not hatch 

 until July. A few species are known to winter over as adults. This is true of the species of Stictocephala 

 in the south and of the species oi Euiylia and Publilia in all parts of the country. 



In all parts of the world mating begins almost immediately after the insect reaches maturity. The 

 position assumed in the process is the one not unusual in Hemiptera, with the caudal extremities 

 together and the heads in opposite directions. The insects are very sluggish at this time and seldom 

 move unless disturbed. If molested they fall to the ground, not, however, becoming detached from 

 each other. If movement takes place during copulation, the female generally moves forward, dragging 

 the male backward behind her. The process has been timed from five minutes to one hour in different 

 species. No forms have been observed in flight while in copula. During copulation the styles of the 

 male function asclasping organs and the ovipositor of the female is drawn downward and forward. In 

 the temperate regions species that have more than one brood a year show more or less well defined 

 mating seasons during the summer; but in the tropics the development of nymphs is so irregular that 

 the broods overlap and mating may be observed at practically all times throughout the year. 



There are a number of rather distinct types of oviposition, as regards both the location of the 

 eggs and the mechanics of the process. The eggs are most commonly deposited under the bark of the 

 younger twigs. In most cases a single narrow slit is made in the bark, the ovipositor not reaching the 

 cambium or, if reaching it, slitting down on one side of the twig between the bark and the wood and 

 not penetrating the xylem. In this slit the eggs are deposited and the bark springs back into place over 



