HUNGERFORD: AQUATIC HEMIPTERA. 33 



OVIPOSITION. 



The oviposition of the aquatics and semiaquatics does in 

 large measure consist in affixing the eggs to some inert sup- 

 port in the water. Yet there are two conditions wherein other 

 organisms are involved. One, in those cases where the eggs 

 are placed in incisions in plant tissues, and the other where 

 the eggs are deposited upon some animal form. 



In the former case the plants are directly concerned. So 

 long as the eggs are merely glued to li\ing plants for support, 

 a safeguard against their loss in the bottom^ of the pool, they 

 are not considered disturbed by the relation, but when their 

 tissues are punctured and lacerated in the process, there enters 

 a mutual ecological relation. 



The Hebrids and Saldids cache their eggs beneath the leaf 

 sheaths of bog-moss and sphagnum, while the latter employ 

 the shore grasses as well. Mesovelia and Rheumatobates are 

 equipped to puncture plant tissues, and the fact that Mesovelia 

 imbeds her eggs in the stems of spike-rush and leaves of cat- 

 tail, has been elsewhere recorded. Members of each of the 

 genera of the Notonectids can be found that make incisions in 

 the stems of money wort and other submerged plants for the 

 reception of their eggs. Two species of the genus Notonecta in 

 this country, .V. irrorata and A', lutea,* Buenoa margaritacea 

 and Plea striola come in this class. 



The matter of the Corixid that in large measure attaches its 

 eggs to those portions of the body of the crayfish which are 

 bathed by water currents, is discussed under the biology of 

 Ramphocorixa acuminata. (See page 218.) The eggs of this 

 boatman have been found upon smart weed stems of uprooted 

 floating plants and upon dragon fly nymphs, but in very small 

 numbers compared to those aflfixed to the crayfish. Other 

 Corixid eggs have been found covering the shells of living 

 snails, etc., but in such cases little ecological significance can be 

 attached to the phenomenon. 



FEEDING HABITS : THEIR RELATION TO OTHER ORGANISMS. 



The aquatic and semiaquatic Hemiptera are, as a group, no- 

 torious predators, and the records from an early date are re- 

 plete with accounts of their voraciousness. The observations 



* Jud^ng from equipment of female. 

 3 — Sci. Bui. — 1669. 



