Moesz Gusztáv - Soós Lajos (szerk.): A Magyar Természettudományi Múzeum évkönyve 28. (Budapest 1934)

Hungerford, H. B. ; Evans, N. E.: The Hydrometridae of the Hungarian National Museum and other studies in the family. (Hemiptera)

looked by the senior author in his study at the Swedish Museum. In Ameriea Mr. J. R. DE IA TORRE-BUENO, with his characteristic hospitality permitted the senior writer to examine such Hydrometra as he possessed in his own collections. The material in the University of Kansas collections has been increased greatly in recent years by the Entomological Expeditions sent out under the leadership of Dr. R. H. BEAMER. Exotic materials have been added both by collectors employed by the University of Kansas and by friends of the senior author, among whom may be mentioned: Dr. F. X. WILLIAMS, J. G. MYERS, Professor T. ESAKI. Professor R. TAKAHASHI. E. SWENSON, Dr. O. LUNDBLAD, CARL C. ADDISON, W. A. HOFFMAN, and A. CULBERTSON. N a t u r a 1 H i s t o r y a 11 d G e o g r a p h i c a 1 Distribution. The Hydrometridae are exceedingly slender bugs that dwell upon the shores and floating vegetation of the water. We have collected the Hydrometra on the Sphagnunt at the edge of bog ponds, midst the emergent vegetation of shallow waters. on rafts of dead cattail in a marsh and on floating mats of duckweed (Lemna) and of filamentous algae. They prefer thc footing such things afford but can walk upon the water when occasion demands. They are predaceous in habit and the life history of Llydrometra Martini KIRKALDY, common in North America, will illustrate the essential features of what is known concerning these marsh treaders. The curiously sculptured spindle shaped eggs (see Plate I) are attached by the basal end to some support at or above the surface of the water. HUNGERFORD (7) observed one female that deposited 175 eggs, 11 in one day. The eggs hatch in about a week and the nymphs undergo 5 instars." The complete cycle from egg to egg, under the most favorable conditions can occur in 15 days. There are several generations in the season and winter is passed in the adult stage. Mr. TORRE-BUENO (17) on the basis of facts known to him in 1926 gave the distribution of the family as: „Predominantly neogeic — in fact neotropical — one might almost say that the center of dispersal lies in the Caribbean Islands and littoral. . ." The presence of all three genera in fhis region certainly supports him. He recorded * BOLLWEG (2) records 4 nymphal instars for H. stagnorum but O. LUNDBLAD (12) and V. TEYROVSKY (15) give 5. Annales Musei Nutio:ialis Hungarici XXVIII.