Newly discovered leafhopper vectors of California aster-yellows virus

Abstract

Abstract does not appear. First page follows. Introduction Some years ago three species of leafhoppers and a biological race of one of them were reported to transmit the California aster-yellows virus (Severin, 1929), (1934), (1940).3 Recently eight additional leafhopper species were added to the list of vectors of this virus (Severin, 1945), (1946), (1947). The present paper deals with five newly discovered leafhopper vectors of this virus. In a companion paper (DeLong and Severin (1947)) discuss the characters, distribution, and food plants of these species. An investigation was undertaken on the efficiency of the vectors in transmitting the virus by single males and females to healthy celery and asters. Multiple-lot tests were performed with several species. With three species, studies were made of the retention of the virus in single adults. Natural infectivity tests were made with two species. With some species, attempts were made to transmit the viruses of curly top to sugar beets and Pierce’s disease of grapevines to grapevine cuttings or seedlings and the identical virus from alfalfa dwarf to healthy alfalfa. The technique and equipment have been described in previous papers (Severin, 1930), (1931), (1945), (1946), (1947). Cloanthanus Irroratus (Van Duzee) (Plate 1, A, B) Transmissionof Virusto Celeryand Asters. Fifty recently molted males and 50 females of Cloanthanus irroratus (Van Duzee), which had completed the nymphal stage on diseased celery, were kept singly on 100 celery plants until symptoms of the disease developed or during adult life if no symptoms appeared.