262 D. WEBLEY 1): an Early Record of Heterodera Humuli Filipjev in The

262 D. WEBLEY1): An early record of Heterodera humuli Filipjev in the United Kingdom. Franklin (1951) infected Urtica dioica L. with cysts of H. humuli from hops (Humulus lupulus L.), but de Grisse & Gillard (1963) in Belgium found the nematode mainly on hops with few cysts on Urtica dioica and none on U. urens L. This suggested that hop was the main host plant, the other records chance occurrences, but recent observations, using a novel technique, contradict this. Organic debris sealed at the bottom of a filled-in Anglo-Saxon well at Elmham, Norfolk (Wade- Martins, 1972), found by radiocarbon dating to originate in 840 AD ±150 years, was examined with the froth flotation device (Jarman et al., 1972). Plant debris, seeds and many cysts of H. humuli were found together with a few of H. avenae, H. cruciferae, H. rosii, H. galeopsidis and/or H. schachtii. Fig. 1 shows the vulval region of one of the H. humulicysts from Elmham compared with a modern one from the soil of a hop field in Kent. Hops were not introduced into England until the sixteenth century, (Ernle, 1961), therefore the many H. humuli cysts found must have come from another host. The commonest weed seed present in debris with the cysts was Urtica dioica, which suggests that in this case the common nettle must be the host. The present record is also of interest in showing how long cysts last in soil. The ones found here, in conditions where oxidation was minimal, have survived intact over 1000 years, while Davidson & Curtis (1973) have found H. avenae and H. sclzachtiiin Early Iron Age levels, about 2000 years old. I should like to thank Mr Wade-Martins for allowing me to study his excavated material, Mrs H. N. Jarman for her comments on the weeds present and J. J. Hesling for confirming the H. humuli cyst identification. FRANKLIN,M. T. (1951), The cyst-forming species of Heterodera. Commonwealth Agricultural Bureaux, Farnham Royal, Bucks. DE GRISSE,A. & GILLARD,A. (1963), Morphology and Biology of Hop Cyst Eelworm (Heterodera humuli Filipjev 1934). Nematologica9, 41-48. ERNLE,Lord (1961), English Farming, Past and Present. Heinemann, London, p. 92. JARMAN,H. N., LEGGE,A. J. & CHARLES,J. A. (1972), Retrieval of Plant remains from Archaeo- logical sites by Froth Flotation. In : Papers in EconomicPrehistory, by E. S. Higgs, (Ed) Cambs pp. 39-48. WADE-MARTINS,P. (1972), Excavations at North Elmham, Norfolk Archaeology XXXV, p. 419. DAVIDSONJ. & CURTIS,G. J. (1973), An Iron Age Site on the land of the Plant Breeding Institute, Trumpington. Proc. Camb Ant Soc LXIV, 1-14. M. J. KISIEL2), S. HIMMELHOCH3), J. M. CASTILLO2) and B. M. ZUCKERMAN2) : Fine structure of the intestine of Pratylenchus penetrans. The fine structure of the feeding apparatus (Hirumi et al., 1967; Chen & Wen, 1972) and the body wall and vulva area (Kisiel et al., 1972) of Pratylenchus penetrans were previously described. The current paper presents observations on the ultrastructure of the intestine of P. penetrans. P. penetrans were cultured monoxenically on alfalfa callus by the method of Krusberg (1961). In the current studies only gravid females were examined. The nematodes were killed, fixed and 1) Agricultural Development and Advisory Service,66 Ty Glas Road, Llanishen, Cardiff, S. Wales, England. 2) Laboratory of Experimental Biology, College of Food and Natural Resources, University of Massachusetts, East Wareham, Massachusetts, U.S.A. 3) Section of Biological Ultrastructure, Weizmann Institute, Rehovoth, Israel. D. WLBLFYEarly : record of Heterodera humuli Fig. 1. Vulval region of a cyst of H. humulifrom North Elmham (9th century)-bottom photograph- compared with one from the soil of a hop field in Wye, Kent, (20th century) .

Load more