Advances in VIRUS RESEARCH VOLUME 62 ADVISORY BOARD DAVID BALTIMORE BERNARD MOSS ROBERT M. CHANOCK ERLING NORRBY PETER C. DOHERTY J. J. SKEHEL H. J. GROSS R. H. SYMONS B. D. HARRISON M. H. V. VAN REGENMORTEL PAUL KAESBERG Advances in V I R U S R E S E A R C H Edited by AARON J. SHATKIN Center for Advanced Biotechnology and Medicine Piscataway, New Jersey VOLUME 62 KARL MARAMOROSCH Department of Entomology Rutgers University New Brunswick, New Jersey FREDERICK A. MURPHY School of Veterinary Medicine University of California, Davis Davis, California This book is printed on acid-free paper. Copyright � 2003, Elsevier Inc. All Rights Reserved. No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopy, recording, or any information storage and retrieval system, without permission in writing from the Publisher. The appearance of the code at the bottom of the first page of a chapter in this book indicates the Publisher’s consent that copies of the chapter may be made for personal or internal use of specific clients. This consent is given on the condition, however, that the copier pay the stated per copy fee through the Copyright Clearance Center, Inc. (222 Rosewood Drive, Danvers, Massachusetts 01923), for copying beyond that permitted by Sections 107 or 108 of the U.S. Copyright Law. This consent does not extend to other kinds of copying, such as copying for general distribution, for advertising or promotional purposes, for creating new collective works, or for resale. Copy fees for pre-2003 chapters are as shown on the title pages. If no fee code appears on the title page, the copy fee is the same as for current chapters. 0065-3527/2003 $35.00 Permissions may be sought directly from Elsevier’s Science & Technology Rights Department in Oxford, UK: phone: (+44) 1865 843830, fax: (+44) 1865 853333, e-mail: