SPECIAL ISSUE BIOCHEMISTRY, ENDOCRINOLOGY, AND PHYSIOLOGICAL ECOLOGY OF INSECT HOST-PARASITE SYSTEMS .1. PARASITE-INDUCED ENDOCRINE, BIOCHEMICAL, AND PHYSIOLOGICAL-CHANGES IN THE HOST, SYMPOSIUM PROCEEDINGS FROM THE XVIII-INTERNATIONAL-CONGRESS-OF-ENTOMOLOGY, VANCOUVER, BRITISH-COLUMBIA, CANADA JULY 1988 - PREFACE