The Fruit Flies Or Tephritidae of California
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Urophora formosa (Coq.) ovipositing in flower head of Grindelia Camporurn Greene. (Courtesy of I. E. Savage and G. M. Bwton.) Paracantha bntilis. Her. ovipositing in thistle, Mill Valley, V-54. (Courtesy of E. S. Ross.) BULLETIN OF THE CALIFORNIA INSECT SURVEY VOLUME 7 THE FRUIT FLIES OR TEPHRITIDAE OF CALIFORNIA BY RICHARD H. FOOTE (Entomology Research Division, Agricultural Research Service, United States Department of Agriculture, Washington, D.C.) AND F. L. BLANC (Bureau of Entomology, California Department of Agriculture, Sacramento) UNIVERSITY OF CALIFORNIA PRESS BERKELEY AND LOS ANGELES 1963 BULLETIN OF THE CALIFORNIA INSECT SURVEY Editors: E. G. LINSLEY,R. M, BOHART,P. D. HURD,R. L. USINGER Volume 7 Submitted by editors April 6, 1962 Issued June 15, 1963 Price, $4.00 UNIVERSITY OF CALIFORNIA PRESS BERKELEY AND LOS ANGELES CAMBRIDGE UNIYERSITY PRESS LONDON, ENGLAND 0 1963 BY THE REGENTS OF THE UNIVERSITY OF CALIFORNIA PRINTED BY OFFSET IN THE UNITED STATES OF AMERICA CONTENTS Introduction ............... 1 Morphology .............. .2 About this Bulletin ............. 4 Acknowledgments ............. 4 Systematic Treatment ............. 5 Key to the California genera of Tephritidae ....... 5 Genus Acinia Robineau-Desvoidy ......... 6 Genus Aciurina Curran ............ 7 Genus Anastrepha Schiner ........... 11 Genus Chetostoma Rondani ........... 12 Genus Cryptotreta Blanc and Foote ......... 14 Genus Dacus Fabricius ............ 14 Genus Dioxyna Frey ............ 15 Genus Epochra Loew ............ 16 Genus Euaresta Loew ............ 17 Genus Euarestoides Benjamin ..........22 Genus Euleia Walker ............ 27 Genus Eutreta Loew ............ 27 Genus Myoleja Rondoni ........... 32 Genus Neaspilota Osten Sacken .......... 33 Genus Neotephritis Hendel ...........35 Genus Orellia Robineau-Desvoidy ......... 38 Genus Oxyna Robineau-Desvoidy ......... 40 Genus Paracantha Coquillett .......... 41 Genus Paraterellia Foote ........... 44 Genus Paroxyna Hendel ............ 46 Genus Procecidochares Hendel .......... 50 Genus Prececidocharoides Foote ......... 54 Genus Rhagoletis Loew ........... 54 Genus Stenopa Loew ............ 63 Genus Strauzia Robineau-Desvoidy ......... 63 Genus Tephritis Latreille ........... 64 Genus Tomoplagia Coquillett .......... 72 Genus Trupanea Guettard ........... 73 Genus Trypeta Meigen ............88 Genus Urophora Robineau-Desvoidy ........ 89 Genus VaIentibulla Foote and Blanc ........ 91 Genus Xenochaeta Snow ........... 92 Host List ................93 Trap Record ...............100 Literature Cited ..............102 Index to Scientific Names of Fruit Flies ........105 THE FRUIT FLIES OR TEPHRITIDAE OF CALIFORNIA BY RICHARD H. FOOTE AND F. L. BLANC INTRODUCTION THEFAMILY TEPHRITIDAE is restricted to the temper- groups, especially the second, some species fall outside ate, subtropical, and tropical parts of the world. About this general pattern by mining in and forming galls 4,000 species have been described. Of the approxi- on leaves, stems, and roots. mately 230 North American species, 105 have been Host races are common, probably because larvae found in California. The body lengths of species of are restricted so completely to live, healthy plant this family range from 1 to over 20 mm, and the tissue as a source of food. Available evidence indicates wings usually have yellow, brown, or black spots or that host races may be rather rapidly formed within stripes, in positions characteristic of the species. a species. It is generally assumed that physiological differences, the first to appear, enable a population Members of the family are intimately associated formerly using only one species of plant as a host to with plants. In the typical developmental cycle, maintain itself on another with apparent ease. These gravid females insert their eggs into their plant hosts populations are often beyond detection by the with an eversible, sclerotized ovipositor. The devel- museum taxonomist if the differences are of rela- oping larva sheds its skin twice as it feeds and grows. tively recent origin; they are among the most difficult An inactive fourth-instar larval stage within the of taxonomic problems. It is also generally assumed puparium precedes the formation of a pupa. This that morphological differences eventually appear if process may take place within or on the host plant, the original physiological differences are maintained, but pupation itself most often occurs in the soil. and the degree to which these observable characters Upon emergence the adult gradually attains sexual are distinct then becomes, in a general way, a maturity and mates, and the life cycle is completed. criterion of how long the physiological differences Diapause is inherent in many temperate-zone have existed. As debatable as these assumptions tephritids but has been inadequately studied. may be, the fact remains that some species are The family can be divided into two major morphol- morphologically separable only by extremely obscure ogical groups, both illustrated by species present in characters, even in flies as highly decorated as some California. One of these groups is represented by the tephritids, and satisfactory identifications can be subfamily Tephritinae, most species of which oviposit made only when such supporting data as host, in the flower heads of a large number of plants, locality, and date are supplied with the specimen. principally composites. The larvae are short and Some of the most perplexing of these host rela- stout and live in the ovaries and seeds of their host tionships-especially in California-are found in the plants. Adults can almost always be recognized by genus Rhapoletis, in which the adaptation of certain the wing pattern, a dark field containing numerous morphologically distinct adults to unusual host plants, hyaline spots. All other subfamilies are of the second or their restriction to others, is still unstudied. Details group, which is characterized by a larger size, an of some of these relationships will be found in the elongated larva, and an adult wing pattern of dark discussions of pertinent species in this Bulletin; a spots or stripes, or a combination of both, on a review of these relationships and other biological hyaline field. Larvae of the second group usually live observations will be found in Christenson and Foote in and often seriously damage all kinds of fleshy (1960). fruits and some vegetables. However, within both Several species of Dacus, Anastrepha, Ceratitis, and 2 Bulletin of the California Znsect Survey Rhagoletis are highly destructive of commercially measured between the eyes at the vertex and between grown fruits and vegetables throughout the world. the vertex and the lunule (fig. 1). The upper fronto- Of these, the genus RhagoIetis is the only one orbital bristles are always present, usually in two indigenous to the State. Its economic importance is pairs, but one or three pairs may be present. The discussed on pages 54 and 55. Dams mmrbitae lower fronto-orbitals vary from one to five pairs, but Coq., D. dorsalis Hend., and Anastrepha Iudens (Lw.) are usually present in two or three pairs. have been field collected in California and are also Face.-That portion of the head extending from discussed below. These three species, and the Medi- the antennae to the anterior oral margin (fig. 1). The terranean fruit fly, Ceratitis capitata (Wid.), could gena is measured vertically from the oral margin to exist indefinitely within the borders of California, as the bottom of the compound eye. Its genal bristle is shown by climatic cabinet studies. Because the usually found directly below the eye. The antere California climate is favorable, and because an ever- lateral margin of the oral opening is occasionally increasing likelihood of their introduction there exists, rather heavily haired. The postocular bristles are these species pose a constant threat to the State’s agri- always present and may be dark and slender or rather cultural and economic future. robust, light colored, and blunt tipped. The first taxonomic summary of North American Antenna.-The third segment, usually rounded Tephritidae was presented by Loew (1862). In this apically, sometimes has a distinct apicodorsal point, work Loew placed all the known species in the as in all species of the genus Rhagoletis, and is genus Trypeta. In 1873 he again reviewed the family, provided with an arista, which may be varicolored but in much greater detail, assigning the North but is never plumose. American species to various genera on the basis of Mouthparts.-These consist of a rostrum and his experience with the European fauna. Little more labellum. In such genera as Dioxyna, Paroxyna, was done until the turn of the century, when the Rhynencina, and Urophora, the labellum is slender work of Snow, Dome, Cresson, and Coquillett added and attached by its anterior end to the rostrum, thus the descriptions of many new species, especially from forming a geniculate structure (fig. 8). the southwestern United States, to the North Ameri- Thorax can literature. From the 1920’s to the present, refine- (Figs. 2-5, 8, 9) ments have been made by Benjamin, Johnson, Curran, The mesonotum and scutellum of many species of Phillips, Malloch, Quisenberry, and others. In spite tephritids are ornamented with a color pattern of of the widespread interest in these beautiful flies, the tomentum or pollinosity, usually of specific or generic North American members of the family have never significance. The mesonotum is always interrupted