SMITHSONIAN MISCELLANEOUS COLLECTIONS VOLUME 106, NUMBER 15 ^bomas Xincoln Case^ jfunb LADYBEETLES OF THE GENUS EPILACHNA (SENS. LAT.) IN ASIA, EUROPE, AND AUSTRALIA (With 21 Plates) BY G. H. DIEKE fSi^ yORB (Publication 3860) CITY OF WASHINGTON PUBLISHED BY THE SMITHSONIAN INSTITUTION JANUARY 20, 1947 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOLUME 106, NUMBER 15 Itbomas Xincoln Caee^ dfunb LADYBEETLES OF THE GENUS EPILACHNA (SENS. LAT.) IN ASIA, EUROPE, AND AUSTRALIA (With 27 Plates) BY G. H. DIEKE (Publication 3860) CITY OF WASHINGTON PUBLISHED BY THE SMITHSONIAN INSTITUTION JANUARY 20, 1947 BALTIMOHS, MV., U. 8. A. CONTENTS Page Introduction i The genus EpUachna and the subfamily Epilaclininac 5 Comparison of EpUachna and Afissa 9 Source of material 21 Remarks on the figures 21 Genus EpUachna Chevrolat 22 Enneasticta group 100 Giittatopiistulafa group 104 Afidenta, new genus log Afissa, new genus 113 I. Adiiiirahilis group 115 II. Fallax group 124 III. Flavicollis group 133 IV. Complicata group 1 57 V. S::echuana group 163 VI. Chapini group 166 Epivcrta, new genus 169 SubcocciiieUa znginfiqitaftuorpiincfata ( Linnaeus ) 170 Cyuegctis impunctata (Linnaeus ) 171 List of all known Epilachninae : China 172 Philippine Islands 174 Bibliography 1 75 Index 181 t!D|)omafl! Lincoln €a&tp jFunb LADYBEETLES OF THE GENUS EPILACHNA (SENS. LAT.) IN ASIA, EUROPE, AND AUSTRALIA ^ By G. H. DIEKE (With 27 Plates) INTRODUCTION About one-sixth of all the described species of the Coccinellidae belong to the subfamily Epilachninae, and almost all these to the single genus Epilachna. The members of this subfamily are readily recognized by certain morphological characteristics and are distin- guished from the rest of the Coccinellidae not only by these structural differences but also by marked differences in their food preferences. The true coccinellids are carnivorous, feeding on other insects; the epilachnines and psylloborines, on the contrary, are phytophagous, the former feeding on leaf tissue, the latter on fungus spores. The species of Epilachna feed almost exclusively on leaves of plant species belonging to Solanaceae and Cucurbitaceae, with a few species attack- ing plants of other families, particularly the Fabaceae and the Com- positae. As many of our important cultivated plants, such as potato, tomato, squash, and bean, are members of these plant families and are at times subjected to devastating attacks by species of Epilachna, the genus may be considered as economically one of the most im- portant among the beetles. Reports from China have told of the destruction of whole potato crops by Epilachna beetles (Reh, 1913). In Australia they are among the worst enemies of tomato, eggplant, and squash, and similar con- ditions prevail wherever these beetles are found. The example of Epilachna varivestis Mulsant, the Mexican bean beetle, in the United States has shown that the invasion of some species into new territory may be expected with devastating effects. A thorough knowledge of the genus is therefore of great practical importance. At the time (1837) when Chevrolat split off the genus Epilachna from the by that time unwieldy number of species of the original 1 This is the sixth contribution to be published by the Smithsonian Institu- tion under the Thomas Lincoln Casey Fund. SMITHSONIAN MISCELLANEOUS COLLECTIONS, VOL. 106, NO. 15 I 2 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I06 genus Coccinella, only isolated descriptions of species of this genus had appeared. Redtenbacher (1843) apparently was the first to call attention to the fact that the species of this genus are phytophagous in contrast to the majority of the other coccinellids that feed on plant lice. He also was the first to give a description in words of the morphological characteristics of the genus. Mulsant, in the big mono- graph "Species des Coleopteres Trimeres Securipalpes" (1850), de- scribed a large number of new species and brought the known number from 37 to 152. He was also the first to try a systematic grouping of the species of the whole world. The only attempt to do this after Mulsant was made by Crotch in his revision of the Coccinellidae (1874), when the number of species had grown to 200. Whereas Mulsant's monograph suffers from lengthy descriptions and the repe- tition of not very important details, Crotch's work, on the other hand, is rather sketchy. After Crotch's revision no further account of the genus as a whole has appeared—only descriptions of new species scattered wic[ely over the literature. Korschefsky's Catalog (1931) lists 457 species of Epilachna, and a few have been described since. Mulsant and Crotch's descriptions and identifications of the species, and even more the earlier ones, are almost completely based on super- ficial characters like color and spot patterns. It has turned out since that in many genera of the Coccinellidae coloration is not a safe cri- terion for the fixation of a species, as it may vary widely in one species or be almost the same in two different species that are not even closely related. Nevertheless, most of the subsequent descriptions were chiefly based on coloration, probably partly because morphological characters that can be observed easily tend to be very uniform throughout the genus. The situation that confronts the student of the genus is therefore very unsatisfactory. In order to identify a species he must look through descriptions scattered through a large number of periodicals, many of them very difficult of access to the average entomologist. Even when he succeeds in collecting all the descriptions, and after he ha« taken the trouble of reading each one, he finds that in many cases it is totally impossible to identify the species from the descrip- tion because the latter may fit a number of allied species equally v.-ell, or because it may not fit the particular specimens at all, as they may deviate in unessential details of coloration from the type. I found this particularly true when, on Dr. Chapin's suggestion, I tried to identify the extensive material from the Philippines in the NO. 15 LADYBEETLES OF THE GENUS EPILACITNA DIEKE 3 United States National Museum. A thorough revision of the genus seems to be the only satisfactory remedy. The present paper is the first contribution to such a revision.- It deals with the species from Europe, Asia, the Indomalayan Archipelago, Australia, and the Pa- cific Islands. The material from the Philippines, which contains the Baker collection, is probably more complete than anything from this locality ever gathered together before. The material from China is also rather extensive, with long series of some species. There is considerable material from Java, the South Pacific Islands, and British India, and a more scattered representation from the rest of the region. Although a complete revision of the genus must wait until a de- tailed study of the African and American species will have been accomplished, the present paper hopes to make it possible that in future the species with which it deals may be identified without much uncertainty. That is very desirable because of the great eco- nomic importance of several species and because the inability to rec- ognize them has caused some confusion in the accounts of their biology. Unfortunately, even for the restricted region with which we are dealing, some of the species had to be left out, as I was unable to obtain them, and I have included in this paper only material on thf morphology and taxonomy I have been able to check by personal observation. The analysis had to proceed almost exclusively along morpho- logical lines, as information on the geographic distribution and the biology of the genus is in general yet too scanty to enable one to treat the species as biological entities rather than to define them by morpho- logical characters. Such a morphological analysis, however, is the necessary prerequisite for all further studies. As many of the older descriptions, perhaps most of them, are not sufficient to enable one - Although after Crotch's Revision no further general study of the genus Epilachna has appeared, there are a number of monographs of the faunas of certain more restricted regions that have included the genus Epilachna. How- ever, those of Europe or North America are of little help because of the verj' restricted number of species occurring in those regions. The home of the genus is definitely in the Tropics, and only feeble branches of it extend into the more temperate regions. Sicard (1907) gave a synopsis of the species of Madagascar, Fauvel (1903) one of New Caledonia. Mader's "Die Evidenz der palaeark- tischen Coccinelliden" (1926) contains 29 species. However, in most cases he gives only a copy of the original description and in all cases restricts himself chiefly to coloration and maculation, which, as mentioned before, are not suffi- cient for a definition and the recognition of the various species. 4 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I06 to recognize the species beyond any reasonable doubt, I have en- deavored to give new descriptions embodying such characters by which the species may be recognized without question in the future. As the type of none of these species is available at the present time, the names I have attributed to some of them may be in error. If that should prove to be the case, no great harm is done, as the error can easily be rectified if the types can be compared with the new description. As in so many other genera of the Coccinellidae, the male geni- talia have proved a great help in the study of the genus, and without them no disentanglement of some of the more closely allied species would have been possible. Very little systematic use has previously been made of the genitalia for taxonomic purposes in Epilachna.