THE MYRMECOPHILOUS PTINIDAE (COLEOPTERA), WITH A KEY TO AUSTRALIAN SPECIES JOHN F. LAWRENCE' AND HANS REICHARDT" CONTENTS INTRODUCTION Alistract 1 The family Ptinidae includes about 50 Introduction _ 1 genera and 600 species, which are dis- Notes on Terminology , 2 tributed the of Classification of Myrmecophiles 3 throughout major regions The Australian Ectrephines 5 the world but are particularly abundant Key to the Genera and Species of Myrme- in the drier parts of the subtropical and cophilous Ptinidae Occurring in Australia __ 7 temperate zones. Of the described species, Notes on the Genera 8 almost 50 have been recorded from the Origin and Evolution of Myrmecophily in the Ptinidae 10 nests of ants and at least 42 appear to be Haliitats and Food Habits 10 true inquilines. The purposes of this paper Bi()lo,g\- of the Myrmecophilous Species .. 11 are 1 to certain in ( ) propose changes the Origin of Myrmecophily 13 classification of the myrmecophilous species E\olutionary Trends 15 on the basis of discovered Catalogue of the Myrmecophilous Ptinidae 16 newly characters, List of Ant Host Species and Associated In- (2) to provide a key to the species oc- 21 in quilines curring Australia, ( 3 ) to summarize what Acknowledgments 22 is presently known about the biology and Literature Cited 23 distribution of mynnecophilous ptinids in the form of a and to ABSTRACT catalogue, (4) spec- ulate on the possible origin and evolution A review is presented of the current of myrmecophily in the family. knowledge on ptinid beetles known to Those species of Ptinidae which are here occur with ants. Inckided are: 1) a cata- considered to be true ant guests fall into of the 2 a five logue myrmecophilous Ptinidae, ) main groups: the two tropical Amer- summar)' of biological and distributional ican genera Gnostus and Fabrasia, the data, 3) a revision of the genera and key South African Diplocotidus, the southeast to the species occurring in Australia, and Asian genus Myrmecoptimis, and the sev- a 4) discussion of the origin and evolution eral Australian genera which have usually of mynnecophily in the family. Eight gen- been placed in the subfamily Ectrephinae. era and 43 species are treated, and 8 The first four of these will be discussed previously recognized genera are placed briefly below and the last will be treated into synonymy. A Hst of ant host species in detail in a later section. is also given. In addition to the above, several ptinids have been recorded from the nests of ants. ^ Museum of Harvard Comparatixe Zoology, Tlie Ptinus Sturm and University, Cambridge, Mass. European suhpilostis - P. Panzer have been taken Departamento de Zoologia, Secretaria da Agri- scxpunctatiis cultura, Sao Paulo, Brazil. with the ants Acanthomyops fuliginosus Bull. Mus. Comp. Zool., 138(1): 1-28, April, 1969 1 Vol. No. 1 2 BuUetin Museum of Comparative Zoology, 138, scribed from the same area. The (Latreille) and A. hnmneus (Latreille); species both beetles occur in other habitats as well species differs considerably from other and (Linsley, 1944; Howe, 1959). The species mvrmecophilous ptinids probably rep- an line. The construc- Diplocotidus moscii Braiins was described resents independent the sub- from specimens collected under a rock with tion of the prothorax (Fig. 29), the ant Mcmnopliis peringucyi Emery in quadrate and concave clypeus (Fig. 3), South Africa (Wasmann and Brauns, 1925). and the aedeagus with reduced parameres the are all The Andreae (in litt.) has examined type (Figs. 26, 27) unique. grooves to and considers it to be an old and rubbed on the pronotum are somewhat similar Fair- those of P. and some of the South specimen of Pscudomczium coqucrcli ( coqucrcli but the does not maire). This record with ants is probably African gibbiines, species to related to of these. accidental. Finally, the species Leioptinus appear be closely any — hutteli infhtus \\'asmann (1928) was described yiyrmccoptinus. Myrmecoptinus 1916 was described from from a nest of Mijnnicoria amchnoides ^^'asmann ( ) Smith on Sumatra. This species may be Sumatra and associated with the ant Crc- hutteli Forel. Was- myrmecophilous, but from the description mafogastcr Although several and illustration it does not appear to us to mann's type has not been examined, from belong in the family Ptinidae. specimens have been seen Geylon, Gnostus and Fohrosia.—These two gen- Borneo, China, North Vietnam, and Burma that well with the era, which contain all of the New ^^'orld conform fairl>- descrip- in the same mvrmecophiles, have been treated else- tion and probably belong where (Lawrence and Reichardt, 1966a) group. The elytral humeri are well devel- and will not be discussed in detail here. oped, the wings are present, the clypeus is that in Ptinus Since the publication of the above revision, flattened and triangular like 2 antennal modifications are however, two new records have come to ( Fig. ) , and our attention. A specimen of Fohrasia completely absent. The pronotum is rela- horfimcicri Lawrence and Reichardt, in the tively simple but has a well-defined, nar- collection of the Departamento de Zoologia, row, transverse groove at the base, which was collected at P090S de Caldas, Minas connects lateral pairs of processes resem- with the Gerais, Brazil, in February, 1933, bling the trichomes found in other inqui- scnc.x ant Camponotus (Mijnnohrachys) lines. The color is black and the vestiture This a southern (F. Smith). represents is sparse, consisting of fine hairs as in other extension and a new of ant range species m\rmecophilous forms. One of the speci- host. A of F. wheeleri Lawrence specimen mens examined was collected by Mjoberg and Reichardt, in the collection of the in an ant nest, but the locality is indecipher- CaHfornia Insect Survey, was collected 6.3 able. These beetles are probably myrme- miles west of Tehuantepec, Oaxaca, Mexico, cophiles, but they do not appear to be on July 21, 1952, by E. E. Gilbert and C. D. closely related to the other groups. MacXeill (ant host not recorded). This is —The majorit\' of myrme- the first record of Fabrosia from Mexico Ectrephinae. cophilous Ptinidae occur in Australia and and represents a considerable northern are placed in the subfamily Ec- range extension for F. wheeleri, kno\\n generally These will be discussed further previously from Colombia. trephinae. below. Diplocotidus.—\\'ith the removal of D. moseri (see above), this genus contains a Notes on Terminology single species, D. formicola Peringuey, which occurs in the interior of South Africa. There are a few terms used in the key litt. to true and discussions that need clarification, Andreae ( in ) considers these be may the same myrmecophiles and has seen two unde- although the usage is essentially Myrmecophilous Ptinidae • Lawrence and Reichardt as that found in Lawrence and Reichardt two processes arising on different sides of (1966a). a cleft or fovea. Perhaps this is a device This is to Chjpcus. equixalent the area for collecting a drop of liquid. In the fol- referred to Stickne\- 1923 as the all by ( ) post- lowing discussions of these prothoracic ch'peus. In most Ptinidae it consists of a structures are called trichomes. Patches of well-defined, broad, triangular plate lying short hairs or pile are usually found on the just in front of and between the antennal last antennal segment (Figs. 17-19), and in fossae, the anatomical base of the plate some species they are concealed within a the of the forming apex triangle (Fig. 2). concavity at the tip of the segment (Figs. The word "apex" in the text refers to the 15, 16). Occasionally the hairs may be anatomical apex to which the labrum is absent (or rubbed off), but the extremely attached. Many of the myiTnecophilous fine punctation may indicate the presence ha\e a more and tumid of a area 22 . species elongate glandular ( Fig. ) clypeus (Figs. 1, 4, 7, 8), while in several Measurements. The total length is the others it consists of a flattened, cleft plate maximum length as measured from above (Figs. 5, 6, 9, 10). (tips of elytra to the most anterior point TricJwmes. In the to Torre- of the . E\\^ supplement clypeus ) EL and refer to great- Bueno's Glossary of Entomology (Tulloch, est elytral length and greatest elytral width, I960), trichomes are defined as "modified respectively. hairs present on certain mynnecophilous insects which give off secretions which ants CLASSIFICATION OF MYRMECOPHILES imbibe." the word be used Although may The placement of myrmecophiles in a to describe any group of hairs which are system of classification has always pre- to be it is thought glandular, commonly sented a problem to taxonomists because of restricted to distinct setiferous processes the development in these fonns of special usually found on the prothorax, antennae, adaptations associated with inquilinous or abdomen of elytra, myrmecophilous habits. In some groups normally consena- beetles. statements about the Actually, tive characters, such as the number or function of these structures are seldom, if shape of antennal segments, may be highly ever, accompanied by histological or behav- variable, while in others entirely new struc- ioral studies (see p. 12). tures, such as trichomes, may be present. In the Ptinidae there are four main kinds It is not surprising that a number of these of structures which be 1 glandular: ( ) may species have been placed in separate fam- femoral elytral pores, (2) trichomes, (3) ilies until more careful studies have clarified pronotal trichomes, and (4) antennal pilos- their relationships. A few of the many ity. The first two structures are found only beetle families originally proposed for in the genus Fabrasia; the elytral pores the inclusion of inquilines but no longer secrete a white waxHke substance. In some recognized are the Pseudomorphidae ptinids, such as Ectrephes fonnicanim Carabidae ( ) , Clavigeridae ( Pselaphidae ) , Pascoe 28 and Enasiha tristis Olliff ( Fig.