J. HYM. RES. Vol. 9(1), 2000, pp. 71-84

Afrotropical (: Formicidae): Taxonomic Progress and Estimation of Species Richness

Hamish G. Robertson

Life Sciences Division, South African Museum, P.O. Box 61, Cape Town 8000, South Africa; e-mail: [email protected]

Abstract. —Forty-three of the 82 Afrotropical genera (52%) have been revised to modern standards resulting in a 50% increase in number of species. There are currently 1705 species of ants known from the Afrotropical region, a figure that could increase to over 2136 species if all ant genera receive a modern revision. To incorporate all undescribed species, total Afrotropical ant species richness was calculated by extrapolating from data on the proportion of undescribed species collected at Mkomazi Game Reserve in Tanzania and the Cape of Good Hope section of the Cape Peninsula National Park in South Africa. On this basis there are an estimated 3105 species of ants in the Afrotropical region, with 45% undescribed or currently occupying an infraspecific taxonomic rank. This extrapolation assumes that the average range sizes of described and unde- scribed species are similar, which in reality is unlikely because widely distributed species are more likely to have been collected and described. I present a method that distinguishes between widespread and localised species to correct for this problem, which extrapolates 4093 Afrotropical ants species, with 58% of species estimated to be undescribed or currently recognised only at infraspecific rank. It would take a highly productive systematist at least 21 years to complete revisions of the unrevised ant genera. A strategy is presented for improving specimen collection and of Afrotropical ants.

Until recently, working on the taxono- be problematic when such revisions are my of ants and identifying them to based on collections with limited geo- was hindered by poor, out-dated cata- graphic coverage that omit species and logues and inadequate keys. Ant system- population variation. Older taxonomic atists, however, now have three books that works (mainly pre-1965) are difficult to provide a synthesis of our current knowl- use for identifying species because they edge: Bolton has produced keys to ant are often burdened with poorly applied genera of the world (Bolton 1994) and a quadrinomials (genus, species, subspecies, catalogue of world ants (Bolton 1995b) variety) that do not correspond with evo- and Ward et al. (1996) have provided a lutionary relationships. With the catalogue thoroughly researched bibliography of ant by Bolton (1995b), the bibliography by taxonomic literature. In addition, the book Ward ct al. (1996), and a wealth of new by Shattuck (1999) makes identification of material collected using modern survey Australian ant genera much easier than methods, the tools are available to tackle before. the revision of neglected ant genera. How- Despite the relative ease with which ever, at present there is no strategy in ants can now be identified to genus, spe- place for accomplishing this remaining cies identification is much more difficult work and basic information on approxi- because many ant genera have not been mately how much work remains is nec- recently revised. Species-level identifica- essary for establishing goals and priorities. tions in recently revised genera can also Although Bolton (1995a) has provided a 72 Journal of Hymenoptera Research

taxonomic and zoogeographical census of alternative approach, which involves dis- documented ant diversity, he did not as- tinguishing between widespread and lo- sess the current taxonomic health of all calised species, is presented here to ad- ants, nor does he address the issues of the dress the problem of range size differences proportion of ant genera that lack modern between described and undescribed spe- taxonomic treatment, and the effort that cies. such treatment will require. The Afrotropical region is defined here In addition to our inability to estimate according to Bolton (1994) as Africa south the effort that will be required to revise all of the Sahara and the southern half of the ant genera to modern taxonomic stan- Saudi Arabian Peninsula. Madagascar and dards, we are also unable to reliably esti- its nearby islands are excluded. Our mate how many ant species exist and how knowledge of the ant fauna of this region many are undescribed. On a world level, is the product mainly of the following tax- Gauld & Bolton (1988) estimated 15,000, onomists (see Ward et al. 1996 for publi- and Holldobler and Wilson (1990) esti- cation details): F. Smith (1851-1879); Mayr mated 20,000 species in total, these esti- (1853-1908); Forel (1869-1920's); Emery mates being largely intuitive. By the end (1869-1926); Santschi (1906-1941); Arnold of 1993, 9538 described valid ant species (1905-1962, including "A monograph of in the world were recognised (Bolton the Formicidae of South Africa", pub- 1995a), so according to the above two es- lished 1915-1926); Brown (1943-1995); and timates, 36-52% of ant species either re- Bolton (published 1969 to present), main undescribed or currently occupy an The present paper is aimed at establish- infraspecific rank. ing the current level of taxonomic knowl- Estimates of total diversity are often edge of Afrotropical ant species by assess- made using data from particular localities ing the proportion of ant genera that re- where it has been possible to estimate the main to be revised to modern taxonomic proportion of species that are unde- standards and the effort required to un- scribed, and to use this proportion to ex- dertake these revisions. In addition, I es- a trapolate to wider level (e.g. Hodkinson timate total ant species richness in the Af- and Casson 1991, Hodkinson 1992 for He- rotropical region using data on the pro- miptera). This approach implies that the portion of undescribed species collected at average range sizes of described and two widely separated localities in Africa, undescribed species are similar (Hodkin- namely Mkomazi Game Reserve in Tan- son and Hodkinson 1993; Hammond zania and the Cape of Good Hope section 1995). In practice, this is highly unlikely as of the Cape Peninsula National Park in widely distributed species are more likely South Africa. At both sites, ants have been to be captured and described than species intensively collected using a variety of with more localised distributions. Hodkin- methods, thereby increasing the probabil- son and Hodkinson (1993) examined this ity that the observed ratio of undescribed problem by comparing data from two to described species is a good estimate of sites and providing a statistical test of the ratio for those species that have not whether the of probability capture of de- been collected. I conclude by suggesting a scribed species was different from the strategy for improving both the collecting probability of capture of undescribed spe- and the taxonomic treatment of Afrotrop- cies and then using the ratio of these two ical ants, to the final estimate of probabilities adjust METHODS species diversity. The outcome of such a on the simi- comparison depends largely Estimation of species number increment and of the sites. larity proximity two An from revision of genera. — I divided the Af-

Yfti«*i Volume 9, Number 1, 2000 73

rotropical ant genera between those that Cape of Good Hope section of the Cape have received a modern revision (defined Peninsula National Park, South Africa. here as from 1965 onwards) and those that Ants were collected in Mkomazi Game have revisions to Reserve not; prior 1965 are either using pitfall traps, malaise traps, incomplete or use the old quadrinomial Winkler bag leaf litter extractions, soil system. Genera represented only by intro- sieving, light traps, sweeping, and collect- duced species (Linepithema humile (Mayr), ing by hand (Robertson 1999). Mkomazi Wdsmannia auropunctata (Roger)) have Game Reserve has a wide range of vege- been excluded. Genera that have received tation types such as grassland, open and a modern revision are henceforth referred closed woodland, and hilltop forest. It lies in a to as 'revised genera' and the remaining region that does not have a long his- of ant genera as 'unrevised genera'. For each re- tory collecting although the vege- tation it contains have been vised genus I calculated the species incre- types sampled in ment coefficient, i.e. the number of valid other regions such as Kenya and Zim- babwe. species divided by the number prior to re- The of Good section of the vision. Descriptions of new species and Cape Hope Peninsula National Park consists of the raising of subspecies to species in- Cape creased the increment coefficient whereas mesic mountain fynbos, west coast strand- veld and a few relict small of in- synonymising of previously valid species patches forest. Because of its decreased it. Lowering of rank from spe- digenous evergreen near the southern of cies to subspecies was not encountered in position tip Africa, naturalists have collected in the any of the revisions. In genera which have many Peninsula and received more than one revision since Cape one might thus expect the ant fauna to be well known. However, 1970 (e.g. Ocymyrmex), I calculated the many cryptic species went unnoticed until number of valid species before the first re- the recent systematic use of vision and the number by completion of collecting methods such as pitfall trapping and the last revision. Subsequent papers de- Winkler bag leaf litter extraction. scribing additional new species in revised For each of these two localities, I deter- genera were also included in the analysis. mined the ratio of undescribed species An increment coefficient for all revised that belong to revised genera: genera was calculated based on the total = number of valid species before and after U/K u/k for all revisions and new descriptions. Therefore For unrevised genera, I counted the = number of valid species and multiplied U u(K/k) this the increment coefficient for re- by where U is the number of undescribed vised genera to arrive at an estimate of the species in the Afrotropical region, u is the total number of species after revision. The number of undescribed species at the lo- total species for the revised genera plus cality, K is the number of known (i.e. val- this estimated value for the unrevised id) species in the Afrotropical region and genera gives the 'Total estimated revised k is the number of known species at the species'. locality. As already discussed, this ap- Estimation total richness. —An of species proach assumes that the average range estimate of total ant richness in the species size of known and undescribed species is Afrotropical region was obtained by de- similar (Hodkinson and Hodkinson 1993; termination of the of de- proportions Hammond 1995) which in reality is un- scribed and undescribed in species Mkom- likely because widely distributed species azi Game Reserve, Tanzania, and in the would be more likely to have been col- 74 Journal of Hymenoptera Research

lected and described. In order to reduce years from 1972 to 1987 he worked single- at various ant the bias, I arbitrarily categorised all mindedly revising genera, of his taxonomic known Afrotropical species in revised For each publications of whether genera between 'widespread species' that during this period, irrespective have recorded distributions over three or they concerned Afrotropical ants, I record- valid before the more countries and 'localised species' that ed the number of species have been recorded from only one or two revision, the number of new species de- countries (based on information obtained scribed and the number of valid species from the revisions as well as from records resulting from the revision. The number of in the South African Museum ant com- valid species in an unrevised genus divid- of initial valid puter database). The average range size of ed by the average number the localised species is likely to be more species processed per year by Bolton, similar to the average range size of the un- gives the number of years it would take described species than that of all known to revise the genus (at maximum produc- species together. By reducing the bias in tivity). this wav, the ratio of undescribed to lo- calised species at an Afrotropical level number increment should therefore be similar to the ratio of Estimation of species— undescribed to localised species at a local from revision of genera. Modern revision level and therefore of 43 (52%) of the Afrotropical ant genera ... has resulted in an overall 50% increase in

number of species, so that the number of where, for recently revised genera, L is the species at the completion of the revisions number of localised known species in the was 1.5 times greater than the initial num- Afrotropical region and 1 is the number of ber (Table 1). At the one extreme are gen- localised known species at a particular lo- era such as Anochetus, Psalidomyrmex, Pris- cality. tomyrmex and Platythyrea that decreased in Accumulation described as number of as a result of of — species afunc- species species tion of collecting date. As an alternative being synonymised in the revision. At the way of assessing the proportion of ant other extreme are genera such as Axinidris, species that are still undescribed, for a Cyphoidris, Ocymyrmex, Paedalgus, Pyrami- sample of revised genera I recorded the ca and Strumigenys that more than dou- year the type was collected for each valid bled in size mainly as a result of the de- species and plotted the accumulation of scription of new species, species as a function of collection date. There are 862 valid species in the 39 The collection date was not recorded for (48%) unrevised Afrotropical genera (Ta- many of the earlier types and for these I ble 2) and as the initial number of species used the publication date instead. The ear- in the revised genera amounted to 561 ant taxonomists such as and For- 1 of ly Emery (Table ), based on the relative number el usually provided descriptions for new species we are therefore about 39% of the species within one or two years subse- way through revision of the genera to quent to their collection. — modern standards. Revision of the unre- Time taken to revise genera. In order to vised genera over a similar time period as estimate the time that it would take to re- the revised genera would have swelled

vise the I unrevised ant genera, analysed the number of species from 862 species to the of the world's productivity most pro- about 1293 (Table 2). Together with the ductive ant systematist, Barry Bolton, who 843 species in the revised genera (Table 1) has also done most of the revisionary there is a total of 2136 estimated revised work on Afrotropical ants. During the 16 species, an increase of 20% over the 1705

Ihnaut Volume 9, Number 1, 2000 75

Table 1. List of the Afrotropical ant genera that have received one or more modern taxonomic revisions (1965 onwards). The initial number of valid species before the first modern revision, the final number of valid species known at present, and the increment coefficient (used in Table 2) are shown. 76 Journal of Hymenoptera Research

Table 2. Afrotropical ant genera that have not received a modern taxonomic revision. The number of estimated species after revision was calculated by multiplying the number of valid species currently known by the Increment coefficient (1.5) in Table 1. The minimum years to revise a genus is calculated on the basis of before a at a rate of that B. Bolton processed species (i.e. the number species revision) 42/year.

Number of

Acropyga Aenictogiton Aenictus Amblyopone Anoplolepis Asphinctopone Camponotus (excl. fulvopilosus-gioup) Carebara

Cataglyphis Centromyrmex Cerapachys Crematogaster Cryptopone Discothyrea Don/Ins

Ecphorella Hypoponera Lepisiota Leptanilla Myrmicaria Mystrium Oecophylla Oligomyrmex Pachycondyla Paratrechina Phasmomyrmex Pheidole

Pheidologeton Phrynoponera Plagiolepis Prionopelta Proceratium Pseudolasius Santschiella

Solenopsis Streblognathus Tapinoma hi hnomynnex Tetraponera Total Volume 9, Number 1, 2000 77

Table 3. Ant species diversity and composition in Mkomazi Game Reserve in Tanzania, Cape of Good Hope section of the Cape Peninsula National Park (CGH) in South Africa, and in the Afrotropical region as a whole. 78 Journal of Hymenoptera Research

based the of Table 4. Estimates of total ant species diversity in the Afrotropical region, on proportion in of Good section of the undescribed species in Mkomazi Game Reserve in Tanzania and Cape Hope Cape first the ratio of total Peninsula National Park (CGH) in South Africa (Table 3). The estimate uses known the second the ratio of localized known here as species at a regional and local level and species (defined or two at a and local level Methods species that have been recorded from only one countries) regional (see for explanation of formulae).

Estimated using data from:

Mkomazi CGH Both sites

1. Revised genera, based on total known species 401 No. undescribed species (=uK/k) 376 Total species 1219 Ratio Total /Known 1.4462

2. Revised genera, based on localized species = 1566 No. undescribed species ( uL/l) Total species 2409 Ratio Total /Known 2.8577

1 Estimated total species in all genera

Based on (1) above 3089

Based on (2) above 6104

2 % new species or species currently at infraspecific rank

Based on (1) above 44.8 Based on (2) above 72.1 Volume 9, Number 1, 2000 79

Table 5. Number of ant species revised and de- scribed by B. Bolton over a 16 year period (includes an extra year to account for the preparation time for the 1973 publications). Initial species refers to the number of valid species before the revision began. = Average number initial species processed per year 672/16 = 42.

Year published 80 Journal of Hymenoptera Research

a area such as the re- genera recorded at the two localities in the of large Afrotropical is intensive present study. gion through inventory-based On the basis that 18% of the world's de- sampling of particular localities by general a of scribed ant species are found in the Afro- collecting and combination replicated Winkler leaf litter ex- tropical region (calculated from Bolton pitfall trapping, bag or of 1995a), the species diversity estimates pre- tractions, beating sweeping vegeta- sented here can be extrapolated to a world tion, chemical knockdown of arboreal fau- level to give an estimated world diversity na and soil sampling. The use of replicable of between 17250 and 22739 species. How- sampling methods makes it possible to ever, as the Nearctic and Palaearctic ant statistically compare sites using tech- faunas are much better known than those niques described in Colwell & Codding- from other regions, the 18% Afrotropical ton (1994) and Chazdon et al. (1998) and ant species is likely to be an underesti- in this way to make scientifically based as- mate. — sessments of alpha, beta and gamma di- Progress with sampling of ants in Africa. versity. Fisher (1996, 1998, 1999) has pio- Awareness about the threats to biodiver- neered this approach in Madagascar al- litter fau- sity have increased funding for inventory- though only for leaf and ground based conservation research and as ants na. Recent studies, still unpublished (e.g. are a favoured indicator taxon (Andersen Fisher and Robertson in prep, for a site 1997), there has been a consequent tre- near Ambositra in Madagascar), have mendous recent growth in ant collections. used a wider range of replicated sampling Intensive sampling projects in the Afro- techniques. Superficial general collecting tropical region include: Mbalmayo Forest of many localities is of more limited value Reserve in southern Cameroon (Watt et al. than the inventory approach although it is 1997); coastal and interior forest in Gabon useful for providing distributional data. (Fisher, in prep.); Mkomazi Game Reserve As ants are dominant and ecologically im- in Tanzania (Robertson 1999); Cape of portant organisms in terrestrial ecosys- Good Hope, Robben Island, Brenton-On- tems, growth of collections will also con- Sea, Fairfield Farm near Napier, Kogel- tinue due to the submission of specimens berg Biosphere Reserve, and other sites in by ecologists and agricultural researchers the Cape fynbos, South Africa (Robertson for identification by ant systematists. and co-workers, in prep.); Cape indige- Inventory-based assessments of areas nous evergreen forests (Fisher, in prep.); for conservation using ants will ensure Mondi Estate in Kwazulu-Natal (Fisher, in continued funding of scientifically-based prep.); and widespread pitfall trapping by ant collecting in the Afrotropical region, E. Marais in Namibia. However, there are provided there remains backup by ant still enormous gaps in our coverage. systematists. The areas to be sampled will Countries such as Angola, Mozambique, be largely dictated by the conservation Central Malawi, Zambia, African Repub- funding bodies and by the political stabil- lic, Ethiopia and Sudan have yet to be ity of the areas that need assessment. Not- sampled using modern inventory tech- withstanding the political issues, the ne- niques. Even the best sampled countries glected countries such as those listed such as South Africa and Zimbabwe re- above, need attention. With this increased main patchily sampled and there is not ant collecting, the need for more taxonom- one country in the Afrotropical region ic work on ants will become all the more where ants have been sampled adequately apparent. in all major vegetation regions. Current progress with Afrotropical ant tax- Future — — strategies for collecting. The best onomy. Based on relative proportion o\ approach to adequately sampling the ants species, we are about 39% of the way

^( «!»-" Volume 9, Number 1, 2000 si through revision of the Afrotropical ant tiveness and productivity of current ant genera to modern standards and to revise systematists. Regarding the first aspect, it the remaining genera would take one per- is vital that the museums holding impor- son 21 years to complete at 'Bolton speed'. tant ant collections are committed to em- On a world level, there are about 41 ploying ant systematists. It is remarkable people currently working on the taxono- that the most important ant collection in my of ants. Although this seems a large the world at the Harvard Museum of number, the productivity of most of these Comparative Zoology has no full-time ant taxonomists is much less than that of B. systematist committed to alpha taxonomy Bolton and their work is often limited to and has a curator that can work only part- regional faunas. In addition, a number of time on this vital collection. The Natural our key established 'global view' system- History Museum in London, with the sec- atists have either recently retired or are ond largest ant collection in the world, about to retire. We could end up with a should continue its support of a position situation similar to that in termite taxon- in ant systematics once the present incum- omy (Eggieton 1999) although we are like- bent retires. The South African Museum ly to remain stronger in terms of number holds the largest ant collection in Africa of systematists. and should also remain committed to sup- The low taxonomic productivity of most porting ant systematics, especially as it is ant systematists can be attributed largely important to maintain an ant identification to their occupation with other endeavours: service for applied entomologists in Afri- ecological and biological research on their ca. study organisms, administration, contract Training is an important aspect of safe- identification work, computer program- guarding the future body of ant systema- ming, and teaching duties. Revising ant tists because filling of positions in system- genera at the rate that B. Bolton has atics is usually controlled more by the achieved is therefore rarely attained and quality of the candidate than by the group for most systematists one would need to he/she works on. Hence, the contribution settle for a speed of revision at best half to training by ant systematists at univer- or even quarter of Bolton's rate. However, sities is essential to the future growth of there is room for improvement and I feel ant systematics. that ant systematists need to prioritise al- Regarding the second component in the pha taxonomy and not let it take a back strategy, there are five ways in which the seat which seems to be increasingly the effectiveness and productivity of current case. ant systematists could be improved: (1) In Unlike the situation in North America, order to cope with the conflict between Europe, South America and Asia, there is projects geared to collection growth as op- only one resident ant systematist in Africa posed to taxonomic projects, we need to and hence progress with documenting Af- make the latter a priority and plan time to rotropical ants will depend largely on the spend on them. For instance, university involvement of outside 'global-view' sys- lecturers often find it easiest to plan time tematists working on taxa that are repre- for taxonomic work over the King vaca- sented in the Afrotropical region. tions. (2) Dedicated funding of ant taxo- Strategies for advancing Afrotropical ant nomic revisions along the same lines as taxonomy. —The two goals of a strategy to the Australian Biological Resources fund- in is al- improve ant taxonomy are firstly, to en- ing for catalogues, which money sure that the number oi ant systematists located in proportion to the size of the tax- does not dwindle but remains stable or on, would be ideal for improving goal-set- grows and secondly, to improve the effec- ting and productivity. In reality, this type 82 Journal of Hymenoptera Research of funding is rare because a taxonomic re- cultural and behavioural ant research. The vision does not answer applied problems present study provides the information for a to directly. (3) A more realistic approach to planning funded strategy document obtaining funding for ant taxonomy the Afrotropical ant fauna. The challenge would be to link it to more easily obtained is to create a synergy between the differ- funding for applied field-based projects. ent role players (systematists, ecologists, that individual Funding from these projects can be used funding bodies) so efforts for employing and training parataxono- are not swamped by the immensity of the mists for time-consuming sorting, mount- job at hand. ing and curation of ants. Funding bodies ACKNOWLEDGMENTS should commit themselves to permitting a

I thank Brian Fisher for his comments on the man- direct taxonomic component in the project and the and individ- so that there are funds to employ people uscript following organisations uals for helping with field work and processing of to measure specimens and funds to visit samples: Royal Geographical Society, Tanzanian De- overseas ant collections to examine types. partment of Wildlife, Simon van Noort, Tony Russell- Funding should also be built into these Smith, Daniel Mafunde, Omari Mohamed, Tandi Dawn Peninsula National Park projects for storage and curation of the Russell, Larsen, Cape (and prior to its formation, the management of the specimens. (4) There is a great need for Cape of Good Hope Nature Reserve) and Miemsie of, and of ideas be- training exchange Troskie. tween, established ant systematists, espe- cially the large number residing outside LITERATURE CITED North America and Europe. Better com- Andersen, A. 1997. Ants as indicators of ecosystem munication via e-mail would but the help, restoration following mining: a functional group funding of one or more training and plan- approach. Pp. 319-325 in P. Hale and D. Lamb Conservation Outside Nature Reserves. Bris- ning meetings would be ideal. (5) As there (eds) bane: of Queensland. is still so much work to be done in revis- University Arnold, G. 1915-1924. A monograph of the Formici- ing all Afrotropical ant genera (at least 21 dae of South Africa. Annals of the South African man-years), it is important to prioritise Museum 14: 1-766. groups for revision. In the Afrotropical re- Arnold, G. 1926. A monograph of the Formicidae of South Africa. the gion, the unrevised groups encountered Appendix. Annals of South Af- rican Museum 23: 191-295. most frequently when identifying ants are Belshaw, R. and B. Bolton 1994. A new myrmicine Pheidole, Crematogaster and Camponotus. ant genus from cocoa leaf litter in Ghana (Hy- These also to be groups happen among menoptera: Formicidae). journal of Natural Histo- the most diverse of the unrevised genera ry 28: 631-634. (Table 2) and are also among the most dif- Bolton, B. 1973a. The ant genus Poh/rhachis F. Smith in the Formici- ficult taxonomically, either because of Ethiopian region (Hymenoptera: dae). Bulletin of the British Museum (Natural His- worker polymorphism (Pheidole and Cam- tory). Entomology 28: 283-369. or because of a of external ponotus) paucity Bolton, B. 1973b. A remarkable new arboreal ant ge- morphological species-discriminating nus (Hym. Formicidae) from West Africa. Ento- characters (Crematogaster). Not surprising- mologist's Monthly Magazine 108: 234-237. Bolton, B. 1974a. A revision of the ar- ly therefore, these groups have been palaeotropical boreal ant genus Cataulacus F. Smith (Hymenop- avoided and to get them done quickly it tera: Formicidae). Bulletin of the British Museum would be best to a funded strat- develop (Natural History). Entomology 30: 1-105. egy- Bolton, B. 1974b. A revision of the ponerine ant genus Plectroctena F. Smith Ants are an economically and ecologi- (Hymenoptera: Formicidae). Bulletin of the British Museum (Natural cally important group in terrestrial eco- History). Entomology 30: 309-338. systems in the and im- Afrotropical region B. 1975a. Bolton, A revision of the ant genus l.epto- their would in turn im- proving taxonomy gem/s Roger (Hymenoptera: Formicidae) in the the of prove networking ecological, agri- Ethiopian region with a review of the Malagasy Volume 9, Number 1, 2000 83

species. Bulletin of the British Museum (Natural (Hymenoptera: Formicidae). journal of Natural History). Entomology 31: 235-305. History 33: 1639-1689. Bolton, B. 1975b. A revision of the African ponerine Bolton, B. and R. Belshaw 1993. Taxonomy and bi- ant genus Psalidomyrmex Andre (Hymenoptera: ology of the supposedly lestobiotic ant genus Formicidae). Bulletin of the British Museum (Nat- Paedalgus (Hym.: Formicidae). Systematic Ento- ural History). Entomology 32: 1-16. mology 18: 181-189. B. tribe Bolton, 1976. The ant Tetramoriini (Hyme- Bolton, B.^ W. H. Gotwald Jr. and J. M. Leroux 1979 noptera: Formicidae). Constituent genera, review ("1976"). A new West African ant of the genus of smaller genera and revision of Triglyphothrix Plectroctena with ecological notes (Hymenoptera: Forel. Bulletin of the British Museum (Natural His- Formicidae). Annates de VUniversite Abidjan. Sene 9: tory). Entomology 34: 281-379. E (Ecologie) 371-381. Bolton, B. 1980. The ant tribe Tetramoriini (Hyme- Bolton, B. and A. C. Marsh 1989. The Afrotropical noptera: Formicidae). The genus Tetramorium thermophilic ant genus Ocymyrmex (Hymenop- Mayr in the Ethiopian zoogeographical region. tera: Formicidae). journal of Natural History 23: Bulletin of the British Museum (Natural History). 1267-1308. Entomology 40: 193-384. Brown, W. L. Jr. 1974a. Concoctio genus nov. Pilot Reg- Bolton, B. 1981a. A revision of the ant genera Mer- ister of Zoology Card No. 29. anoplus F. Smith, Dicroaspis Emery and Calypto- Brown, W. L. Jr. 1974b. Concoctio concenta. Pilot Reg- myrntex Emery (Hymenoptera: Formicidae) in ister of Zoology Card No. 30. the Ethiopian zoogeographical region. Bulletin of Brown, W. L. Jr. 1974c. Dolioponera genus nov. Pilot the British Museum (Natural History). Entomology Register of Zoology Card No. 31. 42: 43-81. Brown, W. L. Jr. 1974d. Dolioponera fustigera species Bolton, B. 1981b. A revision of six minor genera of nov. Pilot Register of Zoology Card No. 32. (Hymenoptera: Formicidae) in the Brown, W. L. Jr. 1975. Contributions toward a reclas- Ethiopian zoogeographical region. Bulletin of the sification of the Formicidae. V. Ponerinae, tribes British Museum (Natural History). Entomology 43: Platythyreini, Cerapachvini, Cviindromvrmecini, 245-307. Acanthostichini, and Aenictogitini. Search. Agri- Bolton, B. 1982. Afrotropical species of the myrmicine culture (Ithaca, N. Y.) 5(1): 1-115. ant genera Cardiocondyla, Leptothorax, Melissotar- Brown, W. L. Jr. 1976. Contributions toward a reclas- sus, Messor and Cataulacus (Formicidae). Bulletin sification of the Formicidae. Part VI. Ponerinae, of the British Museum (Natural History). Entomol- tribe Ponerini, subtribe Odontomachiti. Section ogy 45: 307-370. A. Introduction, subtribal characters. Genus Bolton, B. 1983. The Afrotropical dacetine ants (For- Odontomachus. Stadia Entomologica 19: 67-171.

micidae). Bulletin of the British Museum (Natural Brown, W. L. Jr. 1978. Contributions toward a reclas- History). Entomology 46: 267-416. sification of the Formicidae. Part VI. Ponerinae, Bolton, B. 1985. The ant genus Triglyphothrix Forel a tribe Ponerini, subtribe Odontomachiti. Section svnonvm of Tetramorium Mayr (Hymenoptera: B. Genus Anochetus and bibliographv. Studia En- Formicidae). journal of Natural History 19: 243- tomologica 20: 549-638.

248. Brown, W. L. Jr., W. H. Gotwald Jr. and J. Levieux Bolton, B. 1986. A taxonomic and biological review 1971 ("1970"). A new genus of ponerine ants of the tetramoriine ant genus Rhoptromyrmex from West Africa (Hvmenoptera: Formicidae) (Hymenoptera: Formicidae). Systematic Entomol- with ecological notes. Psyche (Cambridge) 77: 259- ogy 11: 1-17. 275. B. 1987. of R. R. K. Bolton, A review the Solenopsis genus- Chazdon, L., Colwell, J. S. Penslow and M. group and revision of Afrotropical Monomortum R. Guariguata 1998. Statistical methods for esti- Mayr (Hymenoptera: Formicidae). Bulletin of the mating spei ies richness of woodv regeneration in British Museum (Natural History). Entomology 54: primary and secondary rain forests of northeast- 263-452. ern Costa Rica. Pp. 285-309 in F. Pallmeier and B. 1994. Guide to the Ant Bolton, Identification Genera J. A. Comiskey (eds) Forest Research, of the World. Cambridge, Massachusetts: Harvard Monitoring and Modeling: Conceptual Background University Press, 222 pp. and Old World Case Studies. Paris, France: Parthe- Bolton, B. 1995a. A taxonomic and zoogeographical non. census of the extant ant taxa (Hymenoptera: For- Collingwood, C. A. 1993. Description of the host ant micidae). journal of Natural History 29: 1037-1056. of Cossyphodinus bremeri Ferrer sp. nov. (Hyme- t B. the » Bolton, 1495b. A New General Catalogue of Ants noptera, Formicidae). Pp. 22 231 in 1 Ferrer and of the World. Cambridge, Massachusetts: Harvard C. A. Collingwood, New species oi Cossyphodinus University Press, 504 pp. from Africa (Coleoptera, Tenebrionidae) and de- B. 1999. Bolton, Ant genera of the tube Pacetonini scription of the host ant Messoi ferreri sp. nov. 84 Journal of Hymenoptera Research

(Hymenoptera, Formicidae). Entomofauna 14: rica (Hymenoptera, Formicidae). Annals of the 221-232. South African Museum 94: 1-11. 1994. Robertson, H. G. 1990. the Colwell, R. K. and J. A. Coddington Estimating Unravelling Campouotus For- terrestrial biodiversity through extrapolation. fulvopilosus species complex (Hymenoptera: micidae). Pp. 327-328 in G. K. Veeresh, B. Mallik Philosophical Transactions of the Royal Society of and C. A. Viraktamath (eds) Social and the London. B. Biological Sciences 345: 101-118. Environment. Proceedings of the 11th International Eggleton, P. 1999. Termite species description rates Congress of ILISSI, 1990. New Delhi: Oxford & and the state of termite taxonomy. Insectes So- IBH Publishing Co. ciaux 46: 1-5. Robertson, H. G. 1999. Ants (Hymenoptera: Formici- Fisher, B. L. 1996. Ant diversity patterns along an ele- dae) of Mkomazi. Pp. 321-336 in M. Coe, N. vational gradient in the Reserve Naturelle Inte- McWilliam, G. Stone and M. J. Packer (eds) Madagascar. Fieldiana: Zool- grale d'Andringitra, Mkomazi: the Ecology, Biodiversity and Conservation 85: 93-108. ogy of a Tanzanian Savanna. London: Royal Geograph- B. L. 1998. Ant an ele- Fisher, diversity patterns along ical Society (with the Institute of British Geog- vational in the Reserve gradient Speciale raphers). d'Anjanaharibe-Sud and on the Western Masoala Robertson, H. G. and C. Zachariades 1997. Revision Peninsula, Madagascar. Fieldiana: Zoology 90: 39- of the Campouotus fulvopilosus (De Geer) species- 67. group (Hymenoptera: Formicidae). African Ento- 5: 1-18. Fisher, B. L. 1999. Improving inventory efficiency: a mology S. O. 1991. Revision of the dolichoderine ant case study of leaf-litter ant diversity in Mada- Shattuck, Axinidris Formicidae). gascar. Ecological Applications 9: 714-731. genus (Hymenoptera: Sys- tematic 16: 105-120. Gauld, I. and B. Bolton (Eds) 1988. The Hymenoptera. Entomology Shattuck, S. O. 1999. Australian Ants: their Biology and Oxford: Oxford University Press, xii + 322 pp. Identification. Collingwood, Victoria: CSIRO Hammond, P. M. 1995. Described and estimated spe- Press, 226 pp. cies numbers: an objective assessment of current Snelling, R. R. 1979a. Three new species of the Pa- knowledge. Pp. 29-71 in D. Allsopp, R. R. Col- laeotropical arboreal ant genus Cataulacus (Hy- well and D. L. Hawksworth (eds) Microbial Di- menoptera: Formicidae). Contributions in Science versity and Ecosystem Function. Wallingford, UK: (Los Angeles) 315: 1-8. CAB International. Snelling, R. R. 1979b. Aphomomyrmex and a related Hodkinson, I. D. 1992. Global revis- diversity new genus of arboreal African ants (Hymenop- ited, 8: 505-508. journal of Tropical Ecology tera: Formicidae). Contributions in Science (Los I. D. and D. Casson 1991. lesser Hodkinson, A pre- Angeles) 316: 1-8. dilection for bugs: Hemiptera (Insecta) diversity Snelling, R. R. 1992. Two unusual new myrmicine in tropical rain forests. Biological journal of the Liu- ants from Cameroon (Hymenoptera: Formici- nean Society 43: 101-109. dae). Psyche (Cambridge) 99: 95-101. R. W. 1965. revision of Hodkinson, I. D. and E. Hodkinson 1993. Pondering Taylor, A monographic the rare ant the imponderable: a probability-based approach tropicopolitan genus Probolomyrmex Formicidae). Transactions to estimating insect diversity from repeat faunal Mayr (Hymenoptera: of the Royal Society of London 117: 345- samples. Ecological Entomology 18: 91-92. Entomological 365. Holldobler, B. and E. O. Wilson 1990. The Ants. Cam- Ward, P. S., B. Bolton, S. O. Shattuck and W. L. bridge, Massachusetts: Harvard University Press, Brown, jr. 1996. A Bibliography of Ant Systematica. xii + 732 pp. Berkeley: University of California Press, 417pp. Kutter, H. 1976. Beitrag zur kenntnis der gattung Sim- Watt, A. dJ N. E. Stork, P. Eggleton, D. Srivastava, opone Forel. Mitteilungeu iter Schweizerischeu Eu- B. Bolton, T. B. Larsen, M. J. D. Brendell and D. tomologischen Gesellschaft 49: 273-276. E. Bignell 1997. Impact of forest loss and regen- H. Kutter, 1977. Zweiter beitrag zur kenntnis der gat- eration on insect abundance and diversity. Pp. Forel. der tung Simopone Mitteilungen Schweizer- 274-286 in A. D. Watt, N. E. Stork and M. D. ischen Entomologischen Gesellschaft 50: 173-176. Hunter (eds) Forests and Insects. London: Chap- A. I'nns, | 1983. A new ant genus from southern Af- man ^nd I lall.