The Afrotropical thermophilic ant genus Ocymyrmex (Hymenoptera: Formicidae)

The taxonomy and biology of the Afrotropical thermophilic ant genus Ocymyrmex is reviewed and updated. A new key to workers for the 37 recognized species is presented and species-groups within the genus are delimited. Revised genus-level diagnoses for all castes are given and a check-list with known distributions of all species is included. Nine new species are described. The previously known biology of the genus is reviewed in the introduction and fresh biological and ecological information on a number of species is given in the introduction and under the individual species headings.     

A taxonomic and zoogeographical census of the extant ant taxa (Hymenoptera: Formicidae)

The numbers of extant ant taxa in the world are analysed taxonomically and zoogeographically. A table detailing numbers of subfamilies, tribes and genera, and the numbers of species they contain, and one analysing the number of species per genus per zoogeographical region, are presented. Subfamilies are analysed by number and percentage of genera and species; the most speciose genera are isolated and listed in terms of absolute size and speciosity per subfamily. Tables detailing total numbers of genera and species per subfamily per region, and endemic genera per subfamily per region are given, and the endemicity and speciosity of genera are tabulated on a regional basis.     

Prey choice and raiding behaviour of the Ponerine ant Pachycondyla analis (Hymenoptera: Formicidae)

Termite raiding behaviour of the African poneromorph ant Pachycondyla analis was studied at Mpala, Kenya. In all, 330 raids were observed with the raiding activity showing peaks in the morning and evening. Time spent at the termite source was positively correlated with the numbers of termites taken. The sizes of foraging parties, number of termites taken, distance travelled and time spent at termite sources also showed a positive correlation. Pachycondyla analis preyed significantly more on Microtermes spp. than they did on Odontotermes spp. but no significant differences were found in terms of predator efficiency even though many ants were injured in raids on Odontotermes spp. compared with those on Microtermes spp. Our results indicate that P. analis seems to forage optimally, balancing the costs of energy with prey reward and prey choices were not only influenced by prey abundance, but also by the costs of foraging, as influenced by prey defences, size and foraging behaviour.     

New distribution record for the social parasitic ant Anergates atratulus (Schenck, 1852) (Hymenoptera: Formicidae): an ICUN red-listed species

The International Union for Conservation of Nature and Natural Resources red-lists a number of ant species. One species is Anergates atratulus (Schenck, 1852), a rarely collected social parasite introduced from Europe. The known distribution in North America is along the Atlantic seaboard. This note reports a huge range expansion in North America, to include Colorado. This finding is important because it provides useful information about the conservation and dispersal patterns of a rare, introduced, socially parasitic ant species.     

Social facilitation and food partitioning in the queenless ant Dinoponera quadriceps (Hymenoptera: Formicidae)

Social facilitation occurs when an animal is more likely to behave in a certain way in response to other animals engaged in the same behaviour. For example, an individual returning to the nest with food stimulates other ants to leave and to forage. In the present study we demonstrate the existence of new facets in the colony organization of Dinoponera quadriceps: a positive feedback between the incoming food and the activation of new foragers, and the occurrence of incipient task partitioning during the food sharing. Lower-ranked workers located inside the nest process protein resources and higher-ranked workers handle smaller pieces and distribute them to the larvae. In conclusion, D. quadriceps has a decentralized pattern of task allocation with a double regulatory mechanism, which can be considered a sophisticated aspect of division of labour in ponerine ants.     

Biogeographic analysis of the ant genus Gnamptogenys Roger in South-East Asia-Australasia (Hymenoptera: Formicidae: Ponerinae)

The distribution range of ants of the genus Gnamptogenys is analysed, with special reference to the Old World species, and two closely related genera: Rhytidoponera and Ectatomma. The study is based upon a cladistic biogeographic analysis, recognizing the following areas of endemism: Central America, South America, Philippine Islands, New Guinea, Australia, Solomons/Fiji and South-East Asia. These results are followed by a consensus of different information sources (phylogenetic, natural history, past and present distribution, palaeogeographical and palaeoclimatological) for explaining the present and past distribution of Gnamptogenys and related genera. The area cladogram shows repeated instances of sister relations between Old World and New World taxa at different depths within the tree. Subtree analysis further suggests a common sister relation between Gondwanan landmasses. The distribution of the Gnamptogenys is interpreted as a product of vicariance, starting with the separation of Gondwana, and subsequent dispersal into South-East Asia and Melanesia via rafting on the Australian craton. The desiccation of Australia during the Oligocene was detrimental to the presence of Gnamptogenys but favoured expansion of Rhytidoponera. The study illustrates that a cladistic biogeographic scenario may be supported by a consensus of data from various sources, and also suggests a pre-Tertiary diversification of ant fauna.     

The ant genus Triglyphothrix Forel a synonym of Tetramorium Mayr. (Hymenoptera: Formicidae)

The myrmicine ant genus Triglyphothrix Forel is newly synonymized with Tetramorium Mayr. Six replacement names are proposed for the secondary homonyms resulting from this synonymy.     

A preliminary study of nest structure and composition of the weaver ant Polyrhachis (Cyrtomyrma) delecta (Hymenoptera: Formicidae)

Polyrhachis weaver ants build their nests from vegetation bound together using silk produced by their larvae. Here we provide a pilot study of the composition and the physical structure of three arboreal silk nests of Polyrhachis (Cyrtomyrma) delecta based on examination of three colonies. We found broadly similar nest architecture and size of the nests with each containing six or seven identifiable chambers, and describe the distribution of ants of different castes and life stages between them. We also note the construction of silk ‘girder’ structures, which spanned larger chambers, and we hypothesize that these provide additional strength to the internal nest structure. This study highlights the importance of more detailed investigation of the internal nest structure and composition in Polyrhachis, and other weaver ant species, which will help to develop our understanding of this specialized form of nest construction and nesting habits in a diverse group of ants.     

Nest of Formica propinqua (Hymenoptera: Formicidae)

The nest of the ant Formica propinqua W. M. Wheeler is reported from Washoe Co., Nevada.     

Carton nest building and trophobiont manipulation in the south-east Asian ant Dolichoderus sulcaticeps (Mayr 1870) (Hymenoptera: Formicidae)

Dolichoderus sulcaticeps, a rare canopy living dolichoderine ant, was studied in the rainforest of Malaysia. It forms large polycalyc colonies comprising partial nests on trees and climbers. The three dimensional multichambered partial nests are situated on the leaf underside. Fibrous nest material is gathered from the surface of the nesting plants and soaked with water from the plant surface. Building activity, therefore, is strictly dependent on the presence of rainfall or dew. Within the cell with plant leaf surface contact, as well as on free feeding sites, non specific coccid and membracid throphobionts, are tended. Free feeding sites are permanently protected. Mealybugs are transported between existing and new free feeding sites, as well as to and from nest pavilions, especially during their construction or destruction. Prey hunting has not been observed in D. sulcaticeps. The workers, however, recruit to offered dead prey, and scavenged. During the day they were permanently on the surface of plants around their nests and feeding sites.     

Qualitative relations of egg size,egg production and colony size in some ponerine ants (Hymenoptera: Formicidae)

The sizes of eggs and reproductives of 13 species of ponerine ant were measured, and information about the mature colony sizes, ovarial anatomy and individual fecundities of a selection of ponerine species was assembled. Inter-specific variation in the size of colonies was found to be poorly related to aspects of individual fecundity, and although the few cases of polygyny were associated with larger colony sizes, monogynous species often attained even larger sizes. Within the subfamily individual fecundity may be increased primarily by a decrease in the maternal investment in individual eggs, and perhaps to a lesser extent by an increase in the number of ovarioles in each ovary or an increase in the length of each ovariole. The diet of a species and the longevity of adult worker ants relative to the duration of their larval development are suggested as factors besides reproductive characteristics that might also contribute to differences in colony size.     

Biological characterization of the obligate symbiosis between Acropyga sauteri Forel (Hymenoptera: Formicidae) and Eumyrmococcus smithii Silvestri (Hemiptera: Pseudococcidae: Rhizoecinae) on Okinawa Island,southern Japan

The ant Acropyga sauteri Forel has an obligate, mutualistic symbiosis with a mealybug, Eumyrmococcus smithii Silvestri, on Okinawa Island, southern Japan. The mealybugs live inside ant nests nearly all their lives, and the ants depend on them for food. Alate foundress queens carry mealybugs during their nuptial flights, using them to establish new colonies at new sites. However, important aspects of the symbiosis have not yet been elucidated. The present study characterizes the basic biology of the symbiosis and describes for the first time the morphologies of all growth stages of E. smithii. Our study suggests that E. smithii has only one nymphal stage, followed by a female pupal stage or male prepupal stage. Intensive sampling of ant nests across seasons showed that A. sauteri prefers nest sites 5–20 cm underground. Acropyga sauteri produced reproductive stages mainly in mid‐March or early April, and numbers of both ant workers and mealybugs increased from spring to summer. Experimental determination of colony identity with a method using nestmate recognition by ants suggested that each ant colony rarely has a perimeter greater than 30 cm, that the ants are monogynous, and that different ant colonies are densely aggregated along the root system of a plant, adjacent to each other but not interflowing. Both symbiotic partners were vulnerable to attacks by several common subaerial ant species following physical disturbance to their nests.     

Ant fauna (Hymenoptera: Formicidae) of the Socotra Archipelago (Yemen): zoogeography,distribution and description of a new species

The animal fauna of the Socotra Archipelago is influenced by three biogeographical regions, the Afrotropical, the Oriental and the Palaearctic. Consequently, the Archipelago shares faunal elements of these three regions in addition to unique endemic taxa. The ant fauna of Socotra Island was studied and is reviewed based on literature and newly collected material. In total, 28 species, belonging to 10 genera and four subfamilies, were collected from the main island. Eighteen of these (64%) are successful invasive species, seven are native (25%), and three are considered endemic (11%), Cardiocondyla longiceps Seifert, Monomorium elghazalyi sp. nov. and Monomorium nimihil Collingwood et al. Two genera are recorded for the first time from the island, Hypoponera Santschi, and Syllophopsis Santschi. Ten species are recorded for the first time, Cardiocondyla mauritanica Forel, Cardiocondyla minutior Forel, Monomorium atomum Forel, Monomorium dichroum Forel, Monomorium exiguum Forel, Pheidole pallidula (Nylander), Syllophopsis cryptobia (Santschi), Tetramorium pauper Forel, Tetramorium transformans Santschi and Hypoponera punctatissima (Roger). Ten invasive species are recorded from Socotra, reflecting human impacts on the Archipelago. These species are Tapinoma melanocephalum (Fabricius), Cardiocondyla emeryi Forel, Monomorium exiguum Forel, Pheidole indica Mayr, Syllophopsis cryptobia (Santschi), Tetramorium lanuginosum Mayr, Tetramorium simillimum (Smith), Tetramorium caldarium (Roger), Trichomyrmex destructor (Jerdon) and Trichomyrmex mayri (Forel). Our survey indicated a mixture of Afrotropical faunal elements (10 species, 36%), followed by cosmopolitan (nine species, 32%), Palaearctic (five species, 18%) and Oriental (four species, 14%) taxa. Two new synonyms of Monomorium exiguum Forel are proposed: Monomorium exiguum Forel = Monomorium baushare Collingwood & Agosti syn. nov. = Monomorium qarahe Collingwood & Agosti syn. nov. Tetramorium transformans Santschi is removed from synonymy with Tetramorium caldarium (Roger) and elevated to species rank. Ecological and biological notes for each species are given. Distribution maps for all species known from the Socotra Archipelago are provided.

http://zoobank/urn:lsid:zoobank.org:pub:89612083-9CE6-48E8-8975-1CE5334E098B     

Review and reclassification of Cataglyphis (Hymenoptera,Formicidae)

Exactly 100 years ago Forel made a misidentification of Cataglyphis viaticus as C. megalocolus, one of the most characteristic insects of North Africa. This farreaching error has influenced the systematics of the genus ever since. What really are the species of Cataglyphis? Cataglyphis is unique among formicine ants in that the morphology of the male genitalia is highly diverse: their characteristics are used for the differentiation of species groups and as a basis for postulated phylogenetic relationships within the genus. A synopsis, a key to the species-groups, and a full catalogue of all the available names are given. Of the 104 taxa currently recognized as valid, Cataglyphis albicans var. mixtus is a new combination, Cataglyphis cursor ssp. flavicornis is transferred to Alloformica, and Cataglyphis mauritanicus and Cataglyphis nigripes are given a new status. Camponotus phaenogaster is a new synonym, and Cataglyphis hispidus is a nomen nudum. A lectotype has been fixed for Cataglyphis savignyi.     

Evolutionary trends in the reproductive biology of ponerine ants (Hymenoptera: Formicidae)

The colony sizes and ovariole numbers of eight ponerine, one cerapachyine and one doryline species are reported. The ergatoid queens of five of these species are described briefly. Workers of the Hypoponera, Leptogenys and Anochetus species entirely lack ovaries, the first report of obligate sterility in this subfamily. Three evolutionary trends in the reproductive biology of the Poneriae are discussed: an increase in ovariole numbers and specialization for reproduction in the queen caste; worker sterility and increasing reproductive differentiation between the castes; and the evolutionary loss of specialization for dispersal in ergatoid queens.     

A note on manna feeding by ants (Hymenoptera: Formicidae)

The production of manna is often associated with the feeding injuries of the coreid, Amorbus obscuricornis (Westwood) (Hemiptera: Coreidae). The manna produced as a result of the injuries caused by A. obscuricornis is extremely attractive to ants and it is often taken right from underneath feeding bugs. Observations of a number of Tasmanian ant species feeding upon eucalpyt manna, suggest that this substance is an important source of carbohydrate for the ants. The possible significance of manna secretion is considered.     

Larval stages of 17 rare and poorly known British hoverflies (Diptera: Syrphidae)

Third stage larvae of three species of phytophagous (Portevina maculata, Cheilosia albitarsis and C. antiqua), thirteen species of saprophagous (Callicera aurata, Brachyopa bicolor, B. insensilis, B. pilosa, Hammerschmidtia ferruginea, Myolepta potens, Brachypalpus laphriformis, Caliprobola speciosa, Criorhina berberina, C. floccosa, C. ranunculi, Pocota personata and Xylota tarda) and one possibly predatory species (Microdon devius) of Syrphidae are described. Most of the saprophagous species breed in dead wood and many are European rarities. Nine of the 17 species described are included in the British Red Data Books: 2. Insects (Shirt, 1987). For the larva of each species, recognition features and breeding sites are described.     

Foraging ecology of the giant Amazonian ant Dinoponera gigantea (Hymenoptera,Formicidae, Ponerinae): activity schedule,diet and spatial foraging patterns

This study provides a detailed account of the natural history and foraging biology of the ponerine ant Dinoponera gigantea in a rainforest in north Brazil. The species nests on the ground and the colonies contain 70–96 workers. Ant activity is negatively correlated with temperature, and is more intense at dawn and dusk. Foragers leave the nest independently and search for food individually on the leaf litter, within ca 10 m around the nest. Workers are opportunistic feeders that collect seeds and fruits, and hunt for live prey as well as scavenge for dead animal matter. The dry weight of food items ranges from <10 mg (spiders, insect parts) to >400 mg (seeds, fruits). There is no nestmate recruitment during the search for or retrieval of food, irrespective of food type and size. Foragers have a high directional fidelity, and ants from neighbouring colonies may engage in ritualized territorial contests at the border of their foraging areas. The foraging ecology of D. gigantea is compared with other ponerine species living in tropical forests, as well as with other ant groups showing similar behavioural patterns.     

Nesomyrmex micheleae,a new ant species (Hymenoptera: Formicidae) from the Dhofar Governorate,Oman, with a synoptic list,distribution map and key to the Arabian Nesomyrmex

ABSTRACT

A new species of the myrmicine ant genus Nesomyrmex Wheeler, 1910, N. micheleae Sharaf sp. nov., is described and illustrated from Oman based on the worker caste. The new species is a member of the N. angulatus species group and can be diagnosed by the golden yellow gaster that contrasts with the dark brown body; the irregular longitudinal rugulose sculpture on the cephalic surface; and the finely punctate mesonotum and propodeal dorsum. A synoptic species list, an updated key and a distribution map to the Arabian Nesomyrmex species are presented. Continued ant species discoveries are central to large-scale diversity patterns, conservation biology and macroecology.

http://www.zoobank.org/urn:lsid:zoobank.org:pub:FBCEACA7-E543-4B10-AB9D-D63319DCB31F http://www.zoobank.org/urn:lsid:zoobank.org:act:1D2EC498-3B2E-43CD-A3C0-1C6C237471E2