Patterns of energy allocation within foragers of Formica planipilis and Pogonomyrmex salinus

Foraging workers of Formica planipilis and Pogonomyrmex salinus were collected at various distances from their colony by pitfall traps in the former species and by catching workers recruited to food at known locations in the latter. In F. planipilis the number of larger workers increased in proportional representation to distance from the nest. Larger workers also weighed relatively less with distance from the nest, indicating that energy or water allocated for maintaining all foragers is patterned such that resource loss with forager mortality is minimized. However, the smallest size class involved in foraging shows the opposite pattern, with heavier individuals being found farther from the nest. Thus, it is possible that smaller size classes function as mobile reserves of energy or water to maintain foraging activity of larger classes at a distance from the colony. In P. salinus all sizes of workers were equally likely to be found at any distance. Foragers weighed significantly less than mound workers of the same head size, again suggesting resource conservation in provisioning foraging workers. Differences in patterns of energy allocation to foragers are discussed relative to the species' ecologies.     

Nest of Formica propinqua (Hymenoptera: Formicidae)

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

Adapting Salt Creek pupfish ( Cyprinodon salinus ) to fresh water

The Salt Creek pupfish, Cyprinodon salinus , is adapted to fresh water in aquaria.     

Observations on mermithid parasitism (Nematoda: Mermithidae) in two species of Lasius ants (Hymenoptera: Formicidae)

The morphological effects of nematode parasitism by Pheromermis myrmecophila were investigated in two species of ants, Lasius flavus and Lasius niger, collected on Clare Island, Ireland. Infected males and queens were found for L. flavus but only infected queens in L. niger. The numbers of nematodes present in each infected specimen were counted and their lengths were measured. Head width, femur length and wing measurements were made for infected and non-infected individuals of both species. In queens, the length of the nematodes decreased as the number per ant increased. When single nematodes were present their mean lengths were significantly greater in L. flavus than in L. niger. In addition to the reduction in wing size for all parasitized specimens, head widths and femur lengths of the queens were significantly different in both species. A log–log graph of radial cell length versus width suggested a linear reduction of wing size.     

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.     

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.     

Dispersal of sagebrush-steppe seeds by the western harvester ant ( Pogonomyrmex occidentalis )

Like many seed-harvesting ants, the western harvester ant ( Pogonomyrmex occidentalis ) can act as both a predator and a seed disperser. Dispersal results when seeds are dropped en route to the nest, are left in nest granaries when colonies die or are abandoned, or are removed from granaries and discarded in nest middens. This study examined the density and species identity of seeds discarded in harvester ant nest middens and compared them with those found in nearby soils. Nineteen species of seeds were recovered from middens, compared with 13 species in 5-m reference areas and 9 species in adjacent disk areas. Total density of sound seeds was nearly 3 times higher in middens than at 5 m from the nest and nearly 50 times higher than in disk soils. Moreover, 4 of the 6 most common species overall were significantly more abundant in middens. One species, Munro globemallow ( Sphaeralcea munroana ), was recovered from nearly 50% of middens but was not found in the other 2 areas. These findings suggest that the western harvester ant is a potentially important disperser of some sagebrush-steppe plant species.     

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.     

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.     

A key to Neodohrniphora (Diptera: Phoridae), parasites of leaf-cutter ants (Hymenoptera: Formicidae)

A key to the females of Neodohrniphora Malloch is provided. A species referred to as Apocephalus sp. by Eibl-Eibesfeldt and Eibl-Eibesfeldt (1967) is assigned to N. attae sp. nov., and to a newly designated subgenus Eibesfeldtphora for the N. curvinervis (Malloch) group of species. Neodohrniphora frontalis (Curran) is confirmed as a synonym of N. (E). curvinervis. The paratype of N. (N.) acromyrmecis Borgmeier differs from the lectotype, and is reassigned to N. (N.) similis Prado. A new subgenus, Wallerphora, is designated for N. (W.) mexicanae sp. nov. from Mexico.     

The first Leptanilloides species (Hymenoptera: Formicidae: Leptanilloidinae) from eastern South America

We describe a species of the exclusively Neotropical dorylomorph ant genus Leptanilloides (Leptanilloidinae), Leptanilloides atlantica sp. nov., based on workers collected in the Atlantic Forest, São Paulo, south-eastern Brazil. The 11 species of Leptanilloides described are known from relatively high altitudes in western America (from the Andes foothills in Bolivia to Sierra Morena in Mexico). The discovery of a Leptanilloides species in south-eastern Brazil represents a significant range extension for the genus; this new species shares characters with Leptanilloides biconstricta (Bolivia), Leptanilloides femoralis (Venezuela) and Leptanilloides gracilis (Mexico) and may be distinguished based on a combination of traits. The hypogaeic habits of Leptanilloidinae combined with inefficient collecting techniques may explain the paucity of information and of specimens of this group in most museum collections as well as its present apparent disjunct distribution. We compare Leptanilloides distribution to that of other organisms that show similar disjunct patterns in the Andes and montane sites in the Brazilian Atlantic Forest. http://www.zoobank.org/urn:lsid:zoobank.org:pub:E7E334AA-58C0-455D-A0A6-724D29226DD0     

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.     

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.     

Assembly of Myrmelachista Roger (Formicidae: Formicinae) in twigs fallen on the leaf litter of Brazilian Atlantic Forest

The nests of Myrmelachista are found in tree trunk cavities and branches. The biology of these arboreal ants is still relatively unknown. We investigated the nesting behaviour of this genus in fallen dry twigs in the Atlantic rainforest of southeastern Brazil. Physical characteristics of the nests, colony demographics, presence of breeders and ant worker sizes were recorded. Samples were collected weekly for 12 months, along open, sunny and undisturbed trails within forest remnants. In all, 202 nests were collected and six species were recorded. Myrmelachista ruszkii had the highest population of immatures and the greatest number of nests found. Myrmelachista nodigera had the smallest workers, was the least populous and the colony was housed in the finest branches. These results expand the current knowledge about the diversity and biology of Myrmelachista in the Brazilian Atlantic forest, and describe polydomic nests and competitive behaviour of M. ruszkii.     

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.     

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.     

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.     

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.     

Ecology and field biology of two dominant Camponotus ants (Hymenoptera: Formicidae) in the Brazilian savannah

Camponotus renggeri and C. rufipes are very abundant in Brazilian cerrado savannah, where they feed extensively on liquid rewards and commonly associate with plants bearing extrafloral nectaries and honeydew-producing insects. Here, we provide a qualitative and quantitative field account on the natural history and ecology of these two ant species. The study was carried out in a cerrado reserve in south-eastern Brazil across a rainy/hot season (summer) and a dry/cold season (winter). The ants were found in two vegetation physiognomies: all nests of C. rufipes were located in the cerrado sensu stricto (scrub of shrubs and trees, 3–8 m tall), whereas C. renggeri occurred mostly in the cerradão (forest with more or less merging canopy, 10–12 m tall). Both species nested in fallen or erect dead trunks, as well as underground. In addition, C. rufipes built nests using dead plant material arranged or not around shrub bases. Colonies of C. rufipes were generally more populous than those of C. renggeri, and both species had colonies with more than one dealated queen. Both species were active mainly at night and foraged for resources near their nests, mainly extrafloral nectar and hemipteran honeydew (aphids and mealybugs). The average size of the home ranges of C. renggeri in cerrado sensu stricto and cerradão varied from ≈ 2.8 to 4.0 m² and apparently were not affected by season. In C. rufipes, however, foraging grounds in cerrado sensu stricto showed a twofold increase from dry/cold (≈ 4.5 m²) to rainy/hot season (≈ 9.8 m²). Our study highlights the importance of natural history data to understand the foraging ecology and role of these ants in cerrado savannah.