Immigration and formation of mixed colonies in red wood ants (Hymenoptera,Formicidae)

Long-term field studies of the composition and spatial structure of settlements of ants of the Formica rufa group were carried out in two regions of Russia (Moscow and Arkhangelsk provinces). Fragmentation of damaged nests followed by reintegration of the fragments is the main way of formation of mixed colonies of ants from different nests (including different species). The principal factor of nest fragmentation is their damage by wild boars, bears, and in some localities, by poachers. The formation of mixed nests and nest complexes with participation of different Formica species was observed. They are formed by joining the ants from several damaged nests or by a colony from a destroyed nest immigrating into an intact one. Regular damage of many nests leads to the formation of broad zones of mixed colonies. The mixed colonies including 2–3 species of wood ants have recently become common. The phenomenon of mixed colonies raises a question as to the relative importance of two basic principles (sociality and specific identity) in the life of ant societies and demonstrates the priority of the social principle.     

Miocene ants (Hymenoptera,Formicidae) from Crimea

Ant imprints, new and previously known, from Middle Miocene deposits near Kerch (Crimean Peninsula, Russia) are described or redescribed. A new Myrmicinae species, Solenopsis atavinus sp. nov., is described based on a wingless female. A winged female similar to the earlier described Dolichoderus tauricus Dlussky, 1981 is found: due to the excellent preservation of this specimen, the new specimen and the holotype of D. tauricus are redescribed and can be reclassified as Ponerites tauricus (Dlussky, 1981), comb. nov. Oecophylla taurica sp. nov. is described based on a partly preserved imprint of a female thorax with a forewing, the venation of which allows it to be positively identified as a weaver ant. Two other species are transferred from the formal genus Camponotites to Oecophylla based on forewing venation: O. kraussei (Dlussky et Rasnitsyn, 1999), comb. nov. (Early Eocene, United States) and O. macroptera (Dlussky, 1981), comb. nov. (Middle Miocene, Stavropol, Russia). One of the studied forewing imprints is similar in venation to Paraphaenogaster microphthalmus Dlussky, 1981, described from the Middle Miocene of Vishnevaya Balka (Stavropol province, Russia) and so is attributed to this species. Dolichoderus tavridus sp. nov. is described based on a forewing.     

Karyological studies of Japanese ants (Hymenoptera,Formicidae)

The karyotypes of nine Japanese ants in three subfamilies (Ponerinae, Formicinae, and Myrmicinae) were successfully analysed by the improved squash technique. Three ponerine species had 2n=7 and n=4 (Ponera scabra), 2n=22 (Brachyponera sinensis), and 2n=28 and n=14 (Cryptopone sauteri). Four formicine species had 2n=18 and n=9 (Camponotus sp. and C. tokioensis), 2n=26 and n=13 (Camponotus japonicus), and 2n=30 and n=15 (Lasius niger). Two myrmicine species had 2n=18 and n=9 (Leptothorax congruus), and 2n=37, 38, 39, and n=17, 18, 19, 20 (Pheidole nodus). It was found that the variation of chromosome number observed in P. nodus was caused by Robertsonian type polymorphism.     

Catalogue of the ants (Hymenoptera, Formicidae) of Bulgaria

The present catalogue of the ants (Hymenoptera, Formicidae) of Bulgaria is made on a base of critical reconsideration of literature (covering the period from 1892 till 2009 and part of 2010) as well as on examination of the authors' and several museum's collections. A lot of data were omitted in the previous Bulgarian monograph on ants, lots of new data were recently added and many important additions and alterations were made due to taxonomic revisions of Eurasian Formicidae during the last three decades. Two new species are reported for the country [Temnothorax graecus (Forel, 1911) and Temnothorax cf. korbi (Emery, 1924)].This catalogue contains a list of 163 ant species belonging to 40 genera of 6 subfamilies now known from Bulgaria. Synonyms and information on the previously reported names in relevant publications are given. Known localities of the species are grouped by geographic regions. Maps with concrete localities or regions for each species were prepared. The conservation status of 13 ant species is given as they are included in IUCN Red List of Threatened Species and Bulgarian Biodiversity Act. In comparison with adjacent Balkan regions the ant fauna of Bulgaria is quite rich and its core is composed of South European elements.     

Respiratory patterns in nurses of the red wood ant Formica polyctena (Hymenoptera, Formicidae)

Summary Cycles of discontinuous gas exchange (DGCs) and abdominal ventilatory movements were studied in nurses of red wood ant, Formica polyctena, using an electrolytic respirometer and an infra-red (IR) gas analyser or flow-through respirometry. Both respirometry systems were combined with an IR actographic device based on IR-emitting and IR-sensor diodes. After recovering from handling and apparatus stress, lasting 1–3 h, completely motionless intact ants displayed regular DGC. After decapitation the ants displayed DGC whose frequency was somewhat lower than that of the intact individuals (7.17 ± 0.79 mHz and 10.43 ± 01.12 mHz, respectively). In headless ants, there occurred continuous slow movements of legs. Bursts of carbon dioxide in the intact and in the headless ants always coincided with a bout of telescoping movements (contractions) of abdominal segments, which was interpreted as active ventilation. During interburst periods, the headless ants exhibited telescoping movements characterised by rapid protraction, lasting 0.07–0.09 s, followed by a slow retraction of segments, suggesting passive ventilation. The intact ants were very sensitive to the flowing air and tended to be continuously active during flow-through respirometry. The decapitated ants, on the contrary, were insensitive to the air current.Received 26 March 2003; revised 30 July 2003; accepted 6 August 2003.     

The internal phylogeny of ants (Hymenoptera: Formicidae)

Abstract. The higher phylogeny of the Formicidae was analysed using 68 characters and 19 taxa: the 14 currently recognized ant subfamilies plus 5 potentially critical infrasubfamilial taxa. The results justified the recognition of 3 additional subfamilies: Aenictogitoninae Ashmead (new status), Apomyrminae Dlussky & Fedoseeva (new status), and Leptanilloidinae Bolton (new subfamily). A second analysis on these better delimited 17 subfamilies resulted in 24 equally most parsimonious trees. All trees showed a basal division of extant Formicidae into two groups, the first containing (Myrmicinae, Pseudomyrmecinae, Nothomyrmeciinae, Myrmeciinae, Formicinae, Dolichoderinae, Aneuretinae) and the second the remaining subfamilies. Clades appearing within these groups included the Cerapachyinae plus 'army ants', the Nothomyrmeciinae plus Myrmeciinae, the 'formicoid' subfamilies (Aneuretinae + Dolichoderinae + Formicinae), and the Old World army ants (Aenictinae + Aenictogitoninae + Doryline), but relationships within the last two groups were not resolved, and the relative positions of the Apomyrminae, Leptanillinae and Ponerinae remained ambiguous. Moreover, a bootstrap analysis produced a consensus tree in which all branches were represented in proportions much lower than 95%. A reconstruction of the ground plan of the Formicidae indicated that the most specialized of all recent ants are the members of the subfamily Dorylinae and the least specialized ones are the monotypic Apomyrminae.     

Common names for Australian ants (Hymenoptera: Formicidae)

Abstract Most insects do not have common names, and this is a significant barrier to public interest in them, and to their study by non-specialists. This holds for even highly familiar insect groups such as ants. Here, I propose common names for all major native Australian ant genera and species-groups, as well as for many of the most abundant and distinctive species. Sixty-two genera, 142 species-groups and 50 species are given names. The naming system closely follows taxonomic structure; typically a genus is given a general common name, under which species-group and species names are nested.     

Characterizing the interaction between fire ants (Hymenoptera: Formicidae) and developing soybean plants

This research characterizes the interaction between the fire ants Solenopsis invicta Buren and developing soybean plants. Phagostimulant studies showed that fire ant foraging on soybean seeds increased once the seeds imbibed water. During seedling development over a 5-d germination period, fire ant foraging shifted from the stem/cotyledons to the roots, despite continual increases in fresh weights for each region, and the fact that stem/cotyledon tissue contained the majority of food reserves. Carbohydrate analysis showed that although 2-d-old seedlings had higher concentrations of phagostimulant carbohydrates, especially sucrose, than tissues of mature plants, all tissues analyzed had enough of these sugars to induce a phagostimulant response. Fire ant association with seeds/seedlings germinated in soil resulted in reduced seedling vigor, as determined by a doubling of seedling emergence time, a threefold increase in malformed seedlings, and visible damage to cotyledons. Seeds germinated and grown to mature plants in association with fire ants, allocated 43% more assimilate into pods, but produced 28% less root dry matter, 11% less total dry matter, and there was an 81% reduction in the number of root nodules compared with control plants. We propose that reduced root development and inhibitions of nodule formation would be major yield limiting factors under field conditions. This work demonstrates that fire ant damage to soybeans is not limited to seedling establishment and that more research should be directed at the subterranean activities of the fire ant.     

Some aspects of interrelations between ants (Hymenoptera,Formicidae) and polistine wasps (Hymenoptera,Vespidae)

Embodied, situated and enactive aspects of relationships of polistine wasps with ants are considered within the framework of the theory of autopoiesis. The idea of the embodied interaction implies specific nestbuilding and protective behavior in polistine wasps. The paper examines the adaptive role of applying ant repellent on the petiole and nest and the latitude gradient of such behavior in re-social wasp species. The situated interaction is considered in the environmental context: the mortality of Polistes gallicus (L.) colonies as a result of predatory attacks of ants Myrmica bergi Ruzsky is analyzed in the Lower Dnieper basin (Ukraine). The enactive interaction includes both spontaneous autonomous activity of its participants as a result of self-organization and specific features of the spatial structure of the prey’s population forming under the impact of the predator. The applicability of some “predator-prey” models is discussed.     

Further records of ants (Hymenoptera: Formicidae) from Iran

Wide ranging surveys of the ant fauna of Iran have enabled us to add a further 30 named species to the country list. A review of almost all the published literature and of photographs of unidentified specimens within the public domain gives a grand total of 248 species, from seven subfamilies and 37 genera. In the majority of instances, our own specimens were compared with type images available from antweb.com. This has led us to propose new or revised status for Cataglyphis turcomanica Crawley 1920, Lepisiota integrisquama (Kuznetsov-Ugamsky, 1929), Lepisiota surchanica (Kuznetsov-Ugamsky, 1929) and Messor obscurior Crawley 1920. We note that the total includes a number of what may be misidentifications and a small number of named species that seem unlikely to occur in Iran.     

Repellency and toxicity of mint oil granules to red imported fire ants (Hymenoptera: Formicidae)

Repellency and toxicity of 2% mint oil granules were evaluated against worker red imported fire ants. Solenopsis invicta Buren, in a series of laboratory and field experiments. In continuous exposure experiments, LT50 values ranged from 1.2 h with 164.8 mg/cm2 of 2% mint oil granules to 15.3 h with 1.65 mg/cm2 of granules. LT50 values declined exponentially with increasing rate of mint oil granules. Limited exposure to 164.8 mg/cm2 mint oil granules resulted in > 50% knock down (KD) after 30 min; however, there was no KD at 15 min. Twenty-four hour mortality increased linearly with increasing exposure time. Mean repellency of worker red imported fire ants ranged from 49.2 +/- 5.4% for 0 mg/cm2 (untreated control) of mint oil granules at 30 min to 100% for 147.8 mg/cm2 of mint oil granules at 3 h. Repellency increased with increasing milligrams per square centimeter of mint oil granules and exposure time. In field tests, 100% of mounds opened and treated with mint oil granules were abandoned 5 d after treatment and ants had relocated or formed satellite mounds by 2 d after treatment. Unopened mounds treated topically with mint oil granules were not abandoned, but ants formed satellite mounds 2 d after treatment. Mint oil granules could provide another tool for red imported fire ant integrated pest management, particularly in situations in which conventional insecticides would be inappropriate.     

A preference assay for quantifying symbiont choice in fungus-growing ants (Attini, Formicidae)

We describe a bioassay for the quantification of cultivar preference (symbiont choice) of fungus-growing ants. The bioassay simultaneously presents mycelium of multiple pure cultivar genotypes to worker ants in a cafeteria-style test arena, and preferred versus non-preferred cultivar genotypes can then be identified based on the ants’ quantifiable behavioral tendencies to convert any of the offered mycelium into a fungus garden. Under natural conditions, fungus-growing ants are likely to express such cultivar preferences when mutant cultivars arise in a garden, or when colonies acquire a novel cultivar from a neighboring colony to replace their resident cultivar. We show that workers from different nests of the fungus-growing ant Cyphomyrmex costatus exhibit repeatable preferences vis-à-vis specific cultivar genotypes. The identified preferred and rejected cultivars can then be used in a performance assay to test whether the ants prefer cultivar genotypes that are superior in enhancing colony fitness (measured, for example, as garden productivity or colony growth), as predicted by symbiont-choice theory. Received 24 February 2006; revised 23 June 2006; accepted 26 June 2006.     

Conservation of (TTAGG)(n) telomeric sequences among ants (Hymenoptera,Formicidae)

To determine the telomere sequence in Tapinoma nigerrimum, we carried out in situ hybridization using TTAGGG and TTAGG repeat polymerase chain reaction (PCR)-generated probes. No hybridization signals were found when TTAGGG was used as a probe. However, strong signals were observed at the end of the chromosomes with the TTAGG probe. Southern blot analysis carried out on genomic DNA using TTAGG as a probe showed a strong hybridization signal even under highly stringent conditions. Similar results were obtained in Southern blot analysis carried out on genomic DNA of 19 species of ants belonging to three different subfamilies. In accordance with all the results shown in this article, the TTAGG repeat seems to be the major component of the telomere sequence in the majority of ant species.     

New fossil ants of the subfamily Myrmeciinae (Hymenoptera, Formicidae) from Germany

Two new fossil members of the subfamily Myrmeciinae are described: Archimyrmex wedmannae, sp. nov (Grube Messel, Germany, Middle Eocene) and Prionomyrmex wappleri, sp. nov. (Rott, Germany, Late Oligocene). Members of the genus Archimyrmex were known earlier from Eocene deposits of the United States and Argentina, and members of the genus Prionomyrmex were known from Late Eocene Baltic amber.     

Oral trophallaxis in adult leaf-cutting ants Acromyrmex subterraneus subterraneus (Hymenoptera, Formicidae)

Adult leaf-cutting ants of the subspecies Acromyrmex subterraneus subterraneus were fed with an Evans Blue dye solution, which allowed the investigation of subsequent exchange of liquids between ants by oral trophallaxis. Trophallactic behavior was filmed and the antennation patterns of donor and recipient ants were described. The ants’ crop capacity was measured following ad libitum feeding on dye solution. Ants previously fed on the dye solution (donors) were placed individually with unfed ants of the same caste (recipients) and the amount of dye solution passed from the donor to the recipient by oral trophallaxis was measured after one hour. The volume received was 0.26 ± 0.15μL (mean ± SD) and the residual volume of dye in the crop of the donors was 0.49 ± 0.23μL. There were 38 trophallactic events recorded for 50 pairs of ants. Trophallaxis was observed from 2.3 min to 21.5 min after initial exposure, with a mean latency of 8.4 ± 5.6 min. The mean duration of a trophallatic event was 2.3 ± 1.3 min. As far as we know, this is the first time that trophallaxis in leaf-cutting ants has been described and quantified. Received 2 December 2005; revised 6 April 2006; accepted 10 April 2006.