The growth and development of the overwintering larvae in the ant Lasius flavus (Hymenoptera: Formicidae)

The growth and development of the larvae of the ant Lasius flavus (F.) have been traced from the autumn to the following summer. The changes in fresh weight, dry weight, protein content and food reserves in the form of fats and carbohydrates are given. The course of development of the larvae is discussed in relation to the production of queens, workers and males.     

Respiration during the metamorphosis of sexuals in Lasius flavus (Hymenoptera, Formicidae)

ABSTRACT. The respiration of metamorphosing gyne Lasiusflavus Fab. has been measured in field and laboratory populations. Twelve morphological stages are identified and their respiratory rate investigated. Only five physiological phases are distinguished. The specific respiratory rate varies between these phases, to produce the U-shape characteristic of insects. There is good agreement between the data from English field and Danish laboratory populations. The minimum rate is only 40% of the maximum. Except at the beginning and end of metamorphosis, the Q₁₀ is significantly different in the two temperature intervals 10–20 and 20–30C. Metamorphosis was completed in approximately 33 days at 20C. The total oxygen consumption by the gynes during metamorphosis was 2.4 ml. Their weight loss amounted to 2.2 mg, or 36% of the dry weight and, of this, 0.67mg was accounted for by fat. Assuming the rest was carbohydrate, consumption of these reserves would release 62.9 J, which, for this combination of fat and carbohydrate, can be calculated to be equivalent to 3.1 ml oxygen which is in reasonable agreement with the figure calculated from the measurement of oxygen consumption. The specific respiratory rate in English field populations of male pupae varies in the same way as the gyne-pupae, but it is about 50% higher.     

Eleven microsatellite loci in the sociobiologically enigmatic ant Lasius austriacus (Hymenoptera: Formicidae)

We describe the isolation and characterization of 11 microsatellite loci in the sociobiologically enigmatic ant Lasius austriacus. The polymerase chain reaction primers were tested on a population in East Austria. The number of alleles ranged from four to 19 and the observed heterozygosity from 0.200 to 0.900. Cross‐species amplification tests were performed, with some loci polymorphic in all species tested, for the closely related invasive species Lasius neglectus, three further Lasius species, another formicine, Formica polyctena, and the invasive myrmicine species Tetramorium tsushimae.     

New chemicals from the dufour gland of the formicine ant Lasius niger (Hymenoptera:Formicidae)

A series of esters of C₈-C₁₃ fatty acids formed with C₁₀-C₁₂ straight chain alcohols, representing 3.7% of the glandular contents, was found in the Dufour gland of workers of the formicine ant Lasius niger. Altogether, nearly 50 components, among them hydrocarbons, alcohols, acetates and propionates were identified in the glandular liquid by means of gas chromatography (GC) and mass spectrometry (MS), using a solid injection technique. The wax esters and the propionates—decyl, dodecyl, octadecyl and farnesyl—have not been previously reported from ant secretions.     

Nestmate discrimination and cuticular profiles of a temporary parasitic ant Lasius sp. and its host L. fuliginosus (Hymenoptera, Formicidae)

Workers of the temporary parasitic ant Lasius sp. were perfectly compatible with their hosts Lasius fuliginosus. Aggression was never seen between allospecific nestmates in either field or laboratory. In the laboratory, trophallaxis and allogrooming between allospecific nestmates were statistically more frequent than that between conspecifics. These ants were highly aggressive toward individuals of either species from another mixed colony located 1 km away, indicating that they discriminated nestmates and nonnestmates regardless of the species to which they belonged. No aggressive actions, however, were observed between two neighboring mixed nests located 5 m apart. We have not considered, however, the relationship of the two neighboring nests: the two nests may have been two subunits of the same family or sister colonies, or may have been different colonies but discriminated from distant aliens. Gas chromatography analysis on the total cuticular extracts showed that Lasius sp. and L. fuliginosus possess distinct cuticular profiles, even though they were collected from the same mixed colony. Received: December 13, 1999 / Accepted: April 25, 2000     

A taxonomic study of the ant genus Lasius Fabricius in the British Isles (Hymenoptera: Formicidae)

The taxonomic status of the species Lasius mixtus, L.umbratus and L.rabaudi is discussed. Keys are given to the males, females and workers of the seven British species of the genus, and taxonomic notes on these species are included.     

Biological constraints and colony founding in the polygynous invasive ant Lasius neglectus (Hymenoptera, Formicidae)

Summary. The polygynous invasive ant Lasius neglectus was described from Budapest, Hungary, as an unicolonial species, with no apparent colony barriers, and inferred intra-nidal mating without a nuptial flight. Here we analyze additional morphological characteristics of gynes, their physiological condition at emergence and at the time of mating and we describe the productivity of different types of colony founding in the laboratory. A low increase in dry weight and in fat content from emergence to mating indicates that gynes can only succeed in dependent colony founding. However, the queen-worker thorax volume ratio is typical of a species with independent colony founding and we were able to demonstrate independent colony founding in the laboratory (both haplo- and pleometrotic). Brood development in independent founding is rapid and the number of nanitics higher than in other Lasius species. Both colony budding and dependent colony founding could also be demonstrated in the laboratory. Worker oviposition was absent. The carbohydrate content of newly mated queens is consistent with the observed loss of mating flight of this species. However the relative wing area clearly indicates that L. neglectus queens should be able to fly. Therefore, both queen morphology and physiological state at maturity show that L. neglectus is intermediate between a monogynous, free-living, non pest ant and a multiqueened (polygynic) invasive tramp ant. This neglected ant thus offers interesting opportunities to study the origin of unicoloniality and the spread of this species in northeast Spain.     

Phylogeny and bionomics of Lasius austriacus (Hymenoptera,Formicidae)

Summary Phylogenetic analysis based on sequence data of the mitochondrial COI gene confirms the species status of the recently described Lasius austriacus. The five haplotypes of L. austriacus do not cluster according to their geographic origin, indicating a recent gene flow among the populations. The molecular data corroborate the morphology based hypothesis that L. austriacus belongs to the Lasius (Lasius s.str.) brunneus group. The invasive species Lasius neglectus forms a sister taxon with L. turcicus, both next related to L. austriacus. Other phylogenetic relationships within the genus Lasius are in accordance with morphological data.First data on the bionomics of L. austriacus are discussed in context with its phylogenetic position. Based on gyne and male morphology, excavations of nests, pitfall trapping and observations in formicaries, we hypothesize that L. austriacus is a mainly hypogaeic, monogynous species with nuptial flight. These are characters of the Lasius brunneus group in general, except the polygynous-polycalic, intranidally copulating L. neglectus. Aggression tests, however, revealed non-aggressive behaviour (antennation) between separated L. austriacus populations, but pronounced interspecific aggression against L. neglectus. This confirms the species status of L. austriacus and indicates a reduced level of intraspecific aggression, similar to L. neglectus.The status of L. austriacus as a native species in Central Europe is confirmed.Received 10 February 2003; revised 24 June 2003; accepted 23 July 2003.     

Factors affecting distribution of the mound-building ant Lasius neoniger (Hymenoptera: Formicidae) and implications for management on golf course putting greens

Lasius neoniger (Emery), a cosmopolitan ant species, can be a serious pest when its mound-building activities occur on golf course putting greens and other closely mowed turfgrass sites. We mapped the distribution of 735 ant mounds on 30 sand-based putting greens of three golf courses. We then examined factors that might explain why >90% of the mounds on such greens were concentrated in a 2-m wide band just inside the perimeter. Root aphids (Homoptera: Aphididae) from which L. neoniger obtains honeydew were largely absent from high-sand root zone mix of greens but present in surrounding turfgrass on natural soil. Main ant nests, with brood, also were absent from sand-based greens but abundant in adjacent roughs. Although more root aphids were found within ant nests than away from nests, their numbers seem too low to be the main factor restricting the ants' distribution to edges of putting greens. In manipulative experiments, ants responded to low cut (scalped) turf and to sand-filled holes by increased mound building. We suggest that most ant mounds on sand-based greens are associated with subnests, used by foraging workers, which are connected to main nests located just outside the collar in natural soil. Encroachment of mounds into greens occurs when the polydomous colonies seasonally expand their foraging territories, accounting for mounds being concentrated around the perimeter. Control actions for L. neoniger on golf courses should focus on the perimeter of sand-based greens.     

Comparative ultrastructure of ant spermatozoa (Formicidae: Hymenoptera)

Mature spermatozoa from spermathecae of founding queens were obtained from 5 species of ants, representing the major subfamilies Myrmicinae (Acromyrmex versicolor, Crematogaster sp.) and Dolichoderinae (Tapinoma sessile, Conomyrma insana, Conomyrma wheeleri). The ultrastructure of ant spermatozoa has many features in common with that of higher insects and is similar to that of other Hymenoptera. Structural similarities to spermatozoa of other Hymenoptera include an acrosome containing an internal rod that extends into the nucleus, two elongate mitochondrial derivatives, a centriolar adjunct, and an axonemal arrangement of 9 + 9 + 2 that includes well-developed coarse, or accessory, tubules. Spermatozoa obtained from A. versicolor, a species that is known to store and utilize viable sperm from this supply for over 10 years, show greater development of the mitochondrial derivatives than do the other species. The most distinctive feature of ant spermatozoa in comparison to other Hymenoptera is the large size of the centriolar adjunct relative to the other organelles. The centriolar adjunct is located posterior to the nucleus, anterior to the mitochondrial derivatives, and opposite the axoneme.     

Parasitism and biology of Myrmosicarius grandicornis (Diptera, Phoridae) in relationship to its host, the leaf-cutting ant Atta sexdens (Hymenoptera, Formicidae)

Summary. The parasitic phorid Myrmosicarius grandicornis Borgmeier is commonly found around nest entrances of the leaf-cutting ant Atta sexdens (L.) in Brazil, but there is no information about the importance of this fly for A. sexdens. We evaluated the parasitic capability of female M. grandicornis collected in the field and released in laboratory nests of A. sexdens and compared ants' foraging rhythm before and after M. grandicornis were released. We also determined biological characteristics of the parasitoid. Presence of M. grandicornis elicited foragers to abandon their loads and return to the nest, an effect previously described for the phorid Neodohrniphora sp., which is a more abundant A. sexdens parasitoid. Both phorid species occur at the same foraging trails during part of the year and attack ants of different size classes. Therefore, they may have a combined effect on the reduction of A. sexdens foraging. Myrmosicarius grandicornis pupariated inside hosts' head capsules, which are detached from their bodies and deposited in the nest's refuse pile. Adults emerged through the hosts' mouth cavity about a month after oviposition. The characteristics of M. grandicornis biology suggest that this parasitoid completes its development inside A. sexdens nests.     

Ultrastructure des organes retrocerebraux de Lasius niger l. (Hymenoptera : Formicidae)

The ultrastructure of the retrocerebral system has been studied in hyperactive workers of the ant, Lasius niger. The paired elongated corpora cardiaca consist of 2 parts: the glandular part that lies in a dorsolateral position, and the more developed nervous part. In the neural area, 4 types of neurosecretory axons can be distinguished according to the size and density of their granules. The glandular cells contain numerous dense granules and large dense bodies whose nature is uncertain; they mingle with the axons of only one type. Each of the 2 anterior corpora allata is located near the nervous part of each corpus cardiacum; they consist of about 12 large cells whose plasma membrane shows many digitations; 2 types of axons can be seen in the dilated intercellular spaces.     

The ant subfamily Pseudomyrmecinae (Hymenoptera: Formicidae): generic revision and relationship to other formicids

Three genera are recognized in the ant subfamily Pseudomyrmecinae: Myrcidris new genus (monotypic; type species M. epicharis , new species, from Amazonas, Brazil); Pseudomyrmex Lund (c. 150 nominal taxa; southern Nearctic and Neotropical regions); and Tetraponera F. Smith (c. 110 nominal taxa; Palaeotropical region). New generic synonymies are: Pseudomyrmex Lund = Ornatinoda Enzmann = Clavanoda Enzmann = Triangulinoda Enzmann = Apendunculata Enzmann = Latinoda Enzmann; and Tetraponera F. Smith = Pachysima Emery = Viticicola Wheeler = Sima Emery (nee Roger) = Parasima Donisthorpe. Autapomorphies are identified for the subfamily and for its constituent genera, indicating the monophyly of all four taxa. Based on available character-state information, Myrcidris is most parsimoniously interpreted as a sister-group to all other Pseudomyrmecinae {Pseudomyrmex + Tetraponera) , although there is almost equally strong support for an alternative grouping: Tetraponera + (Myrcidris + Pseudomyrmex). Phylogenetic relationships of the Pseudomyrmecinae and other ant subfamilies within the 'poneroid complex' ( sensu Taylor, 1978) were assessed by a cladistic analysis of eleven representative ant genera. At the level of subfamily relationships the results suggest that: (1) The Myrmicinae and the Pseudomyrmecinae are sister groups. (2) Within the 'poneroid complex' is an unresolved trichotomy composed of: (i) Pseudomyrmecinae + Myrmicinae, (ii) Myrmeciinae, and (iii) Ponerinae + Leptanillinae + (Cerapachyinae + Dorylinae (s.l.)). (3) The Nothomyrmeciinae are a basal lineage within the 'poneroid complex', rather than being allied with the 'formicoid complex' (Formicinae, Dolichoderinae and Aneuretinae).     

Revision of the dolichoderine ant genus Turneria (Hymenoptera: Formicidae)

Abstract. The Australasian ant genus Turneria is revised. T.bidentata Forel, T.dahlii Forel and T.pacifica Mann are redescribed and a lectotype designated for T.bidentata. T.frenchi Forel is transferred to Stigmacros (comb.n.), and T.butteli Forel is transferred to Iridomyrmex (comb.n.). Three new species, T.arbusta, T.collina and T.postomma, are described from Papua New Guinea. Males of the genus are described for the first time. A key to the workers of recognized species and a distribution map are provided. The group is analysed cladistically and the resulting species relationships are discussed, along with a comment on the use of polymorphic characters.     

Generic-level relationships within the ant subfamily Dolichoderinae (Hymenoptera: Formicidae)

A cladistic analysis was undertaken to determine relationships among extant genera of the ant subfamily Dolichoderinae. Twenty-one of the twenty-two currently recognized genera within the subfamily were examined using 104 morphological characters. A single fully resolved, most-parsimonious tree was found when a combination of ordered and unordered characters was used. When all characters were coded as unordered, seventy most-parsimonious trees were found. The following results were found with both character coding methods. Leptomyrmex was placed basal to the remainder of the subfamily and the monophyletic sets Dolichoderus + Liometopum + Axinidris + Tapinoma + Technomyrmex, Froggattella + Iridomyrmex + Ochetellus + Papyrius + Philidris + Turneria , and Bothriomyrmex + Dorymyrmex + Forelius + Loweriella were suggested. The genera Linepithema and Doleromyrma showed a small amount of instability in moving between neighbouring sister groups when the character coding method changed. The genera Anillidris and Anonychomyrma were difficult to place as they showed major differences in their positions between the two character coding methods.     

Molecular phylogeny of the ant tribe Myrmicini (Hymenoptera: Formicidae)

The interrelationships within ant subfamilies remain elusive, despite the recent establishment of the phylogeny of the major ant lineages. The tribe Myrmicini belongs to the subfamily Myrmicinae, and groups morphologically unspecialized genera. Previous research has struggled with defining Myrmicini, leading to considerable taxonomic instability. Earlier molecular phylogenetic studies have suggested the nonmonophyly of Myrmicini, but were based on limited taxon sampling. We investigated the composition of Myrmicini with phylogenetic analyses of an enlarged set of taxa, using DNA sequences of eight gene fragments taken from 37 representatives of six of the seven genera (Eutetramorium, Huberia, Hylomyrma, Manica, Myrmica, and Pogonomyrmex), and eight outgroups. Our results demonstrate the invalidity of Myrmicini as currently defined. We recovered sister‐group relationships between the genera Myrmica and Manica, and between Pogonomyrmex and Hylomyrma. This study illustrates that to understand the phylogeny of over 6000 myrmicine species, comprehensive taxon sampling and DNA sequencing are an absolute requisite. © 2010 The Linnean Society of London, Zoological Journal of the Linnean Society, 2010, 160 , 482–495.     

A review of Bahamian ant (Hymenoptera: Formicidae) biogeography

Abstract. The results of recent surveys for ants on Staniel Cay, Exumas (and surrounding small cays) and the northeastern region of Andros are presented. These records are compiled with all previously published collection records of ants from the Bahamas into a single database. A list of all known Bahamian species is presented, in accord with current taxonomy. Distributions within the Bahamas are given, along with the status of each species with reference to its origin (endemic, native, or exotic). At present seventy-five named species of ants are known from the Bahamas, which shares 60% of its ant fauna with Florida and 71% with Cuba. More than one third of the species (37%) are exotics, which appear to exist primarily in areas characterized by human disturbance, and apparently have not invaded the native vegetation to a large degree. Both historical and ecological factors are likely to have played important roles in shaping present-day Bahamian ant species diversity and distribution. The number of species on all major Bahamian islands from which ants have been collected is presented as a function of island area. Most islands have not been very thoroughly surveyed. The species-area relationship for the more thoroughly surveyed islands is relatively flat (z= 0.06). Further collecting in this archipelago will probably lead to the discovery of additional species.