Larval oophagy in the ant <Emphasis Type="Italic">Amblyopone silvestrii</Emphasis> (Hymenoptera,Formicidae)

Summary Larvae pass through five instars in the temperate, subterranean ponerine ant, Amblyopone silvestrii. Field colonies displayed a large decrease in the number of eggs during mid-summer, despite the fact that queens maintained fully developed ovaries with mature eggs. Observations of laboratory colonies indicate that cannibalism by 1st and 2nd instar larvae caused this decrease in egg number. These instars consumed a total of 66–75% of eggs in the nest, with each larva consuming 2–3 eggs before molting to the 3rd instar. At that time the larvae began to feed on arthropods. The preferred prey of A. silvestrii consists of entire centipedes; the large size of these prey items relative to the size of early instar larvae makes it difficult for the larvae to feed on these prey. Additionally, workers of A. silvestrii do not engage in oral trophallaxis. Consequently, oophagy is a plausible method to feed these very small larvae.     

A synoptic review of the ant genera (Hymenoptera, Formicidae) of the Philippines

An overview of the history of myrmecology in the Philippine archipelago is presented. Keys are provided to the 11 ant subfamilies and the 92 ant genera known from the Philippines. Eleven ant genera (12%), including 3 undescribed genera, are recorded for the first time from the Philippines. The biology and ecology of the 92 genera, illustrated by full-face and profile photo-images, of Philippine ants are summarized in the form of brief generic accounts. A bibliography of significant taxonomic and behavioral papers on Philippine ants and a checklist of valid species and subspecies and their island distributions are provided.     

The pretarsal footprint gland of the ant Amblyopone reclinata (Hymenoptera,Formicidae) and its role in nestmate recruitment

Workers of the ant Amblyopone reclinata employ solitary prey retrieval when prey is small, but recruit nestmates to large prey. In the latter case, the scout forager paralyses the prey with its powerful sting, and quickly returns to the nest. During this homeward journey, it deposits a trail pheromone, that originates from the well developed footprint glands in its hindlegs. Recruited workers follow this trail to reach the prey, which is then jointly dragged to the nest. The footprint gland is only found in ants of the genus Amblyopone, and is formed by a glandular differentiation of the dorsal tegumental epidermis in the hindleg pretarsi. The secretory epithelium is approximately 15–20 μm thick, and shows apical microvilli and basal invaginations. The cytoplasm contains numerous mitochondria. Narrow pores with a diameter of 0.1 μm run through the cuticle, although they were not seen to open at the pretarsus external surface. Careful observation of trail-laying workers reveals that during trail-laying the hindleg pretarsus is twisted in a peculiar position, which explains how secretion from the dorsally located footprint gland is deposited onto the substrate.     

Observation of group recruitment to prey in a primitive ponerine ant,Amblyopone sp. (reclinata group) (Hymenoptera: Formicidae)

Summary Group recruitment during foraging was observed in a primitive ponerine ant,Amblyopone sp. (reclinata group) under laboratory condition. Workers searched for prey singly; however, if a item of prey was stung by a worker, other ants joined the attack. After the prey became immobile, one of the workers laid a trail directly toward the nest. This scout worker recruited additional workers (between 3 and 33). They formed a single file procession to the point of prey capture, and cooperatively transported the prey. A scout worker could stimulate nest workers to leave the nest without direct contact, and the recruited workers could trace the trail without guidance by the scout worker. This is the first report of recruitment behavior during foraging in the primitive antAmblyopone.     

New myrmicine ant genera from the Oriental Region Hymenoptera: Formicidae

Abstract. Four new myrmicine ant genera are described from the Oriental Region. Vombisidris gen.n. (twelve species) is predominantly an arboreal genus that ranges from India to Queensland, with the majority of species in Malaysia and Indonesia. Rotastruma gen.n. (two species) is known from China, Singapore, and East Malaysia and is also arboreal. Tetheamyrma gen.n. is monotypic and known only from a single leaf litter sample from East Malaysia. The three species of Kartidris gen.n. are terrestrial and have been found in mountainous areas in southern China. Thailand and India.     

New exocrine glands in the legionary ants of the genus Leptanilla (Hymenoptera,Formicidae, Leptanillinae)

Summary This paper reports the results of the first detailed study of the morphology of exocrine glands in two species of the ant subfamily Leptanillinae. Workers of Leptanilla escheri and L. japonica possess a large, unpaired sternal gland in the VIIth abdominal sternite, and an hypertrophied poison gland which is surrounded by a massive muscle layer. The sternal gland is absent in the queen of L. japonica, and the poison gland is highly degenerated. The queen is, however, endowed with a series of large, paired, intersegmental tergal and sternal glands, which occur between the IVth through the VIIth segments. The queen also posseses large spiracular plate glands.     

Queen polymorphism and queen-morph related facultative polygyny in the ant, <Emphasis Type="Italic">Myrmecina graminicola</Emphasis> (Hymenoptera,Formicidae)

Summary: Polymorphism of the functional queens in Myrmecina graminicola is analyzed. Both gynomorphs (G-§§ G) and a wide range of intermorphs (I-§§ I) occur, which all are usually mated and egg-laying. Colonies having a gynomorphic queen are always monogynous, whereas about 57% of all colonies with intermorphic queens are polygynous, having two or more coexisting functional queens. The female sexual offspring of individual gynomorphic queens either consists of gynomorphs only, or exclusively of intermorphs. Intermorphic queens may have exclusively intermorphic female sexual progeny, or simultaneously both gynomorphs and intermorphs. Single colonies in laboratory culture produce the same kind of female progeny over several subsequent breeding cycles (artificially compressed "years" of 9-10 months). No environmental influence on queen morph determination could be detected. A genetically mediated queen polymorphism, as in Harpagoxenus sublaevis and Leptothorax sp. A, is suggested. Colony sizes vary considerably, with polygynous I-queen colonies being largest (57.2 - 34.3 s.d. workers), followed by G-queen colonies (44.6 - 22.7 s.d.) and monogynous I-queen colonies (34.4 - 23.7 s.d.), suggesting occasional budding of polygynous colonies.     

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.     

Microsatellites for the Neotropical ant,Camponotus leydigi (Hymenoptera: Formicidae)

Ants (Hymenoptera: Formicidae) are dominant social insects that play important ecological roles in terrestrial ecosystems. Camponotus leydigi (Forel) is widely distributed in the Neotropical region and is frequently found in the Brazilian cerrado savanna interacting with plants and other insects. Field observations indicate that C. leydigi has a polydomous nesting habit, but little is known about the genetic relationship among workers. In this study, we identify the first nine microsatellite loci for C. leydigi that will allow further investigation on its genetic diversity. We used a microsatellite-enriched library method. According to this method, repetitive sequences are captured with (CT)₈ and (GT)₈ biotin-linked probes, with subsequent recovery by streptavidin magnetic-coated beads. We observed that eight loci were polymorphic. The mean (± standard error) observed and expected heterozygosities were 0.55 ± 0.23 and 0.73 ± 0.28, respectively. The rarified allelic richness ranged from 1 to 5.32. The polymorphism contents were similar to diversity estimates found in markers previously developed for other Camponotus ants. These markers will be useful for future studies on population genetics and ecology of Camponotus ants in cerrado, including nesting ecology, colony structure, dispersal and conservation.     

Decyl acetate synthesis in the ant,Formica schaufussi (Hymenoptera: Formicidae)

Decyl acetate occurs in high amounts in the Dufour's gland of Formica schaufussi. When worker ants were fed [¹⁴C]-acetate the acetate moiety of decyl acetate was labelled preferentially indicating that decyl acetate is synthesized via an esterification reaction.     

Wingless reproductives in the slave‐making ant Polyergus samurai: specialized producers of males (Hymenoptera: Formicidae)

Three wingless reproductives of Polyergus samurai Yano were collected in the reproductive season. These wingless reproductives had developed ovaries and laid eggs immediately after collection. They lacked spermatheca and the eggs produced by wingless reproductives finally become adult males. These observations suggest that the wingless reproductives of P. samurai are potential producers of males.     

Integration raids in the Amazon ant Polyergus rufescens (Hymenoptera, Formicidae)

Summary. Groups of enslaved Formica fusca workers from mixed colonies of Polyergus rufescens with numerous slave workforce tend to split off and found small and almost homospecific nests around the main nest, with at least some of them connected with the latter with underground passages. Their inhabitants are able, at least temporarily, to adopt young F. fusca gynes. P. rufescens invades these satellite nests in a manner similar to the normal slave raids, and carries the slaves back to the main nest. The supposed evolutionary cause of this behaviour is to keep integrity of mixed colonies and prevent possible emancipation of slaves.Received 18 August 2004; revised 27 September 2004; accepted 11 October 2004.     

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.     

Secostruma, a new subterranean tetramoriine ant genus (Hymenoptera: Formicidae)

Abstract. Secostruma , a very specialized new subterranean ant recovered from a soil-core sample taken in Sabah, East Malaysia, is described for the first time. Its most striking adaptations and their possible functions are discussed, and its affinities investigated. Analysis of its main features and comparison with two possible parent-groups leads to the conclusion that Secostruma is a member of the Tetramorium-group of genera.     

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.     

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.