Alloethic efficiency in the patrolling networks of a polymorphic ant,Tapinoma nigerrimum (hymenoptera: Formicidae)

This study analyses some aspects of the role of alloethism in the networks of patrolling workers of a polymorphic ant species (Tapinoma nigerrimum) in the nest surroundings. We focus on the analysis of movement and distribution patterns of different-sized individuals, and their relationship to the potential transfer of information between each other via contacts during patrolling activities. Our results suggest that small workers are potentially more efficient in these kind of activities (information discovery and transfer), because they contact each other more than could be expected by a random process based on their proportions and, also, because their deduced energetic expenditure per unit of information found or transferred is lower than that of large workers. These differences in the contacts between patrolling ants for small and large workers cannot be explained by their movement patterns (velocity, time spend in movement, turning angles), which do not differ between both groups but, rather, seem to be a consequence of their resulting distribution patterns (overdispersed for large ants and random for small ones).     

Interactions between the ant Tapinoma nigerrimum (Hymenoptera: Formicidae) and the main natural enemies of the vine and citrus mealybugs (Hemiptera: Pseudococcidae)

Honeydew-excreting hemipterans, such as mealybug pests, can be protected from their natural enemies by tending ants in return for honeydew, thereby compromising the aims of biological control. In this respect, antagonistic interactions between the ant Tapinoma nigerrimum, native to the Mediterranean basin, and the main natural enemies of both the vine mealybug (VMB), Planococcus ficus, and the citrus mealybug (CM), Planococcus citri, were assessed in laboratory conditions. Parasitism of vine and CMs by their respective parasitoids, Anagyrus sp. nr. pseudococci and Leptomastix dactylopii, was negatively affected by the ant T. nigerrimum. Similarly, T. nigerrimum was shown to significantly disrupt the predatory potential of ladybird larvae, Cryptolaemus montrouzieri, when foraging on host CMs. By contrast, the presence of the ant did not negatively influence the predatory activity of C. montrouzieri adults when feeding on CMs. Consequently, the encyrtid parasitoids A. sp. nr. pseudococci and L. dactylopii and the larval stage of the predator C. montrouzieri may be considered as T. nigerrimum-sensitive, whereas the adults of C. montrouzieri may be regarded as T. nigerrimum-resistant predators. Accordingly, the ant T. nigerrimum constitutes a threat to the biological control of mealybugs by either the encyrtids A. sp. nr. pseudococci and L. dactylopii or the larval stage of the ladybird C. montrouzieri. Hence, adequate control of T. nigerrimum is highly recommended before any release of these mealybugs' natural enemies.     

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.     

Strategies for controlling the ghost ant,Tapinoma melanocephalum (Hymenoptera: Formicidae) with liquid bait

The ghost ant, Tapinoma melanocephalum (F.), is a household pest and a considerable nuisance. The aim of this study is to demonstrate the toxicity and control efficacy of boric acid in liquid bait against queen and worker ghost ants. The LT₅₀ values for workers fed with 0.5%–2.5% boric acid and 2% chicken peptone in 20% sucrose water solutions were 4.3–2.4 days. The lethal times (LT₅₀ = 5.2–7.6 days) for queen ghost ants fed with various concentrations of a boric acid solution depended on the feeding behavior of the queens. The high boric acid (4%) content solutions were not repellent to the ghost ant workers. The liquid bait formulation of 1% boric acid, which caused a 100% worker, brood, and queen population reduction in 4, 4, and 5 weeks, respectively, was significantly more effective than the solid bait formulation containing the same concentration (p ≦ 0.05). The simulation tests involved using chicken peptone and sucrose as the attractant, and colonies were provided an alternate food source (20% sucrose solution and dog food) to achieve a more accurate assessment of bait acceptability in screening for the efficacy of the liquid boric acid bait. The control efficiency attained 99.9% in week 4. The results demonstrated that liquid bait, containing 2% chicken peptone, 20% sucrose as a food attractant, and 1% boric acid as the toxin, is efficient and highly recommended for ghost ant control.     

The distribution of genes on chromosomes: A cytological approach

Studies during the last 20 years have shown that the chromosomes of many organisms, especially those of higher vertebrates, consist of a series of segments having different properties. These can be recognized as, for example, G- and R-bands. Recent studies have indicated that genes tend to lie in the R-bands rather than in the G-bands, although the number of genes that has been mapped with high precision is, as yet, only a very small proportion of the total, probably much less than 1%. We have therefore sought to study the distribution of genes on chromosomes using a cytological approach in conjunction with “universal” markers for genes. Such markers include mRNA and the gene-rich, G + C-rich H3 fraction of DNA, both of which can be localized using in situ hybridization, and DNase I hypersensitivity, and digestion by restriction enzymes known to show selectivity for the CpG islands associated with active genes, both of which can be detected using in situ nick translation. We have chosen to use the approaches involving in situ nick translation and have shown that the patterns of DNase I hypersensitivity and of CpG islands on human chromosomes show a strict correspondence to R-banding patterns: Deviations from R-banding patterns reported by previous investigators who have made similar studies appear to be attributable to excessive digestion. On the other hand, we have not found the expected differentiation between the active and inactive X chromosomes; this may perhaps be attributable to such factors as the demethylation of some non-island CpGs in the inactive X and the possible alterations of chromatin structure caused by methanol-acetic-acid fixation affecting DNase I hypersensitivity. Presented at the NATO Advanced Research Workshop onGenome Organization and Evolution, Spetsai, Greece, 16–22 September 1992     

Influences on the structure of suburban ant (Hymenoptera: Formicidae) communities and the abundance of Tapinoma sessile

Urbanization can alter the organization of ant communities and affect populations of urban pest ants. In this study, we sampled ant communities in urban and suburban yards to understand the habitat factors that shape these communities and influence the abundance of a common pest species, Tapinoma sessile (Say). We used pitfall traps to sample ant communities and a combination of pitfall traps and baiting to collect T. sessile at 24 sites in Knoxville, TN. In total, we collected 46 ant species. Ant species richness ranged from seven to 24 species per yard. Ant species richness tended to be lowest near houses, whereas T. sessile abundance was highest near houses. The best predictors of ant species richness in yards were canopy cover and presence of leaf litter: ant species richness peaked at mid-levels of canopy cover and was negatively correlated with the presence of leaf litter. Tapinoma sessile abundance increased with presence of logs, boards, or landscaping timbers and leaf litter in yards. Our results indicate that ant communities and the abundance of particular pest species in these urban and suburban landscapes are shaped by many of the same factors that structure ant communities in less anthropogenically disturbed environments.     

Analysis of the local ant fauna (Hymenoptera, Formicidae) in Southern Vietnam

The ant fauna of Nam Cat Tien in the southern part of the Cat Tien Biosphere Reserve (Dong Nai Prov., Southern Vietnam) was studied in 2007–2008. The zonal type of vegetation under study is closed deciduous tropical forests dominated by Lagerstroemia spp. in association with Dipterocarpaceae and Fabaceae. The local ant fauna comprises 272 species from 68 genera and 12 subfamilies. The maximum number of species was found in the genera Polyrhachis (31), Camponotus (21), Pheidole (21), Leptogenys (17), and Crematogaster (13). Seven ant genera (Echinopla F. Sm., Indomyrma Brown, Liomyrmex Mayr, Paratopula Wheeler, Proatta For., Protanilla Taylor, and Rotastruma Bolton) are reported from Vietnam for the first time. The ecological pattern of the ant fauna in the main forest biotopes of the study area is considered. In the dipterocarp forests in the central part of the reserve, the complex of stratobiont species was the most diverse. In the bamboo forests, the stratobiont complex is less diverse but the fraction of dendrobionts is greater. The forests with similar layer structure occurring on sand and loamy soils were shown to differ in the species composition of ant assemblages. Repeated population inventories of ants were carried out in 8 model plots of 100 m2 each during the dry and rainy season. The specificity of revealing species of different biomorphs is discussed in the seasonal aspect. The structure of the ant fauna of Nam Cat Tien is compared to that in other territories of the Oriental Region. The zoogeographic unity of the study area and some localities of the Indo-Malayan Subregion (Borneo, Java) is demonstrated.     

Structure of multi-species ant assemblages (Hymenoptera,Formicidae) in the Mountain Crimea

The multi-species ant assemblages were studied in the Crimea Mountains, in 9 types of plant associations in the plateau pastures as well as on the southern and northern slopes of the Main Range. A list of 18 ant species with data on their distribution in biotopes and also layers and the structure of their foraging territories is given. The hierarchical organization of multi-species ant assemblages and different strategies of nest location of the influents depending on the dominant species and its territoriality were investigated. Territoriality of each dominant species was determined by the frequency of foraging areas without nests of other species. Depending on dominant territoriality and the number of dominant species, the following classification of multi-species assemblages is proposed. (1) Monodominant assemblages with weakly expressed territoriality of the dominant species. Low density of the workers of Camponotus aethiops in the foraging territory determines weak interactions with influent species. The settling pattern of the influents shows no evident dependence on the dominant. Weakly expressed territoriality of the dominant allows non-territorial species to exist on the dominant’s territory. Such species were not found in other types of ant assemblages. (2) Monodominant assemblages with strongly expressed territoriality of the dominant species. The settling pattern of the influents shows the subordinate species to avoid those of higher ranks in the hierarchy, thus decreasing the probability of conflicts. The influents settle in the neutral zones as well as in the foraging territory of the dominant, so as to reduce competition with the subdominant species Formica cunicularia. Such a strategy reduces the probability of interspecific conflicts in biotopes with fewer vegetation layers than in the forests. (3) Bidominant assemblages with a variable dendrobiont dominant are typical among forest assemblages. Coexistence of two dominant species is possible when foraging of one of them is completely or partly restricted to one vegetation layer. The subdominant species avoid settling in the foraging territory of the dominant that occupies the same layer. When the dendrobiont dominant Crematogaster schmidti drops out of the assemblage, it (and its role in the assemblage) is replaced by other dendrobiont species Lasius emarginatus which otherwise acts as the 1st order subdominant in C. schmidti assemblages. (4) Polydominant assemblages are characterized by the presence of as many as 3 dominant species, namely Crematogaster schmidti, Camponotus aethiops, and Plagiolepis tauricus. The coexistence of the dominants is possible due to use of different layers (one species is a dendrobiont, the other two are herpeto-hortobionts), different activity periods (round-the-clock in Crematogaster schmidti, night in Camponotus aethiops, and daytime in P. tauricus), and different size classes of the workers (3rd, 5th, and 1st, respectively). The different size classes of workers reduce competition for food. Thus, when the number of dominant species in the assemblage increases, so does the number of mechanisms facilitating their coexistence.     

The effects of halothane on the DNase I activity in an isolated enzyme preparation and in the DNase I-G actin complex

The effects of halothane on the DNase I activity in an isolated enzyme preparation and in a DNase I-globular (G) actin complex was investigated. DNase I, DNase I-G actin complexes and G actin were exposed to various (0.2–4.0 vol./%) halothane concentrations for 3 h. Thereafter, DNase I was mixed with a DNA solution and the extinction of the acid soluble supernatant of the DNase I assay was determined as a measure of DNase I activity. After 10 min of halothane exposure the DNase I activity is inhibited in direct proportion to halothane concentrations between 0.6 and 4.0 vol/%. After 10 min halothane activates inactive DNase I by inhibiting G actin, an inhibitor of DNase I. G actin, exposed to halothane, does not inhibit the activity of DNase I. The results suggest a mechanism by which halothane may contribute to chromosomal defects and disturbances of DNA metabolism in cells.     

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.     

Polymorphic microsatellite loci in the ponerine ant,Hypoponera opacior (Hymenoptera,Formicidae)

The ant genus Hypoponera, with its high diversity of alternative reproductive tactics, is of particular interest in studies on sexual selection. In the species Hypoponera opacior, winged and wingless males and queens co‐occur and molecular markers are essential to study the reproductive success of these sexual tactics. Primers were developed for five polymorphic microsatellite loci isolated from H. opacior. Their variability was tested on 34 colonies from a population in the United States. Nine to 21 alleles per locus were found with observed heterozygosities between 0.1 and 0.7. A significantly positive F_IS value suggests inbreeding in this ant with predominant intracolonial matings.     

The ant genus Carebara Westwood in the Arabian Peninsula (Hymenoptera,Formicidae)

The ant genus Carebara of the Arabian Peninsula is revised. Carebara abuhurayri Sharaf & Aldawood, 2011 is synonymized under Carebara arabica Collingwood & van Harten, 2001. Carebara arabica is redescribed and a Neotype is fixed based on a specimen collected from southwestern Kingdom of Saudi Arabia. A new species, C. fayrouzae sp. n. is described from Saudi Arabia based on queens, major and minor workers. Keys to major and minor workers of the two Arabian Carebara species are given.     

Worker thermal tolerance in the thermophilic ant Cataglyphis cursor (Hymenoptera, Formicidae)

In the thermophilic ant genus Cataglyphis, species differing in their physical caste system have developed alternative mechanisms to face extreme heat by physiological and/or behavioural adaptations. In this study, we tested whether thermal tolerance is related to worker size in the ant Cataglyphis cursor that presents intermediate worker size compared with previously studied species (size range 3.5–10 mm). Thermal tolerance at two temperatures was tested in the laboratory on colonies originating from two habitats (seaside versus vineyard), known to differ in average worker size. As expected large workers were more resistant to high temperature than small workers, but the effect of worker size on thermal resistance was less pronounced under the more extreme temperatures. The pattern of thermal tolerance was similar in the two habitat types. After controlling for worker size, worker thermal tolerance significantly varied amongst colonies, but this variation was not related to colony size. Our results suggest that a higher thermal tolerance can confer an advantage to larger workers especially during foraging and are discussed in the context of the evolution of worker size in ants.     

Karyotypes, C-banding, and chromosomal location of active nucleolar organizing regions in Tapinoma (Hymenoptera, Formicidae)

The haploid and diploid karyotypes of Tapinoma erraticum (n = 8) and Tapinoma nigerrimum (n = 9) were analyzed using C-banding and observation of NOR sites. C-banding showed the existence of heterochromatin in the paracentromeric regions of all chromosomes. The analysis of NOR sites in these species proved the existence of primary activity NOR in one or two chromosomes, respectively, whereas the other chromosomes showed secondary activity NOR, expressed only in a minority of cells. In both species the NOR were located in paracentromeric regions. These results are discussed in relation to a hypothesis of chromosome differentiation of these species.     

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.     

汉、回、蒙古族拇指类型、环食指长、扣手、交叉臂及惯用手的研究

作者于1996年在内蒙古调查了汉、回、蒙古族5项人类遗传学经典指标(拇指类型、环食指长、扣手、交叉臂、惯用手)。研究结果显示:(1)3个民族间拇指类型、扣手出现率存在显著性差异,交叉臂、惯用手出现率则无显著性差异,环食指长出现率蒙-汉、蒙-回间存在显著性差异;(2)拇指类型、扣手、惯用手出现率无性别间差异,环食指长出现率男女间存在显著性差异;(3)惯用手与扣手、惯用手与交叉臂间存在明显的相互关系,交叉臂与扣手之间则无关;(4)与国外人群比较,3个民族环指长出现率高,交叉臂R型出现率较高,扣手R型出现率较低,惯用手L型出现率高于印度的一些群体。 Abstract:Authors in vestigated 5 general indexes of anthrotogical genetics including pollical type,palmar digital formula,hand clasping,arm folding and handedness in Han,Hui and Mongol nationalities in 1996.The results showed as follows:(1)There were significant differences in the frequency of pollical type and hand clasping in 3 nationalities,but those of arm folding and handedness showed nosignificant difference and the frequencies of palmar digital formula between the Mongol and the Hui revealed significant difference.(2)There were no significant sexual difference in the frequency of pollical type,hand clasping and handedness while the long type (R) of ring finger revealed significant sexual difference.(3)There were obvious correlations between handedness and hand clasping,handedness and arm folding but no relation between arm folding and hand clasping.(4)In comparison with foreign ethnic groups,the 3 nationalities showed higher frequencies of long type (R) of ring finger and right-arm folding but the frequence right-hand clasping revealed slightly lower.The findings showed higher frequence of Left-Handedness than that of Indian population.     

The distribution of cofilin and DNase I in vivo

Actin is the principal component of the cytoskeleton, a structure that can be disassembled and reassembled in a matter of seconds in vivo. The state of assembly of actin in vivo is primarily regulated by one or more actin binding proteins (ABPs). Typically, the actions of ABPs have been studied one by one, however, we propose that multiple ABPs, acting cooperatively, may be involved in the control of actin filament length. Cofilin and DNase I are two ABPs that have previously been demonstrated to form a ternary complex with actin in vitro. This is the first report to demonstrate their co-localisation in vivo, and differences in their distributions. Our observations strongly suggest a physiological role for higher order complexes of actin in regulation of cytoskeletal assembly during processes such as cell division.