Sociobiology: Volume 53, Number 2A, 2009

Feature Articles:

Sociobiology: Volume 53, Number 2B, 2009

Feature Articles:

Revision of the Ant Genus Liometopum (Hymenoptera: Formicidae)

By Israel Del Toro, José A. Pacheco & William P. Mackay

ABSTRACT

Liometopum Mayr is a Holarctic ant genus with representatives in North America, Europe, Asia Minor, India and Asia. This genus has never been completely revised. The most comprehensive taxonomic study was completed in 1905, and only included the North American representatives. In this work we address the taxonomy of the eleven extant taxa and provide descriptions, illustrations, maps and identification keys. Additionally, Discriminant and Canonical Correlation Analyses were used to assess morphometric variation. We recognize the validity of seven species, three are found in North America and the remaining four are found Europe, Asia Minor, India and Asia. The valid species are: Liometopum apiculatum Mayr (= Formica masonia Buckley New Synonym), L. lindgreeni Forel, L. luctuosum Wheeler, L. microcephalum Panzer, L. occidentale Emery, Liometopum orientale Karavaiev, and Liometopum sinense Wheeler (= L. sinense var. sericatum Wheeler New Synonym,= L. dentimandibulum Chang He New Synonym). Liometopum minimum Zhou is shown to be a synonym of Chronoxenus myops (Forel) (New Combination).

KEY WORDS:

Return to top

Three-dimensional Reconstruction of Ovaries of Leaf-cutting Ant (Atta sexdens rubropilosa) Queens (Hymenoptera: Formicidae)

By Jônatas Bussador do Amaral & Gláucia Maria Machado-Santelli

ABSTRACT

In this study, the ovary morphology of newly emerged ant queens of Atta sexdens rubropilosa was studied in whole mount preparations by confocal microscopy. The ovaries are composed of approximately 40 ovarioles, showing non-synchronic oocyte maturation. The terminal filament with clusters of undifferentiated cells was found at the distal end of the ovarioles. Next to this region is the germarium, composed of several elongated cystocytes interconnected by cytoplasmic bridges. The nurse cells (23-28 cells) result from asymmetric mitosis. Cytoskeleton analysis showed F-actin concentrated at the muscle cells of the external tunica and in fusomes inside the ovarioles. Microtubules were concentrated around the nuclei of the nurse and follicular cells. In contrast, the oocytes and the external tunica showed faint staining for tubulin.

KEY WORDS: Hymenoptera, Formicidae, Ovary Development, Oocyte, Nurse Cells, Follicular Cells, Confocal Microscopy

Return to top

Comparison of Tunneling in the Laboratory and Field by the Formosan Subterranean Termite, Coptotermes formosanus (Isoptera: Rhinotermitidae)

By Cory E. Campora & J. Kenneth Grace

ABSTRACT

Differences in tunneling between small groups of Formosan subterranean termite, Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae) foragers in the laboratory and foragers in the field environment were investigated. Groups from two different colonies showed no differences in amount of tunneling and wood consumption under controlled laboratory conditions; however, significant differences in tunneling and feeding were found when comparing the same two colonies in the field. Possible reasons for variation in tunneling rate between field colonies are discussed. Population estimates suggested that colony size could be a factor. Observations on tunneling in the field over a three-day period indicated that tunneling rate may also be related to air temperature, with a lag effect.

KEY WORDS:

Return to top

Control of the Big-headed Ant, Pheidole megacephala (Hymenoptera: Formicidae), In Coffee Fields Using Bait Stations Containing Amdro (Hydramethylnon)

By Alton Arakaki, Glenn Taniguchi, Rogerene Arce, Jari Sugano & Steve Fukuda

ABSTRACT

A commercial bait station was used with Amdro ant bait to control the big-headed ant, Pheidole megacephala in mature coffee orchards. Significant control was achieved within 3 months and total control in 8 months. This study demonstrates the feasibility of baiting strategies to control ants in agriculture using IPM principles that are cost-effective and minimize environmental impact.

KEY WORDS: Pheidole megacephala, big-headed ant, Amdro, bait stations, coffee

Return to top

Intra- and Interspecific Analysis of Genetic Diversity and Phylogeny of Termites (Isoptera) in East China Detected by ISSR and COII Markers

By Yanhua Long, Hui Xiang, Lei Xie, Xing Yan, Meizhen Fan, Qian Wang

ABSTRACT

The genetic diversity of five major widespread termite species in Anhui, Jiangsu and Hunan Provinces were analyzed by inter-simple sequence repeat (ISSR) markers. 145 discernible DNA fragments were produced by using 10 primers, of which 144 (99.31%) were polymorphic loci. The observed number of alleles (na) was 1.9931±0.0830; effective number of alleles (ne) was 1.5661±0.3043; Nei’s gene diversity (h) was 0.3355±0.1363; Shannon’s information index (I) was 0.5065±0.1645. Phylogenetic relationships of all these samples were investigated using cytochrome oxidase subunit II (COII). Based on the presented cluster analysis data obtained by PAUP, all samples can be divided into two groups. And the topology partially coincided with that obtained by data of ISSR matrix via PAUP analysis.

KEY WORDS: termites, genetic diversity, ISSR, COII

Return to top

Foraging of Parachartergus fraternus (Hymenoptera: Vespidae: Epiponini) on Cloudy and Sunny Days

By Germi Porto Santos, José Cola Zanuncio, Evaldo Martins Pires, Fábio Prezoto, José Milton Milagres Pereira & José Eduardo Serrão

ABSTRACT

Foraging dynamics of a colony of Parachartergus fraternus (Gribodo) (Hymenoptera: Vespidae, Epiponini) were evaluated in Viçosa, Minas Gerais State, Brazil on cloudy (low brightness) and sunny (high brightness) days from 07:00 A.M. to 06:00 P.M. when the temperature and relative humidity were registered every 15 minutes. The temperature was milder and the relative humidity higher and with lower variations on the cloudy day with the opposite being registered on the sunny days. The combination of the relative humidity and temperature determined foraging dynamics of P. fraternus. In both situations, the temperature had positive effect and the relative humidity negative effect on foraging activity of P. fraternus.

KEY WORDS: Wasps, foraging dynamics, behavior, colony activity

Return to top

Inquilines and Invertebrate Fauna Associated With Termite Nests of Cornitermes cumulans (Isoptera, Termitidae) in the Emas National Park, Mineiros, Goiás, Brazil

By Diogo Andrade Costa, Rodrigo Assis de Carvalho, Guilherme Ferreira de Lima Filho & Divino Brandão

ABSTRACT

Termite nests are an excellent shelter and food source. Specifically, nests of Cornitermes cumulans are large and hard, and attract many animal species. Two quadrats of 2.25 ha-1 were built and all nests of C. cumulans within them were opened to verify the presence of termitophile fauna. All species found belonged to phylum Arthropoda, classes: Arachnida, Chilopoda, Diplopoda and Insecta, including other termites. Some of them were already registered as present in termite nests, while others were not found in the available literature.

KEY WORDS: Cerrado, Cornitermes, inquilines, termites, termitophiles

Return to top

Composition of the Ant Fauna (Hymenoptera: Formicidae) in Public Squares in Southern Brazil

By C.B. Munhae, Z.A.F.N. Bueno, M.S.C. Morini & R.R. Silva

ABSTRACT

The composition of the ant fauna was examined in public squares of three municipalities that compose the hydrographic basin of the Upper Tietê River: Biritiba Mirim, Salesópolis, and Mogi das Cruzes. Richness, frequency of occurrence, similarity, and influence of seasons on the species composition were examined. The method was standardized as sampling units consisted of a set of three baits arranged in a triangle with vertices two meters apart. Sardines in oil were used as attractant. A total of 86 species was collected. Myrmicinae and Pheidole were the richest subfamily and genus, respectively. Eighty species were collected in Mogi das Cruzes, 49 in Salesópolis, and 45 in Biritiba Mirim, with 34 species common to the three areas. The ordination analysis (NMDS) revealed the presence of two distinct communities: one in Mogi das Cruzes and another in Biritiba Mirim-Salesópolis. These data were supported by the dendogram based on the Bray-Curtis dissimilarity index. This result might be associated with the distinct geographic and demographic characteristics of the areas. Regarding seasonality, the composition of the fauna of Mogi das Cruzes is independent of the season of the year, unlike the observed in Biritiba Mirim and Salesópolis.

KEY WORDS: Formicidae; Upper Tietê River; Urban Ecosystem; Public squares

Return to top

Hymenoptera Communities in an Agroecosystem Using Direct Seeding in Southeastern Brazil

By T. O. Mentone, M.S.C. Morini, L. Souza & S.M.P. Braga

ABSTRACT

Hymenoptera is one of the largest orders of insects and comprises wasps, bees, and ants. With the intensification of agriculture and consequently simplification of the structure of agricultural landscapes, this group has received more attention, as it contains key species to the structure of ecosystems such as ants and wasps that control phytophagous insects or bees pollinating the native vegetation. This study aimed at examining the communities of two taxa of Hymenoptera in an agricultural area using direct seeding in Rio Claro city, southeastern São Paulo, with Moericke traps, focusing on the abundance of parasitoids and richness of Formicidae. A total of 5308 parasitoid hymenopterans was collected, comprising 8 superfamilies and 22 families; Mymaridae was the most abundant. Among Formicidae, 6039 individuals, 38 morphospecies, 19 genera, 16 tribes, and 7 subfamilies were collected; Myrmicinae was the richest. The composition of these communities as a result of direct seeding and the importance of the use of Moericke traps in environmental monitoring are discussed.

KEY WORDS: parasitoids, Formicidae, Moericke, richness, abundance

Return to top

A New Species of Carpenter Ant (Hymenoptera: Formicidae: Camponotus) from Paraguay with a Key to the New World Members of the maculatus Species Complex

By William Mackay & Thibaut Delsinne

ABSTRACT

A new ant species, Camponotus taniae, is described from the semi-arid region of Paraguay. This species is very similar to the widespread and common C. conspicuus zonatus, but the minor workers can be separated as the head is narrowed posteriorly, not rectangular-shaped as in C. conspicuus zonatus minors. The major worker and female are essentially identical to those of C. conspicuus zonatus. The male is unknown. A key is provided to separate this new species from the other New World members of the maculatus species complex.

KEY WORDS:

Return to top

Reassessing the Role of Fallen Branches as Part of Leaf-Cutting Ant (Hymenoprera: Formicidae) Trails on Leaf Transport Rates

By H. Mogollón & A. G. Farji-Brener

ABSTRACT

We analyzed the role of fallen branches as part of trunk trails in the leaf-cutting ant Atta cephalotes. Laden ants walked faster along a fallen branch than along trails, but were slower when ascending or descending a fallen branch. When this delay is included, the estimation of the reduction of travel time at the colony level drops up to 60% with respect to earlier measurements. To maximize foraging efficiency, leaf-cutting ants should select long fallen branches.

KEY WORDS: Ants, Costa Rica, foraging costs, tropical rain forests, trunk-trails

Return to top

Large Nest of Polistes dominula (Hymenoptera:Vespidae) Found in Los Angeles County, California

By Hanif Gulmahamad

ABSTRACT

The chronological distributional record of the introduction and spread of Polistes dominula (Christ) (Hymenoptera: Vespidae) in California is discussed. A survey of the major Entomology Collections/Museums/Databases was conducted in California to obtain data on records of this species in the state. The discovery of an unusually large nest of this wasp in Los Angeles County, California is described. Some potential impacts of this invasive wasp on endangered species, threatened species, and species of special concern are discussed.

KEY WORDS:

Return to top

Nest Distribution and Food Preferences of Ectatomma ruidum (Hymenoptera: Formicidae) in Shaded and Open Cattle Pastures of Colombia

By Carlos Santamaría, Inge Armbrecht & Jean-Paul Lachaud

ABSTRACT

Ectatomma ruidum is a common ground-dwelling ant species in the Neotropics which has been reported as a potential biocontrol agent in maize and coffee-cocoa agroecosystems in Mexico and Nicaragua. Its spatial distribution and food preferences were evaluated between February and May 2007, both in shaded (with tree cover) and sunny (open) cattle pastures in the Pescador and El Palmar regions of southwestern Colombia. Two sunny and two shaded cattle pasture plots were selected at each region. Twenty consecutive, equilateral 25 m² parcels were established at each plot. Nest locations were found by following trails from 20 equidistant tuna baits per parcel. The procedure was repeated during the wet and dry seasons with a total of 16 plot records. For determining food preferences, a paper disk providing five live ticks, five honey droplets and five Passiflora ligularis seeds was placed 30 cm away from the nest entrance, at one nest for each of 15 parcels per plot. Nest distribution was aggregated in shaded pastures, with an average nest density of 568 nests/ha, whereas it was mainly random in sunny pastures, with an average nest density of 1945 nests/ha. Whatever the season, E. ruidum nested preferentially in open places in both regions, apparently avoiding soil surfaces under the tree canopy cover in shaded pastures. This could explain the aggregated pattern recorded in these pastures despite some intraspecific competition. Foragers demonstrated a high capacity as seed dispersers, the myrmecochoric P. ligularis seeds representing 74.7% of the total weight of all food items removed. Comparatively, they were significantly less attracted by honey and ticks which were retrieved in similar quantities (14.3% and 11.0% of the total weight removed, respectively). In the course of this study, individual workers were observed carrying in their mandibles wild, natural ticks, captured in the field. This is the first report of ants naturally preying on ticks in Colombia. Our data confirm the status of E. ruidum as an important natural biocontrol agent which could be properly managed for ecological services in Neotropical agroecosystems.

KEY WORDS: Andean mountains, ant spatial distribution, Ectatomma ruidum, land management, open pastures, predation on ticks, shaded pastures, seed dispersion

Return to top

New Record of Messor chicoensis (Hymenoptera: Formicidae) from the San Joaquin Valley of California

By Christopher A. Hamm & Bobby Kamansky

ABSTRACT

New distributional data for Messor chicoensis are presented and discussed in reference to vernal pool and nature preserves in the San Joaquin Valley of California. This discovery extends the range of M. chicoensis approximately 450km south and allows for the possibility that this ant was historically distributed throughout the Sacramento and San Joaquin Valleys of California.

KEY WORDS: Messor chicoensis, M. stoddardi, distribution, vernal pools, California

Return to top

Harvester Ants (Hymenoptera: Formicidae) Discriminate Among Artificial Seeds with Different Protein Contents

By Walter G. Whitford & Yosef Steinberger

ABSTRACT

Workers of colonies of the western harvester ant, Pogonomyrmex occidentalis, were recruited to patches of artificial seed of the same caloric value but different protein content. Rates of forager returns with artificial seeds containing five percent protein were nearly twice those of zero percent protein. Differences in foraging rates on artificial seeds of ten and twenty percent protein compared to foraging rates on zero percent protein seeds were not different from the comparison of foraging rates on five percent and zero percent protein seeds. There were no differences in foraging rates on zero percent protein seeds, 0.5 percent and one percent protein seeds. P. occidentalis presented with patches containing equal amounts of zero, five, ten, and twenty percent protein seeds returned equal amounts of each protein content seed type to the colonies. When presented with high quality seed patches in the same location for four successive days, the rates of forager returns increased over time. When seed patch locations were switched, P. occidentalis' rate of return of zero protein content seeds was the same as for the five percent protein seeds at that location the previous day. Seeds with protein content between one and two percent represent a threshold for seed quality that affects the foraging rate of P. occidentalis workers.

KEY WORDS: Harvester ants, Pogonomyrmex occidentalis, protein, food choices

Return to top

Ascertaining Key Factors Behind the Coexistence of the Native Ant Species Plagiolepis pygmaea with the Invasive Argentine Ant Linepithema humile (Hymenoptera: Formicidae)

By Sílvia Abril & Crisanto Gómez

ABSTRACT

The Argentine ant, Linepithema humile, is a world-wide invasive ant species. Its presence has a strong negative impact on ant diversity. The present study attempts to highlight the reasons for the coexistence of this highly dominant species with Plagiolepis pygmaea, the only native ant species that has proved able to resist the invasion in a natural ecosystem in the north-east of the Iberian Peninsula. To quantify the aggressiveness level of both species we performed aggressiveness tests on workers in different areas: a) Argentine ant workers from areas with P. pygmaea, b) Argentine ant workers from areas without P. pygmaea, c) P. pygmaea from a non-invaded area and d) P. pygmaea from an invaded area. We also confronted Argentine ant workers with P. pallidula and T. nigerrimum. These aggressiveness tests showed that the coexistence of these two species of ants was not due to a habituation process, since the aggressiveness level observed between the four kinds of confrontations were fairly similar. We also found a lack of aggressiveness between Argentine ant workers and P. pygmaea, and highly submissive behavior in the latter when confronted with the invader. The peaceful character of P. pygmaea together with its markedly submissive behavior may be the main factors behind the coexistence of these species in the study area.

KEY WORDS: Aggressiveness, coexistence, dominance hierarchy, Linepithema humile, P. pygmaea

Return to top

Unusual Nesting Behavior in a Neotropical Stingless Bee, Nannotrigona testaceicornis (Hymenoptera: Apidae)

By Lívia Cabral de Castro Paula Netto Silva & Fábio Prezoto

ABSTRACT

This study describes the occurrence of conflicts for the ownership among the bees of an active colony of Nannotrigona testaceicornis (Lepeletier) and the members of a nearby swarm of the same species. The swarm bees that tried to invade the colony were stopped by the guards of the active nest. The invasion attempt phenomenon registered in this study demonstrates a behavioral strategy of N. testaceicornis that suggests an energy economy in the construction phase by the acquisition of a nest in an earlier development phase.

KEY WORDS: stingless bee; behavior; nest occupation; interactions

Return to top

Laboratory Bioassays with Subterranean Termites (Isoptera) – The Importance of Termite Biology

By Michael Lenz

ABSTRACT

Subterranean termites are frequently used in bioassays to assess the effectiveness of biocides and the susceptibility or otherwise of materials to their attack. Termites which appear to be vigorous with high inherent levels of activity are often relied upon, yet by the end of the experiments their survival may be very unsatisfactory, even in unchallenged control groups. Results from such bioassays may thus be meaningless.

Factors that can influence vigorous performance and termite survival such as colony origin; quality of the termite supply; group composition and size; the physical environment under which termites are held and the amount of food offered are discussed. The conclusion is that performance of a given termite source must be judged against standard and accepted levels of activity (i.e. for survival and wood consumption). Only if the experimental termites reach or exceed such minimum standards can a researcher be assured of the adequacy of the termite supply for the experiment in hand, and hence the reliability of the results of assessments for which termite vigor is such a vital part.

KEY WORDS: effectiveness of biocides, resistance of materials, performance standards for laboratory bioassays, subterranean termites

Return to top

Diversity of Bees (Hymenoptera: Apoidea) in a Cerrado Area in the City of Cassilândia, Mato Grosso do Sul, Brazil

By Gustavo Haralampidou da Costa Vieira & Luís Carlos Marchini

ABSTRACT

The aim of this study was to determine the patterns of bee communities in an area of native vegetation (“cerrado”) at the campus of Universidade Estadual de Mato Grosso do Sul, in the city of Cassilândia/MS (19°06'48''S; 51°44'03''W). The insects were collected fortnightly from March/2003 to February/2004 and were caught by systematic captures in flowering plants, along a 3kilometer trail. The bee community was represented by 501 individuals, belonging to 4 families, 7 subfamilies, 12 tribes, 22 genera, and 35 species. The abundance of species was comparable with the pattern found in neotropical communities, which are characterized by presenting many species with a few individuals and a few species with abundant individuals. The latter is represented by Apis mellifera and Trigona spinipes.

KEY WORDS: Apidae, community, faunistic analysis

Return to top