Ants

Ananas comosus var comosus (L.) Merr. is the third most important tropical fruit in the world production and the leading foreign exchange earner among fresh fruits exported from Ghana. A survey was conducted in pineapple farms in the Central region of Ghana to identify floral visitors and their activities on the flowers. Nectar concentration and energetics and effect of floral visitors on fruit production were determined. Fourteen species of butterflies and one ant species were the main insect floral visitors as well as four species of sunbirds. The mean nectar concentration was 23.3% (± 0.39, SE) and pollination limitation did not significantly affect fruit yield (weight: p = 0.285; length: p = 0.056; width: p= 0.268). The study showed that butterflies, ants and sunbirds are the main floral visitors on A. comosus. However their visits did not results in pollination and fruit production was not affected in any way by floral visitation. Still, it was found that A. comosus provides an important nectar resource for its foragers. Even if pollination is not crucial in pineapple cultivation, it is still essential in pineapple breeding programs to promote genetic diversity and conservation.

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Invasive species can indirectly affect ecosystem processes via the disruption of mutualisms. The mutualism between the whistling thorn acacia (Acacia drepanolobium) and four species of symbiotic ants is an ecologically important one; ants strongly defend trees against elephants, which can otherwise have dramatic impacts on tree cover. In Laikipia, Kenya, the invasive bigheaded ant (Pheidole megacephala) has established itself at numerous locations within the last 10-15 years. In invaded areas on five properties, we found that three species of symbiotic Crematogaster ants were virtually extirpated, whereas Tetraponera penzigi co-occurred with P. megacephala. Tetraponera penzigi appears to persist because of its non-aggressive behavior; in a whole-tree translocation experiment, Crematogaster defended host trees against P. megacephala but were extirpated from trees within hours. In contrast, T. penzigi retreated into domatia and withstood invading ants for >30 days. In the field, the loss of defensive Crematogaster ants in invaded areas led to a five-to seven-fold increase in the number of trees catastrophically damaged by elephants compared to un-invaded areas. In savannas, tree cover drives many ecosystem processes and provides essential forage for many large mammal species; thus, the invasion of bigheaded ants may strongly alter the dynamics and diversity of East Africa's whistling thorn savannas by disrupting this system's keystone acacia-ant mutualism.

Nosocomial infections bring a high risk to the health of hospital patients and employees. Ants are common organisms in Brazilian hospitals, where they can act as dispersers of opportunistic microorganisms in places they forage. The occurrence of multi-resistant bacteria carried by ants was analyzed in two public hospitals (HA and HB) in southeastern Bahia, Brazil. In these two hospitals 132 workers belonging to three ant species were collected. The bacteria associated to these ants were identified and their susceptibility to antibiotics was evaluated. More than half (57.3%) of ants collected in HA were associated with some kind of bacteria, with 26.7% of them being opportunist bacteria, while 84,2% of the ants from HB presented associated bacteria growth, with 61.4% of them being opportunist bacteria. Twenty four species of bacteria were isolated. The Gram-positive bacilli of the genus Bacillus were the most frequent, followed by the Gram-positive cocci, Gram-negative bacilli (family Enterobacteriaceae) and Gram-negative non-fermenters bacilli. The profile of sensitivity of the bacterial isolates to drugs pointed out the existence of multi-resistant isolates carried by ants. For the first time, are reported cases of the same bacterial resistant isolates taken form homospecific ant workers that point out the importance of ants to bacteria dissemination and proliferation in a hospital. Our results suggest that the risk of contamination presented by these ants is similar to the one of any other mechanical vector of bacterial dissemination.

Some species of the fungal genus Ophiocordyceps that parasitize ants have evolved some degree of behavioral manipulation to increase their own transmission. Carpenter ants (Camponotus spp.) infected by Ophiocordyceps unilateralis species climb vegetation and bite leaves or other plant parts before death, while other ants infected by other Ophiocordyceps species die buried within or on the leaf-litter, attached to stems and tree trunks. The microenvironment of the host's death location is important for fungal development and dispersal to new hosts, being an interesting example of an extended phenotype. This study investigated the effect of humidity variation in space (15 km 2) and time (14 months) on the occurrence and expression of the extended Ophiocordyceps phenotype parasitizing ants in Central Amazonia. We found O. unilateralis s.l., O. kniphofioides s.l. and O. australis s.l. parasitizing 30 ant species, but O. unilateralis s.l. was by far the most abundant fungus. Parasitized Camponotus atriceps and C. bispinosus were more abundant and died in higher places in periods with greater air humidity. Otherwise, the abundance and height of C. senex cadavers were higher in drier plots. These results provide insights on how the spatial and temporal variation in air humidity may shape the occurrence and behavioral manipulation of ants infected by entomopathogenic fungi at larger scales.

Abstract.  1. We analysed ant species richness-environment relationships across the Subantartic-Patagonian transition, in southern South America. We tested the predictions of the (i) thermal limitation hypothesis: temperature limits ant species richness, (ii) the productivity hypothesis: ant richness is driven by the indirect effect of climate (temperature and precipitation) mediated by changes in plant environment (plant cover and litter accumulation). We also evaluated the effects of (iii) plant species richness, and (iv) habitat use by cattle on richness.2. We collected ants using 450 pitfall traps within a ∼150 × 150 km area. We used path analysis to evaluate the associations of ant richness with environmental predictors. We evaluated the influence of local abundance variation on richness-environment relationships; we applied principal co-ordinates of neighbour matrices to model the spatial autocorrelation in the data and combined spatial and ecological descriptors of ant richness into partial regression.3. Ant richness responded positively to indirect effects of precipitation mediated by shrub cover and tree cover, towards the west, and by litter accumulation, towards the east of the transition. Direct climatic effects on richness were negative or weak throughout. The local increase in plant species richness and habitat disturbance by cattle promoted an increase in ant richness, mostly towards the east of the transition. These results were not seriously affected by variation in local abundance and the spatial autocorrelation in the data.4. We suggest that climate, either directly or indirectly, through its biological effect on plant environment interacts with micro-spatial variation in habitat heterogeneity and disturbance to account for ant species diversity across this transition.

Species range boundaries often form along environmental gradients that dictate the success of the phenotypes present in each habitat. Sociality may allow colonization of environments where related species with a solitary lifestyle cannot persist. Social spiders in the genus Anelosimus appear restricted to low-and mid-elevation moist environments in the tropics, while subsocial spiders, common at higher elevations and latitudes, appear to be absent from the lowland tropical rainforest. Here, we seek factors that may simultaneously prevent subsocial Anelosimus species from colonizing the lowland rainforest while favouring species with large social groups in this habitat. To this end, we transplanted small groups of a subsocial species, which contain the offspring of a single female, from cloud forest habitat in the centre of its natural range to lower montane rainforest on the range margin and to lowland rainforest outside of the species range. Groups transplanted at the range margin and below their range limit were less likely to disperse and experienced increased mortality. This was correlated with greater rainfall intensity and ant abundance. We show that protection from rainfall enhances the performance of small groups of spiders in the lowland rainforest, and suggest that predation or disturbance by ants may influence the geographical range limits of this species.

Leaf-cutting ants (Atta spp.) are known for their extensive defoliation in neo-tropical forests and savannahs. Debate about the costs and benefits of their activities has been largely dominated by their detrimental effects on agriculture and agroforestry. However, the large accumulation of nutrients and changes in soil properties near their nests might benefit plants growing near them. Here, we test whether trees use nutrients that accumulate in debris piles near, or refuse chambers within, leaf-cutting ant nests. At two tropical sites (a moist tropical forest site in Panama and a savannah site in Brazil), we fed leaves labelled with the stable isotope 15N to two species of leaf-cutting ants (Atta colombica and Atta laevigata) and traced the stable isotope label in plants surrounding the two nests. Thus, we show that plants in both sites access resources associated with Atta nests. In addition, leaf tissue of trees near the nests labelled with 15N had significantly higher calcium co...

In the most highly contaminated region of the Chernobyl Exclusion Zone: the 'Red Forest' site, the accumulation of the major dose-affecting radionuclides (90 Sr and 137 Cs) within the components of an ecological system encompassing 3,000 m 2 were characterized. The sampled components included soils (top 0-10 cm depth), Molina caerulea (blue moor grass), Camponotus vagus (carpenter ants) and Pelobates fuscus (spade-footed toad). In a comparison among the components of this ecosystem, the 90 Sr and 137 Cs concentrations measured in 40 separate grids exhibited significant differences, while the frequency distribution of the values were close to a logarithmically normal leptokurtic distribution with a significant right-side skew. While it is important to identify localized areas of high contamination or "hot spots," including these values in the arithmetic mean may overestimate the exposure risk. In component sample sets that exhibited logarithmically normal distribution, the geometrical mean more accurately characterizes a site. Ideally, risk assessment is most confidently achieved when the arithmetic and geometrical means are most similar, meaning the distribution approaches normal. Through bioaccumulation, the highest concentrations of 90 Sr and 137 Cs were measured in the blue moor grass and spade-footed toad. These components also possessed distribution parameters that shifted toward a normal distribution.

RATIONALE: Traditionally, stable isotope analysis of plant and soil water has been a technically challenging, labourintensive and time-consuming process. Here we describe a rapid single-step technique which combines Microwave Extraction with Isotope Ratio Infrared Spectroscopy (ME-IRIS). METHODS: Plant, soil and insect water is extracted into a dry air stream by microwave irradiation within a sealed vessel. The water vapor thus produced is carried to a cooled condensation chamber, which controls the water vapor concentration and flow rate to the spectrometer. Integration of the isotope signals over the whole analytical cycle provides quantitative δ 18 O and δ 2 H values for the initial liquid water contained in the sample. Calibration is carried out by the analysis of water standards using the same apparatus. Analysis of leaf and soil water by cryogenic vacuum distillation and IRMS was used to validate the ME-IRIS data. RESULTS: Comparison with data obtained by cryogenic distillation and IRMS shows that the new technique provides accurate water isotope data for leaves from a range of field-grown tropical plant species. However, two exotic nursery plants were found to suffer from spectral interferences from co-extracted organic compounds. The precision for extracted leaf, stem, soil and insect water was typically better than ±0.3 ‰ for δ 18 O and ±2 ‰ for δ 2 H values, and better than ±0.1 ‰ for δ 18 O and ±1 ‰ for δ 2 H values when analyzing water standards. The effects of sample size, microwave power and duration and sample-to-sample memory on isotope values were assessed. CONCLUSIONS: ME-IRIS provides rapid and low-cost extraction and analysis of δ 18 O and δ 2 H values in plant, soil and insect water (≈10-15 min for samples yielding ≈ 0.3 mL of water). The technique can accommodate whole leaves of many plant species.

In order to decrease the risk of pathogen transmission, ants remove corpses from the vicinity of nests, but little is known about the underlying mechanisms. In particular, it is unclear how the odor profile of corpses changes with time since death and how any changes might relate to behavior. We have addressed these questions in the red ant Myrmica rubra, where we asked how the time since death determines the ability of workers to discriminate a dead individual from a live one, and whether dead workers are removed in a similar way when they originate from the same or an alien colony. We found that ants could discriminate alien from nestmate corpses up to 2 days after death, since the former continued to elicit aggressive behavior over that period. For dead nestmates, only 15 % of corpses were removed when freshly killed but this rises to 80 % for corpses between 1 to 6 days post mortem. Using gas chromatography, we found that oleic and linoleic acids, which are absent on freshly killed corpses, appeared post mortem and were in higher quantities on those corpses that were ejected from the nest vicinity. When added to fresh corpses, linoleic and oleic acids, alone or blended, enhanced removal to levels observed for corpses of 2-6 days postmortem. Thus, oleic and linoleic acids appear to be important cues involved in corpse recognition and necrophoresis over a long timeframe, and we advance the hypothesis that these fatty acids in combination with other cues may also trigger other behaviors such as prey retrieval.

We determined the size characteristics of foragers of the leaf-cutting ant Atta sexdens in a mature eucalyptus forest in Campos dos Goytacazes, Rio de Janeiro State, Brazil, at daytime (7: 30 to 10: 00 hr) and nighttime (19: 00 to 23: 00 hr). There were no significant differences between daytime and nighttime ant mass (Ma), but leaf fragment mass (Ml) and burden (B = [Ma + Ml]/Ma), which indicates relative load capacity, were significantly greater at daytime. There was a positive linear relationship between Ma and Ml for the combined daytime and nighttime data, and increases in Ma resulted in lower B. We compared A. sexdens characteristics with published results for Atta cephalotes, a closely related species. A. sexdens is larger and therefore able to carry heavier loads, but its burden is about 72% of the average value for A. cephalotes. We suggest that the lower load capacity of A. sexdens in comparison to A. cephalotes is related to its relatively larger size.<br>Nós determ...

En este trabajo se ha comparado la organización de los lóbulos antenales (LAs) y su representación topográfica en los cuerpos fungiformes (CFs) en soldados de dos especies de hormigas, Atta mexicana y Camponotus ocreatus. La comparación morfológica sugiere que los LAs de A. mexicana podrían ser más especializados que los de C. ocreatus a expensas de capacidades más generales. En ambas especies, el LA está organizado en seis grupos de glomérulos, cada uno inervado por su propio tracto. La inervación de las neuronas de proyección (NP), las cuales conectan los LAs con los CFs a través de los tractos antenoprotocerebrales (TAP), divide el LA en dos regiones, anterior y posterior. Los cálices de los CFs tienen varias capas que reciben información olfativa segregada: NP que inervan los grupos anteriores de glomérulos envían axones a través del TAP-lateral hacia el cuerno lateral (CL) y después hacia la capa interna del cáliz, mientras que las NP que inervan los grupos posteriores de glomérulos envían axones a través del TAP-medial a la capa externa del cáliz y después al CL. Estos resultados muestran que la organización del LA está representada topográficamente en los CFs formando un mapa odotópico. Las dos vías que conectan los LAs con los CFs podrían representar dos canales para el procesamiento de diferentes clases de olores o diferentes propiedades de los estímulos olfativos. Los resultados neuroanatómicos sugieren una organización funcional conservada en los himenópteros sociales.

A previous report of the discovery of exocrine glands in the antennal club of queens and workers of Solenopsis invicta Buren, 1972 left open the question of the extent to which similar glands occur in the Formicidae family. We wanted to know if these antennal glands are unique to Solenopsis, or they are found in a wider taxonomic group. Using scanning electron microscopy, we examined the antennae of 41 ant species. Presence of the antennal glands was indicated by a characteristic circumferential ring of pores in a distal antennal segment of workers. Pores were found in the 9th antennal segment of all 26 species of Solenopsis examined. Pores were absent in the following: Monomorium minimum, M. pharaonis, Pheidole sp., Crematogaster sp., Linepithema humile, Forelius sp., Dorymyrmex sp., Paratrechina sp., Oecophylla smaragdina, Campanotus sp., Ectatomma ruidum, E. tuberlatum, and Pseudomyrmex ferruginea. However, pores were found in the antennal club of Tetramorium bicarinatum workers and queens. After KOH digestion of T. bicarinatum antennae, internal canals were observed in both workers and queens, and the canals are connected to spherical reservoirs in queens. T. bicarinatum was the only non-Solenopsis species examined, which showed evidence for antennal glands in the distal funiculus. Microsc. Res. Tech., 2008. © 2008 Wiley-Liss, Inc.

A B S T R A C T Changes in land-use and climate increase the flammability of forests across southeast Amazonia, potentially driving abrupt fire-mediated transitions to derived savannas – grass-dominated degraded forests with scattered trees. However, the extent to which the forest fauna undergoes a parallel process remains poorly understood. Here we test the hypothesis that the process of fire-driven forest shifts towards derived savannas has congruent cascading effects on ant communities by causing declines in forest specialists and an influx of open-habitat taxa. In 2013 we collected ants using subterranean, epigaeic and arboreal pitfall traps in three adjacent 50-ha plots: an unburnt control and two treatment plots that were burnt either triennially or annually from 2004 to 2010. Frequent fire was associated with a marked decline of specialist forest species (almost 50%), and an influx of open-habitat taxa that were absent from the unburnt plot. The effects were particularly pronounced for epigaeic ants: their abundance, biomass, species richness and species composition were impacted by fires, and this was the main stratum occupied by the open-habitat species. Previous studies have shown that a similar conversion is not triggered by single fires, and they therefore require recurrent fires. Our results provide experimental evidence that the process of tropical forest conversion towards derived savannas caused by repeated burning is a broad one that affects not only plants, but involves parallel compositional shifts of animal communities. The prevention of recurrent fires is a priority challenge for avoiding widespread biotic conversion of tropical forests to derived savannas.

Insect societies -colonies of ants, bees, wasps and termites -vary enormously in their social complexity. Social complexity is a broadly used term that encompasses many individual and colony-level traits and characteristics such as colony size, polymorphism and foraging strategy. A number of earlier studies have considered the relationships among various correlates of social complexity in insect societies ; in this review, we build upon those studies by proposing additional correlates and show how all correlates can be integrated in a common explanatory framework. The various correlates are divided among four broad categories (sections). Under ' polyphenism ' we consider the differences among individuals, in particular focusing upon ' caste ' and specialization of individuals. This is followed by a section on ' totipotency ' in which we consider the autonomy and subjugation of individuals. Under this heading we consider various aspects such as intracolony conflict, worker reproductive potential and physiological or morphological restrictions which limit individuals ' capacities to perform a range of tasks or functions. A section entitled ' organization of work ' considers a variety of aspects, e.g. the ability to tackle group, team or partitioned tasks, foraging strategies and colony reliability and efficiency. A final section, ' communication and functional integration ', considers how individual activity is coordinated to produce an integrated and adaptive colony. Within each section we use illustrative examples drawn from the social insect literature (mostly from ants, for which there is the best data) to illustrate concepts or trends and make a number of predictions concerning how a particular trait is expected to correlate with other aspects of social complexity. Within each section we also expand the scope of the arguments to consider these relationships in a much broader sense of ' sociality ' by drawing parallels with other ' social ' entities such as multicellular individuals, which can be understood as ' societies ' of cells. The aim is to draw out any parallels and common causal relationships among the correlates. Two themes run through the study. The first is the role of colony size as an important factor affecting social complexity. The second is the complexity of individual workers in relation to the complexity of the colony. Consequently, this is an ideal opportunity to test a previously proposed hypothesis that ' individuals of highly social ant species are less complex than individuals from simple ant species ' in light of numerous social correlates. Our findings support this hypothesis. In summary, we conclude that, in general, complex societies are characterized by large colony size, worker polymorphism, strong behavioural specialization and loss of totipotency in its workers, low individual complexity, decentralized colony control and high system redundancy, low individual competence, a high degree of worker cooperation when tackling tasks, group foraging strategies, high tempo, multi-chambered tailor-made nests, high functional integration, relatively greater use of cues and modulatory signals to coordinate individuals and heterogeneous patterns of worker-worker interaction.

Understanding how anthropogenic disturbance influences patterns of community composition and the reinforcing interactive processes that structure communities is important to mitigate threats to biodiversity. Competition is considered a primary reinforcing process, yet little is known concerning disturbance effects on competitive interaction networks. We examined how differences in ant community composition between undisturbed and disturbed Bornean rainforest, is potentially reflected by changes in competitive interactions over a food resource. Comparing 10 primary forest sites to 10 in selectively-logged forest, we found higher genus richness and diversity in the primary forest, with 18.5% and 13.0% of genera endemic to primary and logged respectively. From 180 hours of filming bait cards, we assessed ant-ant interactions, finding that despite considered aggression over food sources, the majority of ant interactions were neutral. Proportion of competitive interactions at bait cards did not differ between forest type, however, the rate and per capita number of competitive interactions was significantly lower in logged forest. Furthermore, the majority of genera showed large changes in aggression-score with often inverse relationships to their occupancy rank. This provides evidence of a shuffled competitive network, and these unexpected changes in aggressive relationships could be considered a type of competitive network re-wiring after disturbance.

In Formica Malpighian tubules KC1 secretion is driven by a V-type H + ATPase in the luminal membrane in parallel with a H+/K + antiporter. The effect of the protonophore dinitrophenol (DNP) was investigated on the isolated, symmetrically perfused tubule. DNP was applied in two different concentrations : 0.2 mmol/1 and 1 mmol/1. The effects were fast and rapidly reversible. The equivalent short-circuit current (/so) was reduced significantly to respectively 25---3% Cn = 4) and -3 -7% (n = 11) of the control value when 0.2 mmol/ 1 or 1 mmol/1 was added to the bath. When 1 mmol/1 DNP was applied the transepithelial resistance (Rt~) decreased significantly to 74 _+ 11% of the control value (n = 11), and the luminal over basolateral voltage divider ratio (VDR), providing an estimate of luminal over basolateral membrane resistance, decreased to 37 _ 12% of the control (n = 6). A concentration of 1 mmol/1 DNP was also applied from the lumen. The decrease in Lc was significant, but much less pronounced (74 _ 5% of control; n = 6) and no significant changes in Rte and VDR were observed. It is argued that, when the concentration in the bath is high enough, DNP may cross the cell and have a protonophoric effect not only on the mitochondria but also across the luminal cell membrane explaining the drop in transepithelial and in relative luminal membrane resistance. The diminished effectiveness of DNP, when applied from the luminal side, suggests that the luminal membrane is somehow less permeable to toxic substances, but that DNP very rapidly enters the cell via the basolateral membrane and may bring about an initial protonophoric effect across this membrane.

Among social Hymenoptera, only some ant genera have more than one morphological kind of nonreproductive adults. Individuals that are bigger than ordinary workers can function for defence and/or food storage. In Crematogaster (Orthocrema) smithi from Arizona, a third caste exists in addition to winged queens and workers; it is intermediate in size, weight and morphology, and individuals lay many unfertilized eggs that are mostly eaten by larvae . We studied another three species belonging to the subgenus Orthocrema: Crematogaster pygmaea from Brazil, Crematogaster biroi and Crematogaster schimmeri from Taiwan. Using scanning electron microscopy and ovarian dissections, we show that 'intermediates' are a patchwork of queen-like and worker-like traits, just as in C. smithi; importantly the combinations differ across species. 'Intermediates' are numerically few in the colonies, and in C. pygmaea they are produced seasonally. Using histology we confirmed the lack of a spermatheca, thus they are not ergatoid queens. Based on the similarity of their mosaic phenotypes with those in other ant lineages, we suggest that Orthocrema 'intermediates' are a soldier caste with a specialized trophic function. This soldier caste has been reported in other Orthocrema species from Madagascar, Guinea and Costa Rica, suggesting that it is widespread in this subgenus.

A new ant species of Megalomyrmex conducts mass raids to usurp gardens of the fungus-growing ant Cyphomyrmex longiscapus, then lives in the gardens and consumes the cultivated fungus. Unlike attine ants, however, Megalomyrmex sp. does not forage for substrate to manure the gardens; therefore, when gardens become depleted, Megalomyrmex sp. must locate and usurp new gardens. Megalomyrmex sp. workers feed their larvae with attine brood, but only after removing the fungal mycelium that covers the attine larval integument, suggesting that this fungal coat may provide partial protection against other predators. Unlike other known Megalomyrmex species, which coexist as social parasites in attine colonies, Megalomyrmex sp. expels its attine hosts during the garden raids. Megalomyrmex sp. thus maintains a unique agro-predatory lifestyle that is described here for the first time.

We compared the ant assemblages from four very heterogeneous habitats over a short-distance elevational gradient of vegetation (due to the presence of an inselberg) at the Nouragues Research Station, French Guiana. We focused on litter-dwelling ants, combining the use of pitfall traps and the Winkler method according to the Ants of the Leaf Litter Protocol. This permitted us to note (1) a high leaf-litter ant diversity overall, (2) a decreasing diversity gradient from the lowland rainforest to the top of the inselberg, and (3) changes in species density, composition and functional structure. While the ant assemblages on the plateau and inselberg can be considered functionally similar and typical of an Amazonian rainforest, that of the transition forest, relatively homogenous, rather corresponded to an ant fauna typical of open areas. By contrast, the liana forest assemblage was unexpectedly rich and dense, sheltering a litter-dwelling ant fauna dominated by numerous and abundant cryptic species. These taxonomical and functional dissimilarities point out the great influence of the environmental heterogeneity, which, through variable abiotic conditions, contributes to maintaining an exceptionally rich ant biodiversity in these Neotropical habitats.

Ten new state records of Formicidae are reported for Arkansas including Camponotus obliquus Smith, Polyergus breviceps Emery, Proceratium crassicorne Emery, Pyramica metazytes Bolton, P. missouriensis (Smith), P. pulchella (Emery), P. talpa (Weber), Stenamma impar Forel, Temnothorax ambiguus (Emery), and T. texanus (Wheeler). A synopsis of previous records of ant species occurring in Arkansas is provided.

Natural enemies of the gall maker Eugeniamyia dispar (Diptera: Cecidomyiidae) were studied on the urban area of Porto Alegre, RS, Brazil from October 1993 to March 1996. Galls and associated arthropods were followed weekly in the field on individual host plants (Eugenia uniflora, Myrtaceae) and also in the laboratory. Three species of ants attacked the galls, the most common being Pseudomyrmex sp. A proportion of galls was parasitised by Rileya sp. (Eurytomidae). The adults of this solitary ectoparasitoid were also attacked by the ants and fell prey to spider webs.

The rapid growth of the human population, as well as an increase in urbanism, have resulted in the existence of new cities quickly and not adequately studied to be compatible with nature, which led to severe damage to the environment at all levels. The objective of this research is to discuss solutions to reduce the ongoing problems of urban expansion using bio-imitation and reach a vision of a sustainable city by classifying the roles played by biomimetics and their reflections on the performance of the built environment. Indeed, nature was and still is the first teacher of man and the main inspiration. Nature is as much an inspiration to architects as it is to scientists; this paper illustrates the relationship between science and biomimicry in planning new sustainable cities. The research follows the comparative approach that analyzes and compares methodologies for the physical life concepts of some insect colonies like ant colonies and bee settlements in the living world that are similar in their lives to human life, how they are integrated into the framework of physical planning and engaged that with the principles of the sustainable built environment, by showing great ingenuity in the manner they build their dwellings in a way that considers the surrounding environmental and climatic factors such as good Ventilation, control of various temperature and humidity inside the shelter. Concerning that, the case study is a kind of exploration and attempt to reach design guidelines for detailed planning for the built environment in new sustainable cities.

Las hormigas cortadoras de hojas (Atta laevigata) son una plaga económicamente importante en las plantaciones forestales de Pinus sp. y Eucalyptus sp. en la empresa Refocosta S.A.S., cuyo control se fundamenta en el uso de insecticidas orgánicos de síntesis. Con el objeto de evaluar la efectividad de métodos alternativos de control, como insecticidas de origen vegetal, biológico y productos inorgánicos, se seleccionaron 35 nidos activos de la hormiga y se trataron con los hongos entomopatógenos Metarhizium anisopliae, y Beauveria bassiana, el hongo antagónico Trichoderma viride, el macerado de semillas de Canavalia ensiformis, el compuesto fósil tierras diatomeas y el producto químico Attakill (Cuyo ingrediente activo es Sulfluramida) como control. Se evaluó la actividad de los nidos previo al tratamiento y a los 20, 40 y 65 días después de la aplicación. Al final de la tercera revisión no se observó mortalidad en las colonias tratadas con hongos y con C. ensiformis, mientras que las tierras diatomeas disminuyeron la actividad de los nidos solamente las 2 primeras semanas. El producto Attakill produjo un 100% de mortalidad. Se concluye que la efectividad de los métodos alternativos en el control evaluados contra A. laevigata, es inferior a la mortalidad generada por el insecticida orgánico Attakill.

Ants belong to the family Formicidae of the order Hymenoptera and they are one of the world's dominant insect groups. Ants can be present at all stages of carrion decomposition as they are typically observed shortly after death or during the early postmortem period, but even later once the fly maggots had left the body. Their role in the faunal succession varies from predator on the eggs and larvae of other insects (mainly Diptera), thus reducing significantly the rate of decomposition, to scavenger on the flesh or exudates from the corpse itself. As they can deeply affect the occurrence of cadaver entomofauna, the presence or absence of ants should be taken into account in every case involving postmortem interval estimates based on entomological evidence. In fact, the effects of ants on carrion reduction seem to be mainly dependent on species, on their amount or abundance, and on geographic area.

Ants are widely distributed in both tropics and temperate regions at different altitudes. They are both scavengers and predators, and serve as indicators of climate change at micro and macro levels. Monitoring of ants in the context of local environmental dynamics is therefore very important. Among numerous sampling mechanisms for ants, the pitfall trap method is a reliable approach. Relevant information on the different aspects of pitfall trap usage has been presented in this review.

The successful life of insect societies has evolved from the division of labor among more or less specialized individuals, who carry out all necessary tasks for the maintenance and growth of the colony. The extreme division of labor has produced workers specialized in the removal of dead members of the colony, an evident and highly stereotyped behavior called undertaking which consists of the ability to recognize and dispose of the dead members of the colony using specific chemical cues. Although living in enclosed nests has contributed to the ecological success of social insects due to environmental control, it also poses disadvantages. Nests of social insects, containing dense groups of genetically close individuals with frequent physical contact, present ideal conditions for the incidence and dispersion of infectious diseases. To maintain strict microbiological control inside the nest, these insects have evolved hygienic behavioral strategies to avoid and control the proliferation of pathogens. Undertaking behavior is one of the fundamental strategies to exert microbiological control inside the nest by means of suitable management and removal of dead members of the colony, to prevent the emergence of epidemics that may lead the insect society to extinction. Therefore, undertaking behavior has been fundamental to the evolution of social insects. This stereotyped behavior constitutes an excellent model for the understanding of both social evolution and the neurobiological basis of social behavior. In this paper, we review the present knowledge on undertaking behavior, and outline some perspectives of the study of such farreaching behavior of social organization.

The successful life of insect societies has evolved from the division of labor among more or less specialized individuals, who carry out all necessary tasks for the maintenance and growth of the colony. The extreme division of labor has produced workers specialized in the removal of dead members of the colony, an evident and highly stereotyped behavior called undertaking which consists of the ability to recognize and dispose of the dead members of the colony using specific chemical cues. Although living in enclosed nests has contributed to the ecological success of social insects due to environmental control, it also poses disadvantages. Nests of social insects, containing dense groups of genetically close individuals with frequent physical contact, present ideal conditions for the incidence and dispersion of infectious diseases. To maintain strict microbiological control inside the nest, these insects have evolved hygienic behavioral strategies to avoid and control the proliferation of pathogens. Undertaking behavior is one of the fundamental strategies to exert microbiological control inside the nest by means of suitable management and removal of dead members of the colony, to prevent the emergence of epidemics that may lead the insect society to extinction. Therefore, undertaking behavior has been fundamental to the evolution of social insects. This stereotyped behavior constitutes an excellent model for the understanding of both social evolution and the neurobiological basis of social behavior. In this paper, we review the present knowledge on undertaking behavior, and outline some perspectives of the study of such far-reaching behavior of social organization.

Polyphenism is the phenomenon in which alternative phenotypes are produced by a single genotype in response to environmental cues. An extreme case is found in social insects, in which reproductive queens and sterile workers that greatly differ in morphology and behavior can arise from a single genotype. Experimental evidence for maternal effects on caste determination, the differential larval development toward the queen or worker caste, was recently documented in Pogonomyrmex seed harvester ants, in which only colonies with a hibernated queen produce new queens. However, the proximate mechanisms behind these intergenerational effects have remained elusive. We used a combination of artificial hibernation, hormonal treatments, gene expression analyses, hormone measurements, and vitellogenin quantification to investigate how the combined effect of environmental cues and hormonal signaling affects the process of caste determination in Pogonomyrmex rugosus. The results show that the interplay between insulin signaling, juvenile hormone, and vitellogenin regulates maternal effects on the production of alternative phenotypes and set vitellogenin as a likely key player in the intergenerational transmission of information. This study reveals how hibernation triggers the production of new queens in Pogonomyrmex ant colonies. More generally, it provides important information on maternal effects by showing how environmental cues experienced by one generation can translate into phenotypic variation in the next generation.

Identification key for ant subfamilies and genera (Hymenoptera: Formicidae) of Costa Rica. Ants are considered one of the main invertebrate predators and herbivores in Neotropical ecosystems. This versatility is of great economic importance for agriculture, because some ants are considered pests while others play an important role in integrated pest management. Ants can also be indicators of habitat quality, so it is of prime importance to accurately identify them. Currently there are no Spanish keys to the ants of Costa Rica and the use of regional keys may result in misidentifications. To promote a tool for understanding the ant fauna, here I present a list and dichotomous keys for the subfamilies and genera of ants reported from Costa Rica.