Colony Reproduction Research Articles

Revealing the status of Orbicella: Main reef-builder of Morrocoy National Park and Cuare Wildlife Refuge, Venezuela, Southern Caribbean.

Reef-building corals are the main basis of coral reef ecosystems, and the Orbicella genus is currently the most important in the Caribbean region. Although Orbicella species have been extensively studied, gaps in some southern Caribbean areas still exists on their status, which is crucial for management and conservation plans. In this study, we aimed to describe the population status of Orbicella faveolata and Orbicella annularis in two coastal Marine Protected Areas (MPA) of Venezuela: Morrocoy National Park and Cuare Wildlife Refuge. Between 2018-2020, 16 reefs in five sectors were surveyed using the Atlantic and Gulf Rapid Reef Assessment Protocol. Among the two Orbicella species, O. faveolata was dominant in both MPA´s with higher densities and live cover, varying at both reefs and sectors. The central sector of Morrocoy and reefs from Cuare are the most relevant for Orbicella populations, due to the higher live cover and abundance of reproductive colonies. Diseases were the primary threat recorded for both species. Adequate MPA management is essential for the conservation of the Morrocoy-Cuare coral system, including the reduction of local anthropogenic stress sources, such as oil spills, uncontrolled tourism and sewage discharges.

Allee effects limit coral fertilization success

Coral populations are being progressively thinned by climate change, which elevates the risk of reproductive failure from Allee effects during fertilization. Studies have shown that fertilization success improves during more intense and synchronized spawning, but the local dependence of fertilization on coral density remains unknown in wild populations. Here, we measure the fertilization success of individual colonies of the common table coral, Acropora hyacinthus in Palau, Micronesia. We find strong evidence of spatial Allee effects such that fertilization averaged 30% when colonies were in close proximity (<0.5 m), but this declined rapidly to less than 10% at a separation of 10 m and virtually zero by 15 to 20 m. The distance of a nearest neighbor conspecific, gravid colony is a better predictor of observing Allee effects than local colony density measured at several alternative scales (2 to 10 m). Spawning synchrony increases when corals are in close proximity, which may reinforce Allee effects as reproductive colonies become further separated. Fertilization success declined nearly threefold on a second night of spawning with higher wind despite there being more intensive spawning of colonies, highlighting the potential importance of prevailing weather in driving the outcome of mass spawning events. Overall, we find that the local population of A. hyacinthus achieved 71% of its fertilization potential. Further studies of spatial patchiness in coral populations are needed to generalize the likelihood of Allee effects, how climate change impacts reproductive function on reefs, and opportunities for restoration to safeguard reproductive success by reconnecting depleted coral populations.

Assessing helminth infection in some reproductive colonies of Southern Giant Petrel (Macronectes giganteus) from Antarctica

Assessing helminth infection in some reproductive colonies of Southern Giant Petrel (Macronectes giganteus) from Antarctica

Environmental pollution effect on honey bees and their derived products: a comprehensive analysis

AbstractSeveral factors, including environmental degradation, air pollution, intense urbanization, excessive agriculture, and climate change, endanger the well-being of animals and plants. One of the major issues with an increasingly negative impact is agricultural contamination with pesticides and antibiotics. Seed coatings with neonicotinoid insecticides used as a protective layer against pests are shown to exceed the permissible limits in most cases. Neonicotinoid compounds bind to nicotinic acetylcholine receptors, therefore affecting the honey bees’ brain. Heavy metals in higher concentrations are lethal for honey bees, and the residue in bee products might pose a threat to human health. Highly effective acaricides used to treat Varroa destructor infestations in honey bee colonies have negative effects on honey bee reproduction, olfaction, and honey production. Furthermore, amitraz and fluvalinate are mostly found in the highest amounts and lead to decreased honey production and reduced colony reproduction, along with decreased learning ability and memory. However, scientific studies have shown that honey bees act as a reliable bio-indicator of environmental pollution. In response to the growing demand for bee products, the effects of adulteration and improper storage conditions have gotten worse and represent a new risk factor. In light of the shifting global economy, it is important to analyze consumer expectations and adjust manufacturing accordingly. By ensuring the manufacture of high-quality, traceable products devoid of drug residues, consumers will be better protected from subsequent health problems. This review’s objectives are based on the necessity of identifying the risks associated with honey bees and bee products. Graphical abstract

Enhancing flame retardancy and antibacterial properties of wood veneer by promoting crosslinking in metal-organic framework structures

Decorative veneer, rotary cut from wood, serving as the outermost layer of decorative plates and is exposed to potential risks of fire hazards and bacterial growth. In this study, following the principle of eco-friendly and cost-effective, the polyamino polyether methylene phosphonate (PAPEMP) and magnesium chloride (MgCl2) were sequentially impregnated into the veneer, and then the alkaline environment was employed to facilitate the complexation, leading to the formation of cross-linked chains within the porous wood structure. Consequently, the modified wood veneer, endowed with exceptional flame retardancy, smoke suppression, antibacterial properties, and good wettability was successfully achieved. Through optimization in an alkaline environment, the modified decorative veneer exhibits a remarkable increase in limiting oxygen index from 19.7% in the pure veneer to 36.9%, coupled with a significant reduction of 19.38% in total heat release and 65.22% in total smoke release compared to the pure veneer. Additionally, the peak mass loss rate (PLMR) of the modified veneer was 66.41% lower than that of the pure veneer, and the char residue increased to 46.1%, representing a 149.19% improvement over the pure veneer. Compared with pure veneer, the wettability of modified veneer increased by 37.93%. Additionally, the tensile strength parallel to the grain of the modified veneer was enhanced by 22.09% compared to the veneer without NaOH solution treatment, and exhibits strong inhibitory effects on colony reproduction. The developed flame-retardant and antibacterial treatment processes for decorative veneers offer a novel and environmentally friendly method for utilizing precious tree veneers, suitable for a variety of precious woods, and successfully applied to decorative wooden doors and wooden fire-resistant doors.

Risk-taking behavior by a cavity-nesting parrot breeding at northern Patagonia, Argentina

The increase in human population poses great challenges to birds inhabiting coastal areas, and studying their behavioral responses against these disturbances is an effective approach to understanding how tolerant species are. Our main goal was to describe the risk-taking behavior of breeding burrowing parrots (Cyanoliseus patagonus) against an approaching person. For this, we measured flight initiation distance (FID) and latency time of nesting burrowing parrots on a reproductive colony situated northwest of the San Matias Gulf, northern Argentine Patagonia. We also inquired how anthropic, environmental and ethological variables affected this behavior, and checked if the species´ reproductive success of the species varied against such disturbance. The mean FID estimated and the mean latency time were only affected by cloud coverage, and both increased with overcast conditions. burrowing parrots did not modify their FID throughout the breeding season, but returned to previous activities sooner as the breeding season progressed. The effect of our experimental disturbance did not affect the reproductive success of the species. Our results suggest that burrowing parrots show a tameness to the disturbance caused by a human approach, as reflected by their relatively short flight initiation distances, an effect also reported in other bird species inhabiting urban habitats.

Salinity-mediated limitation of asexual reproduction in the colonial ascidian Polyandrocarpa zorritensis

Ascidians are among the most common invasive marine invertebrates worldwide. Many species of non-indigenous ascidians (NIAs) have successfully colonized the Mediterranean Sea, notably within anthropized coastal lagoons and harbors. Although invasive species are generally characterized by their broad ecological tolerance, different ascidian species exhibit varied responses to biotic and abiotic environmental stressors, including temperature and salinity. Acquiring a better understanding about of the impact of such parameters on ascidian life history is crucial for predicting the invasive potential of NIAs. In this study, we investigated the impact of various salinities on the reproduction of the colonial ascidian Polyandorcarpa zorritensis, a species indigenous to Peru and a thriving invader. P. zorritensis undergoes asexual reproduction via a peculiar form of budding named vasal budding and produces resistant spherules, which likely facilitated its dissemination over long distances. Despite its widespread distribution along the Pacific and Atlantic coasts, it is only found in a few Mediterranean coastal areas with a low salinity. We tested the impact of different salinity conditions on the sexual and asexual reproduction rates of P. zorritensis in a controlled laboratory setting. Our experiments showed that the rate of asexual reproduction in colonies bred at 29 or 36 ppt salinity levels, corresponding to the natural range inhabited by P. zorritensis, was higher than those grown in 40 ppt salinity, commonly found in Mediterranean marinas and harbors. The results suggest that, although P. zorritensis has been present in the Mediterranean for several decades, its potential for invasion could be constrained by an intolerance to high salinity.

From infamy to truth. Epistemic coloniality and knowledges in resistance: an approach to the cases of Inés Fernández Ortega and Valentina Rosendo Cantú

PurposeThe purpose of the article is to show the regime of truth in the institutional commissions that have the objective of restoring history by establishing a democratic, equitable, comprehensive, inclusive and fair criterion against the attempts of re-victimization and suppression of memory that Western political and cultural traditions have installed through their mechanisms of power.Design/methodology/approachBased on the analysis of the cases of Inés Fernández Ortega and Valentina Rosendo Cantú, they establish the material conditions from which prejudices and hegemonic stereotypes are intertwined to reproduce serious violations of human rights in democratic political and epistemic frameworks. The colonial function of the truth commissions in Mexico is analyzed, which are presented as mechanisms for social development, political and colonial reproduction of liberal democracy.FindingsThe qualitative results allow considering the way in which the different truth commissions in Mexico have been strongly linked to epistemic mechanisms in which truth and justice favor the reproduction of established relationships based on race, social class and gender. Especially in the so-called democratic transition, violence, truth and justice come together to highlight power relations in situations that have been disavowed by the intelligentsia.Research limitations/implicationsThe limitations of the research are found in the historical configuration of the truth commissions in Mexico. The data, references and assessments are crossed by the initial function of the truth commissions and the establishment of apparatuses and mechanisms based on transitional justice. Based on this, it can be considered a methodological oversight to shift the analysis of truth commissions toward a critical assessment of the truth as a regime of government and hegemonic and colonization criteria from two very specific cases.Originality/valueThe originality of the work is found in the critical discernment of truth as a political category and the coloniality of power.

A review of predator exclusion fencing to create mainland islands in Hawai'i.

Invasive species are the primary threat to island ecosystems globally and are responsible for approximately two-thirds of all island species extinctions in the past 400 years. Non-native mammals-primarily rats, cats, mongooses, goats, sheep, and pigs-have had devastating impacts on at-risk species and are major factors in population declines and extinctions in Hawai'i. With the development of fencing technology that can exclude all mammalian predators, the focus for some locations in Hawai'i shifted from predator control to local eradication. This article describes all existing and planned full predator exclusion fences in Hawai'i by documenting the size and design of each fence, the outcomes the predator eradications, maintenance issues at each fence, and the resulting native species responses. Twelve predator exclusion fences were constructed in the Hawaiian Islands from 2011-2023 and six more were planned or under construction; all were for the protection of native seabirds and waterbirds. Fences ranged in length from 304-4,877m and enclosed 1.2-640 ha. One-third of the 18 fences were peninsula-style with open ends; the remaining two-thirds of the fences were complete enclosures. The purpose of twelve of the fences (67%) was to protect existing bird populations, and six (33%) were initiated for mitigation required under the U.S. Endangered Species Act. Of the six mitigation fences, 83% were for the social attraction of seabirds and one fence was for translocation of seabirds; none of the mitigation fences protected existing bird populations. Rats and mice were present in every predator exclusion fence site; mice were eradicated from five of six sites (83%) where they were targeted and rats (three species) were eradicated from eight of 11 sites (72%). Mongoose, cats, pigs, and deer were eradicated from every site where they were targeted. Predator incursions occurred in every fence. Rat and mouse incursions were in many cases chronic or complete reinvasions, but cat and mongoose incursions were occasional and depended on fence type (i.e., enclosed vs. peninsula). The advent of predator exclusion fencing has resulted in great gains for protecting existing seabirds and waterbirds, which demonstrated dramatic increases in reproductive success and colony growth. With threats from invasive species expected to increase in the future, predator exclusion fencing will become an increasingly important tool in protecting island species.

Reproduction of Varroa destructor depends on well-timed host cell recapping and seasonal patterns

Resistance traits of honeybees (Apis mellifera) against their major parasite Varroa destructor have fascinated scientists and breeders for long. Nevertheless, the mechanisms underlying resistance are still largely unknown. The same applies to possible interactions between host behaviours, mite reproduction and seasonal differences. Two resistance traits, reproductive failure of mites and recapping of brood cells, are of particular interest. High rates of recapping at the colony level were found to correspond with low reproductive success of mites. However, the direct effect of recapping on mite reproduction is still controversial and both traits seem to be very variable in their expression. Thus, a deeper knowledge of both, the effect of recapping on mite reproduction and the seasonal differences in the expression of these traits is urgently needed. To shed light on this host-parasite interaction, we investigated recapping and mite reproduction in full-grown colonies naturally infested with V. destructor. Measurements were repeated five times per year over the course of 3 years. The reproductive success of mites as well as the recapping frequency clearly followed seasonal patterns. Thereby, reproductive failure of mites at the cell level was constantly increased in case of recapping. Interestingly, this did not apply to the occurrence of infertile mites. In line with this, recapping activity in fertile cells was most frequent in brood ages in which mite offspring would be expected. Our results suggest that mite offspring is the main target of recapping. This, in turn, leads to a significantly reduced reproductive success of the parasite.

Breeding ecology, helpers presence, habitat use and trophic activity of the Greater Short-toed Lark &lt;i&gt;Calandrella brachydactyla&lt;/i&gt;: five years of study in Central Adriatic Italy

The Greater Short-toed Lark Calandrella brachydactyla is a migrant bird, considered of conservation concern, but poorly studied in Italy about his breeding ecology and habitat use. In this work, we aimed to study both of these components in the airfield of Fano (Central Italy, Marches, Pesaro-Urbino province). The study, relating to the 2018-2022 reproductive seasons, describes the nesting habitat used by the species, providing also data about the plants on which the species feed on. We hypothsized the importance of the choice of fenced areas for the less predation and we highlighted the presences of young helpers in the feeding of the second brood. Furthermore, we observed the formation of crèches for the young fledglings, controlled by some adult males. It’s confirmed here a semi-colonial condition that leading to the formation of extra-family groups before migration. The study area turns out to be the main reproductive colony of the species in the Marches region, with an average density of 1.5 pairs per 10 ha (maximum 2.4), one of the best know in central Italy.

Late Holocene seasonal human predation of otariids in Santa Cruz River mouth, Southern Patagonia, Argentina

According to archaeological data, Otaria flavescens and Arctocephalus australis were exploited at the mouth of the Santa Cruz River by hunter-gatherers in the late Holocene. These studies suggest the past existence of reproductive colonies from where individuals of different ages were taken, highlighting the offspring available in the austral summer. This paper presents new information on sex, age, and season of death based on the study of teeth growth layers and rings recorded on canines of both species recovered in three archaeological sites located in Punta Entrada, on the southern bank of Santa Cruz River. The results confirm that otariids were captured in the austral summer and show that winter and spring were also important seasons. Prey included females, pups, and adult males captured according to the abundance of each age group at different seasons of the year. These data are in agreement with those obtained from other lines of evidence, such as osteometry and sclerochronology, which indicate this sector of the Patagonian coast was occupied recurrently to hunt otariids as one of the main resources taken by hunter-gatherers when visiting Punta Entrada at different times of the year.

Total Lipid Extracts of Honeybee Drone Larvae Are Modulated by Extraction Temperature and Display Consistent Anti-Inflammatory Potential.

Honeybee drone larvae are male bees that develop from unfertilized eggs and play a role in colony reproduction. The nutritional value of honeybee drone larvae is due to their high protein, lipid, and other nutrient contents, making them a profitable food source for humans in some cultures. Drone larvae lipids (DLLs) contribute to drone development; however, few studies have explored their substantial compositions and bioactive functions. In this study, we carried out DLL lipidomics analysis using UPLC-Q-Exactive-Orbitrap-MS prior to in vitro anti-inflammatory activity analysis. The results highlighted the importance of the extraction temperature on the DLL composition. A total of 21 lipids were found in the DLL extract, mostly categorized into five groups: nine phospholipids, three sphingolipids, two neutral lipids, one plant glycoglycerolipid, four lipid acyl, and others. Drying extraction at -20 °C produced more sphingolipids, phospholipids, and unsaturated fatty acids. Of 37 fatty acids, 18 were displayed at -20 °C degrees, as shown by GC-MS quantitative analysis. Myristic (246.99 ± 13.19 μg/g), palmitic (1707.87 ± 60.53 μg/g), stearic (852.32 ± 24.17 μg/g), and oleic (2463.03 ± 149.61 μg/g) acids were the predominant fatty acids. Furthermore, we examined the significant in vitro anti-inflammatory effects of DLL (-20 °C) using lipopolysaccharide (LPS)-challenged RAW264.7 cells. Nitric oxide (NO) and reactive oxygen (ROS) production and mRNA expression of IL-6, IL-10, COX-2, and iNOS were significantly decreased, demonstrating the anti-inflammatory function of DLL. Overall, this study provided insight into the lipid composition of DLL, revealed the influence of temperature, and explored the functionality of DLL (-20 °C), allowing for further application of DLLs as functional foods.

Evidence of Sexual Reproduction in Out-Planted Coral Colonies

Intervention techniques to restore coral communities have become an important management tool to help recover and rehabilitate damaged reefs. The direct transplantation of healthy coral fragments is the most common method; however, there is controversy in the long-term success, as using coral clones may diminish the genetic diversity of the coral population. Genetic recombination can be achieved when the coral colony produces gametes and eventually reproduces; therefore, it is important to provide evidence that restored colonies produce gametes as their naturally recruited counterparts with similar colony size (age). Natural and restored Pocillopora coral colonies of the same size range (between 40 and 50 cm in diameter) were tagged and sampled during the rainy season to determine gamete maturation. Our results show no differences in the reproductive activity among colonies: natural and restored coral colonies matured gametes from June to October, with a peak in sexually active coral colonies in July. Also, gamete malformation was not observed. During the gamete production period, the area’s temperature ranged from 27.9 to 30.02 °C. The results’ evidence that coral colonies formed through active restoration contribute not only to the increase in live coral cover as seen in previous studies but potentially contribute in the medium term (&gt;5 years after out-planting) to the production of larvae and local and subsidiary recruitment, since they exhibit the same reproductive patterns as their naturally formed counterparts and no differences in the reproductive activity among coral colonies. Therefore, long-term coral restoration projects contribute to maintaining the live coral cover and the genetic diversity in the region, eventually rehabilitating the coral community.

Reproductive benefits and reduced investment in parental care behavior associated with reproductive groups of males in Abudefduf troschelii.

Fishes of the family Pomacentridae present a wide diversity of mating systems, ranging from polygyny to promiscuity and from individual territorial defense to the establishment of reproductive colonies of males. The damselfish species Abudefduf troschelii has a reproductive colony mating system, in which males temporarily aggregate in reproductive areas to court and attract females. Males defend an individual territory where they receive eggs and perform paternal care behaviors for their offspring. The present study evaluated the advantages of the colonial mating system in A. troschelii. During an entire reproductive period, in a breeding colony within a rocky reef, we located, marked, geo-referenced, and measured the distances between the territories of all males. We quantified the variance among males in their patterns of paternal care investment, eggs acquired, hatching success, reproductive success, body size, and changes in body coloration. We found that males spatially distributed their nests in groups or independently (i.e., solitary nests). Nesting groups are formed by larger males that show intense nuptial coloration during the entire receptivity period. They are located centrally to the colony and consist of three to six males whose territories overlap. In contrast, small solitary males that fail to acquire or maintain nuptial coloration during the receptivity period establish their nests peripherally to the colony, away from the territories of other males. Our results highlight that the reproductive benefits of colonial nesting are unequal for males, as the spatial distribution of nests within the colony determines the reproductive success of males. Group nesting confers the highest reproductive benefits to males regarding eggs obtained, hatching success, and relative fitness and also enables males to reduce their parental investment in brood care behaviors. The preference of females for oviposition could be associated with greater intrasexual competitiveness, defense ability, body condition, or experience of group-nesting males located at the center of the colony or because their progeny will have a lower probability of predation than they would in solitary nests males.

Reduced parasite burden in feral honeybee colonies

Abstract Bee parasites are the main threat to apiculture and since many parasite taxa can spill over from honeybees (Apis mellifera) to other bee species, honeybee disease management is important for pollinator conservation in general. It is unknown whether honeybees that escaped from apiaries (i.e. feral colonies) benefit from natural parasite‐reducing mechanisms like swarming or suffer from high parasite pressure due to the lack of medical treatment. In the latter case, they could function as parasite reservoirs and pose a risk to the health of managed honeybees (spillback) and wild bees (spillover). We compared the occurrence of 18 microparasites among managed (N = 74) and feral (N = 64) honeybee colony samples from four regions in Germany using qPCR. We distinguished five colony types representing differences in colony age and management histories, two variables potentially modulating parasite prevalence. Besides strong regional variation in parasite communities, parasite burden was consistently lower in feral than in managed colonies. The overall number of detected parasite taxa per colony was 15% lower and Trypanosomatidae, chronic bee paralysis virus, and deformed wing viruses A and B were less prevalent and abundant in feral colonies than in managed colonies. Parasite burden was lowest in newly founded feral colonies, intermediate in overwintered feral colonies and managed nucleus colonies, and highest in overwintered managed colonies and hived swarms. Our study confirms the hypothesis that the natural mode of colony reproduction and dispersal by swarming temporally reduces parasite pressure in honeybees. We conclude that feral colonies are unlikely to contribute significantly to the spread of bee diseases. There is no conflict between the conservation of wild‐living honeybees and the management of diseases in apiculture.

Adaptive Response to Gillnets Bycatch in a North Sardinia Mediterranean Shag (Gulosus aristotelis desmarestii) Population.

Mediterranean Shag (Gulosus aristotelis desmarestii) is a seabird endemic to the Mediterranean and Black Seas, recently included in the IUCN list of threatened Species. Most of the reproductive colonies are hosted in Sardinia and surrounding islets. Bycatch in fishing nets is one of the most significant threats for this population. Our work aimed to assess alterations in the sex ratio caused by bycatch and to study the adaptive response of the population to a skewed adult sex ratio. The sex ratio of Mediterranean Shags found drowned in the gillnets near the colonies and that of the nestlings of the Corcelli (northeast Sardinia) colony was determined using the sex-linked polymorphism of the gene Chromobox-Helicase-DNA-binding 1. The data of the shags found drowned in gillnets evidenced a high mortality rate (83.3%; p < 0.001) and a larger size of males (35% heavier than females, p < 0.05) compared to females, supporting the theory that heavier individuals are able to forage at great depths. With 64.8% of the nestlings being male, the sex ratio of nestlings was statistically different from parity (p < 0.05). Furthermore, it was related to the brood size. In one- and two-chick broods, 73% and 70% of nestlings, respectively, were males, while in three-chick broods, only 33% were males. Our data identify the higher rate of male shags drowned in gillnets as a factor causing an alteration of the sex ratio in the Mediterranean Shag population. According to the Sex Allocation Theory, an adaptive adjustment of sex made by adult females restores the Mendelian sex ratio in the population.

Sunflower plantings reduce a common gut pathogen and increase queen production in common eastern bumblebee colonies.

Community diversity can reduce the prevalence and spread of disease, but certain species may play a disproportionate role in diluting or amplifying pathogens. Flowers act as both sources of nutrition and sites of pathogen transmission, but the effects of specific plant species in shaping bee disease dynamics are not well understood. We evaluated whether plantings of sunflower (Helianthus annuus), whose pollen reduces infection by some pathogens when fed to bees in captivity, lowered pathogen levels and increased reproduction in free-foraging bumblebee colonies (Bombus impatiens). Sunflower abundance reduced the prevalence of a common gut pathogen, Crithidia bombi, and reduced infection intensity, with an order of magnitude lower infection intensity at high sunflower sites compared with sites with little to no sunflower. Sunflower abundance was also positively associated with greater queen production in colonies. Sunflower did not affect prevalence of other detected pathogens. This work demonstrates that a single plant species can drive disease dynamics in foraging B. impatiens, and that sunflower plantings can be used as a tool for mitigating a prevalent pathogen while also increasing reproduction of an agriculturally important bee species.

Local and landscape environmental heterogeneity drive ant community structure in temperate seminatural upland grasslands.

Environmental heterogeneity is an important driver of ecological communities. Here, we assessed the effects of local and landscape spatial environmental heterogeneity on ant community structure in temperate seminatural upland grasslands of Central Germany. We surveyed 33 grassland sites representing a gradient in elevation and landscape composition. Local environmental heterogeneity was measured in terms of variability of temperature and moisture within and between grasslands sites. Grassland management type (pasture vs. meadows) was additionally included as a local environmental heterogeneity measure. The complexity of habitat types in the surroundings of grassland sites was used as a measure of landscape environmental heterogeneity. As descriptors of ant community structure, we considered species composition in terms of nest density, community evenness, and functional response traits. We found that extensively grazed pastures and within-site heterogeneity in soil moisture at local scale, and a high diversity of land cover types at the landscape scale affected ant species composition by promoting higher nest densities of some species. Ant community evenness was high in wetter grasslands with low within-site variability in soil moisture and surrounded by a less diverse landscape. Fourth-corner models revealed that ant community structure response to environmental heterogeneity was mediated mainly by worker size, colony size, and life history traits related with colony reproduction and foundation. We discuss how within-site local variability in soil moisture and low-intensity grazing promote ant species densities and highlight the role of habitat temperature and humidity affecting community evenness. We hypothesize that a higher diversity of land cover types in a forest-dominated landscape buffers less favorable environmental conditions for ant species establishment and dispersal between grasslands. We conclude that spatial environmental heterogeneity at local and landscape scale plays an important role as deterministic force in filtering ant species and, along with neutral processes (e.g., stochastic colonization), in shaping ant community structure in temperate seminatural upland grasslands.

Equivalent Colony Growth of Hybrids of Two Invasive Coptotermes Species Can Threaten Urban Areas.

Coptotermes formosanus Shiraki and C. gestroi (Wasmann) are economically important structural pests in urban areas. Due to anthropogenic activity, both species have been introduced into the United States, with their respective invasive ranges now overlapping in Florida, and the two species have the capability to hybridize. The potential for structural damage from subterranean termite colonies primarily depends on colony size. However, long-term colony growth and wood consumption capabilities of hybrid Coptotermes colonies remain to be investigated, to determine the potential pest status of field-established hybrid colonies. In this study, we investigated long-term colony development over four years to determine if aging hybrid colonies display vigor in terms of colony growth. In addition, we compared wood consumption rate of hybrid colonies to compare their potential impact as structural pests with the two parental species. In aging colonies (four-year-old), both hybrid mating types displayed a colony growth equivalent to C. formosanus. However, the wood consumption rates of four-year-old colonies of the two parental Coptotermes species and their hybrids were similar, indicating equal damaging potential. We also found multiple secondary reproductives in hybrid colonies, even in the presence of primary reproductives, which may favor their potential establishment and spread. Although hybrid colonies or hybrid alates have yet to be detected in the field, our results suggest that such hybrid colonies would be an additional termite threat in the future if they were established in the field.