Nest Fragmentation Research Articles

Prehistoric nests of Mud Dauber Wasps (Hymenoptera: Sphecidae) discovered in Transylvania, Romania

Fragments of mud dauber wasp’s nests dating from the Bronze Age (Noua culture, about 1500–1200 BC) from a Romanian archaeological site are described. The present discovery represents, to our knowledge, the first reported fragments of mud dauber nests recuperated from an archaeological site in Romania and probably among the rare ones from Europe. The archaeological site called Zoltan-“Nisipărie” is placed in the Covasna County, south-eastern Transylvania. The five fragments belong to two nests made by Sceliphron sp. wasps genus and they were described in terms of general and detailed morphology and morphometry. Two nest fragments preserve in situ secondary cells, showing evidence of nest reoccupation by other insects. Another important aspect of this discovery is the opportunity to extract and analyse a whole secondary cell from the original nest fragment. Various impressions of vegetal material (grass, straws etc.) and a seed on the nest fragments’ surface were observed using microscopic techniques. The preserved pieces recovered from archaeological investigations provide important data regarding the local environmental conditions during the recent period of Bronze Age in an anthropized environment of the Noua culture.

Nanoencapsulation Edible Bird Nest (collocalia sp.) Fragment by Modified Corn Starch and Maltodextrin

Edible Bird Nest Fragments (EBNF) have high levels of bioactive compounds as antioxidants. In the form of hydrolyzate nanocapsules, it will be able to increase the antioxidant activity of protecting the active compounds in the capsules and more stable. The purpose of this study were to determine the antioxidant activity of nanocapsules with the powder as core material compared to protein hydrolyzate and to determine the best encapsulant composition. This study were used two factors, including the material type and ratio coating material. The material were EBNF protein hydrolyzate and EBNF powder. The ratio of the coating materials were modified corn starch and maltodextrin (25%:75%, 50%:50%, 75%:25%). Several parameters were observed including yield, encapsulation efficiency, antioxidant activity, size and distribution of nanocapsules, and morphology of nanocapsules. The best formulation was obtained from the core material of EBNF hydrolyzate with 75% modified corn starch and 25% maltodextrin encapsulation. The best formulation has nano encapsulated characteristics with a yield of 14.07%, encapsulation efficiency of 78.17%, the antioxidant activity of 54.66%, the lowest polydispersity index value (0.69), and spherical morphology, smooth surface with slight depressions (near perfect). Further, these characteristics represent that nanocapsule EBNF hydrolysate is a promising food additive.

A Culture-Based Study of Micromycetes Isolated from the Urban Nests of Grey Heron (Ardea cinerea) in SW Poland.

Simple SummaryFungi inhabiting bird nests may pose a serious threat to living organisms. Therefore, the main goal of the study was to identify cultivable fungi in the nest of grey heron (Ardea cinerea) located near the city centre of Wrocław (Poland). Overall, 10 different fungal species were obtained which were both cosmopolitan and potentially hazardous to humans, homoiothermous animals and plants. The greatest number of fungal species was obtained from the nest fragments with visible fungal growth, and the least from western conifer seed bugs (Leptoglossus occidentalis) inhabiting the nests. The damp chamber allowed isolation of Aspergillus fumigatus, Penicillium coprophilum, and P. griseofulvum as directly related to the occurrence of visible fungal growth on plant fragments of grey heron nests.There are many positive relationships between micromycetes and birds: They can spread fungal spores, and fungi facilitate cavity woodpecker excavation by preparing and modifying excavation sites. In turn, bird nests are mainly a source of potentially zoopathogenic fungi. The Wrocław city centre hosts the biggest grey heron breeding colony in Poland with at least 240 breeding birds pairs. To assess the possible public health risks associated with bird nests, the goal of the present study was to identify cultivable fungi present in the nests of grey herons (Ardea cinerea) in Wrocław. Additionally, attempts were made to determine whether the obtained species of fungi may pose a potential threat to animal health. Fungi were cultured at 23 and 37 ± 0.5 °C, and identified based on phenotypic and genotypic traits. Moreover, during routine inspection, visible fungal growth in some of the nests was found. Overall, 10 different fungal species were obtained in the study (Alternaria alternata, Aspergillus fumigatus, Botryotrichum piluliferum, Cladosporium cladosporioides, Epicoccum layuense, Mucor circinelloides, M. hiemalis, Penicillium atramentosum, P. coprophilum, and P. griseofulvum). They are both cosmopolitan species and a source of potential threat to humans, homoiothermous animals and plants. The greatest number of fungal species was obtained from the nest fragments with visible fungal growth incubated at 23 °C, and the least from western conifer seed bugs (Leptoglossus occidentalis) inhabiting the nests. The species such as A. fumigatus, P. coprophilum, and P. griseofulvum can be directly related to the occurrence of visible fungal growth on plant fragments of grey heron’s nests.

Русская народная культура в зеркале словообразования

The article examines the cognitively significant, culturally and historically noteworthy derived words representing Russian dialects. The vocabulary of Russian dialectal word formation is viewed in the aspect of studying the patterns of organization of its complex units – various fragments of lexical word-building nests. The analysis of such derived dialectal words as facts reflecting Russian material and spiritual culture can present highly valuable and, in many respects, theoretically and practically important material for characterizing the derivational potential of the Russian language as a system, on the whole.Special attention should be paid to words possessing cognitively significant semantics representing meanings but having no one-word expression in the system of the Russian literary language. In the author’s opinion, it is appropriate to view such words not discretely but in the structure of various fragments of lexical word-building nests. The latter can consist entirely of dialectal words or present a synthesized type of nest fragments in which the words of the Russian literary language and the dialectal units are viewed together within a group of related words.

Acceptance of alien queens by the ruby ant Myrmica rubra (Hymenoptera: Formicidae): Gene flow by queen flow

Social insect colonies, especially of ants, often include several egg-laying queens that are not always closely related to each other. At least in some cases, the ants seem to accept non-related queens into their colonies. Here I test whether the colony queen status (with or without a queen), genetic and geographic differences between source and recipient nests and the average relatedness of the workers in the recipient colony affect the acceptance of alien queens. I used field collected ruby ant Myrmica rubra colonies as a model system. Only the queen status significantly affected the acceptance process. Colonies without queens accepted alien queens more frequently than colonies with a queen. The nests without queens and nest fragments may act as vectors for gene flow by the movement of queens between nests, i.e., queen flow.

Ants: The strategy of population concentration

Ants are provided with a system of balanced responses to the initial small size of societies or to their secondary depopulation, which can be described as the strategy of population concentration. The successful production of workers and fertilized queens is a necessary condition for the survival and sustained development of an ant community. This requires nests sufficiently large to provide optimal conditions for reproduction. The strategy of population concentration is aimed at rapid attainment (or restoration) of a state of sustained development by concentrating the ant population present in a number of accessible viable nests. This strategy is realized at all stages in the life of ant nests by (a) fusing family cells left by founding queens, (b) fusing small offshoots in the course of artificial relocations, (c) uniting diminished societies or merging them into other nests, and (d) reintegrating secondary nests following exogenous nest fragmentation. Merging (compensating for demographic deficiency through external sources) is the most efficient and quickest way of establishing or restoring the threshold level of abundance. Using this strategy, ants solve the paramount problems of preserving a society (settlement) at any particular time and providing for its future development. These tasks are so vital to ant societies that they take priority over other important factors such as genetic kinship or even species identity. The priority of the social principle over the genetic one is unequivocally confirmed by the widespread phenomenon of mixed ant families. A necessary condition for the realization of the strategy of population concentration is tolerance to a diversity of forms and to deviations from the norm observed in highly developed social systems. Employment of the same mechanism at all stages in the life of both individual societies and large ant settlements gives evidence of this strategy’s universality and its undeniable importance in the life of ant communities.

Immigration and formation of mixed colonies in red wood ants (Hymenoptera, Formicidae)

Long-term field studies of the composition and spatial structure of settlements of ants of the Formica rufa group were carried out in two regions of Russia (Moscow and Arkhangelsk provinces). Fragmentation of damaged nests followed by reintegration of the fragments is the main way of formation of mixed colonies of ants from different nests (including different species). The principal factor of nest fragmentation is their damage by wild boars, bears, and in some localities, by poachers. The formation of mixed nests and nest complexes with participation of different Formica species was observed. They are formed by joining the ants from several damaged nests or by a colony from a destroyed nest immigrating into an intact one. Regular damage of many nests leads to the formation of broad zones of mixed colonies. The mixed colonies including 2–3 species of wood ants have recently become common. The phenomenon of mixed colonies raises a question as to the relative importance of two basic principles (sociality and specific identity) in the life of ant societies and demonstrates the priority of the social principle.

Colony Budding and its Effects on Food Allocation in the Highly Polygynous Ant, Monomorium pharaonis

AbstractTo advance our understanding of the causes and the consequences of budding (colony multiplication by fragmentation of main nests), we investigated nest movement in the facultatively polydomous Pharaoh ant, Monomorium pharaonis. Demographic data revealed that Pharaoh ants are highly polygynous and have a relatively low worker to queen ratio of 12.86. Budding experiments demonstrated that the number of available bud nests has a significant effect on colony fragmentation and increasing the number of bud nests resulted in smaller colony fragments. The overall distribution among bud nests was uneven, even though there was no evidence that the different life stages and castes partitioned unevenly among the bud nests and the analysis of individual colonies revealed no evidence of an uneven split in any of the colonies. This demonstrates that Pharaoh ants have the ability to exert social control over colony size and caste proportions during budding, which may contribute to their success as an invasive ant. The intensity of nest disturbance had a significant effect on whether or not the ants migrated into bud nests. Major disturbance resulted in the ants abandoning the source nest and migrating to bud nests and minor disturbance did not stimulate the ants to abandon the source nest. The results of the successive budding experiment which allowed the ants the opportunity to bud into progressively smaller nest fragments demonstrate that Pharaoh ants maintain a preferred minimum group size of 469 ± 28 individuals. Food allocation experiments utilizing protein marking revealed that nest fragmentation in Pharaoh ants has no negative impact on intracolony food distribution. Overall, our results suggest that nest units in the Pharaoh ant behave like cooperative, rather than competitive, entities. Such cooperation is most likely facilitated by the fact that individuals in all bud nests are genetically related, remain in close proximity to each other, and may continue to exchange individuals after budding.

Predatory abilities favour the success of the invasive ant Pheidole megacephala in an introduced area

Abstract: The invasive African big‐headed ant, Pheidole megacephala, is a dominant species in the many areas it has invaded. We examined whether one potential reason for its ecological success might be its predatory efficiency. We compared the density of termite nests in an area of Mexico invaded by P. megacephala with an adjacent area where P. megacephala is not present. We also compared the success of P. megacephala in preying on termites with that of 13 native ant species. We found that termite nest density was significantly lower in areas invaded by P. megacephala (0.33 vs. 1.05 nests per 30 m transect). In field trials, we established that P. megacephala workers were significantly more successful at capturing termite workers from termite nest fragments than even the most successful native ant species, Dorymyrmex pyramicus. For both P. megacephala and D. pyramicus, single scouts could trigger the mass recruitment of nestmates, but P. megacephala was able to recruit greater numbers of nestmates. Combined with their aggressiveness towards other ant species, their highly efficient predatory capacities help explain the ecological success of P. megacephala and demonstrate how it can be a major threat to invertebrate biodiversity in the areas it invades.

Efficient and accurate analytical modeling of whole-program data cache behavior

Data caches are a key hardware means to bridge the gap between processor and memory speeds, but only for programs that exhibit sufficient data locality in their memory accesses. Thus, a method for evaluating cache performance is required to both determine quantitatively cache misses and to guide data cache optimizations. Existing analytical models for data cache optimizations target mainly isolated perfect loop nests. We present an analytical model that is capable of statically analyzing not only loop nest fragments, but also complete numerical programs with regular and compile-time predictable memory accesses. Central to the whole-program approach are abstract call inlining, memory access vectors, and parametric reuse analysis, which allow the reuse and interference both within and across loop nests to be quantified precisely in a unified framework. Based on the framework, the cache misses of a program are specified using mathematical formulas and the miss ratio is predicted from these formulas based on statistical sampling techniques. Our experimental results using kernels and whole programs indicate accurate cache miss estimates in a substantially shorter amount of time (typically, several orders of magnitude faster) than simulation.

Exposure to nest paper hydrocarbons is important for nest recognition by a social wasp, Polistes metricus Say (Hymenoptera, Vespidae)

Colonies of P. metricus were collected from the field and maintained in the laboratory. Pupae that were destined to become workers were excised from nests and isolated individually. Upon eclosion, workers were exposed to either an untreated fragment of the natal nest, to a fragment of the natal nest from which the surface hydrocarbons had been removed with hexane, or to no nest fragment. Four days after emergence, each wasp was released into an observation box which contained a nest fragment from her own nest and a nest fragment from a foreign nest. Each wasp was observed for 30 min on the first day and 30 min on the second day, and the time that the wasp spent on the nest fragments was recorded. P. metricus workers that had emerged on an untreated nest fragment spent significantly more time on the natal nest fragment than on the foreign nest fragment. Workers that emerged in the absence of a nest fragment spent less time on either nest fragment than did the wasps that had emerged in the presence of a fragment of their natal nest. This is the first report to document the importance of prior exposure to nest paper hydrocarbons for social wasps to be able to discriminate between their natal nest and a foreign nest.

Breeding behaviour, relatedness and sex‐investment ratios inLeptothorax tuberumFabricius

AbstractThe ant speciesLeptothorax tuberumwas shown to be predominantly monogynous. Queens usually mate once only but some nests may have a multiply‐mated queen or are partially or serially polygynous. As expected from these results, within nest relatedness between workers and between workers and alate queens was found to be high. Almost fifty percent of nests had no nest queen which may indicate high queen mortality, queens leaving to found new nests or nest fragmentation. Observed female investment frequencies (IFo) were not significantly different from those expected on the basis of worker control of sexual production and the relatedness estimates of workers to alate queens and workers to males calculated from isozyme data (IFE). These values were not consistent with queen control. There was no evidence for lower IFos in queenless nests nor for higher IFos in larger nests classified by worker number. When nests were classified by sexual productivity, however, there was a strong rank correlation between productivity and female bias. This is the first study of an ant species to test observed IF against expected IF calculated without inferring between caste relatedness from worker data or pooling of data from different castes.

Effects of nest paper hydrocarbons on nest and nestmate recognition in colonies ofPolistes metricus say

The role of nest paper hydrocarbons in nest and nestmate recognition for the social waspPolistes metricus was examined. Newly emergedP. metricus workers maintained in the laboratory spent four days alone on a fragment of nest paper that was subjected to one of the following tretments: untreated, extracted with hexane to remove surface hydrocarbons, or extracted with extract reapplied. Test wasps were returned to their natal nest with nestmates and observed for 1 h. Time spent on nest by test wasp and its behaviors were recorded. Wasps exposed to untreated and reapplied nest fragments spent an average of 34.13 and 31.75 min on their nests, respectively, while wasps from extracted fragments averaged 17.19 min. Behavior of wasps exposed to extracted paper differed significantly from wasps exposed to paper with hydrocarbons. These results suggest that exposure to nest paper hydrocarbons is important for both nest and nestmate recognition.

Ordered deletions for DNA sequencing andin vitromutagenesis by polymerase extension and exonuclease gapping of circular templates

A simple method is described for generating nested deletions from any fixed point in a cloned inset. Starting with a single-stranded phagemid template, T4 DNA polymerase is used to extend an annealed primer. This leads to a fully double-stranded circular molecule with a nick or small gap just 5' to the primer. Exonuclease III initiates progressive digestion from the resulting 3' end. Removal of timed aliquots and digestion with a single-strand specific endonuclease leads to a series of linear nested fragments having a common end corresponding to the 5' end of the primer. These molecules are circularized and used to transform cells, providing large numbers of deletion clones with targeted breakpoints. The 6-step procedure involves successive additions to tubes, beginning with a single-stranded template and ending with transformation; no extractions, precipitations or centrifugations are needed. Results are comparable to those obtained with standard Exonuclease III-generated deletion protocols, but there is no requirement for restriction endonuclease digestion or for highly purified double-stranded DNA starting material. This procedure provides a strategy for obtaining nested deletions in either direction both for DNA sequencing and for functional analysis.

DISPERSAL AND POPULATION-GENETIC STRUCTURE OF THE COOPERATIVE SPIDER, AGELENA CONSOCIATA, IN WEST AFRICAN RAINFOREST.

Dispersal experiments and gel electrophoresis of allozyme polymorphisms were used to investigate the selective mode underlying cooperative behavior in the rainforest spider, Agelena consociata. Previous work has indicated that individual selection alone does not explain the cooperative and even altruistic behavior noted for this African species, which exists in groups of up to hundreds of adults. We found no evidence for active dispersal by reproductives or any age class of this spider. Nest fragmentation by falling tree limbs and storms is indicated as the cause of new nest formation within local areas, while passive dispersal by vertebrate carriers that either have some association with the nests (bats) or move through them is indicated as the probable mode of longer-distance dispersal. The population-genetic structure observed for A. consociata supports the data obtained on dispersal. Wright's FST statistic and G tests for genetic heterogeneity indicate that the populations are subdivided into genetically heterogeneous colonies. Comparisons utilizing Nei's genetic distance show colonies separated by as few as 30 m to be as genetically distinct as are colonies separated by many kilometers. There is also a marked scarcity of heterozygotes, and individuals within nests and associated colonies are genetically related about as much as are full siblings. The results of these analyses indicate that kin selection or some type of family-group selection may have been important in the evolution of cooperative behavior in the species.