Ants (Formicidae, Hymenoptera) play an important role in seed bank, seedling establishment andplant composition of arid ecosystems. Thus, knowing plant-ant interaction provides useful information formanagers to design...Ants (Formicidae, Hymenoptera) play an important role in seed bank, seedling establishment andplant composition of arid ecosystems. Thus, knowing plant-ant interaction provides useful information formanagers to design restoration and conservation plans. In this study, the roles of desert harvester ants (Messorintermedius and Messor melancholicus) and scavenger ants (Cataglyphis nodus and Lepisiota semenovi) on plantcommunities were investigated in arid ecosystems of southeastern Iran. Two vegetation types weredistinguished in the study area and the nest density of ant species was determined. Furthermore, plantcomposition and soil seed bank were estimated at different distances from the ant nests. Results showed thatthe density of M. intermedius and M. melancholicus nests was higher in dwarf shrub-shrub vegetation type and thedensity of C. nodus and L. semenovi nests was higher in dwarf shrub vegetation type. The harvester and scavengerants had enhanced the seed bank to 55% and 70%, respectively. Therefore, the role of scavenger ants on theplant communities' seed bank was greater than that of harvester ants. Although the scavenger ants were moreinfluential on the annuals and the invasive plant species, the radius impact of the harvester ants on theperennials was greater, i.e., a positive interaction existed between the perennial plants and the harvester ants. C.nodus and L. semenovi played an important role in enhancing the ecosystem's potential for restoration throughestablishment of pioneer species in early stage of succession. The activity of M. intermedius is crucial for thedevelopment and maintenance of climax plant communities in arid ecosystems through assisting the plantspecies' establishment in late stage of succession. It is essential to preserve the diversity of these key ant speciesfor the maintenance and sustainability of shrubs in arid ecosystems.展开更多
Livestock ranching is one of the main productive activities in arid regions of the world.Grazing produces changes in animal as well as plant communities(e.g.richness,abundance and species dominance relationships).Ants...Livestock ranching is one of the main productive activities in arid regions of the world.Grazing produces changes in animal as well as plant communities(e.g.richness,abundance and species dominance relationships).Ants are good biological indicators due to the environmental fidelity of some of their community parameters.We described the functional structure of the ant community in the central Monte of Mendoza,Argentina,and examined the effect of grazing using richness,diversity and the functional group scheme.We used pitfall traps to sample ants at a reserve with 30-year cattle exclusion and at an adjacent ranch.Eleven of the 27 recorded species showed significant differences in their abundance and two species were absent at the ranch.While richness and diversity did not reflect these differences,functional groups did.Hot Climate Specialists were more abundant at the ranch while Cryptic Species and Generalized Myrmicinae increased at the reserve.This study supports the utility of the functional group scheme to study the effects of grazing disturbance in ant communities of arid regions.展开更多
We examined the relationship between seasonal livestock grazing (late summer and late winter) and the abundance of two ant species,<em> Dorymyrmex insana and Forelius pruniosus</em>, on three types of plan...We examined the relationship between seasonal livestock grazing (late summer and late winter) and the abundance of two ant species,<em> Dorymyrmex insana and Forelius pruniosus</em>, on three types of plants (mesquite shrubs, snakeweed sub-shrubs, and mixed grasses) dominated by black grama (<em>Bouteloua eriopoda</em>). Stocking rates were adjusted to remove 75% of the available forage. Since Chihuahuan Desert grasslands are not in transition to shrublands, the grasses and some herbaceous plants are the only available forage. We hypothesized that neither rainfall nor cattle grazing would affect the abundance of these ants on mesquite (<em>Prosipis glandulosa</em>) or snakeweed (<em>Gutierrezia sarothrae</em>). Linear regressions of monsoon rainfall on mesquite (<em>Prosopis glandulosa</em>) produced an r<sup>2</sup> nearly equal to that with the annual precipitation. Monsoon rainfall on the evergreen sub-shrub, <em>Gutierrezia sarothrae</em>, resulted in June-July rainfall accounting for 47% - 83% of the variation in densities of <em>D. insana</em> on snakeweed. The number of <em>D. insana</em> was more than double the number of <em>F. pruinosus</em> on grasses, mesquite, and snakeweed. There were significant reductions in the abundance of <em>F. pruinosus</em> on the grass in the grazed plots;each year the plots were grazed. There were no significant effects of grazing on the abundance of either of the ant species sampled from <em>G. sarothrae</em> canopies. There were significantly fewer <em>D. insana</em> on mesquite in summer grazed plots than on<em> P. glandulosa</em> in winter grazed and ungrazed plots in the second and third years of grazing. Pre-grazing effects were compromised by the high annual (more than double) precipitation.展开更多
Symbiotic relations are present in the nature and can contribute to the success of the organisms involved. Endophytic fungi live within the leaf tissues without causing any harm to the host plant, and some of them can...Symbiotic relations are present in the nature and can contribute to the success of the organisms involved. Endophytic fungi live within the leaf tissues without causing any harm to the host plant, and some of them can be a defense mechanism against the attack by the leaf-cutting ants. Ants of the genus <em>Atta</em> are known as leaf-cutting ants and have an obligatory association with the fungus <em>Leucoagaricus gongylophorus</em>, cutting pieces of leaves and bringing them back to the colony to the fungus. The present study aimed to find out the endophytic fungi community of an attractive plant (<em>Acalypha wilkesiana</em>) and a less attractive plant (<em>Colocasia esculenta</em>) to the ants <em>Atta sexdens</em>. We found out that the communities are different in quantity and in composition and 73% of the isolated fungi were from <em>A. wilkesiana</em>, which has fungi known as attractive to leaf-cutting ants, such as genus<em> Colletotrichum</em>, <em>Pestalotiopsis</em>, <em>Phomopsis </em>and <em>Xylaria</em>. On the other hand, in <em>C. esculenta</em>, there was found the genus<em> Fusarium</em>, known to be reject by the leaf-cutting ants, and less fungal diversity than in the attractive plant <em>A. wilkesiana</em>. Therefore, our data suggest that attractivity or repelence of a plant to the leaf-cutting ants could be related to presence or ausence of determinated fungi more than the quantity of fungi present in a leaf.展开更多
The ants are one of the mega diverse insets found in all terrestrial environments, and occur in great diversity, richness and abundance, acting at all trophic levels. The present study was conducted to verify the know...The ants are one of the mega diverse insets found in all terrestrial environments, and occur in great diversity, richness and abundance, acting at all trophic levels. The present study was conducted to verify the knowledge of ant fauna at Caxiuanã National forest. All available ant literature and some collection in Caxiuanã were compiled and analyzed in EXCEL program. Caxiuanã is one Brazilian Amazonia forest that has good biological conservation. A total of 197 species belonging to 52 genera of the nine subfamilies are present in Caxiuanã. Many studies need to be done in this place to understand the ant community pattern to give base for other studies and proposal for use, management and conservation of this interesting Amazonia place.展开更多
The ants are one of the mega diverse insets found in all terrestrial environments, and occur in great diversity, richness and abundance, acting at all trophic levels. The present study was conducted to verify the know...The ants are one of the mega diverse insets found in all terrestrial environments, and occur in great diversity, richness and abundance, acting at all trophic levels. The present study was conducted to verify the knowledge of ant fauna at Caxiuanã National forest. All available ant literature and some collection in Caxiuanã were compiled and analyzed in EXCEL program. Caxiuanã is one Brazilian Amazonia forest that has good biological conservation. A total of 197 species belonging to 52 genera of the nine subfamilies are present in Caxiuanã. Many studies need to be done in this place to understand the ant community pattern to give base for other studies and proposal for use, management and conservation of this interesting Amazonia place.展开更多
Ants like to live together under the surface of the ground.Different ants are doing different jobs.The worker ants look for food all day long and they are good atrepairing nests.Some food and nests are for the mselves...Ants like to live together under the surface of the ground.Different ants are doing different jobs.The worker ants look for food all day long and they are good atrepairing nests.Some food and nests are for the mselves.The rest are for the others.When it is sunny,sometimes they are moving damp food to the outside of their nests in order to make it dry.The soldier ants act as guards and so ldiers.When enemy insects are coming,they swarm towards them.Though many soldier ants often get hurt to death,the rest go on fighting to a finish.An expert on animals made an experiment on ants.He put a burningcandle into anantsnest.He found that the ants moved carefully and in good order.They spent only fifty seconds in putting展开更多
In this paper, we have conducted a literature review on the recent developments and publications involving the vehicle routing problem and its variants, namely vehicle routing problem with time windows (VRPTW) and the...In this paper, we have conducted a literature review on the recent developments and publications involving the vehicle routing problem and its variants, namely vehicle routing problem with time windows (VRPTW) and the capacitated vehicle routing problem (CVRP) and also their variants. The VRP is classified as an NP-hard problem. Hence, the use of exact optimization methods may be difficult to solve these problems in acceptable CPU times, when the problem involves real-world data sets that are very large. The vehicle routing problem comes under combinatorial problem. Hence, to get solutions in determining routes which are realistic and very close to the optimal solution, we use heuristics and meta-heuristics. In this paper we discuss the various exact methods and the heuristics and meta-heuristics used to solve the VRP and its variants.展开更多
2-tridecanone is a major constitute of defensive secretion in tawny crazy ants, Nylanderia fulva that is an ant species reported to be able to displace red imported fire ants, Solenopsis invicta in the field. 2-tridec...2-tridecanone is a major constitute of defensive secretion in tawny crazy ants, Nylanderia fulva that is an ant species reported to be able to displace red imported fire ants, Solenopsis invicta in the field. 2-tridecanone was proven to be toxic to S. invicta. Although 2-tridecanone is commercially available, utilization of this naturally occurring compound in fire ant management has received little attention. In this study, toxicity and efficacy of two 2-tridecanone formulations were assessed against S. invicta. Two emulsifiable concentrates were prepared using 2-tridecanone as an active ingredient, vegetable oil as a solvent and polyoxyethylene tridecyl ether as a surfactant. Piperonyl butoxide (PBO) was used as a synergist in one formulation. Both formulations showed significant toxicity in laboratory bioassays. In a field trial, at application rate of 5.28 mL/L and 14 days after mound drench treatment, 100% control was achieved for formulation with PBO and 90% control for the formulation without PBO. In conclusion, both formulations had significant efficacy against S. invicta. Due to the low mammalian toxicity of 2-tridecanone, no involvement of hazardous synthetic organic solvents, no phytotoxicity at applied concentrations, and relatively low cost, both formulations are promising alternatives to commercial insecticide products for fire ant mound drench. The outstanding efficacy of both formulations observed in this study warrants further research on their efficacy against other pest insects.展开更多
The compositions of two kinds of ants (Formica cunicu Laria and Polyrhachis vicina Roger) were determined with modern apparatuses. The result was that content of crude protein, fat, vitamin E, formic acid were 43.95%,...The compositions of two kinds of ants (Formica cunicu Laria and Polyrhachis vicina Roger) were determined with modern apparatuses. The result was that content of crude protein, fat, vitamin E, formic acid were 43.95%, 22.90%, 15.61 mg / Kg, 4.2% respectively forFormica cunicu Laria, and 42.56%, 21 .90%, 131 .2 mg / Kg, 3.8% respectively for Polyrhachlk vicina Roger.展开更多
This study was conducted in the Korhogo region in an age gradient of mango orchards. The goal was to assess diversity and determine the influence of the environment on the composition of these organisms. Sampling was ...This study was conducted in the Korhogo region in an age gradient of mango orchards. The goal was to assess diversity and determine the influence of the environment on the composition of these organisms. Sampling was done using pitfall traps, threshing and manual collection. A total of 82 ant species were sampled on all plots. The cultivated plots are richer in ant species than the natural environment. Of the three (3) sampling methods, the Manual Collection proved to be more efficient (eff = 79.52%), followed by threshing (eff = 75.15%) and finally the least effective trap pit (eff = 73.39%). The number of individuals of the species varies according to the environment. The highest value was obtained in the young plot (485 individuals), followed by the intermediate plot (478 individuals), then the older plot (426 individuals) and finally the control plot (320 individuals). The species Camponotus acvapimensis was harvested mainly with 159 individuals. On the other hand, the species Lepisiota sp.1;Camponotus rufigenis, Camponotus sericeus and Oecophylla longinoda were specifically harvested in the control, young, intermediate and aged plots, respectively.展开更多
Improving routing algorithm performance not only leads to appreciate the quality of data transmission, but also increases the speed of data transfer. In this paper we propose a hybrid method which is a combination of ...Improving routing algorithm performance not only leads to appreciate the quality of data transmission, but also increases the speed of data transfer. In this paper we propose a hybrid method which is a combination of traffic classification by the help of colored pheromones and helping ants method in the intermediate nodes. This combination increases the convergence speed and decreases the delay and Jitter in the network. Also we compare the obtained results with two known routing algorithms that are based on the ant colony.展开更多
Black ant, Carebara vidua (Smith) is an edible insect of critical value in nutrition. The population abundance of black ants has reduced drastically and they have become scarce in all the agro ecological zones in West...Black ant, Carebara vidua (Smith) is an edible insect of critical value in nutrition. The population abundance of black ants has reduced drastically and they have become scarce in all the agro ecological zones in Western Kenya. Understanding factors influencing the distribution and abundance of C. vidua remains a challenge as C. vidua is an endangered species in many parts of Country Kenya. The decline in the insect population is worrying since black ants are an important source of food across the world. Our study aimed at determining the eco-climatic conditions influencing the distribution of black ants. Several factors and conditions have contributed to the decline in the population of black ants. The study was carried out in different agro ecological zones of Kisumu, Siaya, and Homabay Counties. The research presumed a cross-sectional approach to community representation. The purposive sampling technique was used to select the population for the qualitative study. Data was collected through Focused Group Discussion and Key Informant Interviews to get in-depth knowledge on the factors contributing to the change in the distribution of back ants. Verbatim transcription was done to the audio recorded data then data was translated into English. Thematic analysis was done using ATLAS.ti software version 7.5. The results showed various factors that led to the change in distribution and reduction of the population of black ants emerging across the lower midland zones, the factors include;climate change, advancement in agricultural equipment, land degradation, and habitat destruction. These factors made the emergence of the insect unpredictable. Over the years across the Lower midland zones, there have been changes in the distribution of C. vidua and the population of insects emerging has reduced hence the insect is disappearing.展开更多
Wolbachia is a bacterium that infects many arthropods with horizontal or vertical transmission. The introduction and spreading of Solenopsis invicta in new areas may have influenced the acquisition of Wolbachia as thi...Wolbachia is a bacterium that infects many arthropods with horizontal or vertical transmission. The introduction and spreading of Solenopsis invicta in new areas may have influenced the acquisition of Wolbachia as this ant species spread from its South America origin to other parts of the globe. The wsp gene of Wolbachia was analyzed using the WSP Typing and a similarity analysis was conducted to analyse the sharing of the symbiont among nests of S. invicta ants. The analyses revealed the presence of two groups of Wolbachia: strain A belonging to InvA S. invicta subgroup, and the strain B belonging to Acromyrmex insinuator. The wsp gene and its hypervariable regions are shared among the Wolbachia present in different types of ants inhabiting in the New World. Wolbachia strains found in the nests of S. invicta are ant-specialist symbionts which may have spread by several means among the ant population.展开更多
Foragers use several senses to locate food,and many animals rely on vision and smell.It is beneficial not to rely on a single sense,which might fail under certain conditions.We examined the contribution of vision and ...Foragers use several senses to locate food,and many animals rely on vision and smell.It is beneficial not to rely on a single sense,which might fail under certain conditions.We examined the contribution of vision and smell to foraging and maze exploration under laboratory conditions using Cataglyphis desert ants as a model.Foraging intensity,measured as the number of workers entering the maze and arriving at the target as well as target arrival time,were greater when food,blue light,or both were offered or presented in contrast to a control.Workers trained to forage for a combined food and light cue elevated their foraging intensity with experience.However,foraging intensity was not higher when using both cues simultaneously than in either one of the two alone.Following training,we split between the two cues and moved either the food or the blue light to the opposite maze corner.This manipulation impaired foraging success by either leading to fewer workers arriving at the target cell(when the light stayed and the food was moved)or to more workers arriving at the opposite target cell,empty of food(when the food stayed and the light was moved).This result indicates that ant workers use both senses when foraging for food and readily associate light with food.展开更多
文摘Ants (Formicidae, Hymenoptera) play an important role in seed bank, seedling establishment andplant composition of arid ecosystems. Thus, knowing plant-ant interaction provides useful information formanagers to design restoration and conservation plans. In this study, the roles of desert harvester ants (Messorintermedius and Messor melancholicus) and scavenger ants (Cataglyphis nodus and Lepisiota semenovi) on plantcommunities were investigated in arid ecosystems of southeastern Iran. Two vegetation types weredistinguished in the study area and the nest density of ant species was determined. Furthermore, plantcomposition and soil seed bank were estimated at different distances from the ant nests. Results showed thatthe density of M. intermedius and M. melancholicus nests was higher in dwarf shrub-shrub vegetation type and thedensity of C. nodus and L. semenovi nests was higher in dwarf shrub vegetation type. The harvester and scavengerants had enhanced the seed bank to 55% and 70%, respectively. Therefore, the role of scavenger ants on theplant communities' seed bank was greater than that of harvester ants. Although the scavenger ants were moreinfluential on the annuals and the invasive plant species, the radius impact of the harvester ants on theperennials was greater, i.e., a positive interaction existed between the perennial plants and the harvester ants. C.nodus and L. semenovi played an important role in enhancing the ecosystem's potential for restoration throughestablishment of pioneer species in early stage of succession. The activity of M. intermedius is crucial for thedevelopment and maintenance of climax plant communities in arid ecosystems through assisting the plantspecies' establishment in late stage of succession. It is essential to preserve the diversity of these key ant speciesfor the maintenance and sustainability of shrubs in arid ecosystems.
基金partially funded by a grant from the National Council of Research (Argentina) Number 4678 for the project"Insect Biodiversity of the Monte"
文摘Livestock ranching is one of the main productive activities in arid regions of the world.Grazing produces changes in animal as well as plant communities(e.g.richness,abundance and species dominance relationships).Ants are good biological indicators due to the environmental fidelity of some of their community parameters.We described the functional structure of the ant community in the central Monte of Mendoza,Argentina,and examined the effect of grazing using richness,diversity and the functional group scheme.We used pitfall traps to sample ants at a reserve with 30-year cattle exclusion and at an adjacent ranch.Eleven of the 27 recorded species showed significant differences in their abundance and two species were absent at the ranch.While richness and diversity did not reflect these differences,functional groups did.Hot Climate Specialists were more abundant at the ranch while Cryptic Species and Generalized Myrmicinae increased at the reserve.This study supports the utility of the functional group scheme to study the effects of grazing disturbance in ant communities of arid regions.
文摘We examined the relationship between seasonal livestock grazing (late summer and late winter) and the abundance of two ant species,<em> Dorymyrmex insana and Forelius pruniosus</em>, on three types of plants (mesquite shrubs, snakeweed sub-shrubs, and mixed grasses) dominated by black grama (<em>Bouteloua eriopoda</em>). Stocking rates were adjusted to remove 75% of the available forage. Since Chihuahuan Desert grasslands are not in transition to shrublands, the grasses and some herbaceous plants are the only available forage. We hypothesized that neither rainfall nor cattle grazing would affect the abundance of these ants on mesquite (<em>Prosipis glandulosa</em>) or snakeweed (<em>Gutierrezia sarothrae</em>). Linear regressions of monsoon rainfall on mesquite (<em>Prosopis glandulosa</em>) produced an r<sup>2</sup> nearly equal to that with the annual precipitation. Monsoon rainfall on the evergreen sub-shrub, <em>Gutierrezia sarothrae</em>, resulted in June-July rainfall accounting for 47% - 83% of the variation in densities of <em>D. insana</em> on snakeweed. The number of <em>D. insana</em> was more than double the number of <em>F. pruinosus</em> on grasses, mesquite, and snakeweed. There were significant reductions in the abundance of <em>F. pruinosus</em> on the grass in the grazed plots;each year the plots were grazed. There were no significant effects of grazing on the abundance of either of the ant species sampled from <em>G. sarothrae</em> canopies. There were significantly fewer <em>D. insana</em> on mesquite in summer grazed plots than on<em> P. glandulosa</em> in winter grazed and ungrazed plots in the second and third years of grazing. Pre-grazing effects were compromised by the high annual (more than double) precipitation.
文摘Symbiotic relations are present in the nature and can contribute to the success of the organisms involved. Endophytic fungi live within the leaf tissues without causing any harm to the host plant, and some of them can be a defense mechanism against the attack by the leaf-cutting ants. Ants of the genus <em>Atta</em> are known as leaf-cutting ants and have an obligatory association with the fungus <em>Leucoagaricus gongylophorus</em>, cutting pieces of leaves and bringing them back to the colony to the fungus. The present study aimed to find out the endophytic fungi community of an attractive plant (<em>Acalypha wilkesiana</em>) and a less attractive plant (<em>Colocasia esculenta</em>) to the ants <em>Atta sexdens</em>. We found out that the communities are different in quantity and in composition and 73% of the isolated fungi were from <em>A. wilkesiana</em>, which has fungi known as attractive to leaf-cutting ants, such as genus<em> Colletotrichum</em>, <em>Pestalotiopsis</em>, <em>Phomopsis </em>and <em>Xylaria</em>. On the other hand, in <em>C. esculenta</em>, there was found the genus<em> Fusarium</em>, known to be reject by the leaf-cutting ants, and less fungal diversity than in the attractive plant <em>A. wilkesiana</em>. Therefore, our data suggest that attractivity or repelence of a plant to the leaf-cutting ants could be related to presence or ausence of determinated fungi more than the quantity of fungi present in a leaf.
文摘The ants are one of the mega diverse insets found in all terrestrial environments, and occur in great diversity, richness and abundance, acting at all trophic levels. The present study was conducted to verify the knowledge of ant fauna at Caxiuanã National forest. All available ant literature and some collection in Caxiuanã were compiled and analyzed in EXCEL program. Caxiuanã is one Brazilian Amazonia forest that has good biological conservation. A total of 197 species belonging to 52 genera of the nine subfamilies are present in Caxiuanã. Many studies need to be done in this place to understand the ant community pattern to give base for other studies and proposal for use, management and conservation of this interesting Amazonia place.
文摘The ants are one of the mega diverse insets found in all terrestrial environments, and occur in great diversity, richness and abundance, acting at all trophic levels. The present study was conducted to verify the knowledge of ant fauna at Caxiuanã National forest. All available ant literature and some collection in Caxiuanã were compiled and analyzed in EXCEL program. Caxiuanã is one Brazilian Amazonia forest that has good biological conservation. A total of 197 species belonging to 52 genera of the nine subfamilies are present in Caxiuanã. Many studies need to be done in this place to understand the ant community pattern to give base for other studies and proposal for use, management and conservation of this interesting Amazonia place.
文摘Ants like to live together under the surface of the ground.Different ants are doing different jobs.The worker ants look for food all day long and they are good atrepairing nests.Some food and nests are for the mselves.The rest are for the others.When it is sunny,sometimes they are moving damp food to the outside of their nests in order to make it dry.The soldier ants act as guards and so ldiers.When enemy insects are coming,they swarm towards them.Though many soldier ants often get hurt to death,the rest go on fighting to a finish.An expert on animals made an experiment on ants.He put a burningcandle into anantsnest.He found that the ants moved carefully and in good order.They spent only fifty seconds in putting
文摘In this paper, we have conducted a literature review on the recent developments and publications involving the vehicle routing problem and its variants, namely vehicle routing problem with time windows (VRPTW) and the capacitated vehicle routing problem (CVRP) and also their variants. The VRP is classified as an NP-hard problem. Hence, the use of exact optimization methods may be difficult to solve these problems in acceptable CPU times, when the problem involves real-world data sets that are very large. The vehicle routing problem comes under combinatorial problem. Hence, to get solutions in determining routes which are realistic and very close to the optimal solution, we use heuristics and meta-heuristics. In this paper we discuss the various exact methods and the heuristics and meta-heuristics used to solve the VRP and its variants.
文摘2-tridecanone is a major constitute of defensive secretion in tawny crazy ants, Nylanderia fulva that is an ant species reported to be able to displace red imported fire ants, Solenopsis invicta in the field. 2-tridecanone was proven to be toxic to S. invicta. Although 2-tridecanone is commercially available, utilization of this naturally occurring compound in fire ant management has received little attention. In this study, toxicity and efficacy of two 2-tridecanone formulations were assessed against S. invicta. Two emulsifiable concentrates were prepared using 2-tridecanone as an active ingredient, vegetable oil as a solvent and polyoxyethylene tridecyl ether as a surfactant. Piperonyl butoxide (PBO) was used as a synergist in one formulation. Both formulations showed significant toxicity in laboratory bioassays. In a field trial, at application rate of 5.28 mL/L and 14 days after mound drench treatment, 100% control was achieved for formulation with PBO and 90% control for the formulation without PBO. In conclusion, both formulations had significant efficacy against S. invicta. Due to the low mammalian toxicity of 2-tridecanone, no involvement of hazardous synthetic organic solvents, no phytotoxicity at applied concentrations, and relatively low cost, both formulations are promising alternatives to commercial insecticide products for fire ant mound drench. The outstanding efficacy of both formulations observed in this study warrants further research on their efficacy against other pest insects.
文摘The compositions of two kinds of ants (Formica cunicu Laria and Polyrhachis vicina Roger) were determined with modern apparatuses. The result was that content of crude protein, fat, vitamin E, formic acid were 43.95%, 22.90%, 15.61 mg / Kg, 4.2% respectively forFormica cunicu Laria, and 42.56%, 21 .90%, 131 .2 mg / Kg, 3.8% respectively for Polyrhachlk vicina Roger.
文摘This study was conducted in the Korhogo region in an age gradient of mango orchards. The goal was to assess diversity and determine the influence of the environment on the composition of these organisms. Sampling was done using pitfall traps, threshing and manual collection. A total of 82 ant species were sampled on all plots. The cultivated plots are richer in ant species than the natural environment. Of the three (3) sampling methods, the Manual Collection proved to be more efficient (eff = 79.52%), followed by threshing (eff = 75.15%) and finally the least effective trap pit (eff = 73.39%). The number of individuals of the species varies according to the environment. The highest value was obtained in the young plot (485 individuals), followed by the intermediate plot (478 individuals), then the older plot (426 individuals) and finally the control plot (320 individuals). The species Camponotus acvapimensis was harvested mainly with 159 individuals. On the other hand, the species Lepisiota sp.1;Camponotus rufigenis, Camponotus sericeus and Oecophylla longinoda were specifically harvested in the control, young, intermediate and aged plots, respectively.
文摘Improving routing algorithm performance not only leads to appreciate the quality of data transmission, but also increases the speed of data transfer. In this paper we propose a hybrid method which is a combination of traffic classification by the help of colored pheromones and helping ants method in the intermediate nodes. This combination increases the convergence speed and decreases the delay and Jitter in the network. Also we compare the obtained results with two known routing algorithms that are based on the ant colony.
文摘Black ant, Carebara vidua (Smith) is an edible insect of critical value in nutrition. The population abundance of black ants has reduced drastically and they have become scarce in all the agro ecological zones in Western Kenya. Understanding factors influencing the distribution and abundance of C. vidua remains a challenge as C. vidua is an endangered species in many parts of Country Kenya. The decline in the insect population is worrying since black ants are an important source of food across the world. Our study aimed at determining the eco-climatic conditions influencing the distribution of black ants. Several factors and conditions have contributed to the decline in the population of black ants. The study was carried out in different agro ecological zones of Kisumu, Siaya, and Homabay Counties. The research presumed a cross-sectional approach to community representation. The purposive sampling technique was used to select the population for the qualitative study. Data was collected through Focused Group Discussion and Key Informant Interviews to get in-depth knowledge on the factors contributing to the change in the distribution of back ants. Verbatim transcription was done to the audio recorded data then data was translated into English. Thematic analysis was done using ATLAS.ti software version 7.5. The results showed various factors that led to the change in distribution and reduction of the population of black ants emerging across the lower midland zones, the factors include;climate change, advancement in agricultural equipment, land degradation, and habitat destruction. These factors made the emergence of the insect unpredictable. Over the years across the Lower midland zones, there have been changes in the distribution of C. vidua and the population of insects emerging has reduced hence the insect is disappearing.
基金the Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior(CAPES)for the financial support to the first author
文摘Wolbachia is a bacterium that infects many arthropods with horizontal or vertical transmission. The introduction and spreading of Solenopsis invicta in new areas may have influenced the acquisition of Wolbachia as this ant species spread from its South America origin to other parts of the globe. The wsp gene of Wolbachia was analyzed using the WSP Typing and a similarity analysis was conducted to analyse the sharing of the symbiont among nests of S. invicta ants. The analyses revealed the presence of two groups of Wolbachia: strain A belonging to InvA S. invicta subgroup, and the strain B belonging to Acromyrmex insinuator. The wsp gene and its hypervariable regions are shared among the Wolbachia present in different types of ants inhabiting in the New World. Wolbachia strains found in the nests of S. invicta are ant-specialist symbionts which may have spread by several means among the ant population.
基金We thank the German Research Foundation for funding this research project(DFG,grant no.FO 298/31-1).
文摘Foragers use several senses to locate food,and many animals rely on vision and smell.It is beneficial not to rely on a single sense,which might fail under certain conditions.We examined the contribution of vision and smell to foraging and maze exploration under laboratory conditions using Cataglyphis desert ants as a model.Foraging intensity,measured as the number of workers entering the maze and arriving at the target as well as target arrival time,were greater when food,blue light,or both were offered or presented in contrast to a control.Workers trained to forage for a combined food and light cue elevated their foraging intensity with experience.However,foraging intensity was not higher when using both cues simultaneously than in either one of the two alone.Following training,we split between the two cues and moved either the food or the blue light to the opposite maze corner.This manipulation impaired foraging success by either leading to fewer workers arriving at the target cell(when the light stayed and the food was moved)or to more workers arriving at the opposite target cell,empty of food(when the food stayed and the light was moved).This result indicates that ant workers use both senses when foraging for food and readily associate light with food.