Pheidole oxyops builds subterranean nests, with an external architecture that is distinctive and easily recognizable by its wide and specific entrance hole, measuring up to 12.2 cm in diameter, denoting a pitfall-trap...Pheidole oxyops builds subterranean nests, with an external architecture that is distinctive and easily recognizable by its wide and specific entrance hole, measuring up to 12.2 cm in diameter, denoting a pitfall-trap. In order to study the nests＇ internal architecture, seven nests were excavated; four were identified with neutral talc, while the others were cast in cement and then excavated. Measurements were made in order to gain a better understand- ing of their structures, and a photographic documentation was obtained as well. The excavations revealed that the nests are perpendicular relative to the ground, beginning with a cylindrical channel with a mean length of 13.5 cm, containing irregular formations, and whose diameter becomes progressively narrower until the first chamber is formed. As the channel continues, dish-like chambers appear, interconnected by channels that become progressively narrower and longer, while the chambers are arranged at greater distances from each other as nest depth increases. Both channels and chambers are located on the vertical projection of the entrance hole. Nests may reach a depth of up to 5.09 m, with a number of chambers ranging between 4 and 14.展开更多
Habitat fragmentation is a major cause of biodiversity loss.Fragmentation can alter thermal conditions on the remaining patches,especially at habitat edges,but few studies have examined variations in thermal tolerance...Habitat fragmentation is a major cause of biodiversity loss.Fragmentation can alter thermal conditions on the remaining patches,especially at habitat edges,but few studies have examined variations in thermal tolerance of species in fragmented habitats.Ants are sensitive to both habitat fragmentation and temperature changes,and are an ideal taxon for studying these impacts.Here,we focused on the dimorphic ant species Pheidole nodus in a fragmented habitat island system(Thousand island lake)in China.We assessed critical thermal maximum(CTmax),minimum(CTmin),and range(CTrange)temperatures for both minor(workers)and major workers(soldiers)of 2307 individuals from 117 edge and interior colonies across 9 islands during relatively hot and cold seasons.Using mixed-effect linear models,we explored the effects of island area,habitat type(edge vs.interior),season,and caste(worker vs.soldier)on CTmax,CTmin,and CTrange.We found temperatures were 1-3°C higher in edge than interior sites in relatively hot season.Yet,only CTmax and CTrange in edge populations were higher than those of interior sites on smaller islands.CTmax was higher in relatively hot season and CTmin was lower in relatively cold season,indicating seasonal plasticity in thermal tolerance.Workers consistently had higher CTmax and lower CTmin than soldiers.These findings underscore the importance of seasonality,worker caste,and interactive effect between island area and habitat type in shaping thermal tolerance of a dominant dimorphic ant species on fragmented habitat islands.Our study provides a roadmap for integrating thermal biology into studies of how fragmentation impacts biodiversity.展开更多
Examples of predator–prey interactions in which flies rob ants are uncommon.To date,this behavior has only been recorded in the genus Bengalia Robineau-Desvoidy(Bengaliinae,Diptera,Calliphoridae).These predatory flie...Examples of predator–prey interactions in which flies rob ants are uncommon.To date,this behavior has only been recorded in the genus Bengalia Robineau-Desvoidy(Bengaliinae,Diptera,Calliphoridae).These predatory flies ambush ants,and rob them of the food or offspring that they are carrying.However,because of the rarity of this behavior,the reasons and consequences(evolutionary advantages)are unknown,and indeed,the behavior has been sometimes considered anecdotal.In this study,we employed field investigations and behavioral analyses to investigate whether the sex of the fly Bengalia varicolor,or the weight and quality of the food carried by Pheidole nodus ants influenced fly–ant interactions in their natural habitats.We show that food weight and quality influenced the behavior of B.varicolor independent of the fly’s sex.Robbing behavior by the flies was more successful when the food robbed was of high-quality and light in weight.Furthermore,the weight of the food robbed modulated the escape distance the flies could carry it.This then may affect the food quality and weight transported by the ants.This is a novel example of deciphering the relationship between highwayman flies and their ant victims.Given the widespread distribution of Bengalia flies,we suggest that such interspecific predator–prey encounters may shape the robbery interactions and the carrying behavior of further ant species in nature.展开更多
文摘Pheidole oxyops builds subterranean nests, with an external architecture that is distinctive and easily recognizable by its wide and specific entrance hole, measuring up to 12.2 cm in diameter, denoting a pitfall-trap. In order to study the nests＇ internal architecture, seven nests were excavated; four were identified with neutral talc, while the others were cast in cement and then excavated. Measurements were made in order to gain a better understand- ing of their structures, and a photographic documentation was obtained as well. The excavations revealed that the nests are perpendicular relative to the ground, beginning with a cylindrical channel with a mean length of 13.5 cm, containing irregular formations, and whose diameter becomes progressively narrower until the first chamber is formed. As the channel continues, dish-like chambers appear, interconnected by channels that become progressively narrower and longer, while the chambers are arranged at greater distances from each other as nest depth increases. Both channels and chambers are located on the vertical projection of the entrance hole. Nests may reach a depth of up to 5.09 m, with a number of chambers ranging between 4 and 14.
基金supported by the National Nature Science Foundation of China(#32101278 and#32261160374)China Postdoctoral Science Foun-dation(#2023M731111).
文摘Habitat fragmentation is a major cause of biodiversity loss.Fragmentation can alter thermal conditions on the remaining patches,especially at habitat edges,but few studies have examined variations in thermal tolerance of species in fragmented habitats.Ants are sensitive to both habitat fragmentation and temperature changes,and are an ideal taxon for studying these impacts.Here,we focused on the dimorphic ant species Pheidole nodus in a fragmented habitat island system(Thousand island lake)in China.We assessed critical thermal maximum(CTmax),minimum(CTmin),and range(CTrange)temperatures for both minor(workers)and major workers(soldiers)of 2307 individuals from 117 edge and interior colonies across 9 islands during relatively hot and cold seasons.Using mixed-effect linear models,we explored the effects of island area,habitat type(edge vs.interior),season,and caste(worker vs.soldier)on CTmax,CTmin,and CTrange.We found temperatures were 1-3°C higher in edge than interior sites in relatively hot season.Yet,only CTmax and CTrange in edge populations were higher than those of interior sites on smaller islands.CTmax was higher in relatively hot season and CTmin was lower in relatively cold season,indicating seasonal plasticity in thermal tolerance.Workers consistently had higher CTmax and lower CTmin than soldiers.These findings underscore the importance of seasonality,worker caste,and interactive effect between island area and habitat type in shaping thermal tolerance of a dominant dimorphic ant species on fragmented habitat islands.Our study provides a roadmap for integrating thermal biology into studies of how fragmentation impacts biodiversity.
基金Support for this study was provided by grants from the Key Project of Basic Research of Yunnan Province,China(202101AS070035202201AS070337)+1 种基金the Yunnan Ten Thousand Talents Plan Young&Elite Talents Project(YNWR-QNBJ-2018-017)the CAS Interdisciplinary Innovation Team of“Light of West China”Program,and the National Natural Science Foundation of China(31970443).
文摘Examples of predator–prey interactions in which flies rob ants are uncommon.To date,this behavior has only been recorded in the genus Bengalia Robineau-Desvoidy(Bengaliinae,Diptera,Calliphoridae).These predatory flies ambush ants,and rob them of the food or offspring that they are carrying.However,because of the rarity of this behavior,the reasons and consequences(evolutionary advantages)are unknown,and indeed,the behavior has been sometimes considered anecdotal.In this study,we employed field investigations and behavioral analyses to investigate whether the sex of the fly Bengalia varicolor,or the weight and quality of the food carried by Pheidole nodus ants influenced fly–ant interactions in their natural habitats.We show that food weight and quality influenced the behavior of B.varicolor independent of the fly’s sex.Robbing behavior by the flies was more successful when the food robbed was of high-quality and light in weight.Furthermore,the weight of the food robbed modulated the escape distance the flies could carry it.This then may affect the food quality and weight transported by the ants.This is a novel example of deciphering the relationship between highwayman flies and their ant victims.Given the widespread distribution of Bengalia flies,we suggest that such interspecific predator–prey encounters may shape the robbery interactions and the carrying behavior of further ant species in nature.
