Carrion beetles （Nicrophorus spp.） use small vertebrate carcasses for food and reproduction. Their ecology and behaviors are highly affected by the availability of carcasses and the surrounding environmental conditi...Carrion beetles （Nicrophorus spp.） use small vertebrate carcasses for food and reproduction. Their ecology and behaviors are highly affected by the availability of carcasses and the surrounding environmental conditions. Our results revealed that in subtropical Fushan, northern Taiwan, N. nepalensis was mainly active in spring （February to May）, and could also be found in autumn （October and November）; but there was no capture record in summer （June to September） and winter （December and January）. A laboratory temperature tolerance study indicated that N. nepalensis adults become inactive at temperatures above 26℃, and had the highest mortality when the temperature was raised from 27℃ to 28℃. Furthermore, N. nepalensis became sexually mature at 20℃, depending on the photoperiod： the longer the day, the lower the percentage of sexually mature 2-week-old females after emergence. In another experiment, N. nepalensis virgins were paired under three possible conditions at Fushan. At 15℃ and 20℃, if carcasses were presented to the pairs within 3 days after emergence, all laid eggs in the second week after emergence. If carcasses were presented 1 week after emergence, most began to reproduce at 20℃ with 12.5 h of daylight. However, at 15℃ with 1 l h of daylight, the carrion beetles hibernated first, and reproduced in the ninth week after emergence. At 25℃ with 14 h of daylight, carrion beetles did not bury the mouse carcasses, the females did not lay eggs, and the adult lifespan was only one-third of that at 20℃. This study revealed that both photoperiod and temperature influence the time needed to reach the sexual maturity of N. nepalensis; and also implied that the narrow temperature tolerance range and dormancy behavior of carrion beetles are highly regulated by those environmental factors.展开更多
Burying beetles Nicrophorus orbicollis exhibit facultative biparental care of young. To reproduce, a male-female burying beetle pair bury and prepare a small vertebrate carcass as food for its altricial young. During ...Burying beetles Nicrophorus orbicollis exhibit facultative biparental care of young. To reproduce, a male-female burying beetle pair bury and prepare a small vertebrate carcass as food for its altricial young. During a breeding bout, male and female behavior changes synchronously at appropriate times and is coordinated to provide effective care for offspring. Although the ecologicaJ and evolutionary factors that shape this remarkable reproductive plasticity are well characterized, the neuromodulation of parental behavior is poorly understood. Juvenile hormone levels rise dramat- ically at the time beetle parents accept and feed larvae, remain highly elevated during the stages of most active care and fall abruptly when care is terminated. However, hormonal fluctuations alone cannot account for this elaborate control of reproduction. The biogenic amines octopamine （OA）, dopamine （DA）, and serotonin （5-HT） mediate a diversity of insect reproductive and social behav- iors. In this study, we measured whole brain monoamine levels in individual male and female bury- ing beetles and compared OA, DA, and 5-HT profiles between breeding （parental） and nonbreed- ing, unmated beetles. Remarkably, after 24 h of care, when parental feeding rates begin to peak, DA brain levels increase in breeding beetles when compared to nonbreeding controls. In contrast, brain OA and 5-HT levels did not change significantly. These results provide the first evidence for a potential role of DA in the modulation of burying beetle parental behavior.展开更多
Background:The breakdown of dead organic matter is driven by a diverse array of organisms and is an important process increasingly impacted by a range of contaminants.While many studies have documented how contaminant...Background:The breakdown of dead organic matter is driven by a diverse array of organisms and is an important process increasingly impacted by a range of contaminants.While many studies have documented how contaminants affect food webs that are fueled by decaying plant litters,much less is known about how contaminants affect organisms that rely on dead animal material.Here,we begin to explore the effects of food contamination—using silver nanoparticles(AgNPs)as a model contaminant—on the carrion beetle Nicrophorus vespilloides that buries carcasses of small vertebrates in soils as food source and larval nursing grounds.Results:Our data show that a single ingestion of a non-lethal dose of 1μg mL^(−1) AgNPs by adult female beetles does not affect overall gut microbial activity but results in shifts in the gut microbial community composition towards pathogens including Alcaligenes,Morganella,and Pseudomonas.While no effects were observed in offspring clutch size,some reductions were visible in clutch weight,number of larvae,and number of eclosing pupae in exposed N.vespilloides in comparison with controls.Repeated ingestion of AgNPs over several weeks led to a decrease in survival of adult beetles,suggesting that more environmentally realistic exposure scenarios can directly affect the success of carcass-feeding animals.Conclusions:Sub-lethal carcass contamination with a model pollutant can affect the gut microbial composition in female beetles and reduce offspring fitness.This encourages consideration of currently overlooked propagation routes of contaminants through necrophagous food webs and inherent consequences for ecological and evolutionary processes.展开更多
文摘Carrion beetles （Nicrophorus spp.） use small vertebrate carcasses for food and reproduction. Their ecology and behaviors are highly affected by the availability of carcasses and the surrounding environmental conditions. Our results revealed that in subtropical Fushan, northern Taiwan, N. nepalensis was mainly active in spring （February to May）, and could also be found in autumn （October and November）; but there was no capture record in summer （June to September） and winter （December and January）. A laboratory temperature tolerance study indicated that N. nepalensis adults become inactive at temperatures above 26℃, and had the highest mortality when the temperature was raised from 27℃ to 28℃. Furthermore, N. nepalensis became sexually mature at 20℃, depending on the photoperiod： the longer the day, the lower the percentage of sexually mature 2-week-old females after emergence. In another experiment, N. nepalensis virgins were paired under three possible conditions at Fushan. At 15℃ and 20℃, if carcasses were presented to the pairs within 3 days after emergence, all laid eggs in the second week after emergence. If carcasses were presented 1 week after emergence, most began to reproduce at 20℃ with 12.5 h of daylight. However, at 15℃ with 1 l h of daylight, the carrion beetles hibernated first, and reproduced in the ninth week after emergence. At 25℃ with 14 h of daylight, carrion beetles did not bury the mouse carcasses, the females did not lay eggs, and the adult lifespan was only one-third of that at 20℃. This study revealed that both photoperiod and temperature influence the time needed to reach the sexual maturity of N. nepalensis; and also implied that the narrow temperature tolerance range and dormancy behavior of carrion beetles are highly regulated by those environmental factors.
文摘Burying beetles Nicrophorus orbicollis exhibit facultative biparental care of young. To reproduce, a male-female burying beetle pair bury and prepare a small vertebrate carcass as food for its altricial young. During a breeding bout, male and female behavior changes synchronously at appropriate times and is coordinated to provide effective care for offspring. Although the ecologicaJ and evolutionary factors that shape this remarkable reproductive plasticity are well characterized, the neuromodulation of parental behavior is poorly understood. Juvenile hormone levels rise dramat- ically at the time beetle parents accept and feed larvae, remain highly elevated during the stages of most active care and fall abruptly when care is terminated. However, hormonal fluctuations alone cannot account for this elaborate control of reproduction. The biogenic amines octopamine （OA）, dopamine （DA）, and serotonin （5-HT） mediate a diversity of insect reproductive and social behav- iors. In this study, we measured whole brain monoamine levels in individual male and female bury- ing beetles and compared OA, DA, and 5-HT profiles between breeding （parental） and nonbreed- ing, unmated beetles. Remarkably, after 24 h of care, when parental feeding rates begin to peak, DA brain levels increase in breeding beetles when compared to nonbreeding controls. In contrast, brain OA and 5-HT levels did not change significantly. These results provide the first evidence for a potential role of DA in the modulation of burying beetle parental behavior.
文摘Background:The breakdown of dead organic matter is driven by a diverse array of organisms and is an important process increasingly impacted by a range of contaminants.While many studies have documented how contaminants affect food webs that are fueled by decaying plant litters,much less is known about how contaminants affect organisms that rely on dead animal material.Here,we begin to explore the effects of food contamination—using silver nanoparticles(AgNPs)as a model contaminant—on the carrion beetle Nicrophorus vespilloides that buries carcasses of small vertebrates in soils as food source and larval nursing grounds.Results:Our data show that a single ingestion of a non-lethal dose of 1μg mL^(−1) AgNPs by adult female beetles does not affect overall gut microbial activity but results in shifts in the gut microbial community composition towards pathogens including Alcaligenes,Morganella,and Pseudomonas.While no effects were observed in offspring clutch size,some reductions were visible in clutch weight,number of larvae,and number of eclosing pupae in exposed N.vespilloides in comparison with controls.Repeated ingestion of AgNPs over several weeks led to a decrease in survival of adult beetles,suggesting that more environmentally realistic exposure scenarios can directly affect the success of carcass-feeding animals.Conclusions:Sub-lethal carcass contamination with a model pollutant can affect the gut microbial composition in female beetles and reduce offspring fitness.This encourages consideration of currently overlooked propagation routes of contaminants through necrophagous food webs and inherent consequences for ecological and evolutionary processes.
