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Full-Text Articles in Entomology

Polyandry In The Absence Of Fitness Benefits In A Species With Female-Biased Sexual Size Dimorphism, Marie Claire Chelini, Eileen A. Hebets Aug 2016

Polyandry In The Absence Of Fitness Benefits In A Species With Female-Biased Sexual Size Dimorphism, Marie Claire Chelini, Eileen A. Hebets

Eileen Hebets Publications

Most studies exploring the evolution of female mating systems focus on species in which females are either monandric (mate with a single male) or highly polyandric (mate with multiple males), but less is understood about variation in mating decisions within a species. How and why do females of a single species decide whether or not to copulate with additional mates? In this study we attempt to answer this question in the highly dimorphic crab spider, Mecaphesa celer, whose females may be either monandric or polyandric. We tested three hypotheses: (1) a female’s decision to remate is based on sequential mate …


Nocturnal Foraging Enhanced By Enlarged Secondary Eyes In A Net-Casting Spider, Jay A. Stafstrom, Eileen A. Hebets May 2016

Nocturnal Foraging Enhanced By Enlarged Secondary Eyes In A Net-Casting Spider, Jay A. Stafstrom, Eileen A. Hebets

Eileen Hebets Publications

Animals that possess extreme sensory structures are predicted to have a related extreme behavioral function. This study focuses on one such extreme sensory structure—the posterior median eyes of the net-casting spider Deinopis spinosa. Although past research has implicated the importance of vision in the nocturnal foraging habits of Deinopis, no direct link between vision in the enlarged eyes and nocturnal foraging has yet been made. To directly test the hypothesis that the enlarged posterior median eyes facilitate visually based nocturnal prey capture, we conducted repeated-measures, visual occlusion trials in both natural and laboratory settings. Our results indicate that D. …


Benefits Of Size Dimorphism And Copulatory Silk Wrapping In The Sexually Cannibalistic Nursery Web Spider, Pisaurina Mira, Alissa G. Anderson, Eileen Hebets Feb 2016

Benefits Of Size Dimorphism And Copulatory Silk Wrapping In The Sexually Cannibalistic Nursery Web Spider, Pisaurina Mira, Alissa G. Anderson, Eileen Hebets

Eileen Hebets Publications

In sexually cannibalistic animals, male fitness is influenced not only by successful mate acquisition and egg fertilization, but also by avoiding being eaten. In the cannibalistic nursery web spider, Pisaurina mira, the legs of mature males are longer in relation to their body size than those of females, and males use these legs to aid in wrapping a female’s legs with silk prior to and during copulation. We hypothesized that elongated male legs and silk wrapping provide benefits to males, in part through a reduced likelihood of sexual cannibalism. To test this, we paired females of random size with …


Amblypygids: Model Organisms For The Study Of Arthropod Navigation Mechanisms In Complex Environments?, Daniel D. Wiegmann, Eileen A. Hebets, Wulfila Gronenberg, Jacob M. Graving, Verner P. Bingman Jan 2016

Amblypygids: Model Organisms For The Study Of Arthropod Navigation Mechanisms In Complex Environments?, Daniel D. Wiegmann, Eileen A. Hebets, Wulfila Gronenberg, Jacob M. Graving, Verner P. Bingman

Eileen Hebets Publications

Navigation is an ideal behavioral model for the study of sensory system integration and the neural substrates associated with complex behavior. For this broader purpose, however, it may be profitable to develop new model systems that are both tractable and sufficiently complex to ensure that information derived from a single sensory modality and path integration are inadequate to locate a goal. Here, we discuss some recent discoveries related to navigation by amblypygids, nocturnal arachnids that inhabit the tropics and sub-tropics. Nocturnal displacement experiments under the cover of a tropical rainforest reveal that these animals possess navigational abilities that are reminiscent, …


The Behavioral Ecology Of Amblypygids, Kenneth J. Chapin, Eileen A. Hebets Jan 2016

The Behavioral Ecology Of Amblypygids, Kenneth J. Chapin, Eileen A. Hebets

Eileen Hebets Publications

Arachnologists have uncovered tantalizing details about amblypygid behavioral ecology—the study of the fitness consequences of their behavior. Thus, it is the aim of this review to position Amblypygi as a useful system in which to investigate the principles of animal behavioral ecology. We synthesize amblypygid habitat preference and navigation modalities; predator, prey, parasite, parasitoid, cannibal, and commensal interactions; resource contests and territoriality; mating systems and mate choice; parental investment and sociality; and genetics and genomics as they relate to behavioral ecology. We present ideas for future research in each of these areas and discuss future directions for Amblypygi behavioral ecology …


Absence Of Mate Choice And Postcopulatory Benefits In A Species With Extreme Sexual Size Dimorphism, Marie-Claire Chelini, Eileen A. Hebets Jan 2016

Absence Of Mate Choice And Postcopulatory Benefits In A Species With Extreme Sexual Size Dimorphism, Marie-Claire Chelini, Eileen A. Hebets

Eileen Hebets Publications

Most hypotheses related to the evolution of female-biased extreme sexual size dimorphism (SSD) attribute the differences in the size of each sex to selection for reproduction, either through selection for increased female fecundity or selection for male increased mobility and faster development. Very few studies, however, have tested for direct fitness benefits associated with the latter – small male size. Mecaphesa celer is a crab spider with extreme SSD, whose males are less than half the size of females and often weigh 10 times less. Here, we test the hypotheses that larger size in females and smaller size in males …


Absence Of Mate Choice And Postcopulatory Benefits In A Species With Extreme Sexual Size Dimorphism, Marie Claire Chelini, Eileen Hebets Jan 2016

Absence Of Mate Choice And Postcopulatory Benefits In A Species With Extreme Sexual Size Dimorphism, Marie Claire Chelini, Eileen Hebets

Eileen Hebets Publications

Most hypotheses related to the evolution of female-biased extreme sexual size dimorphism (SSD) attribute the differences in the size of each sex to selection for reproduction, either through selection for increased female fecundity or selection for male increased mobility and faster development. Very few studies, however, have tested for direct fitness benefits associated with the latter – small male size. Mecaphesa celer is a crab spider with extreme SSD, whose males are less than half the size of females and often weigh 10 times less. Here, we test the hypotheses that larger size in females and smaller size in males …