scholarly journals Nematodes Follow a Leader

2021 ◽  
Vol 9 ◽  
Author(s):  
Hilal Erdogan ◽  
Karin Cruzado-Gutierrez ◽  
Glen Stevens ◽  
David Shapiro-Ilan ◽  
Fatma Kaplan ◽  
...  
Keyword(s):  
Population Structure ◽  
Reproductive Success ◽  
Entomopathogenic Nematodes ◽  
Interspecific Interactions ◽  
Aggregation Behavior ◽  
Infected Host ◽  
Trail Following ◽  
Fitness Consequences ◽  
External Stimuli ◽  
Insect Parasites

Aggregated movement and population structure are known in entomopathogenic nematodes, which are obligate insect parasites. Aggregation behavior in the absence of external stimuli suggests communication among individuals, often in the form of trail-following, which has not been shown by nematodes of any kind. Interactions among individuals are an essential basis of following behaviors and can have significant fitness consequences. We explored intraspecific and interspecific interactions among three Steinernema species (S. glaseri, S. carpocapsae, and S. feltiae) in terms of trail following, and fitness outcomes of following heterospecific individuals. We found that the following behavior is context dependent. Following behavior among conspecifics was significantly increased when the lead nematode had prior contact with host cuticle. However, we did not find a clear association between the following response to heterospecific IJs and their reproductive success in a co-infected host.

scholarly journals Does vegetation change over 28 years affect habitat use and reproductive success?

The Auk ◽  
2019 ◽  
Vol 137 (1) ◽  
Author(s):  
Karolina Fierro-Calderón ◽  
Thomas E Martin
Keyword(s):  
Reproductive Success ◽  
Habitat Use ◽  
Nest Survival ◽  
Selection Function ◽  
Patch Use ◽  
Fitness Consequences ◽  
Long Term Changes ◽  
Changes Over Time ◽  
Over Time

Abstract Individuals should prefer and use habitats that confer high fitness, but habitat use is not always adaptive. Vegetation in natural landscapes changes gradually and the ability of species to adaptively adjust their habitat use to long-term changes is largely unstudied. We studied nest patch and territory use over 28 yr in Orange-crowned Warblers (Oreothlypis celata) in a system that has undergone natural long-term changes in vegetation. Abundance of maple (Acer grandidentatum), its preferred nesting habitat, gradually declined from 1987 to 2015. We examined whether habitat use and its fitness consequences changed as the availability of preferred habitat decreased. We used resource selection function models to determine changes over time in the probability of using a nest patch given available patches, and the probability of using a territory given available territories. We estimated nest survival to evaluate changes over time in the fitness consequences of nest patch use. We also compared habitat use (nest patch and territory) and fitness (nest survival) between areas with naturally reduced abundance of maple and experimentally increased abundance of maple (fenced areas). Nest patch use depended on maple abundance and did not change drastically across 28 yr, even though the availability of preferred maple patches decreased over time. In contrast, nest survival tended to decrease over time. We did not see differences in nest patch use and nest survival between unfenced and fenced areas, unlike territory use, which increased with the abundance of maple in fenced areas and decreased in unfenced areas. Our study depicts one example of relatively unchanged habitat use in the face of decreased availability of preferred vegetation across years, with a resulting decrease in reproductive success. Investigating changes in habitat use and fitness consequences for animals exposed to long-term habitat change is necessary to understand adaptive behavioral responses.

scholarly journals Host-Specific Activation of Entomopathogenic Nematode Infective Juveniles

Insects ◽  
2018 ◽  
Vol 9 (2) ◽  
pp. 59 ◽  
Author(s):  
Valentina Alonso ◽  
Shyon Nasrolahi ◽  
Adler Dillman
Keyword(s):  
Entomopathogenic Nematodes ◽  
Morphological Changes ◽  
Entomopathogenic Nematode ◽  
Infection Process ◽  
Bacterial Symbiont ◽  
Infective Juvenile ◽  
Free Living ◽  
Initial Infection ◽  
Host Tissues ◽  
Insect Parasites

Entomopathogenic nematodes (EPNs) are potent insect parasites and have been used for pest control in agriculture. Despite the complexity of the EPN infection process, hosts are typically killed within 5 days of initial infection. When free-living infective juveniles (IJs) infect a host, they release their bacterial symbiont, secrete toxic products, and undergo notable morphological changes. Collectively, this process is referred to as “activation” and represents the point in a nematode’s life cycle when it becomes actively parasitic. The effect of different host tissues and IJ age on activation, and how activation itself is related to virulence, are not well understood. Here, we employed a recently developed bioassay, which quantifies IJ activation, as a tool to address these matters. Appreciating that activation is a key part of the EPN infection process, we hypothesized that activation would positively correlate to virulence. Using the EPNs Steinernema carpocapsae and S. feltiae we found that EPN activation is host-specific and influenced by infective juvenile age. Additionally, our data suggest that activation has a context-dependent influence on virulence and could be predictive of virulence in some cases such as when IJ activation is especially low.

Reproductive strategies in hermaphroditic gastropods: conceptual and empirical approaches

2013 ◽  
Vol 91 (6) ◽  
pp. 367-381 ◽  
Author(s):  
Yumi Nakadera ◽  
Joris M. Koene
Keyword(s):  
Sexual Selection ◽  
Reproductive Success ◽  
Experimental Research ◽  
Reproductive System ◽  
Reproductive Strategy ◽  
Reproductive Strategies ◽  
Sex Allocation ◽  
Fitness Consequences ◽  
The Individual ◽  
Empirical Approaches

An individual optimizes its reproductive success by adopting a particular reproductive strategy. Studying the details of a reproductive strategy leads to an understanding of how sexual selection acts, as the former is the process via which the individual reproduces successfully. Hermaphroditic gastropods display a bewildering diversity of reproductive strategies, which may be due to their mode of gender expression, when compared with well-studied separate-sexed species. Extensive theoretical, observational, and experimental research has been conducted on this topic. However, despite our knowledge about the reproductive system of hermaphroditic gastropods, we still need to fill the gap between pre- and post-copulatory processes and reproductive success. Here, we review and propose conceptual and empirical approaches aimed at understanding reproductive strategies of hermaphroditic gastropods. In sum, our suggestions are (i) to focus on sex-biased traits, (ii) to take biologically reliable measurements at both the pre- and post-copulatory level that relate to reproductive success, and (iii) to examine the fitness consequences of biased sex allocation.

scholarly journals Early experience and parent-of-origin-specific effects influence female reproductive success in mice

2006 ◽  
Vol 2 (2) ◽  
pp. 253-256 ◽  
Author(s):  
Reinmar Hager ◽  
Rufus A Johnstone
Keyword(s):  
Reproductive Success ◽  
Underlying Mechanism ◽  
Short Term ◽  
Female Reproductive Success ◽  
Specific Effects ◽  
Fitness Consequences ◽  
Mixed Litter ◽  
Offspring Growth ◽  
Parent Of Origin

Recent studies on mammals investigating parent-of-origin-specific effects such as genomic imprinting and maternal effects have demonstrated their impact on short-term measures of fitness, for example offspring growth. However, the long-term fitness consequences of parent-of-origin-specific effects and their role outside the immediate mother–offspring interaction remain largely unexplored. Here, we show that female mice mated to males that inherited the same set of paternal and maternal genes as themselves have a higher reproductive success than females mated to males of reciprocal genotype. Furthermore, we demonstrate that the early social environment experienced by an individual influences its reproductive success. Females raised with unrelated siblings in a mixed litter had a subsequent lower reproductive success than those that were fostered together with all their biological siblings in unmixed litters. Our results highlight the important influence of parent-of-origin-specific effects and conditions in early development on long-term reproductive success in mammals and suggest that parent-of-origin-specific effects may provide the underlying mechanism for beneficial coadaptation between genotypes, for example, in mate choice.

scholarly journals Entomopathogenic nematodes increase predation success by inducing cadaver volatiles that attract healthy herbivores

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Xi Zhang ◽  
Ricardo AR Machado ◽  
Cong Van Doan ◽  
Carla CM Arce ◽  
Lingfei Hu ◽  
...  
Keyword(s):  
Reproductive Success ◽  
Natural Enemies ◽  
Entomopathogenic Nematodes ◽  
Entomopathogenic Nematode ◽  
Butylated Hydroxytoluene ◽  
Diabrotica Virgifera ◽  
Major Pest ◽  
Herbivore Species ◽  
Species Specific ◽  
Volatile Cues

Herbivore natural enemies protect plants by regulating herbivore populations. Whether they can alter the behavior of their prey to increase predation success is unknown. We investigate if and how infection by the entomopathogenic nematode Heterorhabditis bacteriophora changes the behavior of healthy larvae of the western corn rootworm (Diabrotica virgifera), a major pest of maize. We found that nematode-infected rootworm cadavers are attractive to rootworm larvae, and that this behavior increases nematode reproductive success. Nematode-infected rootworms release distinct volatile bouquets, including the unusual volatile butylated hydroxytoluene (BHT). BHT alone attracts rootworms, and increases nematode reproductive success. A screen of different nematode and herbivore species shows that attraction of healthy hosts to nematode-infected cadavers is widespread and likely involves species-specific volatile cues. This study reveals a new facet of the biology of herbivore natural enemies that boosts their predation success by increasing the probability of host encounters.

scholarly journals Bolder guppies do not have more mating partners, yet sire more offspring

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Magdalena Herdegen-Radwan
Keyword(s):  
Reproductive Success ◽  
Personality Traits ◽  
Personality Trait ◽  
Poecilia Reticulata ◽  
Direct Evidence ◽  
Animal Groups ◽  
Fitness Consequences

Abstract Background Intra-individual stable but inter-individually variable behaviours, i.e. personalities, are commonly reported across diverse animal groups, yet the reasons for their maintenance remain controversial. Therefore, studying fitness consequences of personality traits is necessary to discriminate between alternative explanations. Results Here, I measured boldness, a highly repeatable personality trait, and reproductive success in male guppies, Poecilia reticulata. I found that bolder males had higher reproductive success than their shyer conspecifics and they sired offspring with females who had larger clutches. Conclusions This result provides direct evidence for fitness consequences of boldness in the guppy. It suggests that the effect may be driven by bolder males mating with more fecund females.

scholarly journals Gone girl: Richardson's ground squirrel offspring and neighbours are resilient to female removal

2019 ◽  
Vol 6 (9) ◽  
pp. 190904 ◽  
Author(s):  
Angela R. Freeman ◽  
Thomas J. Wood ◽  
Kevin R. Bairos-Novak ◽  
W. Gary Anderson ◽  
James F. Hare
Keyword(s):  
Reproductive Success ◽  
Ground Squirrels ◽  
Offspring Survival ◽  
Alarm Calling ◽  
Territory Defence ◽  
Faecal Glucocorticoid Metabolites ◽  
Fitness Consequences ◽  
High Predation ◽  
Pituitary Adrenal Axis ◽  
Urocitellus Richardsonii

Within matrilineal societies, the presence of mothers and female kin can greatly enhance survival and reproductive success owing to kin-biased alarm calling, cooperation in territory defence, protection from infanticidal conspecifics, joint care of young and enhanced access to resources. The removal of mothers by predators or disease is expected to increase the stress experienced by offspring via activation of their hypothalamic-pituitary-adrenal axis, increasing circulating glucocorticoids and reducing offspring survival and reproductive success. Yet, few studies have removed mothers in the post-weaning period to examine the assumed physiological and fitness consequences associated with these mortality events. We examined how the loss of a mother affects juvenile Richardson's ground squirrels' ( Urocitellus richardsonii ) faecal glucocorticoid metabolites and their survival. Given that neighbours are often close kin, we further hypothesized that conspecific removal would similarly diminish the fitness of neighbouring individuals. Upon removing the mother, we detected no impact on offspring or neighbouring conspecific faecal glucocorticoid metabolites in the removal year, or on overwinter survival in the following year. Furthermore, no impact on neighbour reproductive success was detected. Given the high predation rates of ground squirrels in wild populations, resilience to a changing social environment would prove adaptive for both surviving kin and non-kin.

Duetting correlates with territory quality and reproductive success in a suboscine bird with low extra-pair paternity

The Auk ◽  
2019 ◽  
Vol 136 (1) ◽  
Author(s):  
Pedro Diniz ◽  
Regina H Macedo ◽  
Michael S Webster
Keyword(s):  
Reproductive Success ◽  
Cooperative Behavior ◽  
Mate Guarding ◽  
Territory Quality ◽  
Territory Defense ◽  
Extra Pair Paternity ◽  
Female Song ◽  
Fitness Consequences ◽  
Socially Monogamous ◽  
Low Rate

AbstractDuetting has been intensively studied, but we still have little consensus about its fitness consequences. Some studies suggest that duetting functions in acoustic mate guarding to prevent cuckoldry (acoustic paternity guarding hypothesis), whereas other studies argue that duetting is a cooperative behavior to defend common resources (territory defense hypothesis). We tested these 2 hypotheses by investigating the relationships among song traits, extra-pair paternity, territory quality and reproductive success in the Rufous Hornero (Furnarius rufus), a Neotropical, socially monogamous bird. We found a low rate of extra-pair paternity (3.33% of 120 offspring and 6.52% of 46 broods), which suggests that acoustic paternity guarding is probably not a primary function of duetting behavior in this species. Female song output was positively correlated with territory quality, measured as the availability of territory foraging patches. The number of young that survived post-fledging was positively correlated with duet duration, but not with territory features. Our results support the territory defense hypothesis, suggesting that female song in duets might be used in the defense of food resources within territories. Our study provides the first evidence that song traits correlate with both territory features and reproductive success in a duetting species.

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