scholarly journals Insects and incest: Sib‐mating tolerance in natural populations of a parasitoid wasp

2020 ◽  
Vol 29 (3) ◽  
pp. 596-609 ◽  
Author(s):  
Marie Collet ◽  
Isabelle Amat ◽  
Sandrine Sauzet ◽  
Alexandra Auguste ◽  
Xavier Fauvergue ◽  
...  
Keyword(s):  
Natural Populations ◽  
Parasitoid Wasp ◽  
Sib Mating

scholarly journals Thermal sensitivity of the Spiroplasma-Drosophila hydei protective symbiosis: The best of climes, the worst of climes

2020 ◽  
Author(s):  
Chris Corbin ◽  
Jordan E. Jones ◽  
Ewa Chrostek ◽  
Andy Fenton ◽  
Gregory D. D. Hurst
Keyword(s):  
Vertical Transmission ◽  
Evolutionary Ecology ◽  
Thermal Environment ◽  
Thermal Sensitivity ◽  
Natural Populations ◽  
Parasitoid Wasp ◽  
Natural Environments ◽  
Protective Capacity ◽  
Drosophila Hydei ◽  
The Impact

AbstractThe outcome of natural enemy attack in insects has commonly been found to be influenced by the presence of protective symbionts in the host. The degree to which protection functions in natural populations, however, will depend on the robustness of the phenotype to variation in the abiotic environment. We studied the impact of a key environmental parameter – temperature – on the efficacy of the protective effect of the symbiont Spiroplasma on its host Drosophila hydei, against attack by the parasitoid wasp Leptopilina heterotoma. In addition, we investigated the thermal sensitivity of the symbiont’s vertical transmission, which may be a key determinant of the ability of the symbiont to persist. We found that vertical transmission was more robust than previously considered, with Spiroplasma being maintained at 25 °C, 18 °C and with 18/15 °C diurnal cycles, with rates of segregational loss only increasing at 15 °C. Protection against wasp attack was ablated before symbiont transmission was lost, with the symbiont failing to rescue the fly host at 18 °C. We conclude that the presence of a protective symbiosis in natural populations cannot be simply inferred from presence of a symbiont whose protective capacity has been tested under narrow controlled conditions. More broadly, we argue that the thermal environment is likely to represent an important determinant of the evolutionary ecology of defensive symbioses in natural environments, potentially driving seasonal, latitudinal and altitudinal variation in symbiont frequency, and modulating the strength of selection for symbiotic protective systems compared to defensive systems encoded in the nuclear genomes.

scholarly journals Insects and incest: sib-mating tolerance in natural populations of a parasitoid wasp

2017 ◽  
Author(s):  
Marie Collet ◽  
Isabelle Amat ◽  
Sandrine Sauzet ◽  
Alexandra Auguste ◽  
Xavier Fauvergue ◽  
...  
Keyword(s):  
Mate Choice ◽  
Inbreeding Depression ◽  
Evolutionary Biology ◽  
Parasitoid Wasp ◽  
Small Scale ◽  
Kin Discrimination ◽  
Laboratory Studies ◽  
Mate Finding ◽  
Venturia Canescens ◽  
Sib Mating

This preprint has been reviewed and recommended by Peer Community In Evolutionary Biology (http://dx.doi.org/10.24072/pci.evolbiol.100047) 1. Sib-mating avoidance is a pervasive behaviour that likely evolves in species subject to inbreeding depression. Laboratory studies have provided elegant demonstrations of sib-mating avoidance, but small-scale bioassays often minimize the costs associated with mate finding and choice, which could lead to spurious findings. 2. We used the hymenopteran parasitoid wasp Venturia canescens as a model organism, because previous laboratory studies revealed that sib-mating led to a 25% decrease in fertile offspring, and that sib-mating was partially avoided. 3. Our study consisted of a mate choice experiment in laboratory cages to determine if kin discrimination occurs in this species. We further performed a field study in which 86 wild-caught males, 155 wild-caught females and their 226 daughters were genotyped at eighteen microsatellite loci. With these data, we reconstructed the genotype of each female ′s mate and estimated the relatedness of each mating pair. 4. Mate choice experiments confirmed that females are capable of discriminating kin. Time to mating depended on the frequency of female encounters with related and unrelated males. Contrary to previously published results, however, no sib-mating avoidance was detected. In the field, the effective rate of sib-mating did not differ from the probability that sibs encounter one other at random, which corroborates the absence of sib-mating avoidance. We also detected a weak but significant male bias in dispersal, which could reduce encounters between sibs. 5. Our results suggest that, despite kin discrimination, V. canescens tolerates sib-mating in the field. The weak male-biased dispersal cannot explain entirely this pattern. This raises the question as to why kin discrimination is maintained in this species. It further calls into question the idea that inbreeding depression occurs in most species with single-locus complementary sex determination.

scholarly journals Selfish element maintains sex in natural populations of a parasitoid wasp

2001 ◽  
Vol 268 (1467) ◽  
pp. 617-622 ◽  
Author(s):  
R. Stouthamer ◽  
M. van Tilborg ◽  
J. H. de Jong ◽  
L. Nunney ◽  
R. F. Luck
Keyword(s):  
Natural Populations ◽  
Parasitoid Wasp ◽  
Selfish Element

Heterosis in F2-Generations of Drosophila-Melanogaster

1989 ◽  
Vol 37 (6) ◽  
pp. 609 ◽  
Author(s):  
NG Ehiobu ◽  
ME Goddard
Keyword(s):  
Drosophila Melanogaster ◽  
Gene Action ◽  
Natural Populations ◽  
Inbred Lines ◽  
Hybrid Breakdown ◽  
Dominance Model ◽  
English Population ◽  
Sib Mating ◽  
Australian English ◽  
F2 Generation

Three crosses among inbred lines of Drosophila melanogaster generated by eight generation full-sib mating, three Australasian population crosses, and two Australian/English population crosses were raised to the F2 generation, to examine evidence of hybrid breakdown. Inbred line crosses produced F2 generations that retained, on average, 54% of the F1 heterosis, which was not significantly different from the retention of 50% F1 heterosis expected under a dominance model of heterosis. Australasian population crosses produced F2 generations with significantly less than 50% of the F1 heterosis, while crosses between Australian and English populations produced a F2 generation that generally performed worse than midparent purebred populations. These results imply epistatic gene action. Because inbred lines contain random combinations of genes, recombination does not necessarily produce hybrid breakdown. However, in crosses between natural populations, recombination is likely to disrupt co-adapted gene combinations leading to poor F2 performance. Populations which rarely exchange migrants are more likely to have alternative gene combinations and to show hybrid breakdown than populations which regularly exchange migrants. The implications of these findings for livestock crossbreeding programs is discussed.

High-voltage electron microscopy of maxillary gland of spirochete-infected brine shrimp: lesion of efferent tubule

1988 ◽  
Vol 46 ◽  
pp. 362-363
Author(s):  
G. E. Tyson ◽  
M. J. Song
Keyword(s):  
Electron Microscopy ◽  
High Voltage ◽  
Brine Shrimp ◽  
Natural Populations ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
High Voltage Electron Microscopy ◽  
Voltage Electron ◽  
High Voltage Electron ◽  
Infected Adult

Natural populations of the brine shrimp, Artemia, may possess spirochete- infected animals in low numbers. The ultrastructure of Artemia's spirochete has been described by conventional transmission electron microscopy. In infected shrimp, spirochetal cells were abundant in the blood and also occurred intra- and extracellularly in the three organs examined, i.e. the maxillary gland (segmental excretory organ), the integument, and certain muscles The efferent-tubule region of the maxillary gland possessed a distinctive lesion comprised of a group of spirochetes, together with numerous small vesicles, situated in a cave-like indentation of the base of the tubule epithelium. in some instances the basal lamina at a lesion site was clearly discontinuous. High-voltage electron microscopy has now been used to study lesions of the efferent tubule, with the aim of understanding better their three-dimensional structure.Tissue from one maxillary gland of an infected, adult, female brine shrimp was used for HVEM study.

Effect of acid deposition on trichome morphology and dogwood anthracnose biology

1992 ◽  
Vol 50 (1) ◽  
pp. 840-841
Author(s):  
Kyle T. Thornham ◽  
R. Jay Stipes ◽  
Randolph L. Grayson
Keyword(s):  
Acid Deposition ◽  
Disease Incidence ◽  
Natural Populations ◽  
Tree Disease ◽  
Flowering Dogwood ◽  
Discula Destructiva ◽  
Disease Induction ◽  
Dogwood Anthracnose ◽  
Trichome Morphology ◽  
Precipitation Events

Dogwood anthracnose, caused by Discula destructiva (1), is another new catastrophic tree disease that has ravaged natural populations of the flowering dogwood (Cornus florida) in the Appalachians over the past 15 years, and the epidemic is prognosticated to continue (2). An estimated 9.5 million acres have been affected, primarily in the Appalachian Mountains, from VA southwards, alone, and an estimated 50% of all dogwoods in PA have been killed. Since acid deposition has been linked experimentally with disease induction, and since the disease incidence and severity are more pronounced at higher elevations where lower pH precipitation events occur, we investigated the effect of acidic foliar sprays on moiphologic changes in the foliar cuticle and trichomes (3), the initial sites of infection and foci of Discula sporulation.

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