Multiple phenotypes conferred by a single insect symbiont are independent

Many microbial symbionts have multiple phenotypic consequences for their animal hosts. However, the ways in which different symbiont-mediated phenotypes combine to affect fitness are not well understood. We investigated whether there are correlations between different symbiont-mediated phenotypes. We used the symbiont Spiroplasma , a striking example of a bacterial symbiont conferring diverse phenotypes on insect hosts. We took 11 strains of Spiroplasma infecting pea aphids ( Acyrthosiphon pisum ) and assessed their ability to provide protection against the fungal pathogen Pandora neoaphidis and the parasitoids Aphidius ervi and Praon volucre . We also assessed effects on male offspring production for five of the Spiroplasma strains. All but one of the Spiroplasma strains provided very strong protection against the parasitoid P. volucre . As previously reported, variable protection against P. neoaphidis and A. ervi was also present; male-killing was likewise a variable phenotype. We find no evidence of any correlation, positive or negative, between the different phenotypes, nor was there any evidence of an effect of symbiont phylogeny on protective phenotype. We conclude that multiple symbiont-mediated phenotypes can evolve independently from one another without trade-offs between them.

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Non-consumptive effects stabilize herbivore control over multiple generations

PLoS ONE ◽

10.1371/journal.pone.0241870 ◽

2020 ◽

Vol 15 (11) ◽

pp. e0241870

Author(s):

Kathryn S. Ingerslew ◽

Deborah L. Finke

Keyword(s):

Natural Enemy ◽

Acyrthosiphon Pisum ◽

Empirical Studies ◽

Pea Aphid ◽

Aphidius Ervi ◽

Large Field ◽

Aphidius Colemani ◽

Pea Aphids ◽

Over Time ◽

Aphid Abundance

Understanding the factors that influence predator-prey dynamics requires an investigation of oscillations in predator and prey population sizes over time. However, empirical studies are often performed over one or fewer predator generations. This is particularly true for studies addressing the non-consumptive effects of predators on prey. In a previous study that lasted less than one predator generation, we demonstrated that two species of parasitoid wasps additively suppressed aphid populations through a combination of consumptive and non-consumptive effects. However, the non-consumptive effects of one wasp reduced the reproductive success of the other, suggesting that a longer-term experiment may have revealed antagonism between the wasps. The goal of our current study is to evaluate multi-generation consumptive and non-consumptive interactions between pea aphids (Acyrthosiphon pisum) and the wasps Aphidius ervi and Aphidius colemani. Aphidius ervi is a common natural enemy of pea aphids. Aphidius colemani is a non-consumptive enemy that does not consume pea aphids, but negatively affects pea aphid performance through behavioral disturbance. Large field cages were installed to monitor aphid abundance in response to the presence and absence of both species of wasp over four weeks (two parasitoid generations). We found that the non-consumptive enemy A. colemani initially controlled the pea aphid population, but control in the absence of parasitism was not sustainable over the long term. Aphidius ervi suppressed pea aphids through a combination of consumptive and non-consumptive effects. This suppression was more effective than that of A. colemani, but aphid abundance fluctuated over time. Suppression by A. ervi and A. colemani together was complementary, leading to the most effective and stable control of pea aphids. Therefore, promoting a diverse natural enemy community that contributes to pest control through consumptive and non-consumptive interactions may enhance the stability of herbivore population suppression over time.

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Influence of “protective” symbionts throughout the different steps of an aphid–parasitoid interaction

Current Zoology ◽

10.1093/cz/zoaa053 ◽

2020 ◽

Author(s):

Corentin Sochard ◽

Laura Bellec ◽

Jean-Christophe Simon ◽

Yannick Outreman

Keyword(s):

Life History ◽

Life History Traits ◽

Acyrthosiphon Pisum ◽

Evolutionary Dynamics ◽

Aphidius Ervi ◽

Parasitic Wasps ◽

Aphid Parasitoid ◽

Trade Offs ◽

Defensive Behaviors ◽

Parasitoid Development

Abstract Microbial associates are widespread in insects, some conferring a protection to their hosts against natural enemies like parasitoids. These protective symbionts may affect the infection success of the parasitoid by modifying behavioral defenses of their hosts, the development success of the parasitoid by conferring a resistance against it or by altering life-history traits of the emerging parasitoids. Here, we assessed the effects of different protective bacterial symbionts on the entire sequence of the host-parasitoid interaction (i.e., from parasitoid attack to offspring emergence) between the pea aphid, Acyrthosiphon pisum, and its main parasitoid, Aphidius ervi and their impacts on the life-history traits of the emerging parasitoids. To test whether symbiont-mediated phenotypes were general or specific to particular aphid–symbiont associations, we considered several aphid lineages, each harboring a different strain of either Hamiltonella defensa or Regiella insecticola, two protective symbionts commonly found in aphids. We found that symbiont species and strains had a weak effect on the ability of aphids to defend themselves against the parasitic wasps during the attack and a strong effect on aphid resistance against parasitoid development. While parasitism resistance was mainly determined by symbionts, their effects on host defensive behaviors varied largely from one aphid–symbiont association to another. Also, the symbiotic status of the aphid individuals had no impact on the attack rate of the parasitic wasps, the parasitoid emergence rate from parasitized aphids nor the life-history traits of the emerging parasitoids. Overall, no correlations between symbiont effects on the different stages of the host–parasitoid interaction was observed, suggesting no trade-offs or positive associations between symbiont-mediated phenotypes. Our study highlights the need to consider various sequences of the host-parasitoid interaction to better assess the outcomes of protective symbioses and understand the ecological and evolutionary dynamics of insect–symbiont associations.

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Fight or Flight? Alternative Defense of the Pea Aphids, Acyrthosiphon pisum on Different Host Plants

Insects ◽

10.3390/insects12070614 ◽

2021 ◽

Vol 12 (7) ◽

pp. 614

Author(s):

Martin John Martin ◽

Yueming Li ◽

Li Ma ◽

Yi Feng ◽

Zhiqiang Lu

Keyword(s):

Host Plant ◽

Host Plants ◽

Acyrthosiphon Pisum ◽

Fungal Infections ◽

Alternative Strategies ◽

Immunological Responses ◽

Offspring Production ◽

Broad Beans ◽

Pea Aphids ◽

Fecundity Compensation

Non-immunological responses are important alternative strategies for animals to deal with pathogens. It has long been recognized that fecundity compensation and production of winged offspring are two common non-immunological responses used by aphids when confronted with predators or pathogens. However, the effects of host plant on these responses have received little attention. This study investigated the effects of host plant on non-immunological defense in the pea aphids, Acyrthosiphon pisum, after bacterial and fungal infections. The aphids were raised in two groups, with one group being raised on broad beans and the other group being raised on alfalfa. The secondary symbiont background was examined, and the aphids were then infected with bacteria and fungus to assess fecundity and winged offspring production. We found that aphids that had been fed alfalfa had fewer offspring than those fed broad beans. Alfalfa-fed aphids produced more winged offspring in response to S. aureus and B. bassiana infections. Our findings suggest that the host plant plays a key role in fecundity and winged offspring production in pea aphid colony.

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Influence of intercropping with spring cereals on the occurrence of pea aphids (Acyrthosiphon pisum Harris, 1776) and their natural enemies in field pea (Pisum sativum L.)

Plant Protection Science ◽

10.17221/40/2010-pps ◽

2011 ◽

Vol 47 (No. 1) ◽

pp. 25-36 ◽

Cited By ~ 6

Author(s):

M. Seidenglanz ◽

I. Huňady ◽

J. Poslušná ◽

A.-K. Løes

Keyword(s):

Pisum Sativum ◽

Entomopathogenic Fungi ◽

Natural Enemies ◽

Acyrthosiphon Pisum ◽

Parasitic Wasp ◽

Aphidius Ervi ◽

Pisum Sativum L ◽

Field Peas ◽

Pea Aphids ◽

Spring Cereals

Occurrences of pea aphids and their natural enemies (syrphids, mummies caused by entomopathogenic fungi Beauveria sp. and by the parasitic wasp Aphidius ervi) were compared in monocultures and mixtures of field peas and spring cereals in three seasons (2008–2010). At the beginning of colonisation, the occurrence of aphids was not substantially influenced by intercropping with cereals. However, the numbers of pea aphids located on inflorescences started to decline earlier in mixtures compared with monoculture. More syrphids (eggs + larvae) were found in mixtures than in monoculture, and more syrphid eggs were found in young aphid colonies (10 to 20 individuals) in mixtures. Intercropping did not influence the occurrence of fungal mummies (Beauveria sp.), but mixtures tended to have more aphid colonies infested by A. ervi in 2008 and 2009.  

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Spatially aggregated parasitism on pea aphids, Acyrthosiphon pisum, caused by random foraging behavior of the parasitoid Aphidius ervi

Oikos ◽

10.1034/j.1600-0706.2000.910106.x ◽

2000 ◽

Vol 91 (1) ◽

pp. 66-76 ◽

Cited By ~ 12

Author(s):

Anders C. Olson ◽

Anthony R. Ives ◽

Kevin Gross

Keyword(s):

Foraging Behavior ◽

Acyrthosiphon Pisum ◽

Aphidius Ervi ◽

Pea Aphids

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Genetic identity and genotype × genotype interactions between symbionts outweigh species level effects in an insect microbiome

The ISME Journal ◽

10.1038/s41396-021-00943-9 ◽

2021 ◽

Author(s):

Melanie R. Smee ◽

Sally A. Raines ◽

Julia Ferrari

Keyword(s):

Species Interactions ◽

Acyrthosiphon Pisum ◽

Parasitoid Wasp ◽

Extensive Study ◽

Genetic Identity ◽

Host Genotype ◽

Species Identity ◽

Microbial Symbionts ◽

And Performance ◽

Multiple Species

AbstractMicrobial symbionts often alter the phenotype of their host. Benefits and costs to hosts depend on many factors, including host genotype, symbiont species and genotype, and environmental conditions. Here, we present a study demonstrating genotype-by-genotype (G×G) interactions between multiple species of endosymbionts harboured by an insect, and the first to quantify the relative importance of G×G interactions compared with species interactions in such systems. In the most extensive study to date, we microinjected all possible combinations of five Hamiltonella defensa and five Fukatsuia symbiotica (X-type; PAXS) isolates into the pea aphid, Acyrthosiphon pisum. We applied several ecological challenges: a parasitoid wasp, a fungal pathogen, heat shock, and performance on different host plants. Surprisingly, genetic identity and genotype × genotype interactions explained far more of the phenotypic variation (on average 22% and 31% respectively) than species identity or species interactions (on average 12% and 0.4%, respectively). We determined the costs and benefits associated with co-infection, and how these compared to corresponding single infections. All phenotypes were highly reliant on individual isolates or interactions between isolates of the co-infecting partners. Our findings highlight the importance of exploring the eco-evolutionary consequences of these highly specific interactions in communities of co-inherited species.

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Identification of the main venom protein components of Aphidius ervi, a parasitoid wasp of the aphid model Acyrthosiphon pisum

BMC Genomics ◽

10.1186/1471-2164-15-342 ◽

2014 ◽

Vol 15 (1) ◽

pp. 342 ◽

Cited By ~ 36

Author(s):

Dominique Colinet ◽

Caroline Anselme ◽

Emeline Deleury ◽

Donato Mancini ◽

Julie Poulain ◽

...

Keyword(s):

Acyrthosiphon Pisum ◽

Parasitoid Wasp ◽

Aphidius Ervi ◽

Venom Protein ◽

Protein Components

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Drop when the stakes are high: adaptive, flexible use of dropping behaviour by aphids

Behaviour ◽

10.1163/1568539x-bja10083 ◽

2021 ◽

pp. 1-21

Author(s):

Rosalind K. Humphreys ◽

Graeme D. Ruxton ◽

Alison J. Karley

Keyword(s):

Host Plant ◽

Acyrthosiphon Pisum ◽

Adalia Bipunctata ◽

Macrosiphum Euphorbiae ◽

Herbivorous Insects ◽

Chrysoperla Carnea ◽

Pea Aphids ◽

Potato Aphids ◽

Antipredator Defence

Abstract For herbivorous insects, dropping from the host plant is a commonly-observed antipredator defence. The use of dropping compared to other behaviours and its timing in relation to contact with a predator was explored in both pea aphids (Acyrthosiphon pisum) and potato aphids (Macrosiphum euphorbiae). Pea aphids dropped more frequently in response to ladybird adults (Adalia bipunctata) than lacewing larvae (Chrysoperla carnea). Potato aphids mainly walked away or backed-up in response to both predator types; but they dropped more frequently relative to other non-walking defences when faced with ladybird adults. Contact with a predator was an important influencer of dropping for both species, and most drops occurred from adjacent to the predator. Dropping appears to be a defence adaptively deployed only when the risk of imminent predation is high; factors that increase dropping likelihood include presence of faster-foraging predators such as adult ladybirds, predator proximity, and contact between aphid and predator.

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SEASONAL ABUNDANCE OF THE PEA APHID, ACYRTHOSIPHON PISUM (HOMOPTERA: APHIDIDAE), IN MANITOBA FIELD PEAS

The Canadian Entomologist ◽

10.4039/ent118601-6 ◽

1986 ◽

Vol 118 (6) ◽

pp. 601-607 ◽

Cited By ~ 18

Author(s):

G.A. Maiteki ◽

R.J. Lamb ◽

S.T. Ali-Khan

Keyword(s):

Pisum Sativum ◽

Acyrthosiphon Pisum ◽

Pea Aphid ◽

Seasonal Abundance ◽

Economic Threshold ◽

Field Peas ◽

Pea Aphids

AbstractPea aphids, Acyrthosiphon pisum (Harris), were sampled from 1980 to 1983 in field peas, Pisum sativum (L.), in Manitoba. Sweep and foliage samples were taken in commercial fields and plots. Aphids were found in late May or early June soon after the crop emerged, but populations were low throughout June. Populations increased in July, when the crop was flowering and producing pods, and peaked in the latter half of July or early August in 3 of the 4 years, when pods were maturing. Populations decreased rapidly after the peak, as the plants senesced. In 1980, a drought year, aphid densities were low and the populations peaked in the middle of August. From 1981 to 1983, densities exceeded the economic threshold in all commercial fields and all but one of the plots that were sampled.

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