Influence of the aphid pathogen Pandora neoaphidis on the foraging behaviour of the aphid parasitoid Aphidius ervi

Below ground and above ground plant–insect–microorganism interactions are complex and regulate most of the developmental responses of important crop plants such as tomato. We investigated the influence of root colonization by a nonmycorrhizal plant-growth-promoting fungus on direct and indirect defenses of tomato plant against aphids. The multitrophic system included the plant Solanum lycopersicum (‘San Marzano nano’), the root-associated biocontrol fungus Trichoderma longibrachiatum strain MK1, the aphid Macrosiphum euphorbiae (a tomato pest), the aphid parasitoid Aphidius ervi, and the aphid predator Macrolophus pygmaeus. Laboratory bioassays were performed to assess the effect of T. longibrachiatum MK1, interacting with the tomato plant, on quantity and quality of volatile organic compounds (VOC) released by tomato plant, aphid development and reproduction, parasitoid behavior, and predator behavior and development. When compared with the uncolonized controls, plants whose roots were colonized by T. longibrachiatum MK1 showed quantitative differences in the release of specific VOC, better aphid population growth indices, a higher attractiveness toward the aphid parasitoid and the aphid predator, and a quicker development of aphid predator. These findings support the development of novel strategies of integrated control of aphid pests. The species-specific or strain-specific characteristics of these below ground–above ground interactions remain to be assessed.

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Ants defend aphids against lethal disease

Biology Letters ◽

10.1098/rsbl.2009.0743 ◽

2009 ◽

Vol 6 (2) ◽

pp. 205-208 ◽

Cited By ~ 37

Author(s):

Charlotte Nielsen ◽

Anurag A. Agrawal ◽

Ann E. Hajek

Keyword(s):

Social Insects ◽

Natural Enemies ◽

Disease Transmission ◽

Field Experiments ◽

Fungal Infections ◽

Pandora Neoaphidis ◽

Aphid Pathogen ◽

Formica Podzolica

Social insects defend their own colonies and some species also protect their mutualist partners. In mutualisms with aphids, ants typically feed on honeydew produced by aphids and, in turn guard and shelter aphid colonies from insect natural enemies. Here we report that Formica podzolica ants tending milkweed aphids, Aphis asclepiadis , protect aphid colonies from lethal fungal infections caused by an obligate aphid pathogen, Pandora neoaphidis . In field experiments, bodies of fungal-killed aphids were quickly removed from ant-tended aphid colonies. Ant workers were also able to detect infective conidia on the cuticle of living aphids and responded by either removing or grooming these aphids. Our results extend the long-standing view of ants as mutualists and protectors of aphids by demonstrating focused sanitizing and quarantining behaviour that may lead to reduced disease transmission in aphid colonies.

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CONSPECIFIC SUPERPARASITISM IN TWO PARASITOID WASPS, APHIDIUS ERVI HALIDAY AND APHELINUS ASYCHIS WALKER: REPRODUCTIVE STRATEGIES INFLUENCE HOST DISCRIMINATION

The Canadian Entomologist ◽

10.4039/ent1231229-6 ◽

1991 ◽

Vol 123 (6) ◽

pp. 1229-1237 ◽

Cited By ~ 20

Author(s):

B. Bai

Keyword(s):

Reproductive Strategies ◽

Acyrthosiphon Pisum ◽

Aphidius Ervi ◽

Parasitoid Wasps ◽

Host Discrimination ◽

Larval Competition ◽

Parasitoid Species ◽

Aphid Parasitoid ◽

Aphelinus Asychis ◽

Physiological Suppression

AbstractConspecific host discrimination and larval competition in two aphid parasitoid species were studied in the laboratory using the pea aphid, Acyrthosiphon pisum (Harris) (Homoptera: Aphididae), as a host. Aphidius ervi Haliday (Hymenoptera: Aphidiidae) used internal host cues to discriminate between unparasitized and conspecific parasitized hosts. When only parasitized hosts were available, females oviposited into recently parasitized ones where their progeny had a good chance to survive, but rejected those parasitized ≥24 h earlier where their offspring normally died. Competitions occurred only after both eggs had hatched. Larvae eliminated supernumeraries by means of physical combat and physiological suppression. In Aphelinus asychis Walker (Hymenoptera: Aphelinidae), factors, or changes in host internal condition, associated with hatching of the first egg resulted in suppression of conspecific competitors which could be in either larval or egg stage. The older larvae always won competitions through physiological means. A wasp’s oviposition decision is shown to be influenced by the probability of its progeny’s survival. Species that have different reproductive strategies may respond differently to identical host conditions.

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Pandora neoaphidis transmission and aphid foraging behaviour

Journal of Invertebrate Pathology ◽

10.1016/j.jip.2005.05.009 ◽

2005 ◽

Vol 90 (1) ◽

pp. 73-76 ◽

Cited By ~ 13

Author(s):

J. Baverstock ◽

P.G. Alderson ◽

J.K. Pell

Keyword(s):

Foraging Behaviour ◽

Pandora Neoaphidis

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Flying with a ‘death sentence’ on board: electrophoretic detection of braconid parasitoid larvae in migrating winged grain aphids, Sitobion avenae (F.)

Bulletin of Entomological Research ◽

10.1017/s000748531000074x ◽

2011 ◽

Vol 101 (4) ◽

pp. 443-449 ◽

Cited By ~ 7

Author(s):

M.P. Walton ◽

H.D. Loxdale ◽

L.J. Allen-Williams

Keyword(s):

Fungal Infection ◽

Fungal Pathogens ◽

Polyacrylamide Gel Electrophoresis ◽

Sitobion Avenae ◽

Aphidius Ervi ◽

Death Sentence ◽

Cereal Aphid ◽

Aphid Parasitoid ◽

Aphidius Rhopalosiphi ◽

Population Structure And Dynamics

AbstractPolyacrylamide gel electrophoresis of enzymes (carboxylesterases) was used for the first time to monitor rates of parasitism in airborne alate (winged) grain aphid, Sitobion avenae (F.) population samples collected by suction trapping in Hertfordshire, UK. Using previously described electrophoretic ‘keys’, the species of hymenopterous parasitoids present in individual aphids were identified and found to be Aphidius ervi (Haliday) and/or Aphidius rhopalosiphi (De Stephani Perez) (Braconidae). Entomophthoralean fungal infection was also detected using this approach. Aphidiid wasp parasitism was detected from early June to mid-August and fungal infection from late June to late July. The results are discussed in relation to parasitoid population structure and dynamics, especially (i) the fact that winged aphids passively transport the early stages of their braconid parasitoids and fungal pathogens, potentially to newly-founded colonies, which may directly impact on the dual aphid-parasitoid populations genetics; and (ii) the approach used to collect and assay parasitised and fungal infected aphids involving both suction trapping and electrophoretic testing may have potential in assessing the level and efficacy of these biological control agents in integrated pest management (IPM) schemes to combat cereal aphid outbreaks.

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