Host stage preference and performance of the aphid parasitoid Diaeretiella rapae (Hymenoptera: Braconidae) on Brevicoryne brassicae and Lipaphis pseudobrassicae (Hemiptera: Aphididae)

2016 ◽  
Vol 36 (01) ◽  
pp. 10-21 ◽  
Author(s):  
Sylvia W.R. Khakasa ◽  
Samira A. Mohamed ◽  
Zipporah O. Lagat ◽  
Fathiya M. Khamis ◽  
Chrysantus M. Tanga
Keyword(s):  
Host Species ◽  
Oviposition Preference ◽  
Aphid Species ◽  
Brevicoryne Brassicae ◽  
Diaeretiella Rapae ◽  
Pest Species ◽  
Aphid Parasitoid ◽  
Significant Difference ◽  
Host Stage ◽  
And Performance

We assessed the host stage preference and performance of the aphid parasitoidDiaeretiella rapae(McIntosh) on two aphid species,Brevicoryne brassicae(L.) andLipaphis pseudobrassicae(Davis). Although the parasitoid parasitized all nymphal instars of both aphid species, it showed a higher oviposition preference for 2nd (48.2 ± 7.74%) and 3rd (41.0 ± 7.82%) instars ofL. pseudobrassicae, and for the 3rd (40.0 ± 4.59%) instar ofB. brassicae. Across the host species, there was no significant difference in parasitoid preference between the 3rd and 4th instars, while 1st and 2nd instars ofL. pseudobrassicaewere significantly more preferred than their counterparts (B. brassicae). Days to mummification among different instars of the same host was not significantly different when the parasitoid was reared onB. brassicae, whereas this was highest on the 2nd, 3rd and 4th instars ofL. pseudobrassicae. Number of mummies was also significantly different among the nymphal instars of both host species and between the two host species for the 1st and 2nd instars. In terms of body size, femaleD. rapaereared onL. pseudobrassicaewere significantly larger than those reared onB. brassicae. We discuss the findings in the context of laboratory mass rearing ofD. rapaeand its potential as a biological control agent for both aphid pest species.

scholarly journals Differing Effects of Cabbage Defense Responses Induced by MEAM1 and MED Cryptic Species of Bemisia Tabaci on Later-Arriving Conspecifics and Heterospecifics

2021 ◽  
Author(s):  
Youjun Zhang ◽  
Jie Hu ◽  
Jintian Lu ◽  
Nina Yang ◽  
Baiming Liu ◽  
...  
Keyword(s):  
Cryptic Species ◽  
Bemisia Tabaci ◽  
Induced Defense ◽  
Oviposition Preference ◽  
Defense Responses ◽  
Key Factors ◽  
Significant Difference ◽  
Phenylpropanoid Biosynthesis ◽  
And Performance ◽  
Induced Defense Responses

Abstract Two cryptic species of the Bemisia tabaci species complex, MEAM1 (Middle East-Asia Minor 1) and MED (Mediterranean), are highly destructive herbivores. Attack by herbivorous insects often induces defense responses in plants, including the accumulation of toxic secondary metabolites, the synthesis of herbivore-induced plant volatiles (HIPVs) and defensive proteins, and the release of volatile organic compounds that attract natural enemies. These defense responses, which often differ depending on the herbivore, may affect the preference and performance of later-arriving con- and heterospecific whiteflies that attack the same plant. In the present study, we found that MEAM1 whiteflies preferred settling and ovipositing on non-infested and MED-infested cabbage over MEAM1-infested cabbage plants, but that MED whiteflies showed no significant difference in settling or oviposition preference among non-infested, MEAM1-infested, and MED-infested plants. MEAM1 infestation increased the contents of total phenols and flavonoids in cabbage, which coincided with the increased expression of the following genes in the phenylpropanoid biosynthesis pathway: PAL2, C4H, and 4CL1. Soluble protein contents were also markedly higher in the MEAM1-infested cabbage plants than in the non-infested and MED-infested cabbage plants. Overall, these results demonstrate that previous infestation by MEAM1 and MED whiteflies induced defense responses in cabbage plants that had different effects on the host preference and performance of later-arriving con- and heterospecific whiteflies. Phenolic compounds may be the key factors influencing host choice by MEAM1 and MED whiteflies on cabbage plants.

‘Bottom-up’ effects in a tritrophic plant–aphid–parasitoid system: Why being the perfect host can have its disadvantages

2019 ◽  
Vol 109 (6) ◽  
pp. 831-839
Author(s):  
M. Mehrparvar ◽  
A. Rajaei ◽  
M. Rokni ◽  
A. Balog ◽  
H.D. Loxdale
Keyword(s):  
Host Plant ◽  
Block Design ◽  
Aphid Species ◽  
Trophic Levels ◽  
Context Dependency ◽  
Diaeretiella Rapae ◽  
Host Specialization ◽  
Aphid Parasitoid ◽  
Cabbage Aphid ◽  
Genotype Effect

AbstractIn this study the host plant genotype effect on cabbage aphid, Brevicoryne brassicae (L.)(Hemiptera: Aphididae) preference and performance, the effect of aphid genotype on parasitoids performance, as well as the indirect effects of plant genotypes on aphid parasitoid performance, were tested using different population samples of the aphid and its primary endoparasitoid wasp, Diaeretiella rapae (M'Intosh) (Hymenoptera: Braconidae). Experiments were run as fully-factorial randomized block design in a greenhouse. Accordingly, host plant cultivar had significant effects on the total number of aphids and aphid-load whilst the fitness of the aphid genotypes were also influenced by plant cultivar. The effect of parasitism on cabbage aphids was significantly different between plant cultivars. Overall, the results revealed that cabbage aphid is under different selective pressures arising from both higher (parasitoid) and lower (host plant cultivar) trophic levels. The host plant cultivar had a significant effect on both aphid fitness and parasitism rate on particular aphid genotypes. This indicates that host-plant-adapted aphid species can create much context-dependency in the nature and strength of ‘fitness benefits parasitism’, which may in turn alter the costs and benefits of host specialization.

scholarly journals Genetics of wild and mass-reared populations of a generalist aphid parasitoid and improvement of biological control

PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0249893
Author(s):  
Estelle Postic ◽  
Yannick Outreman ◽  
Stéphane Derocles ◽  
Caroline Granado ◽  
Anne Le Ralec
Keyword(s):  
Biological Control ◽  
Genetic Differentiation ◽  
Microsatellite Markers ◽  
Host Species ◽  
Ecological Genetics ◽  
Aphidius Ervi ◽  
Weak Efficiency ◽  
Pest Species ◽  
Aphid Parasitoid ◽  
Local Conditions

Due to their ability to parasitize various insect species, generalist parasitoids are widely used as biological control agents. They can be mass-reared and released in agroecosystems to control several pest species in various crops. However, the existence of genetic differentiation among populations of generalist parasitoid species is increasingly recognized and this can be associated with an adaptation to local conditions or to a reduced range of host species. Moreover, constraints of mass-rearing conditions can alter genetic variation within parasitoid populations released. These features could be associated with a reduced efficiency of the control of targeted pest species. Here, we focused on strawberry greenhouses where the control of aphids with the generalist parasitoid Aphidius ervi appears to be inefficient. We investigated whether this inefficiency may have both genetic and ecological bases comparing wild and commercial populations of A. ervi. We used two complementary genetic approaches: one based on the mitochondrial marker COI and one based on microsatellite markers. COI analysis showed a genetic differentiation within the A. ervi species, but the structure was neither associated with the commercial/wild status nor with host species factors. On the other hand, using microsatellite markers, we showed a genetic differentiation between commercial and wild A. ervi populations associated with a loss of genetic diversity within the mass-reared populations. Our ecological genetics study may potentially explain the weak efficiency of biological control of aphids in protected strawberry crops and enable to provide some insights to improve biological control.

Ecological specialization in Diaeretiella rapae (Hymenoptera: Braconidae: Aphidiinae) on aphid species from wild and cultivated plants

2017 ◽  
Vol 108 (2) ◽  
pp. 175-184 ◽  
Author(s):  
Y. Navasse ◽  
S.A.P. Derocles ◽  
M. Plantegenest ◽  
A. Le Ralec
Keyword(s):  
Reproductive Isolation ◽  
Control Strategies ◽  
Chenopodium Album ◽  
Aphid Species ◽  
Diaeretiella Rapae ◽  
Cultivated Plants ◽  
Ecological Specialization ◽  
Aphid Parasitoid ◽  
Genetic Studies

AbstractDiaeretiella rapae is an aphid parasitoid with potential for use in biological control strategies. However, several recent genetic studies have challenged the long held view that it is a generalist parasitoid. We investigated its ecological specialization and ability to use resources in cultivated and uncultivated areas. Ecological specialization would reduce its ability to exploit the diversity of aphid species, particularly in uncultivated areas, and to control pest aphids. Four D. rapae strains were studied, three reared on pest aphids on Brassicaceae and one strain on a non-pest aphid on Chenopodiaceae. For each strain, we performed host-switching experiments, with a total of six aphid species, five of which D. rapae parasitizes in France. We tested cross-breeding ability between strains to detect potential reproductive isolation linked to aphid host species in D. rapae. The strain reared on non-pest aphids was able to develop on aphid species from both cultivated and uncultivated plants. The strains reared on pest aphids, however, exclusively parasitized aphid species on cultivated Brassicaceae. In addition, reproductive isolation was detected between strains from uncultivated and cultivated plants. Thus, the D. rapae populations examined here appear to be showing ecological specialization or they may even be composed of a complex of cryptic species related to the aphid hosts. The role of Chenopodium album as a reservoir for D. rapae, by providing a habitat for non-pest aphids on which it can feed, appears to be severely limited, and thus its efficiency to maintain local populations of D. rapae in the vicinity of crops is questionable.

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