Lysiphlebus Fabarum Research Articles

Population Dynamic of Aphis gossypii, and Their Parasitoids, and Effect of Some Insecticides on Aphids, Chlorophyll Content, Non-Enzymatic and Antioxidant Enzymes Activity in Cantaloupe Leaves in Greenhouses

Under green house, the Population density of Aphis gossypii on cantaloupe plants recorded two peaks on May 9th and 23th with 1409 and 1561 individuals/ 10 leaves in season 2022, while one highest peak, on 16th May with 1650 individuals/ 10 leaves in season 2023. Parasitism status of Aphidius colemani and Lysiphlebus fabarum varied from 1.49% on 25 April to 35.79% on 9th of May with seasonal parasitism 2023 in 2022 and ranged between 0.73% on 25th of April and 30.06% on 16th of May with seasonal parasitism 16.57% in 2023. Acetamiprid, imidacloprid, imidacloprid + abamectin, jojoba oil, orange oil and thiamethoxam + abamectin compounds were tested to control aphids during two seasons. Imidacloprid recorded the highest reduction with all average 97.88 ±1.15 and 97.39 ±1.15 in the first and second season respectively. the highest mean reduction of emergence of the two-parasites caused by thiamethoxam + abamectin by 16.92% followed by Imidacloprid with 16.87%. While the least toxicity to emergence of the parasitoids recorded with jojoba oil 0.0% followed by orange oil 1.93% in season 2022, while in season 2023, the higher parasitoid reduction caused by acetamiprid 18.05% followed by Imidacloprid 17.69% and thiamethoxam + abamectin 17.53%. Chlorophyll content increased with treatment jojoba oil followed by Imidacloprid by 47.91 and 44.73 unit in the first season and Thiamethoxam with abamectin lead to the highest content by 44.05 unit in the leaves followed by jojoba oil with 43.65 unit. The least treatment was Imidacloprid + abamectin with 39.55 unit compared with control treatment 40.43 unit. Treatment Thiamethoxam + abamectin recorded the highest content of carbohydrates (48.43) compared with control (47.71). Treatments of insecticides led to increase of protein, fats and total lipid compared with control. Also, Antioxidant enzymes activity in cantaloupe leaves were found to be increased in the treatment of insecticides compared with control.

Parasitoid species diversity has no effect on protective symbiont diversity in experimental host-parasitoid populations.

How does diversity in nature come about? One factor contributing to this diversity are species interactions; diversity on one trophic level can shape diversity on lower or higher trophic levels. For example, parasite diversity enhances host immune diversity. Insect protective symbionts mediate host resistance and are, therefore, also engaged in reciprocal selection with their host's parasites. Here, we applied experimental evolution in a well-known symbiont-aphid-parasitoid system to study whether parasitoid diversity contributes to maintaining symbiont genetic diversity. We used caged populations of black bean aphids (Aphis fabae), containing uninfected individuals and individuals infected with different strains of the bacterial endosymbiont Hamiltonella defensa, which protects aphids against parasitoids. Over multiple generations, these populations were exposed to three different species of parasitoid wasps (Aphidius colemani, Binodoxys acalephae or Lysiphlebus fabarum), simultaneous or sequential mixtures of these species or no wasps. Surprisingly, we observed little selection for H. defensa in most treatments, even when it clearly provided protection against a fatal parasitoid infection. This seemed to be caused by high induced costs of resistance: aphids surviving parasitoid attacks suffered an extreme reduction in fitness. In marked contrast to previous studies looking at the effect of different genotypes of a single parasitoid species, we found little evidence for a diversifying effect of multiple parasitoid species on symbiont diversity in hosts.

Species and population distribution of plant aphids in agrobiocenose of southeast regions of Uzbekistan

In the years 2022 and 2023, comprehensive investigations and experiments were conducted in the Sardoba district of the Syrdarya region. These efforts aimed to address the threat posed by plant aphids to cotton, vegetable, and rice crops. In 2022, scientific interventions were carried out across a total area of 130 hectares, followed by an expansion to 180 hectares in 2023. The scientific endeavors were centered on identifying and systematically analyzing the types of pests prevalent in the vegetable agrobiocenosis of the Syrdarya region. The research findings revealed the widespread presence of various pests, including moths, white butterflies, spider mites, and plant aphids. Among these, special attention was directed towards studying members of the Aphididae family within the Homoptera order. Moreover, the investigation extended to identifying their natural predators, known as entomophagous species. Specifically, entomophagous species such as Coccinella septempunctata, Chrysopa carnea, and Lysiphlebus fabarum were identified as playing significant roles in regulating the population of plant aphids and maintaining ecological balance. These genera act as natural enemies of aphids, helping to control their numbers and prevent widespread infestations that could damage agricultural crops. This holistic approach not only mitigates the negative impacts of pest outbreaks but also fosters biodiversity and ecosystem resilience. The findings of these investigations provide valuable insights into the ecological dynamics of agricultural ecosystems in the Syrdarya region, Uzbekistan and contribute to the development of integrated pest management practices.

High specificity of symbiont-conferred resistance in an aphid-parasitoid field community.

Host-parasite coevolution is mediated by genetic interactions between the antagonists and may lead to reciprocal adaptation. In the black bean aphid, Aphis fabae fabae, resistance to parasitoids can be conferred by the heritable bacterial endosymbiont Hamiltonella defensa. H. defensa has been shown to be variably protective against different parasitoid species, and different genotypes of the black bean aphid's main parasitoid Lysiphlebus fabarum. However, these results were obtained using haphazard combinations of laboratory-reared insect lines with different origins, making it unclear how representative they are of natural, locally (co)adapted communities. We therefore comprehensively sampled the parasitoids of a natural A. f. fabae population and measured the ability of the five most abundant species to parasitize aphids carrying the locally prevalent H. defensa haplotypes. H. defensa provided resistance only against the dominant parasitoid L. fabarum (70% of all parasitoids), but not against less abundant parasitoids, and resistance to L. fabarum acted in a genotype-specific manner (G × G interactions between H. defensa and L. fabarum). These results confirm that strong species- and genotype-specificity of symbiont-conferred resistance is indeed a hallmark of wild A. f. fabae populations, and they are consistent with symbiont-mediated adaptation of aphids to the parasitoids posing the highest risk.

Replenishment of the species composition of the bioresource collection of Entomoacariphages

Aim. Formation of the species composition of the bioresource collection "State Collection of Entomoacariphages and Microorganisms" of the Lazarev Experimental Plant Protection Station – a branch of Federal Scientific Centre for Biological Plant Protection. The collection is based on species identified in local biocenoses as well as those introduced from regions with similar climatic conditions.Material and Methods. Collection and study of the effectiveness of native, invasive, introduced entomophages, the dynamics of their acclimatization and the possibility of their introduction into laboratory culture on the territory of the Black Sea coast of Sochi. Methods of their application in plant protection systems were tested.Results. The ability of Cryptolaemus montrouzieri Muls. to control the number of coccids, including Icerya purchase Maskell, has been experimentally established. Entomophages which are effective and adaptable to reproduction in laboratory conditions were selected: Dicyphus errans Wolff. and Macrolophus nubilis H.S., the aphidophage Harmonia axyridis Pall. and others.Conclusion. As a result of the study, wide polyphages of Dicyphus errans Wolff were found to be presented in the collection of the Lazarev Experimental Plant Protection Station, as well as and Macrolophus nubilis H.S., Cryptolaemus montrouzieri Muls., Leis dimidiata Fabr., Harmonia axyridis Pall., Encarsia partenopea Masi and Lysiphlebus fabarum Marsh. Acariphages are represented by Phytoseiulus persimilis Ath.‐Henr. and Amblyseius cucumeris Ond. The biological efficacy of Encarsia partenopea Masi has been evaluated in relation to Trialeurodes vaporariorum Westw. in the conditions of the protected ground of Sochi at the parasite ratio:host of 1:30; 68.6%, the best result being obtained with releases of 1:10; 79.19%. Research has begun on the development of methods for the laboratory breeding of Chilocorus renipustulatus.

Potential Impact of Lysiphlebus fabarum (Marshall) Parasitoid against Cowpea Aphid

Potential Impact of Lysiphlebus fabarum (Marshall) Parasitoid against Cowpea Aphid

Arsenophonus: A Double-Edged Sword of Aphid Defense against Parasitoids.

It is widely accepted that endosymbiont interactions with their hosts have significant effects on the fitness of both pests and beneficial species. A particular type of endosymbiosis is that of beneficial associations. Facultative endosymbiotic bacteria are associated with elements that provide aphids with protection from parasitoids. Arsenophonus (Enterobacterales: Morganellaceae) is one such endosymbiont bacterium, with infections being most commonly found among the Hemiptera species. Here, black cowpea aphids (BCAs), Aphis craccivora Koch (Hemiptera: Aphididae), naturally infected with Arsenophonus, were evaluated to determine the defensive role of this bacterium in BCAs against two parasitoid wasp species, Binodoxys angelicae and Lysiphlebus fabarum (both in Braconidae: Aphidiinae). Individuals of the black cowpea aphids infected with Arsenophonus were treated with a blend of ampicillin, cefotaxime, and gentamicin (Arsenophonus-reduced infection, AR) and subsequently subjected to parasitism assays. The results showed that the presence of Arsenophonus does not prevent BCAs from being parasitized by either B. angelicae or L. fabarum. Nonetheless, in BCA colonies parasitized by B. angelicae, the endosymbiont delayed both the larval maturation period and the emergence of the adult parasitoid wasps. In brief, Arsenophonus indirectly limits the effectiveness of B. angelicae parasitism by decreasing the number of emerged adult wasps. Therefore, other members of the BCA colony can survive. Arsenophonus acts as a double-edged sword, capturing the complex dynamic between A. craccivora and its parasitoids.

Predation potential of flower fly Eupeodes nuba (Wiedemann, 1830) (Diptera: Syrphidae) on black bean aphid Aphis fabae Scopoli (Hemiptera: Aphididae) and the parasitoids species on its host in the field

The flower fly species, Eupeodes nuba (Wiedemann, 1830) (Diptera: Syrphidae) is crucial for agroecosystems as it provides various ecosystem services such as pest control through the use of predatory larvae and crop pollination by adults. In this research, the consumption rate of different instars of Aphis fabae (Scopoli, 1763) by E. nuba larvae has been studied under laboratory conditions at 25±2 °C, 60±10% humidity (RH). Fifty aphids and one larva of flower fly were present in each replicate. The results showed that the maximum number of A. fabae consumed by the larvae of E. nuba was 49.13 individuals at the third instar, followed by 35.73 individuals of aphids at the second instar and 16.26 individuals for the first instar of the predator. The highest daily consumption of aphids occurred during the third instar of the predator. A. fabae was heavily parasitized by different aphid parasitoids, Binodoxys acalephae (Marshall, 1896), Lysiphlebus fabarum (Marshall, 1896), and Aphelinus asychis (Walker, 1839) on the broad bean. Parasitization rates of these parasitoids increased during the broad bean plant season. The first recording of A. fabae as a new host for A. psychic. The survey of three parasitoids indicated that L. fabarum had the highest population in December, the parasitoid B. acalephae was the highest in January, and the highest population of A. asychis was recorded in February. It seems that biological control can be used as an alternative to chemical pesticides to control A. fabae.

THE EFFECT OF SOME ATTRACTANT PLANTS Lysiphlebus fabarum PARASITISM ON GREEN PEACH AHIDS Myzus persicae AND BLACK BEAN APHIDS Aphis fabae

This study was conducted in the fields of the College of Agriculture and Forestry / the University of Mosul, to identify the effect of plant species that attract parasites, which included (chamomile, coriander, and basil) in increasing the efficiency of the parasite Lysiphlebus fabarum in biological control programs. The results indicated that the chamomile as an L. fabarum attracting plant gave a height average mummy to Myzus persicae and Aphis fabae gave (45.06 ± 8.78, 262.00 ± 12.16) mummy, followed by the coriander plant which showed (35.80 ± 9.15 and 215.00 ± 8.71) mummy for each Myzus persicae and Aphis fabae, respectively. The basil plant showed the least average number of mummies for the two insects (25.78 ± 2.77 and 192.33 ± 13.65) mummy reach of the Myzus persicae and Aphis fabae. However, it was higher than the control upon the Myzus persicae and Aphis fabae (14.71 ± 2.70 and 124.33 ± 22.27) mummy, respectively. The parasitism rate was affected by the increase in the number of mummies, where the chamomile plant showed the highest parasitization rate on Myzus persicae (70.47 ± 4.05) %, followed by the coriander plant (65.90 ± 5.63%), then basil plant (52.77 ±2.24) %, while the control treatment was the least in parasitism (30.38 ± 4.09) %. On the other hand, the percentage of parasitism on Aphis fabae was superior in all treatments of Aphis fabae above the control group (63.29 ± 2.22, 62.16 ± 1.82, 59.66 ± 5.79 and 30.29 ± 1.52).

Parasitic entomophages against plant lice in vegetable agrobioticenose

The negative impact of pests on world agriculture is estimated at 1.4 trillion dollars, which is 5% of the global gross domestic product. In order to save the crops lost due to agricultural pests in the world, it is of urgent importance to develop effective and fundamentally based control measures against them. In this research, the main studied pests were Aphis craccovora Koch; Aphis gossypii Glow; Brevicoryne brassicae, Lysiphlebus fabarum Marsch, which is parasitic entomophages of Rhopalosiphum nymphaeae and sucking pests. It was found that the parasitic worm Aphis gossypii infects plant juices was on average 79.6 + 0.03. The parasite developed in this type of plant aphids lived for 7.1+0.02 days, the sex ratio was 1:5 (♂:♀). When the mummified and swollen plant aphids were examined due to infection with the parasite, it was found that the degree of damage to the host’s offspring was 67.2%.

Phenology of the black bean aphid, Aphis fabae, on organic crops and effect of parasitoid communities

The data that support the findings of this study is available in the Mendeley Data repository: https://DOI: 10.17632/wnvt4grz9d.1.

Effect of parasitic entomophages in controlling plant lice pests in vegetable crops and their numbers

The impact of pests and diseases on agricultural crops has been amplified due to global environmental changes, resulting in an estimated adverse effect of 1.4 trillion dollars, which is approximately 5% of the world's gross domestic product. Research was conducted on various species of parasitic entomophages, such as Aphidius matricaria Hal, Aphidius gifuensis Ashm, Lysiphlebus japonica Tokawa, Aphidius ervi Hal, Lysiphlebus fabarum Marsh, Lysiphlebus fritzmuelleri Mack, and Lysiphlebus testaceipes Creeson, to determine their efficacy in controlling plant lice. The biological efficiency of the parasite in Aphis craccivora was 52.5%. As well as Aphis gossypii Glow, Acyrthosiphon gossypii Glow. parasite infection of species was 42.1-38.4%. Praon volucre Hal parasite in Aphis craccivora was 49.6%. Aphis Gossypii Glow phytophage infestation was 56.3%, while Acyrthosiphon gossypii Glow plant aphid infestation with Praon volucre Hal was 42.4%.

Biological and molecular characterization of Cladosporium sp. and Acremonium zeylanicum as biocontrol agents of Aphis fabae in a tri‐trophic system

AbstractEntomopathogenic fungi (EPF) are the most important category of microbial agents and considered to be crucial elements in biological control. In this study, two species of EPF, Cladosporium sp. AF98 (Ascomycota: Davidiellaceae) and Acremonium zeylanicum IR87 (Petch) W. Gams & H.C. Evans (Ascomycota: Hypocreaceae), were isolated from infected individuals of the citrus cottony scale, Pulvinaria aurantia Cockerell (Hemiptera: Coccidae), and the melon aphid, Aphis gossypii Glover (Hemiptera: Aphididae), respectively. Based on the nucleotide sequence of the ribosomal DNA, the fungal isolates were subjected to molecular identification and phylogenetic analysis. Pathogenicity of the fungal isolates to the black bean aphid, Aphis fabae Scopoli, was evaluated under laboratory conditions. Both fungal isolates caused considerable aphid mortality and no significant differences were observed in pathogenicity of the isolates. The severity of the fungal isolate effect on the aphid increased as the conidial concentration increased. Time was found to be a more important factor than conidia concentration in isolate efficacy. Olfactory experiments indicated that Lysiphlebus fabarum Marshall (Hymenoptera: Braconidae, Aphidiinae), an important parasitoid wasp of A. fabae, can detect cues from the fungus‐infected aphids and can avoid them. Therefore, fungal isolates have considerable potential for the microbiological control of the aphid and are also compatible with other means of biological control of the pest.

Strong genotype-by-genotype interactions between aphid-defensive symbionts and parasitoids persist across different biotic environments.

The dynamics of coevolution between hosts and parasites are influenced by their genetic interactions. Highly specific interactions, where the outcome of an infection depends on the precise combination of host and parasite genotypes (G × G interactions), have the potential to maintain genetic variation by inducing negative frequency‐dependent selection. The importance of this effect also rests on whether such interactions are consistent across different environments or modified by environmental variation (G × G × E interaction). In the black bean aphid, Aphis fabae, resistance to its parasitoid Lysiphlebus fabarum is largely determined by the possession of a heritable bacterial endosymbiont, Hamiltonella defensa, with strong G × G interactions between H. defensa and L. fabarum. A key environmental factor in this system is the host plant on which the aphid feeds. Here, we exposed genetically identical aphids harbouring three different strains of H. defensa to three asexual genotypes of L. fabarum and measured parasitism success on three common host plants of A. fabae, namely Vicia faba, Chenopodium album and Beta vulgaris. As expected, we observed the pervasive G × G interaction between H. defensa and L. fabarum, but despite strong main effects of the host plants on average rates of parasitism, this interaction was not altered significantly by the host plant environment (no G × G × E interaction). The symbiont‐conferred specificity of resistance is thus likely to mediate the coevolution of A. fabae and L. fabarum, even when played out across diverse host plants of the aphid.

The transgenerational consequences of maternal parasitism for aphid life history and suitability for subsequent parasitism.

Aphids parasitized in later instars can give birth to several nymphs before their reproduction is curtailed by the developing parasitoid. We examined the life histories of Aphis fabae Scopoli born to mothers parasitized by Lysiphlebus fabarum Marshall, and their suitability as subsequent hosts, to test the 'fecundity compensation' hypothesis. Maternal parasitism negatively impacted life history parameters, resulting in reduced estimates of population increase (rm, R0, and λ), and increased generation time (GT) and doubling time (DT). These impacts were greater when the larva developing in the mother turned out to be female rather than male, and greater still when mothers were superparasitized. Maternal parasitism produced aphids with shorter hind tibia (HTL), at birth and at maturity, but their developmental time was unaffected. Although female L. fabarum readily accepted such aphids for oviposition, rates of mummification and wasp emergence were lower, and more so when the maternal parasitoid was female. The resulting parasitoids took longer to develop than progeny from control wasps, had shorter HTLs, lower egg loads, smaller eggs, and produced fewer mummies with lower rates of adult emergence, all differences that were more pronounced when the maternal parasitoid was female. The progeny of these wasps exhibited similar impairments to these biological parameters as their parents, demonstrating that the negative impacts of development in maternally parasitized hosts extended for at least two generations. Thus, our results do not support fecundity compensation, but suggest that any benefits of post-parasitism reproduction will be offset by reduced fitness in both aphid progeny and the parasitoids that develop in them.

Quantitative trait locus analysis of parasitoid counteradaptation to symbiont-conferred resistance

Insect hosts and parasitoids are engaged in an intense struggle of antagonistic coevolution. Infection with heritable bacterial endosymbionts can substantially increase the resistance of aphids to parasitoid wasps, which exerts selection on parasitoids to overcome this symbiont-conferred protection (counteradaptation). Experimental evolution in the laboratory has produced counteradapted populations of the parasitoid wasp Lysiphlebus fabarum. These populations can parasitize black bean aphids (Aphis fabae) protected by the bacterial endosymbiont Hamiltonella defensa, which confers high resistance against L. fabarum. We used two experimentally evolved parasitoid populations to study the genetic architecture of the counteradaptation to symbiont-conferred resistance by QTL analysis. With simple crossing experiments, we showed that the counteradaptation is a recessive trait depending on the maternal genotype. Based on these results, we designed a customized crossing scheme to genotype a mapping population phenotyped for the ability to parasitize Hamiltonella-protected aphids. Using 1835 SNP markers obtained by ddRAD sequencing, we constructed a high-density linkage map consisting of six linkage groups (LGs) with an overall length of 828.3 cM and an average marker spacing of 0.45 cM. We identified a single QTL associated with the counteradaptation to Hamiltonella in L. fabarum on linkage group 2. Out of 120 genes located in this QTL, several genes encoding putative venoms may represent candidates for counteradaptation, as parasitoid wasps inject venoms into their hosts during oviposition.

First Records of Lysiphlebus fabarum and L. fritzmulleri1 in Mexico, and Impact of Insecticides on Parasitism of Melanaphis sacchari2 on Sorghum

The objective of the study was to identify parasitoids and amounts of parasitism of the sugarcane aphid, Melanaphis sacchari (Zehntner), in 15 commercial fields of sorghum (Sorghum bicolor (L.) Moench) at Valle del Evora, near Guamuchil, Sinaloa, during the spring growing season of 2020. Three braconid parasitoids emerged from M. sacchari: Lysiphlebus testaceipes (Cresson), L. fabarum (Marshall), and L. fritzmulleri, with the latter two species being first reports for Mexico. Significantly less parasitism (52%) was observed in fields treated with sulfoxaflor, as compared to parasitism (93%) in nontreated fields.

Наездники (Hymenoptera, Aphelinidae, Aphidiidae) - паразиты тлей (Hemiptera, Aphidoidea) Азербайджана

As a result of many years of research, 30 species of parasites derived from aphids have been identified for the fauna of Azerbaijan. For the first time an annotated list of aphelinids and aphidiids (Hymenoptera: Aphelinidae, Aphidiidae), parasites of aphids of Azerbaijan is given. Of these parasites, there are 14 species of aphelinids (Hymenoptera, Aphelinidae) and 16 species of aphidiids (Hymenoptera, Aphidiidae). Of aphelinids two species are recorded for the first time for the fauna of the South Caucasus, and 4 species for the fauna of Azerbaijan. All the 16 known species of the aphidiids are new for the fauna of Azerbaijan. Aphidiids Adialytus salicaphis, Lysiphlebus fabarum, Aphidius rosae are recorded for the first time for the fauna of the South Caucasus.

Functional insights from the GC-poor genomes of two aphid parasitoids, Aphidius ervi and Lysiphlebus fabarum

BackgroundParasitoid wasps have fascinating life cycles and play an important role in trophic networks, yet little is known about their genome content and function. Parasitoids that infect aphids are an important group with the potential for biological control. Their success depends on adapting to develop inside aphids and overcoming both host aphid defenses and their protective endosymbionts.ResultsWe present the de novo genome assemblies, detailed annotation, and comparative analysis of two closely related parasitoid wasps that target pest aphids: Aphidius ervi and Lysiphlebus fabarum (Hymenoptera: Braconidae: Aphidiinae). The genomes are small (139 and 141 Mbp) and the most AT-rich reported thus far for any arthropod (GC content: 25.8 and 23.8%). This nucleotide bias is accompanied by skewed codon usage and is stronger in genes with adult-biased expression. AT-richness may be the consequence of reduced genome size, a near absence of DNA methylation, and energy efficiency. We identify missing desaturase genes, whose absence may underlie mimicry in the cuticular hydrocarbon profile of L. fabarum. We highlight key gene groups including those underlying venom composition, chemosensory perception, and sex determination, as well as potential losses in immune pathway genes.ConclusionsThese findings are of fundamental interest for insect evolution and biological control applications. They provide a strong foundation for further functional studies into coevolution between parasitoids and their hosts. Both genomes are available at https://bipaa.genouest.org.

Prior adaptation of parasitoids improves biological control of symbiont-protected pests.

There is increasing demand for sustainable pest management to reduce harmful effects of pesticides on the environment and human health. For pest aphids, biological control with parasitoid wasps provides a welcome alternative, particularly in greenhouses. However, aphids are frequently infected with the heritable bacterial endosymbiont Hamiltonella defensa, which increases resistance to parasitoids and thereby hampers biological control. Using the black bean aphid (Aphis fabae) and its main parasitoid Lysiphlebus fabarum, we tested whether prior adaptation of parasitoids can improve the control of symbiont‐protected pests. We had parasitoid lines adapted to two different strains of H. defensa by experimental evolution, as well as parasitoids evolved on H. defensa‐free aphids. We compared their ability to control caged aphid populations comprising 60% unprotected and 40% H. defensa‐protected aphids, with both H. defensa strains present in the populations. Parasitoids that were not adapted to H. defensa had virtually no effect on aphid population dynamics compared to parasitoid‐free controls, but one of the adapted lines and a mixture of both adapted lines controlled aphids successfully, strongly benefitting plant growth. Selection by parasitoids altered aphid population composition in a very specific manner. Aphid populations became dominated by H. defensa‐protected aphids in the presence of parasitoids, and each adapted parasitoid line selected for the H. defensa strain it was not adapted to. This study shows, for the first time, that prior adaptation of parasitoids improves biological control of symbiont‐protected pests, but the high specificity of parasitoid counter‐resistance may represent a challenge for its implementation.