Parasitoid Wasp Species Research Articles

New species of braconid parasitoid wasps from the subfamilies Doryctinae and Brachistinae from late Eocene Baltic amber

Three new fossil species of braconid wasps are described and illustrated from late Eocene Baltic amber: Palaeorhoptrocentrus tenuicornis sp. nov. (Doryctinae), Taphaeus obscurus sp. nov. (Brachistinae: Diospilini), and Eubazus electrus sp. nov. (Brachistinae: Brachistini). Keys to the known species of Palaeorhoptrocentrus Belokobylskij, 2023 and to species of Eubazus Nees, 1812 described from Baltic amber are provided. An illustrated redescription of Blacus (Electroblacus) facialis Brues, 1933 (Brachistinae: Blacini) is also provided, along with digital photographs for the first time of the female of B. (Electroblacus) facialis, whose type material was lost during the World War II. We also provide morphological notes and digital photographs of a male belonging to an undescribed species of Meteorus (Euphorinae).

Three new species of parasitoid wasps of the genus Mnioes Townes, 1946 (Ichneumonidae: Banchinae) in a humid forest in Peru

Mnioes is a predominantly Neotropical genus of Banchinae (Ichneumonidae), currently including 26 species. Three new species of Mnioes are described, found in a humid montane forest in southern Peru, M. chunka sp. nov, M. chusaq sp. nov. and M. isqun sp. nov, and the male of M. huk Alvarado 2020 is also described. DNA barcoding for all the species treated here is included and provides information to match females with males, especially for M. chunka sp. nov., M. chusaq sp. nov., and M. soqta Alvarado 2020 where females are similar to each other and occur in sympatry. Additionally, an updated key to the Peruvian species is provided.

Reproductive ecology and egg parasitism of the Samoan swallowtail butterfly

AbstractWe investigated the reproductive ecology and effects of egg parasitism on the Samoan swallowtail butterfly (Papilio godeffroyi), which survives only on Tutuila Island, American Samoa, after having disappeared from the much larger islands of Upolu and Savai‘i in independent Samoa. During monthly surveys of its only known host plant, Micromelum minutum, across eight sites in 2013 and 2014, we collected eggs, eggshells, larvae, pupae, and pupal exuviae. Live specimens were reared under laboratory conditions to determine reproductive outcomes, developmental rates, and sex ratios, as well as parasitoid attack frequencies, brood sizes, and sex ratios. Sixty‐six of 448 (14.7%) eggs produced larvae, 47 of which became adults. The sex ratio was approximately even overall and within each developmental stage. Eggs were slightly larger on individual host trees and in host tree stands that yielded more eggs per unit of foliage, indicating that ovipositing females responded to some features of host trees and stands. Eggs hatching female or male larvae were similar in size, and the sexes developed at similar rates. A newly described species of parasitoid wasp, Ooencyrtus pitosina (Encyrtidae), emerged from 73.6% of 382 butterfly eggs that failed to hatch in the laboratory (62.7% of 448 eggs overall). Forty‐one other eggs contained dead parasitoid larvae. An additional, unidentified Ooencyrtus wasp species emerged from a single P. godeffroyi egg. No parasitoids were reared from P. godeffroyi larvae or pupae. Of 656 P. godeffroyi eggshells collected in the field and examined in the laboratory, 62.2% showed signs of having been parasitized by O. pitosina. There was no evidence that parasitism rates were density‐dependent. O. pitosina brood sizes ranged from 1 to 5, with the sex ratio skewed toward females (2.40 F:1.00 M). Larger parasitoid broods were associated with slightly larger host eggs, indicating that female wasps may adjust brood size according to host egg size or that fewer wasp larvae are able to complete development in smaller eggs. Techniques used to rear both P. godeffroyi and O. pitosina in the laboratory could be applied to a captive‐rear, wild‐release program, which may facilitate reestablishment of the species in Samoa.

Wolbachia strain diversity in a complex group of sympatric cryptic parasitoid wasp species

BackgroundMaternally-inherited symbionts can induce pre-mating and/or post-mating reproductive isolation between sympatric host lineages, and speciation, by modifying host reproductive phenotypes. The large parasitoid wasp genus Cotesia (Braconidae) includes a diversity of cryptic species, each specialized in parasitizing one to few related Lepidoptera host species. Here, we characterized the infection status of an assemblage of 21 Cotesia species from 15 countries by several microbial symbionts, as a first step toward investigating whether symbionts may provide a barrier to gene flow between these parasitoid host lineages.ResultsThe symbiotic microbes Arsenophonus, Cardinium, Microsporidium and Spiroplasma were not detected in the Cotesia wasps. However, the endosymbiotic bacterium Wolbachia was present in at least eight Cotesia species, and hence we concentrated on it upon screening additional DNA extracts and SRAs from NCBI. Some of the closely related Cotesia species carry similar Wolbachia strains, but most Wolbachia strains showed patterns of horizontal transfer between phylogenetically distant host lineages.ConclusionsThe lack of co-phylogenetic signal between Wolbachia and Cotesia suggests that the symbiont and hosts have not coevolved to an extent that would drive species divergence between the Cotesia host lineages. However, as the most common facultative symbiont of Cotesia species, Wolbachia may still function as a key-player in the biology of the parasitoid wasps. Its precise role in the evolution of this complex clade of cryptic species remains to be experimentally investigated.

First Record of Telenomus dilophonotae (Hymenoptera, Scelionidae), Parasitizing Eggs of Erinnyis ello (Lepidoptera, Sphingidae) in Western Paraná, Brazil, with Molecular Characterization and Records of Occurrences.

There are few records for Telenomus dilophonotae Cameron, 1913 (Hymenoptera, Scelionidae) from South America. In Brazil, the first occurrence was reported in Bahia in rubber crops, Hevea brasiliensis (Willd. ex Adr. de Juss.) Muell. - Arg., there parasitizing eggs of Erinnyis ello Linnaeus, 1758 (Lepidoptera, Sphingidae). It was also found parasitizing the same host in cassava, Manihot esculenta Crantz (Euphorbiaceae). This is the first record of occurrence of T. dilophonotae in the state of Paraná, parasitizing eggs of E. ello in areas of cassava production in the western region of Paraná, this being the southernmost record of the species. Here, photographs, the first sequence of DNA barcode of this species of parasitoid wasp, and a distribution map are provided.

Morphological and biological characteristics of Eriborus sp. (Hymenoptera: Ichneumonidae), a parasitoid wasp of Cydalima perspectalis (Lepidoptera: Crambidae).

The box tree moth (BTM), Cydalima perspectalis Walker, is a pest that infests various plants within the Buxus genus. Although a specific parasitoid wasp species associated with the BTM has been observed in the Republic of Korea, no research on this species has been published. Here, we describe the fundamental morphological and biological characteristics of this parasitoid. We have identified the wasp as belonging to the genus Eriborus (Hymenoptera: Ichneumonidae: Campopleginae). Eriborus sp. parasitizes within the living host body, with 1 wasp emerging from each host. The parasitism rate observed in collected BTM populations was 33.1%. The emergence rate was 87.1%, with all emerging adults being females, resulting in a sex ratio of 0. The pupal period avg 9.5 days, and the adult lifespan avg 10.5 days. Eriborus sp. parasitized BTM larvae from the first to the fourth instar and reproduced by thelytokous parthenogenesis. Eriborus sp. exhibited morphological differences compared with previously reported Eriborus species in Korea, particularly in the length of the ovipositor sheath. Additionally, the proportion of the highest similarity in nucleotide sequences of mitochondrial cytochrome oxidase I DNA was only 94.53%, rendering species identification using GenBank's mt cytochrome c oxidase 1 DNA sequences unfeasible. These data suggest that Eriborus sp. could be used as a biological control agent for managing BTM infestations.

Hyperparasitic showdown: <i>Sclerodermus cereicollis</i>, a non-aggressive but surprisingly secondary hyperparasitoid

This study investigates the dynamics of hyperparasitism within the Bethylidae family, focusing on the interaction between Sclerodermus cereicollis and Goniozus legneri, two parasitoid wasp species characterized by different sociality and aggressivity towards conspecifics. Experimental trials were conducted using Corcyra cephalonica larvae as hosts, with different setups to stimulate competition. The results revealed unexpected behaviors, especially by S. cereicollis, including aggressive interactions, cannibalism, and hyperparasitism. In contrast, despite the typically aggressive nature of G. legneri, no particular hostility was observed toward S. cereicollis. The study highlights the complex dynamics of competition for resources among parasitoids, shedding light on the adaptive strategies and fitness costs associated with hyperparasitism. These findings contribute to a deeper understanding of the ecological interactions within parasitoid wasp communities.

Rainforest transformation reduces parasitoid wasp diversity—Can the enrichment of flowering vegetation alleviate this?

Abstract In Indonesia, the rapid expansion of oil palm and rubber plantations replaces large areas of tropical rainforest. Rainforest transformation alters the diversity and composition of parasitoid wasp communities, but appropriate management strategies to buffer their decline in rainforest transformation landscapes are not yet developed. Here, we studied the effects of rainforest conversion to smallholder rubber and oil palm plantations on parasitoid wasp species richness, abundance and species composition. We also conducted a flowering vegetation enrichment experiment using the flowering weed Asystasia gangetica in all land‐uses to investigate potential mitigation effects on parasitoid wasp diversity and composition. Rainforest transformation to rubber plantations caused a large decrease in species richness (46%) and abundance (59%) of parasitoid wasps. Community structure of parasitoid wasps differed between forest and monoculture habitats with more habitat‐specialised species in forest and a higher proportion of common species in the monoculture. The experimental flowering vegetation enrichment increased parasitoid wasp species richness by 18% and abundance by 127%. Enrichment also enhanced the presence of unique parasitoid species in plantation and furthermore increased differences in community composition between rainforest and plantations. However, the enrichment experiment was confounded by time, meaning that a multi‐year experiment with targeted controls is necessary for statistically more reliable statements. Our study shows the effect of rainforest transformation to oil palm and rubber plantations on parasitoid wasp communities. Although providing additional flowering vegetation in plantations seems to potentially mitigate diversity loss, further research is needed to confirm and to investigate the mechanisms how flowering plants alleviate negative effects of rainforest transformation on parasitoid communities. Thereby, efficient conservation strategies for parasitoids wasps and their biological control services can be developed for rapidly changing tropical landscapes.

Six in one: cryptic species and a new host record for Olixon Cameron (Rhopalosomatidae, Hymenoptera) revealed by DNA barcoding

Olixon testaceum is a widely distributed species of brachypterous parasitoid wasp (Vespoidea: Rhopalosomatidae) occurring in Meso- and South America, but little is known of its biology. Here, the first known host of O. ? testaceum is identified as the cricket Anaxipha sp. (Grylloidea: Trigonidiidae) through DNA barcoding of six Olixon larvae and their hosts. Barcoding results also indicated substantial genetic diversity within nominal O. testaceum specimens. The number of species and statistical significance of these groups were tested using Maximum Likelihood phylogenies, distance-based cluster analyses, and coalescence models. All analyses revealed at least six distinct lineages, which suggests six or more cryptic species within O. ? testaceum. Combined with what is currently known about Rhopalosoma host use, these results indicate that rhopalosomatids may be generalist rather than specialist parasitoids, and further confirm the benefits of open global collaboration and DNA barcoding in advancing taxonomic knowledge.

A comparison of the parasitoid wasp species richness of tropical forest sites in Peru and Uganda – subfamily Rhyssinae (Hymenoptera: Ichneumonidae)

A comparison of the parasitoid wasp species richness of tropical forest sites in Peru and Uganda – subfamily Rhyssinae (Hymenoptera: Ichneumonidae)

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.

New records of three parasitoids, Pteroptrix chinensis, Aphytis hispanicus, and Marlattiella prima (Hymenoptera: Aphelinidae) associated with an exotic scale, Lopholeucaspis japonica (Hemiptera: Diaspididae) in Tennessee.

A survey for parasitoids of Lopholeucaspis japonica Cockerell (Hemiptera: Diaspididae), an exotic scale of woody ornamentals, resulted in the discovery of 3 species of aphelinid parasitoid wasps, Pteroptrix chinensis (Howard), Aphytis hispanicus (Mercet), and Marlattiella prima Howard. This serves as the first report of these parasitoids reared from a host in the state of Tennessee, USA. Despite routine pesticide applications in the surveyed nursery and directed treatments of the infested plants to control the scale outbreak, the percentage of parasitized scale in privet and euonymus shrubs averaged 7.0% and 7.9%, respectively. These parasitoids may be useful in the natural or managed control of this pest in the United States, but additional research is needed to understand how these parasitoids contribute to the control of L. japonica in the landscape and how nursery production practices can be modified to promote parasitoid populations.

Neopulvinaria innumerabilis (Rathvon, 1854), a new species of Coccidae in Serbia

In 2016, the species Neopulvinaria innumerabilis (Rathvon, 1854), belonging to the scale insect family Coccidae, was for the first time found in Serbia, in the location Radmilovac on Cornus sanguinea L. It reproduces by gamogenesis, develops one generation annually, and overwinters as a fertilized female on the trunk or branches of its host plant. During this research, the species was detected on five host plants at six locations in Serbia. It feeds by sucking sap from leaves, young shoots and branches of infested plants, causing desiccation of leaves and individual twigs. Four species of its natural enemies were collected and reared from colonies of N. innumerabilis. Two species of parasitoid wasps, Coccophagus lycimnia (Walker) (Aphelinidae) and Metaphycus hageni Daane and Caltagirone (Encyrtidae), were found, while the ladybird Exochomus quadripustulatus L. (Coccinellidae) and the fly Leucopomyia silesiaca (Egger) (Chamaemyiidae) were identified as predators. The most abundant entomophagous species was L. silesiaca.

The Viromes of Six Ecosystem Service Provider Parasitoid Wasps.

Parasitoid wasps are fundamental insects for the biological control of agricultural pests. Despite the importance of wasps as natural enemies for more sustainable and healthy agriculture, the factors that could impact their species richness, abundance, and fitness, such as viral diseases, remain almost unexplored. Parasitoid wasps have been studied with regard to the endogenization of viral elements and the transmission of endogenous viral proteins that facilitate parasitism. However, circulating viruses are poorly characterized. Here, RNA viromes of six parasitoid wasp species are studied using public libraries of next-generation sequencing through an integrative bioinformatics pipeline. Our analyses led to the identification of 18 viruses classified into 10 families (Iflaviridae, Endornaviridae, Mitoviridae, Partitiviridae, Virgaviridae, Rhabdoviridae, Chuviridae, Orthomyxoviridae, Xinmoviridae, and Narnaviridae) and into the Bunyavirales order. Of these, 16 elements were described for the first time. We also found a known virus previously identified on a wasp prey which suggests viral transmission between the insects. Altogether, our results highlight the importance of virus surveillance in wasps as its service disruption can affect ecology, agriculture and pest management, impacting the economy and threatening human food security.

RNA virus diversity in three parasitoid wasps of tephritid flies: insights from novel and known species.

Parasitoid wasps are a diverse group of parasitoid insects that play a crucial role in biological control and integrated pest management programs due to their wide range of host species and complex behaviors. Previous studies have reported that select RNA viruses in parasitoid wasps can affect either the host-parasitoid wasp or the pest host parasitized by the wasps. Therefore, a study of the dynamics of RNA viruses in parasitoid wasps is essential for artificial breeding programs and improving their parasitic capabilities. In this study, we detected the presence of nine novel and three known RNA viruses with complete genomes in three parasitoid wasp species: Diachasmimorpha longicaudata, Fopius arisanus, and Spalangia endius. These wasps are parasitoids that can parasitel tephritid flies, one of the most important pest groups of fruits and vegetables. In D. longicaudata, the small RNAs derived from the viruses exhibited distinct peaks at 22 nt and were symmetrically distributed across the viral genome. These findings indicate that these viruses can activate the host's RNAi immune response. PCR detection further revealed that DlNaLV efficiently infects female individuals of D. longicaudata with 100% efficiency, and ZcNLV is capable of infecting both D. longicaudata and its host, Zeugodacus cucurbitae. Our findings contribute to a better understanding of RNA viruses in parasitoid wasps and lay the foundation for future research on the triple-level trophic relationships between tephritid flies, parasitoid wasps, and RNA viruses.IMPORTANCEParasitoid wasp populations have developed persistent beneficial symbiotic relationships with several viruses through repeated evolution. However, there have been limited reports on RNA viruses in parasitoid wasps of tephritid flies, a significant pest group affecting fruits and vegetables. This study explores the diversity of RNA viruses in three parasitoid wasps of tephritid flies and highlights the potential biological significance of specific viruses in Diachasmimorpha longicaudata. These findings have important implications for the development of sustainable pest management strategies and the enhancement of artificial rearing techniques for parasitoid wasps.

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.

Mortality in Interspecific Hybrids of Nasonia vitripennis and Nasonia giraulti (Hymenoptera: Pteromalidae)

Abstract Barriers to gene flow can result in populations evolving into separate species, and understanding how these barriers evolve is a key step in understanding the process of speciation. This study investigates a major barrier to gene flow, mortality during development, of two parasitoid wasp species, Nasonia vitripennis Walker and N. giraulti Darling. Previous work has demonstrated high mortality in haploid hybrid males of these species and has shown potential rescue from this mortality in diploid hybrid females through backcrossing. However, this previous work did not directly measure egg clutch sizes in hybrids and also did not account for male eggs in these clutches. Here, we measure female-only egg and adult clutch sizes of both parent species and F2 hybrids, as well as F2 male egg and adult clutch sizes, in order to determine the impact of backcrossing on mortality in these hybrids. We find significant egg-to-adult mortality in diploid F2 hybrid females with a N. giraulti cytotype when backcrossed to N. vitripennis males; yet, these hybrids also experience less mortality than haploid F2 males. These results confirm the mortality and rescue in these F2 hybrid females and indicate that there is likely a combination of nuclear-cytoplasmic and nuclear-nuclear incompatibilities in these hybrids that lead to this mortality. This work provides a foundation for future studies to investigate the genetic basis of this mortality.

Parasitoids associated with ambrosia beetles in the Euwallacea fornicatus species complex (Coleoptera: Curculionidae: Scolytinae) in Taiwan

ABSTRACT Several species of ambrosia beetles in the genera Euwallacea, Xyleborus, and Xylosandrus (Coleoptera: Curculionidae: Scolytinae) are considered major pests in agriculture, forestry and urban areas. Their concealed lifestyle allows them to evade detection, and increases their chances of being introduced to non-native regions. Their reproduction is dominated by sibling mating within maternal galleries, and this behaviour makes them difficult to control. Although a handful of studies have identified natural enemies associated with ambrosia beetles, very few have done this with the goal of creating a classical biological control programme. In this study, we sought to identify hymenopteran parasitoids associated with the invasive Euwallacea fornicatus species complex. We collected branches from infested trees in a native region in Taiwan, recorded parasitoid emergence, and attempted to rear any emerging parasitoids using laboratory reared hosts and experimentally infested logs. We identified three species of parasitoid wasps that successfully parasitised beetles in the E. fornicatus species complex. These species were all new to science belonging to the genera Eucosmophorus (Braconidae), Phymastichus (Eulophidae), and Plastanoxus (Bethylidae).

Full-length transcriptome profiling of Aphidius gifuensis mitochondrial genome with gene rearrangement and control region duplication

Although mitochondrial gene rearrangement has been observed in many insect lineages, little is known about how it affects mitochondrial gene transcription. To address this question, we first constructed a quantitative transcription map for Aphidius gifuensis, a species of parasitoid wasp known to have a highly rearranged mitochondrial genome (mitogenome) and two potential control regions (CRs). Based on this transcription map, we assessed the models of the mitochondrial transcription and post-transcription cleavage. We found that the J and N strand of this mitogenome differ significantly in transcriptional regulation. On the J strand, we found two transcription initiation sites (TISs), five transcription termination sites (TTSs), and six polycistronic primary transcripts whereas only one TIS, one TTS and one polycistronic primary transcript can be found on the N strand. Most of the non-coding regions of both strands were transcribed into primary transcripts and cleaved after transcription. The proposed mode of transcription of A. gifuensis was similar to that of Drosophila, a model organism with no gene rearrangement. And two rearranged gene clusters (trnI-CR1-trnM-CR2-trnQ and trnW-trnY-trnC) seemed to have little effects on the mode of transcription. In addition, our results revealed the presence of TISs in CR1 and CR2, implying that both CRs maybe required for transcriptional regulation. Analysis of the post-transcriptional cleavage process showed that there were both “forward cleavage” and “reverse cleavage” models in A. gifuensis, and more than one way of cleavages were found in three regions. The incomplete transcripts suggested that the direction of mitochondrial RNA degradation was from 5′ to 3′ end and supported the view of polyadenylation-dependent RNA degradation. Our study provides insights into the transcriptional and post-transcriptional regulation processes of highly rearranged insect mitogenomes.

Floral presence and flower identity alter cereal aphid endosymbiont communities on adjacent crops.

Floral plantings adjacent to crops fields can recruit populations of natural enemies by providing flower nectar and non-crop prey to increase natural pest regulation. Observed variation in success rates might be due to changes in the unseen community of endosymbionts hosted by many herbivorous insects, of which some can confer resistance to natural enemies, for example, parasitoid wasps. Reduced insect control may occur if highly protective symbiont combinations increase in frequency via selection effects, and this is expected to be stronger in lower diversity systems.We used a large-scale field trial to analyse the bacterial endosymbiont communities hosted by cereal aphids Sitobion avenae collected along transects into strip plots of barley plants managed by either conventional or integrated (including floral field margins and reduced inputs) methods. In addition, we conducted an outdoor pot experiment to analyse endosymbionts in S. avenae aphids collected on barley plants that were either grown alone or alongside one of three flowering plants, across three time points.In the field, aphids hosted up to four symbionts. The abundance of aphids and parasitoid wasps was reduced towards the middle of all fields while aphid symbiont species richness and diversity decreased into the field in conventional, but not integrated, field-strips. The proportion of aphids hosting different symbiont combinations varied across cropping systems, with distances into the fields, and were correlated with parasitoid wasp abundances.In the pot experiment, aphids hosted up to six symbionts. Flower presence increased natural enemy abundance and diversity, and decreased aphid abundance. The proportion of aphids hosting different symbiont combinations varied across the flower treatment and time, and were correlated with varying abundances of the different specialist parasitoid wasp species recruited by different flowers. Synthesis and applications. Floral plantings and flower identity had community-wide impacts on the combinations of bacterial endosymbionts hosted by herbivorous insects, which correlated with natural enemy diversity and abundance. We recommend that integrated management practices incorporate floral resources within field areas to support a more functionally diverse and resilient natural enemy community to mitigate selection for symbiont-mediated pest resistance throughout the cropping area.