Parasitoid Aphidius Ervi Haliday Research Articles

Aphidius ervi venom regulates Buchnera contribution to host nutritional suitability

The association between the pea aphid, Acyrthosiphon pisum (Harris) (Homoptera: Aphididae), and the endophagous parasitoid wasp Aphidius ervi Haliday (Hymenoptera: Braconidae) offers a unique model system for studying the molecular mechanisms underlying the complex interactions between the parasitoid, its host and the associated primary symbiont. Here, we investigate in vivo the functional role of the most abundant component of A. ervi venom, Ae-γ-glutamyl transpeptidase (Ae-γ-GT), which is known to induce host castration. Microinjections of double-stranded RNA into A. ervi pupae stably knocked down Ae-γ-GT1 and Ae-γ-GT2 paralogue genes in newly emerged females. These females were used to score the phenotypic changes both in parasitized hosts and in the parasitoid’s progeny, as affected by a venom blend lacking Ae-γ-GT. Ae-γ-GT gene silencing enhanced growth both of host and parasitoid, supported by a higher load of the primary bacterial symbiont Buchnera aphidicola. Emerging adults showed a reduced survival and fecundity, suggesting a trade-off with body size. This demonstrates in vivo the primary role of Ae-γ-GT in host ovary degeneration and suggests that this protein counterbalances the proliferation of Buchnera likely triggered by other venom components. Our study provides a new approach to unravelling the complexity of aphid parasitoid venom in vivo, and sheds light on a novel role for Ae-γ-GT in host regulation.

Transgenerational phenotypic plasticity of diapause induction and related fitness cost in a commercial strain of the parasitoid Aphidius ervi Haliday.

Diapause is an adaptation that insects have evolved to synchronize their life cycle with that of seasonal climatic changes and resources availability. However, cues for its induction are not always clear and, in some cases, a maternal effect may be involved. At the population level, just a part of the individuals may exhibit diapause with important consequences in terms of winter survival. Moreover, clear indicators of diapause state are difficult to identify. Diapause induction was thus investigated in the aphid parasitoid species Aphidius ervi Haliday (Hymenoptera: Braconidae) developing in the aphid Sitobion avenae (Hemiptera: Aphididae) at four crossed photothermal regimes (16°C and 8°C, 16:8 h L:D and 8:16 h L:D), and during 2 successive generations. We analyzed the reliability of changes in mummy color to assess for the diapausing state compared to dissections, and we measured parasitoid morphological and physiological traits. We observed that the proportion of dark brown mummies increased after one generation under low photothermal regime compared to other regimes. No diapause was recorded at 16°C, 16:8 h L:D, while we observed 16.2% and 67.5% diapause incidence at 8°C, 8:16 h L:D, at 1st and 2nd generation, respectively. Diapause induction is thus increased by short day-length conditions and low temperatures as well as by maternal effects. All parasitoid life-history traits (weight, size, fat content, water content, egg-load, and longevity) were affected by the photothermal regime and/or the generation. These results raise new questions on the environmental thresholds needed to induce diapause and on survival and adaptation potential of commercially available parasitoid strains in different environments.

Co‐occurrence of defensive traits in the potato aphid Macrosiphum euphorbiae

1. Insecticide usage selects strongly for resistance in aphid populations, but this could entail fitness costs in other resistance traits. The potato aphid Macrosiphum euphorbiae Thomas exhibits intraspecific variation in susceptibility to parasitism by braconid wasps and provides a suitable species to study the relation between the defensive traits of parasitism and insecticide resistance.2. Clonal lines (23 in total) of M. euphorbiae were established from aphids collected in 2013 from geographically separate populations in the U.K. Clonal lines belonged to five aphid genotypes, but one genotype predominated (78% of samples), and the facultative endosymbiont Hamiltonella defensa was detected in c. 40% of lines.3. Total esterase activity in aphid tissues varied significantly between aphid genotypes and collection areas, but there was no clear pattern in relation to H. defensa infection or between collection sites likely to differ in insecticide pressures.4. Five clonal lines representing low to moderate levels of enzyme activity, which included different aphid genotypes and presence/absence of H. defensa infection, were assayed for their susceptibility to the parasitoid wasp Aphidius ervi Haliday. Aphid mummification varied significantly between aphid genotypes, with low values in one genotype of aphids irrespective of H. defensa presence.5. The results revealed that aphid lines belonging to the parasitism‐resistant genotype exhibited moderate levels of total esterase activity, indicating a competitve advantage for this genotype of M. euphorbiae when exposed to chemical and biological control factors in agroecosystems.

Susceptibility of Macrosiphum euphorbiae to the parasitoid Aphidius ervi: larval development depends on host aphid genotype

AbstractThe potato aphid, Macrosiphum euphorbiae Thomas (Hemiptera: Aphididae: Macrosiphini), is a common polyphagous aphid in Europe and North America. However, the factors influencing potato aphid dynamics and susceptibility to natural enemies are largely undescribed, particularly in relation to facultative endosymbiotic bacteria, which can provide protection against parasitism and disease in some aphid species. This study investigated whether potato aphid susceptibility to one of its principal natural enemies, the parasitoid Aphidius ervi Haliday (Hymenoptera: Braconidae: Aphidiinae), varied in relation to aphid genotype and/or endosymbiont presence. Parasitism and aphid fitness assays were conducted on clonal lineages of aphids, harbouring their natural endosymbiont infections, collected over 3 years from separate geographic locations. Parasitized aphids were dissected to quantify parasitoid oviposition, larval development, and mummification. Amongst the 19 clonal lines of M. euphorbiae tested, seven aphid genotypes were identified, and 11 lines harboured one or both of the facultative endosymbionts Hamiltonella defensa Moran et al. and Regiella insecticola Moran et al.; H. defensa infections were associated exclusively with two of the seven M. euphorbiae genotypes. Parasitism resistance was detected in clonal lines belonging to a single aphid genotype and resulted from failure of parasitoid eggs to develop into larvae rather than failure of the parasitoid to oviposit. Contrary with studies of several other aphid species, there was little evidence that H. defensa provided strong protection to M. euphorbiae from parasitism by A. ervi. Furthermore, there were no clear fitness costs to the aphid associated with parasitism resistance or with H. defensa infection. The two M. euphorbiae genotypes in which H. defensa occurred, which included the resistant genotype, exhibited faster development, higher survival, and greater fecundity than the other five aphid genotypes. These findings suggest that biological control of M. euphorbiae using A. ervi alone could exacerbate pest problems by selecting for the fittest parasitism‐resistant genotypes.

Combining lacewings and parasitoids for biological control of foxglove aphids in sweet pepper

AbstractThe role of natural enemy diversity in biological pest control has been debated in many studies, and understanding how interactions amongst predators and parasitoids affect herbivore populations is crucial for pest management. In this study, we assessed the individual and combined use of two species of natural enemies, the parasitoid Aphidius ervi Haliday, and the predatory brown lacewing Micromus variegatus (Fabricius), on their shared prey, the foxglove aphid, Aulacorthum solani (Kaltenbach), on sweet pepper. We hypothesized that the presence of intraguild predation (IGP) and predator facilitation (through induced aphid dropping behaviour) might have both negative and positive effects on aphid control, respectively. Our greenhouse trial showed that overall, the greatest suppression of aphids occurred in the treatment with both the parasitoid and the lacewing. While the combination of lacewings and parasitoids significantly increased aphid control compared to the use of parasitoids alone, the effect was not significantly different to the treatment with only predators, although there was a clear trend of enhanced suppression. Thus, the combined effects of both species of natural enemies were between additive and non‐additive, suggesting that the combination is neither positive nor negative for aphid control. High levels of IGP, as proven in the laboratory, were probably compensated for by the strong aphid suppression provided by the lacewings, whether or not supplemented with some level of predator facilitation. For aphid management over a longer time scale, it might still be useful to combine lacewings and parasitoids to ensure stable and resilient aphid control.

Patch Experience Changes Host Acceptance of the Aphid Parasitoid Aphidius ervi

We investigated patch quality assessment by the parasitoid Aphidius ervi Haliday (Hymenoptera: Braconidae) when exploiting colonies of the lettuce aphid Nasonovia ribisnigri Mosley (Hemiptera: Aphididae). Three host patches of different qualities were sequentially offered to a naive female parasitoid. High quality patches (HQ) consisted of 20 N. ribisnigri reared on susceptible lettuce; low quality patches (LQ) consisted of 20 N. ribisnigri reared on partially resistant lettuce and mixed quality patches (MQ) consisted of equal numbers (10) of aphids reared on both lettuce types. Parasitized aphids were reared until parasitoid emergence; number of mummies and sex ratio were noted. On the first host patch encountered, the mean number of A. ervi mummies produced was significantly higher for HQ host patches (X ± SD; 7.1 ± 5.0) than for LQ host patches (3.8 ± 4.5). This suggests that female A. ervi do not need prior experience to assess patch quality; females probably using an innate estimate of patch quality when encountering a first host patch. This initial patch quality assessment can be modified with experience. When females encountered a MQ patch, they kept their exploitation level constant on the following patch, whatever its quality. Females increased their level of host acceptance on the third patch when three LQ patches were offered successively; accepting low-quality hosts could be preferable when better hosts are not currently available in the habitat. These results suggest that A. ervi females behave in a manner consistent with a Bayesian updating process when foraging for hosts.

Dichotomy of male and female responses to hoverfly-driven cues and floral competition in the parasitoid wasp Aphidius ervi Haliday

The aim of this study was to test the hypothesis that floral visitation and foraging by the hoverfly Episyrphus balteatus De Geer would have no effect on the attraction to, or use of, flowers by the parasitoid wasp Aphidius ervi Haliday. Results demonstrated that in two-way choice tests, air-streams emanating from live Fagopyrum esculentum Moench (buckwheat) flowers were significantly more attractive than clean air to both male and female wasps, by more than one and two orders of magnitude, respectively. When air-streams from flowers presented alone were compared to those from flowers presented with E. balteatus, or exposed to E. balteatus prior to use, no preferences were detected. Nevertheless, air that had passed through chambers containing only live E. balteatus was significantly repellent to female wasps, with individuals spending 18 times less in these air-streams than clean air. Conversely, air passed over E. balteatus was attractive to male A. ervi, with wasps spending more than six times longer in this vs. clean air. We argue that hoverfly floral visitation/use should have minimal impact on floral attractiveness to A. ervi based on these results, and that for male wasps greater benefits might be gained by responding positively to hoverfly volatiles in the absence of floral cues.In a separate experiment, a consistent trend for reduced fitness of female A. ervi on caged F. esculentum was observed under increasing competitive pressure from E. balteatus. High densities of hoverflies significantly reduced wasp longevity by more than 25%, though lower densities had no significant effect. Conversely, male A. ervi appeared to survive for longer where higher densities of hoverflies were present, though results were not as clear-cut statistically. We argue that antagonistic interactions seen between hoverflies and female A. ervi were the result of behavioural interference and would only be observed in the field under conditions of extreme competitive pressure.

Stress intensity and fitness in the parasitoid Aphidius ervi (Hymenoptera: Braconidae): temperature below the development threshold combined with a fluctuating thermal regime is a must

Abstract An increasing intensity of stress is expected to affect the fitness traits of an organism more and more negatively, but in particular cases, extremely resistant individuals have been observed. The present study was undertaken to determine the effects of different stress intensities on fitness traits of the parasitoid wasp Aphidius ervi Haliday. We exposed 1‐day‐old mummies (dead aphids containing the parasitoid pupa) for 4 weeks to combinations of two low temperatures (4 and 0 °C, 0 °C being the most stressful) and two thermal regimes (constant and fluctuating, constant being the most stressful), representing four stress levels. The present results showed that resistant individuals occurred only in the most stressful treatment (0 °C, constant temperature), which induced a higher mortality rate. These resistant individuals performed almost as well as those of the control, but showed a reduction in their size. The fluctuating regimes, at both temperatures, presented a high emergence rate, but at the expense of higher lipid consumption. Unexpectedly, the fluctuating regime associated with the presumably more stressful temperature (0 °C) produced individuals without any decrease in the measured fitness traits, in contrast to the treatment expected to be less stressful (4 °C, fluctuating temperature). This result opens a new area of research in stress ecology and could modify the practice of cold storage in biological control.

Interactions between tomato volatile organic compounds and aphid behaviour

In the tritrophic system consisting of tomato, Solanum lycopersicum (L.), the aphid Macrosiphum euphorbiae (Thomas) and its natural enemy, the parasitoid Aphidius ervi (Haliday), it has been shown that the release of volatile organic compounds following aphid attack is responsible for attracting aphid parasitoids in wind tunnel experiments. The main compounds involved in these multitrophic interactions have been characterized and quantified. In this work, the possible activity of such compounds on plant direct defences against the aphid M. euphorbiae was assessed in laboratory tests. The selected compounds were applied to uninfested tomato plants, either by evaporation or contact, and performance of aphids, in terms of plant acceptance, fixing behaviour and aphid development, calculated in standard conditions. The results showed that two compounds, namely methyl salicylate and cis-hex-3-en-1-ol, alter aphid performance. These two compounds have been reported to be those eliciting the best response by A. ervi in terms of flight behavior (wind tunnel bioassay) and antennal stimulation (EAG bioassay).

Dropping behaviour in Aulacorthum solani (Hemiptera: Aphididae) following attack by Aphidus ervi (Hymenoptera: Braconidae): are sticky stem bands a useful integrated pest management method?

AbstractWe studied the dropping behaviour of the foxglove aphid, Aulacorthum solani (Kaltenbach) (Hemiptera: Aphididae), in response to disturbance by the parasitoid Aphidius ervi Haliday (Hymenoptera: Braconidae). We banded plant stems with sticky tape to prevent aphids from returning to the plants to determine if these would serve as an integrated pest management strategy for A. solani. Stem banding prevented A. solani that had dropped from returning to the plant; but the mortality associated with banding was not necessarily complementary to biological control by A. ervi. Up to 80% of aphids dropped in response to foraging by A. ervi, and thus could be killed on sticky stem bands. The fraction of aphids that dropped to the ground also contained as much as 90% of the parasitoid's offspring. Overall, mortality of aphids on sticky stem bands was not compatible with parasitoids. Although numbers of aphids declined more rapidly in the first 2 weeks of the trial in the presence of stem bands and parasitoids than in the presence of parasitoids alone, the numbers of aphids were identical in the two treatments from the 3rd week onward. Mortality on the stem bands replaced mortality from parasitoids, and reduced recruitment of parasitoids.

Improvement in the cold storage of Aphidius ervi (Hymenoptera: Aphidiinae)

Biological control is beginning to be more commonly used, especially in greenhouses. The inundatory release of insects, especially parasitoids, requires a thorough knowledge of their biology and of mass-rearing techniques. Moreover, to synchronize releases with host presence, the parasitoids have to be kept in cold storage. However, cold storage may lead to a decrease in the viability of the parasitoids, in particular their survival, mobility and sex ratio. The aim of this study was to determine the best temperature at which to keep parasitoid mummies in cold storage. The parasitoid Aphidius ervi Haliday (Hymenoptera, Braconidae) and two of its host aphids, Sitobion avenae and Acyrthosiphon pisum, were used. It is concluded that the mummies can be kept for a maximum of two weeks at 7°C without emergence of adults and for seven weeks at 2°C without emergence or mortality. Moreover, storage of the mummies at 7 or 2°C does not affect fertility. However, parasitoid pupae in A. pisum mummies suffered a higher mortality and took longer to complete their development. The practical implications of these results are discussed.

Host Age Preference Behavior in Aphidius ervi Haliday (Hymenoptera: Aphidiidae)

Many parasitoid species have preference for certain stages of hosts to parasitize but the underlying behavioral mechanisms of such preference are still poorly understood, making it difficult to evaluate host-parasitoid interactions and their effects on the success of biological control programs. Here, we report our work on a parasitoid Aphidius ervi Haliday on the pea aphid Acyrthosiphon pisum (Harris). We show that with the increase of host age, female parasitoids are more likely to encounter and to attack their hosts but the hosts develop increasingly greater defensive capabilities. Encounter almost always triggers attack attempt; however, increasing attack attempts do not proportionally lead to ovipositor probings and increasing ovipositor probings do not proportionally translate into ovipositions. These asymmetric responses may be interpreted as that A. ervi females prefer to parasitize older aphids for higher fitness return but those aphids can better defend themselves, and as a consequence, A. ervi females may achieve the highest gain by attacking aphids of intermediate ages. We suggest that A. ervi females forage in a manner consistent with the optimal foraging theory, trading off host handling time with fitness returns.

Male wing fanning by the aphid parasitoidAphidius ervi(Hymenoptera: Braconidae) produces a courtship song

We, herein, report evidence that wing fanning by the aphid parasitoid Aphidius ervi Haliday (Hymenoptera: Braconidae) constitutes a courtship song. Complete removal of the forewings or only the distal half of them reduced male copulation success in comparison to intact males. Males that achieved copulation within the observation period produced wing fanning at a higher rate than males that did not copulate. Playback of wing fanning sound altered the behaviour of virgin females, increasing the time they devoted to grooming, as compared with subjects that were exposed to silence or white noise. Our findings contribute to the understanding of the acoustic dimension of the sensory modalities employed by this aphid parasitoid in sexual signalling.

Intraguild predation on the parasitoid Aphidius ervi by the generalist predator Harmonia axyridis: the threat and its avoidance

Interactions between natural enemies can be crucial for determining their overall control of pest species, yet the mechanisms that govern such interactions are often poorly understood. The risk of negative effects such as intraguild predation and the possibility of mitigating such risks are important components for ultimately determining the compatibility of biological control agents. We performed a group of experiments to determine whether the coccinellid Harmonia axyridis Pallas (Coleoptera: Coccinellidae) poses an intraguild threat to the parasitoid Aphidius ervi Haliday (Hymenoptera: Braconidae) and to see whether A. ervi is able to avoid predation by responding to the chemical tracks deposited by H. axyridis. We show that although H. axyridis does not readily consume A. ervi mummies, it preferentially consumes parasitized aphids over unparasitized aphids. We also show that A. ervi can defend against this threat by avoiding oviposition in the presence of H. axyridis chemical tracks. Aphidius ervi parasitized far fewer pea aphids Acyrthosiphon pisum (Harris) (Hemiptera: Aphididae) on plants [Vicia faba L. (Fabaceae)] with H. axyridis chemical tracks in a no-choice environment at a single-plant scale. Similarly, when parasitoids could move freely between plants with and without tracks, A. ervi parasitism was higher on plants without tracks. Behavioral observations of A. ervi foraging suggested that this might be because of reduced A. ervi attack rates and patch residence times in the presence of H. axyridis tracks. Despite a risk of intraguild predation by H. axyridis, our study suggests that A. ervi may be able to mitigate this risk by altering its behavior in response to chemical cues.

Potential value of the fibre nettle Urtica dioica as a resource for the nettle aphid Microlophium carnosum and its insect and fungal natural enemies

The perennial stinging nettle (Urtica dioica L.) is a wild plant that provides resources for aphid natural enemies and can therefore benefit crop protection. Stinging nettles producing approximately three times more fibre than Standard nettles are under commercial development for fibre production. Here we assess the relative value of Austrian Clone 2, a high fibre nettle variety, as a resource for the nettle aphid Microlophium carnosum (Buckton) and its associated natural enemies. The intrinsic rate of increase of M. carnosum cultured on Clone 2 was not different to that on a Standard nettle nor was there an effect of nettle variety on the susceptibility of this aphid to the entomopathogenic fungus Pandora neoaphidis (Remaudiere and Hennebert) Humber. The development time of the aphidophagous predator Chrysoperla carnea (Stephens) was not affected by the nettle variety on which M. carnosum was cultured whilst the parasitoid Aphidius ervi (Haliday) fed on honeydew produced by M. carnosum infesting both varieties of nettle. Fibre nettle Clone 2 is therefore able to support non-pest aphids and their natural enemies and, if grown widely in the future, may be useful within conservation biological control and a tool within integrated pest management.

Qualidade de diferentes espécies de pulgões como hospedeiros do parasitóide Aphidius ervi Haliday (Hymenoptera: Braconidae: Aphidiinae)

The suitability of Macrosiphum euphorbiae (Thomas), Aulacorthum solani (Kaltenbach) and Acyrthosiphon kondoi Shinji (Hemiptera: Aphididae) as hosts for the aphid parasitoid Aphidius ervi Haliday was evaluated by assessing host size, host preference, and host quality. Tests were carried out in an environmental chamber at 22±1ºC, 70±10% RH and 12h photophase. Replicates (11) consisted of one 24h-old mated female of A. ervi without a previous oviposition experience. Female was released into a Petri dish (5 cm) with 20 2nd and 3rd instars of one of each aphid species tested on a leaf disc of the host plant onto a 1% water-agar layer. Parasitoid emergency was lower in A. kondoi (78.7%) compared to M. euphorbiae (92.2%) and A. solani (91.7%). Acyrthosiphon kondoi (0.36 mm) was the smallest host. The parasitoid showed preference (74.0% parasitism) for M. euphorbiae, the largest host (hind tibia length=0.73 mm), which in turn yielded larger A. ervi females (0.75 mm).

Effects of pea aphid secondary endosymbionts on aphid resistance and development of the aphid parasitoid Aphidius ervi: a correlative study

AbstractIn order to reduce parasite‐induced mortality, hosts may be involved in mutualistic interactions in which the partner contributes to resistance against the parasite. The pea aphid, Acyrthosiphon pisum Harris (Hemiptera: Aphididae), harbours secondary bacterial endosymbionts, some of which have been reported to confer resistance against aphid parasitoids. Although this resistance often results in death of the developing parasitoid larvae, some parasitoid individuals succeed in developing into adults. Whether these individuals suffer from fitness reduction compared to parasitoids developing in pea aphid clones without symbionts has not been tested so far. Using 30 pea aphid clones that differed in their endosymbiont complement, we studied the effects of these endosymbionts on aphid resistance against the parasitoid Aphidius ervi Haliday (Hymenoptera: Braconidae: Aphidiinae), host–parasitoid physiological interactions, and fitness of emerging adult parasitoids. The number of symbiont species in an aphid clone was positively correlated with a number of resistance measurements but there were also clear symbiont‐specific effects on the host–parasitoid interaction. As in previous studies, pea aphid clones infected with Hamiltonella defensa Moran et al. showed resistance against the parasitoid. In addition, pea aphid clones infected with Regiella insecticola Moran et al. and co‐infections of H. defensa–Spiroplasma, R. insecticola–Spiroplasma, and R. insecticola–H. defensa showed reduced levels of parasitism and mummification. Parasitoids emerging from symbiont‐infected aphid clones often had a longer developmental time and reduced mass. The number of teratocytes was generally lower when parasitoids oviposited in aphid clones with a symbiont complement. Interestingly, unparasitized aphids infected with Serratia symbiotica Moran et al. and R. insecticola had a higher fecundity than unparasitized aphids of uninfected pea aphid clones. We conclude that in addition to conferring resistance, pea aphid symbionts also negatively affect parasitoids that successfully hatch from aphid mummies. Because of the link between aphid resistance and the number of teratocytes, the mechanism underlying resistance by symbiont infection may involve interference with teratocyte development.

Tritrophic effects of organic and conventional fertilisers on a cereal‐aphid‐parasitoid system

AbstractThe impact of parasitoids on pests varies between conventional and low‐intensity agricultural systems. Although the impacts on parasitoid natural enemies of many practices within these agricultural systems are well understood, the role of fertilisers has been less well studied. The effects of organic‐based and conventional fertilisers on Hordeum vulgare L. (Poaceae), the aphid Metopolophium dirhodum Walker (Hemiptera: Aphididae), and its parasitoid Aphidius ervi Haliday (Hymenoptera: Braconidae) was investigated using cage release experiments and measures of aphid and parasitoid fitness were taken. Barley tiller number and aphid weight were increased by fertilisers, particularly under conventional treatments. Adult parasitoid size correlated positively with that of the host, M. dirhodum, whereas percentage parasitism was not affected by fertiliser treatment or host size. The results suggest that the increased parasitoid impact observed in some low‐intensity or organic systems is not a direct result of fertiliser treatment. Our results indicate that fertiliser treatments that improve cereal‐aphid fitness will improve parasitoid fitness as measured by parasitoid size but may not influence percentage parasitism.

First record of Aphidius ervi Haliday in Slovenia

In 2008, a lucerne aphid parasitoid Aphidius ervi Haliday was first recorded in Slovenia. This oligophagous parasitoid is used as biological control agent against bigger aphid species. By sampling aphid mummies on different locations in Slovenia in 2008, we found parasitoid Aphidius ervi on nine host plants (corn, pea, alfalfa, red clover, winter wheat, oat, onion, potato and winter barley). Among 1812 primary parasitoids found in Slovenia in 2008, there were 46 individuals of Aphidius ervi; 21 male and 25 female parasitoids. In the present paper description of the species, its geographic distribution and host plant-aphid-parasitoid associations are given.

The first record of Aphidius ervi Haliday in Slovenia

In 2008, a lucerne aphid parasitoid Aphidius ervi Haliday was first recorded in Slovenia. This oligophagous parasitoid is used as biological control agent against bigger aphid species. By sampling aphid mummies on different locations in Slovenia in 2008, we found parasitoid Aphidius ervi on nine host plants (corn, pea, alfalfa, red clover, winter wheat, oat, onion, potato and winter barley). Among 1812 primary parasitoids found in Slovenia in 2008, there were 46 individuals of Aphidius ervi; 21 male and 25 female parasitoids. In the present paper description of the species, its geographic distribution and host plant-aphid-parasitoid associations are given.