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Background: Sitobion miscanthi is a major wheat pest at the grain-filling stage found in China. Identifying parasitoid species and understanding parasitism rates are keys to controlling the aphids via natural enemies in the wheat field., Results: In the present study, a method based on DNA barcoding for early determination of the community composition of Aphidiinae parasitoids and parasitism on the aphid was developed. The proposed method detected Aphidius gifuensis as the predominant parasite, with parasitism rates of 40.1 ± 2.8% in 2019 and 65.7 ± 3.7% in 2022, and found that the rate varied significantly among different wheat varieties. COI primers efficiently amplified the Aphidiinae parasitoids COI fragments and amplified the aphid COI fragments derived from parasitized (mummified) S. miscanthi. Thus, the COI barcode is not sufficiently specific to unambiguously detect immature parasitoids inside their S. miscanthi hosts. However, it can be used to detect the DNA extracted from mummified aphids. In contrast, the 16S and LWRh primers effectively amplified and identified the parasitoids in parasitized aphids. The 16S primer was reliable even in the early stages of parasitism (24 h) and for DNA samples stored at -20 °C for 5 days. The three barcodes from COI, 16S, and LWRh genes could not clearly distinguish a few certain Aphidiinae species owing to relatively low intraspecific and interspecific diversity., Conclusion: The morphological features remain indispensable when identifying Aphidiinae species. Nonetheless, the COI and 16S primers could be used in combination for monitoring the parasitism rates on S. miscanthi in wheat fields. © 2022 Society of Chemical Industry., (© 2022 Society of Chemical Industry.)

Background: Estimating parasitoid abundance in the field can be difficult, even more so when attempting to quantify parasitism rates and the ecosystem service of biological control that parasitoids can provide. To understand how 'field observed' parasitism rates (in-field mummy counts) of the green peach aphid, Myzus persicae (Sulzer) (Hemiptera: Aphididae) translate to 'laboratory observed' parasitism rates (laboratory-reared parasitoid counts), field work was undertaken in Australian canola fields, over the winter growing season., Results: Overall, laboratory observed parasitism was on average 2.4 times higher than field observed parasitism, with rates an average of four-fold higher in fields from South Australia. Total field observed and laboratory observed parasitism rates (OPRs) of M. persicae varied considerably across regions, but less so among fields within regions. As crop growth stage progressed, the incidence of field observed mummies increased. The incidence of total parasitoids reared also increased with crop growth stage, averaging 3.4% during flowering and reaching 14.4% during podding/senescing. Although there was a greater diversity of reared parasitoid species at later crop growth stages, the laboratory OPR was unaffected by parasitoid species. Diaeretiella rapae was the most commonly reared parasitoid, increasing in absolute abundance with crop growth stage., Conclusion: These findings indicate that field mummy counts alone do not provide a clear representation of parasitism within canola fields. © 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry., (© 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.)

Aphid parasitoids are common in Brazilian wheat fields, and parasitize aphids at the wheat tillering stage. However, there is little information available about when this natural enemy occurs in wheat crops. This study investigated the initial occurrence of aphid parasitoids in four commercial wheat crops in northern Paraná during the 2009 crop season. We installed two Malaise traps at each wheat farm, and 400 tillers were assessed weekly in each field for aphid abundance. During this study, we captured 4,355 aphid parasitoids and 197 aphids. Three species of braconid parasitoids were identified, including Aphidius colemani (Viereck 1912), Lysiphlebus testaceipes (Cresson 1880), and Diaeretiella rapae (McIntosh 1855). The aphids species identified were Rhopalosiphum padi (Linnaeus 1758) and Sitobion avenae (Fabricius 1775). This study showed that aphid parasitoids are present in wheat crops even when aphid densities are low, and in one farm, occurred before the aphids colonization. These reports can justified the high efficiency of these natural enemies against aphids in wheat fields., (© The Author 2015. Published by Oxford University Press on behalf of the Entomological Society of America.)

Trioxys longicaudi Starý, 1978 and T. ademuzi Michelena et Sanchis, 1994 are recorded from Russia for the first time. The distribution of T. iziphyae Mackauer, 1967, T. chaetosiphonis Starý, 1971, and T. microceratus Mackauer, 1968 is clarified. An amended description of T. iziphyae is given, and the differences between the closely related species T. ademuzi and T. chaetosiphonis are discussed. [ABSTRACT FROM AUTHOR]

The genus Diaeretellus is a small group of Aphidiinae wasps, comprising five species from the Palaearctic so far. All members of the genus are highly specialised to semi-aquatic habitats and aphid hosts and plants that occupy them. Because they have practically no economic importance as biocontrol agents, the biology of Diaeretellus species is still somewhat unknown. We describe a new species of this genus, Diaeretellus nymphaealis sp. nov., another member of aphid-parasitoid guilds from wetland habitats and the first species of the genus to be described from the Nearctic. Wetland habitats are under considerable anthropogenic pressure and as such require intensive conservation efforts. Placing the focus of conservation strategies on hyperdiverse entomofauna, instead of only charismatic megafauna, can have positive effects on their outcomes. [ABSTRACT FROM AUTHOR]

Classical biological control is being attempted for the giant willow aphid, Tuberolachnus salignus (Gmelin) (Hemiptera: Aphididae: Lachninae), an invasive pest first recorded in New Zealand in 2013. Giant willow aphid (GWA) feeds primarily on species of Salix, and is also occasionally recorded on species of Populus, Malus and Pyrus in New Zealand where it is causing problems ranging from detrimental impacts on willow trees and honey bees, to honey losses, rising vespid wasp populations and risks to fruit exports. A biological control programme against GWA was initiated by importing into containment a parasitoid wasp, Pauesia nigrovaria (Provancher) (Hymenoptera: Braconidae: Aphidiinae), reared from GWA in California, USA. Host range testing was conducted using five non-target aphid species, including representatives of all aphid subfamilies and tribes in New Zealand that contain any native species (all are distantly related to the target host, GWA), as well as a closely related exotic pest species, Cinara fresai, in the same subfamily as the target host (Lachninae). No-choice tests were negative for all non-target species. A single P. nigrovaria individual attempted to attack two C. fresai during behavioural assays. However these actions did not result in reproductive success. Our results demonstrate that P. nigrovaria is a host specific parasitoid and its release into the New Zealand environment poses negligible environmental risk. [ABSTRACT FROM AUTHOR]

Almost all known Aphidiinae (Hymenoptera: Braconidae) parasitoid species in New Zealand have been introduced as biological control agents (BCAs) for introduced aphids or have self‐introduced. The New Zealand endemic aphid (Hemiptera: Aphididae) fauna consists of a small number of species that are parasitised, on occasion, by Aphidiinae that remain unidentified. A persistent concern has been that introduced BCAs are among the parasitoids attacking the rare endemic aphids. After 14 years of collection, 66 cytochrome oxidase I (COI) gene sequences were obtained from emerged parasitoids, mummies or by specific PCR from parasitised New Zealand aphids. Parasitoid samples were from 13 aphid species (eight endemic, plus five introduced species feeding on native plants) at 20 locations. The Aphidiinae COI sequences comprised two new clades of native New Zealand parasitoids. One species‐rich clade appeared to represent a radiation after dispersal to New Zealand, whereas the second clade consisted only of parasitoids from a single endemic host. The patterns of aphid/parasitoid associations were strongly suggestive of host specificity towards the endemic aphids, while a subgroup of the newly discovered native Aphidiinae was found parasitising four introduced aphid species, despite the short time period these aphids are assumed to have been in New Zealand. We found no evidence for attack of endemic aphids by introduced BCAs or other introduced aphidiines. On the rare occasions that parasitism was detected in the most common endemic Aphidinae aphid, Aphis cottieri Carver, 1999, it was by a native Aphidiinae lineage, not by Aphidius ervi Haliday, 1834. [ABSTRACT FROM AUTHOR]

The first ichneumonoid aphidiine wasp species from Sakhalinian amber (middle Eocene) is described. Ephedrus rasnitsyni Davidian and Kaliuzhna sp. nov. іs the oldest named aphidiine female, the first fossil aphidiine from Asia, and the oldest named species of the Ephedrus. Ephedrus rasnitsyni Davidian and Kaliuzhna sp. nov. and the two fossil species of Ephedrus, i.e., Ephedrus primordialis from Baltic amber (late Eocene) and Ephedrus mirabilis from Camoins-les-Bains (early Oligocene), presumably belong to the Ephedrus plagiator species group of the subgenus Ephedrus sensu stricto, and new species differs from them in having a longer petiole and a rather long 3M vein that does not reach the forewing margin. It additionally differs from E. primordialis by having longer ovipositor sheaths. The new species is most similar to the extant Ephedrus validus and Ephedrus carinatus, from which it differs by the less elongated F1, absence of notauli, and by ovipositor sheaths that are 3.0 times as long as wide.

The first ichneumonoid aphidiine wasp species from Sakhalinian amber (middle Eocene) is described. Ephedrus rasnitsyni Davidian and Kaliuzhna sp. nov. Ñ-s the oldest named aphidiine female, the first fossil aphidiine from Asia, and the oldest named species of the Ephedrus. Ephedrus rasnitsyni Davidian and Kaliuzhna sp. nov. and the two fossil species of Ephedrus, i.e., Ephedrus primordialis from Baltic amber (late Eocene) and Ephedrus mirabilis from Camoins-les-Bains (early Oligocene), presumably belong to the Ephedrus plagiator species group of the subgenus Ephedrus sensu stricto, and new species differs from them in having a longer petiole and a rather long 3M vein that does not reach the forewing margin. It additionally differs from E. primordialis by having longer ovipositor sheaths. The new species is most similar to the extant Ephedrus validus and Ephedrus carinatus, from which it differs by the less elongated F1, absence of notauli, and by ovipositor sheaths that are 3.0 times as long as wide. [ABSTRACT FROM AUTHOR]

Diversitat de parasitoides primaris i secundaris del pugó Myzus persicae (Hemiptera, Aphididae) en la bresquillera Prunus persica (Rosales, Rosaceae) a la província de Mendoza, Argentina Mendoza és la primera productora de fruita de pinyol i la principal elaboradora de bresquilla per a indústria de l’Argentina. Myzus persicae, el “pugó verd”, és una de les principals plagues que afecta aquest conreu. Els himenòpters parasitoides de la família Braconidae destaquen com un dels enemics naturals més eficients d’aquesta plaga. Els objectius d’aquest treball van ser determinar el parasitoidisme natural d’aquest afídid a la bresquillera i conèixer la diversitat de parasitoides associats a aquesta plaga. Durant els anys 2015/2016 es van portar a terme recol·leccions setmanals de setembre a desembre de brots amb afídids que presentaven o no senyals de parasitoidisme. Es van calcular el percentatge de parasitoidisme i la freqüència i abundància relativa de parasitoides. El percentatge de parasitoidisme mitjà per brot va ser de prop del 20 %. Pel que fa a l’associació bresquillera–M. persicae, es van registrar nou espècies de parasitoides primaris i quatre espècies de parasitoides secundaris. Aphidius colemani va ser l’espècie dominant entre els parasitoides primaris.

The bird cherry‐oat aphid Rhopalosiphum padi is a major cereal pest with an almost cosmopolitan distribution. As one of the main groups of biocontrol agents for aphids, numerous Aphidiinae are associated with R. padi, including the genera Binodoxys and Trioxys.As a recently described species parasitizing R. padi, Trioxys sunnysidensis is recorded from Europe for the first time based on morphological and molecular data. Specimens from North America, Europe and New Zealand were used in the analysis of the cytochrome c oxidase subunit I to explore genetic variation among populations. The analysis revealed one of the highest haplotype diversities in Aphidiinae so far, with 25 haplotypes detected. The two most common haplotypes are shared across groups of populations, whereas all of the others are found either in North America or Europe.Because the genetic structure of populations is an important factor to consider when choosing a biocontrol agent, the results obtained in the present study may be helpful in guiding potential biocontrol attempts. [ABSTRACT FROM AUTHOR]

The present study was conducted to investigate the seasonal biodiversity of braconid parasitoids in citrus orchards of Sargodha, Pakistan. Surveys were done during January 2014 to December 2015 from various citrus growing localities. A total of 3,176 parasitoids belonging to five subfamilies (Alysiinae, Aphidiinae, Braconinae, Microgastrinae and Opiinae), 12 genera and 16 species were collected. Out of them, two genera and 12 species were recorded for the first time from this area. Aphidiinae contains 1,107 individuals which showed that it's a dominant braconid subfamily while Opiinae (209) was the least dominant. The richness of braconid parasitoids in different localities of Sargodha was also investigated. Braconid parasitoid populations were higher in the months of February to April and October to December, while less abundant in the remaining months of the year. [ABSTRACT FROM AUTHOR]

Abstract Three species of the Aphidiinae (Hymenoptera: Braconidae) are reported for the first time in Korea: Aphidius rhopalosiphi de Stefani-Perez, 1902, Aphidius uzbekistanicus Luzhetzki, 1960 and Lysiphlebus orientalis Starý and Rakhshani, 2010. Their diagnosis, photographs and host list are included. [ABSTRACT FROM AUTHOR]

Plant-aphid-parasitoid associations in urban green areas of the north-eastern Iberian Peninsula were analysed to identify the diversity of aphid parasitoid species, their trophic relationships and to improve the results of biological control efforts. In 245 tritrophic plant-aphid-parasitoid associations, 33 Aphidiinae species belonging to 13 genera were identified. Only two species, Pseudopraon mindariphagum and Trioxys phyllaphidis, can be considered to be monophagous. Most of the species were narrow, moderate or broad oligophagous but an as-native species, Lysiphlebus testaceipes, was recorded to be associated with 39 aphid species and with seven subfamilies/tribes of aphids in 81 tritrophic associations. The potential role of L. testaceipes and other native and commercialised parasitoid species is discussed. Our results point out that the conservation and enhancement of the both native and as-native local parasitoids is crucial for an aphid biological control strategy in urban green areas. [ABSTRACT FROM AUTHOR]

Abstract: Maternal rearing conditions are expected to affect fitness components of progeny so that maternal effects effectively protect offspring from environmental stressors. The objective of this study was to elucidate the interaction between maternal rearing condition, age, and offspring rearing condition in the parasitoid wasp Lysiphlebus fabarum (Marshall) (Hymenoptera: Braconidae, Aphidiinae). The effects of maternal age, body size, and host instar used for development on fitness components of progeny were evaluated. Host was the black bean aphid, Aphis fabae Scopoli (Hemiptera: Aphididae). Results indicated that small and young mothers (developing in first‐instar hosts) produced progeny with a longer developmental time compared to large and old mothers (developing in second‐instar hosts). Progeny that hatched from larger eggs also had a larger body size. There were, however, no significant differences in the size of progeny that developed in different host instars. Progeny that hatched from large eggs had a higher initial egg load, and progeny produced by younger mothers had larger eggs. These differences were significant only when progeny developed in the first host instar, whereas in the second and fourth instar no differences were observed. Our findings indicate that progeny with larger size at the egg stage had superior fitness. Age‐specific maternal effects were not as strong as the effect of the mother's body size. Although the interaction between host instar of progeny development and maternal rearing condition was not statistically significant, developing in suboptimal instars led to trade‐offs between fitness components in progeny. The ecological significance of these findings is discussed. [ABSTRACT FROM AUTHOR]

Parasitoid wasps of the subfamily Aphidiinae (Hymenoptera: Braconidae) specialize on aphids (Hemiptera: Aphididae) as hosts. The diversity of known and probable aphidiine wasps from South Dakota is itemized, with representation by 13 genera and 42 species, 43% of which are probably adventitious. The wasps and aphids are central to various combinations of multitrophic relationships involving host plants and secondary parasitoids. Selected native and introduced aphid host taxa were quantitatively and qualitatively collected from diverse native and crop host plants in eastern South Dakota and western Iowa. Wasps were reared to confirm plant association, host aphid association, taxonomic diversity, and native or introduced status of the wasps. Acanthocaudus tissoti (Smith) and Aphidius (Aphidius) ohioensis (Smith) were found together on the native aphid Uroleucon (Uroleucon) nigrotuberculatum (Olive), a new host aphid species for both wasps on Solidago canadensis L. (Asterales: Asteraceae). The native wasp Lysiphlebus testaceipes (Cresson) was repeatedly reared in massive numbers from mummies of invasive Aphis glycines Matsumura on soybean, Glycine max (L.) Merr. This wasp was also reared from the non-native Aphis nerii Boyer de Fonscolombe and the native Aphis asclepiadis Fitch, both on Asclepias syriaca L. The introduced wasp Binodoxys communis (Gahan) was not recovered from any Aphis glycines population. Hyperparasitoids from the genus Dendrocerus Ratzeburg (Hymenoptera: Megaspilidae), and the pteromalid (Hymenoptera: Pteromalidae) genera Asaphes Walker, and Pachyneuron Walker were reared from mummies of Uroleucon (Uroleucon) nigrotuberculatum parasitized by either Acanthocaudus tissoti or Aphidius (Aphidius) ohioensis. Hyperparasitoids of the genus Alloxysta (Hymenoptera: Figitidae) were reared from mummies of Aphis glycines and A. nerii parasitized by Lysiphlebus testaceipes. [ABSTRACT FROM AUTHOR]

Aphids represent a major problem for many plant species, due to their ability to serve as pathogen vectors; the use of parasitoids as biological control agents might be a suitable option for long term control of their populations. The objective of this study was to prepare a taxonomic key in order to identify parasitoids and hyperparasitoids of aphids obtained in Costa Rica. In total, during 2008 to 2015, 3009 hymenopteran parasitoids were reared from 25 species of aphids, 2832 (94%) were primary parasitoids and 175 (6%) were hyperparasitoids. A taxonomic key was made for the identification of nine species of primary parasitoids, Braconidae-Aphidiinae, Aphelinidae, Eulophidae, and six species of hyperparasitoids in five families. In addition, the genus Quadrictonus (Aphidiinae), was included in the key and was reported for the first time in this study in Costa Rica. [ABSTRACT FROM AUTHOR]

Samples were collected from eight different habitats by using either a sweeping-net and Malesian trap in Edirne province of European Turkey in the Spring, Summer and Autumn of 2014. A total of six genera and 27 species have been identified. Of these, nine species (Aphidius eadyi Starý, Gonzales & Hall, 1980, A. rosae Haliday, 1834, A. picipes (Nees, 1811), Binodoxys acalephae (Haliday, 1833), Ephedrus persicae Frogatt, 1904, Lysiphlebus confusus Tremblay & Eady, 1978, Praon abjectum (Haliday, 1833), P. pubescens Starý, 1961, P. yomenae Takada, 1968) are new records for the Edirne Aphidiinae fauna and seven of them (Aphidius smithii Sharma & Subba Rao, 1959, A. microlophii Pennachio & Tremblay, 1987, Lysiphlebus fritzmuelleri Mackauer, 1960, Praon athenaeum Kavallieratos & Lykouressis, 2000, P. flavinode (Haliday, 1833), P. nonveilleri Tomanović & Kavallieratos, 2003, P. uroleucon Tomanović & Kavallieratos, 2003) are new records for Turkish Aphidiinae fauna. [ABSTRACT FROM AUTHOR]

The authors of the article used literature data to present the species diversity of the Aphidiinae (Braconidae) subfamily in agricultural crops, forests and urban green space in Poland. In total, 83 species of parasitoids were found in all the environments. Aphidiinae preferred forests most: 61 species of the parasitoids were found there. The agricultural and urban environments did not attract so many Aphidiinae parasitoid species as forests. There were 41 species found in the agricultural environment and 38 species in the urban green space. All the environments were infested by the following 15 species: Aphidius ervi, A. matricariae, A. picipes, A. salicis, A. setiger, A. sonchi, Diaeretiella rapae, Ephedrus persicae, E. plagiator, Lysiphlebus ambiguous, L. fabarum, Praon abjectum, P. volucre, Trioxys acalephae and T. angelicae. [ABSTRACT FROM AUTHOR]

The Palaearctic genus Paralipsis Foerster, 1863 (Hymenoptera: Braconidae: Aphidiinae) is revised and two new species are described: P. tibiator van Achterberg & Ortiz de Zugasti, sp. n. from Spain and P. planus van Achterberg, sp. n. from the Netherlands. Some biological notes are supplied for P. tibiator sp. n. A key to the four known species is added and all species are illustrated. [ABSTRACT FROM AUTHOR]

Insects are highly dependent on ambient temperatures to ensure their biological functions. Their persistence in the environment and their resistance to unfavourable temperatures are governed by their physiological thermal tolerance., Global change extends beyond climatic conditions to encompass modifications to the landscape. Studies of climate change and landscape composition effects on ecosystem services, such as biological control, are commonly performed independently. Moreover, coarse scales are not always relevant when assessing climate change's impacts on ectotherms. We aimed to better understand the ecological relationships that may exist between microclimatic variation and insect thermal tolerance across a landscape composition gradient., To determine how landscape composition may impact insect thermal tolerance, parasitic wasps (Hymenoptera: Braconidae: Aphidiinae) of aphids were sampled along a landscape gradient from 'closed' to 'open' habitats. Sampling was performed during the winter 2013/14 and spring 2014 in cereal fields of Brittany, France. Meteorological data were recorded along this gradient., First, our results show an influence of landscape composition on local microclimate. Additionally, parasitoids from open landscapes had a higher tolerance to low temperatures, leading to higher physiological costs, compared with parasitoids from closed landscapes. This trend was stronger in winter than in spring., These results have numerous implications in the context of climate change, suggesting that targeted landscape management practices could create sheltered microclimatic areas that reduce the physiological costs of thermal tolerance and promote the persistence of biological control agents. [ABSTRACT FROM AUTHOR]

Phylogenetic relationships among 16 genera of the subfamily Aphidiinae (Hymenoptera: Braconidae) were investigated using sequence data from three genes: the mitochondrial large ribosomal subunit (16S), 18S ribosomal DNA and mitochondrial ATPase 6. All sequences were downloaded from the GenBank database. A total of 2775 base pairs of aligned sequence were obtained per species from these three genes. The results support the existence of three-tribes: Ephedrini, Praini and Aphidiini, with the Ephedrini occupying the basal position; Aphidiini could be further subdivided into three subtribes: Monoctonina, Trioxina and Aphidiina. The genus Aphidius is a paraphyletic group. The taxonomic status of the subfamily Aphidiinae within the Braconidae is probably closer to the non-cyclostome than the cyclostome subfamilies.

Extreme temperature events are a great challenge for most ectotherms, particularly for the immature stages of parasitoids, as they do not possess the ability to behaviourally thermoregulate. In this study, we measured the effect of an acute heat shock, combined with desiccation stress (34 °C and 35% r.h. during 10 h) during the mummy stage on several fitness-related traits of emerging adults of the aphid parasitoid Aphidius colemani Viereck ( Hymenoptera: Braconidae: Aphidiinae). Our results showed that the emergence rate was strongly affected by the heat shock (63 ± 2.3 vs. 96.1 ± 0.7% for stress vs. control conditions, respectively), and the resulting population was male biased. Heat stress reduced the lifespan of emerged parasitoids but had no effect on fat reserves and female size. Egg load at emergence and parasitism rate were also reduced by heat treatment. The antennal symmetry was disturbed by the heat treatment, and stressed individuals had reduced mating success compared to control parasitoids. Specifically, time before wing fanning, a typical male courtship behaviour, was significantly longer in parasitoid pairs involving females that had emerged from heat-treated mummies. Additionally, olfactometry tests on experimental females indicated that their response to host odour was similar to that of control individuals, but they required a longer time for perception. These results highlight that exposure to high temperatures during the mummy stage has cumulative detrimental effects that may strongly impact parasitoid populations under natural conditions and hinder the success of biological control programs. [ABSTRACT FROM AUTHOR]

In Algeria, useful entomofauna remains little studied, particularly in the southern regions. It is for this reason that this work was undertaken to assess the biodiversity of these auxiliaries in the region of Ghardaia. Different surveys carried out have an inventory of 15 species of Hymenoptera parasitoids of aphids, which are 09 in the Braconidae and subfamily Aphidiinae. Genera Aphidius and Lysiphlebus are the most represented. The 06 other species of Hymenoptera belong to families Encyrtidae, Alloxystidae, Pteromalidae and Megaspilidae. Species belonging to these families are either secondary parasitoids or hyperparasitoids. The 09 species of primary parasitoids inventoried are collected from aphid mummies of 19 species subservient to 27 plant species belonging to 16 botanical families. A total of 59 associations tri-trophic (plant-aphid-parasitoid primary) was formed at the areas surveyed [ABSTRACT FROM AUTHOR]

Cold storage is one means of preserving parasitoids prior to release in augmentation biological control programs. This study examined the feasibility of storing larval and pupal stages of a sexual population of Lysiphlebus fabarum Marshall (Hymenoptera: Braconidae: Aphidiinae) at 6 ± 1 and 8 ± 1 °C, 50-60% r.h., and L14:D10 photoperiod. These life stages were stored for periods of 1, 2, and 3 weeks under fluctuating thermal regimes (2 h daily at 21 ± 1 °C). Generally, pupae gave better results than larvae, and 6 °C was better than 8 °C, considering wasp survival, wasp size (tibial and antennal lengths), egg load, and egg size. The best results were obtained with pupae stored for 2 weeks under a fluctuating temperature regime at 6 °C. Females emerging from this treatment did not differ from controls (developing directly at 21 °C) in body size, egg size, or progeny sex ratio, and suffered less than 20% mortality. Egg loads were reduced in these wasps, but the reductions were substantially less than occurred in other 2-week-storage treatments. Wasps stored in this manner successfully parasitized similar numbers of aphids as controls and produced similar progeny sex ratios. These results reveal a suitable set of low-temperature conditions that can be used to delay the development of L. fabarum for 2 weeks with minimal impact on wasp fitness. [ABSTRACT FROM AUTHOR]

Organisms can either evade winter's unfavourable conditions by migrating or diapausing, or endure them and maintain their activities. When it comes to foraging during winter, a period of scarce resources, there is strong selective pressure on resource exploitation strategy. Generalist parasitoids are particularly affected by this environmental constraint, as their fitness is deeply linked to the profitability of the available hosts. In this study, we considered a cereal aphid-parasitoid system and investigated (1) the host-parasitoid community structure, host availability, and parasitism rate in winter, (2) the influence of host quality in terms of species and instars on the fitness of the aphid parasitoid Aphidius rhopalosiphi De Stefani-Perez (Hymenoptera: Braconidae: Aphidiinae), and (3) whether there is a detectable impact of host fidelity on parasitism success of this parasitoid species. Host density was low during winter and the aphid community consisted of the species Rhopalosiphum padi L. and Sitobion avenae Fabricius (both Hemiptera: Aphididae), both parasitized by A. rhopalosiphi at non-negligible rates. Aphidius rhopalosiphi produced more offspring when parasitizing R. padi compared with S. avenae, whereas bigger offspring were produced when parasitizing S. avenae. Although aphid adults and old larvae were significantly larger hosts than young larvae, the latter resulted in higher emergence rates and larger parasitoids. No impact of host fidelity on emergence rates or offspring size was detected. This study provides some evidence that winter A. rhopalosiphi populations are able to take advantage of an array of host types that vary in profitability, indicating that host selectivity may drop under winter's unfavourable conditions. [ABSTRACT FROM AUTHOR]

The aphid-associated Charipinae of Serbia, Montenegro and Slovenia have been studied. Nine species are recorded for the first time from these regions: Alloxysta arcuata (Kieffer, 1902), A. brevis (Thomson, 1862), A. castanea (Hartig, 1841), A. fracticornis (Thomson, 1862), A. fuscicornis (Hartig, 1841), A. macrophadna (Hartig, 1841), A. mullensis (Cameron, 1883), A. pleuralis (Cameron, 1879), and A. salicicola Belizin, 1973. Only Alloxysta victrix (Westwood, 1833) was previously recorded from this region. The important morphological characters of these species are briefly described and compared. Two new species, Alloxysta kovilovica Ferrer-Suay & Pujade-Villar sp. nov. and A. slovenica Ferrer-Suay & Pujade-Villar sp. nov., are described and their morphological characters are illustrated. A key for identification of the Charipinae already known from the north-western Balkan Peninsula is provided. [ABSTRACT FROM AUTHOR]

This study presents the results of a survey of aphid parasitoids of the subfamily Aphidiinae (Hymenoptera: Braconidae) in western Iran. Thirty nine species of aphid parasitoids belonging to nine genera were collected and identified in association with 54 aphid species occurring on 77 host plants. In all, 129 parasitoid-aphid associations were recorded, 49 of which are new to Iran. Praon pubescens Starý, 1961 is newly recorded for the fauna of Iran in association with Nasonovia ribisnigri (Mosley, 1841) on Lactuca sativa. The possible existence of endemic subspecies for Praon necans Mackauer, 1959, member of which attack a wider range of host aphids, is discussed. An illustrated key for identification of the genera and species of Aphidiinae in western Iran is presented. [ABSTRACT FROM AUTHOR]