Parasitoid Guild Research Articles

Bottom‐up effects shift top‐down community structure of the parasitoid guild that attacks Asphondylia borrichiae (Diptera: Cecidomyiidae) on Borrichia frutescens (Asteraceae)

Abstract Asphondylia borrichiae induces galls at the apical meristems of its host plant, Borrichia frutescens, and the larvae develop and pupate within the gall. During development, immature stages of the midge are attacked by four species of parasitic wasps; two of these parasitoids, Galeopsomyia haemon and Torymus umbilicatus, are the most common members of the guild, and both are hyperparasitic. In the current study, plots of B. frutescens were randomly assigned to control (unmanipulated), salted or fertilised in a long‐term press experiment. Although plots initially exhibited no differences in stem length, gall and flower densities, after 3 months, they began to exhibit significant differences, suggesting stress (salted plots) and vigour (fertilised plots). Galls produced on plants from fertilised plots were approximately 20% and 31% larger than those from control and salted plots, respectively. Larger gall diameter in fertilised plots resulted in a shift of the parasitoid community towards the largest parasitoid, T. umgbilicatus, whereas smaller galls produced in salted plots became biased towards the smallest, but gregarious, G. haemon; interestingly, this pattern held for T. umbilicatus across treatments, and the effect for G. haemon was not significant when all treatments were combined. This study suggests that abiotic factors that alter host plant characteristics, such as gall diameter, affect the composition of the parasitoid guild that attacks A. borrichiae, which has implications for the acquisition of enemy‐free space during host range expansion of the midge.

Specificity within bird–parasite–parasitoid food webs: A novel approach for evaluating potential biological control agents of the avian vampire fly

Abstract Quantitative food web analyses can provide insights into the specificity of consumers such as herbivores, parasites and parasitoids. Understanding such patterns can be useful in forecasting the potential benefits and risks of biological control agents being considered for introduction against invasive species. The avian vampire fly, Philornis downsi (Diptera: Muscidae), is a neotropical bird parasite that is invasive in the Galapagos Islands, where it is causing substantial mortality of endemic bird species. We used a novel in‐field experimental food web approach within the native range of P. downsi in Ecuador to test the hypotheses that pupal parasitoids known to attack P. downsi specialize on members of the genus Philornis, which occur only in bird nests. We deployed pupae of non‐Philornis fly species adjacent to bird nests to assess specificity of the parasitoids and used two indices to assess specificity: Resource Range (RR), which evaluates the breadth of host use, and Pair Difference Index (PDI), which evaluates interaction strength. The results revealed very strong compartmentalization within the guild of pupal fly parasitoids, with four species attacking only Philornis spp. Both specificity indices indicated significant levels of specificity towards the genus Philornis for two of these species: Conura annulifera and Trichopria sp. novus. We also assessed the specificity of the two dominant Philornis species attacking 11 bird species and preference of the two dominant parasitoid species for bird species. Although there was some significant preference for particular bird species by the Philornis spp., there was no indication that this drove specificity patterns by the parasitoids. Policy implications. Our results confirm previous laboratory studies indicating specificity by C. annulifera and support the hypothesis that this species would produce few, if any, nontarget impacts if released into Galapagos to suppress populations of the P. downsi. These results can inform an environmental risk assessment framework to guide governmental agencies in deliberation on potential field releases of parasitoids in the Galapagos Islands.

Diaeretellus nymphaealis sp. n. (Hymenoptera, Braconidae, Aphidiinae) – a new member of aphid parasitoid guilds associated with wetland habitats, with a key for identification of Diaeretellus species

ABSTRACT 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.

Early-acting competitive superiority in opiine parasitoids of fruit flies (Diptera: Tephritidae): Implications for biological control of invasive tephritid pests

Understanding and predicting potential competitive outcomes is critical in the design of biological control programs when considering multiple agent introductions. Tephritid fruit flies (Diptera: Tephritidae) include some of the most destructive pests of fruit and vegetable crops worldwide. Parasitoid guilds of fruit-infesting tephritids are dominated by opiines (Hymenoptera: Braconidae: Opiinae) that have been the main agents used for biological control of pest tephritids. All opiine parasitoids are solitary koinobiont endoparasitoids that attack host eggs or larvae and emerge as adults from host puparia. Thus, a host initially attacked by an egg-larval parasitoid can be subsequently attacked by a larval parasitoid, providing an ideal system to test the Early-acting Competitive Superiority Hypothesis (i.e., the first species occupying a host or exploiting early host stages has an advantage over competitive species). We reviewed the literature on interspecific competition among opiine fruit fly parasitoids, which reveals strong evidence supporting the early-acting competitive superiority hypothesis by egg-larval over larval parasitoids, through physiological suppression mechanisms. Competitive outcomes among larval parasitoids, however, depend on early action as well as the morphological characteristics used in direct physical competition of their first instars (e.g., size of mandibles). We discuss the range of ecological mechanisms facilitating coexistence of interacting species and highlight the ecological consequences of interspecific competition as evidenced by historical competitive displacements of introduced opiine parasitoids for biocontrol of tephritids. Finally, we provide a framework for exploring the role of interspecific competition, among other factors, in selecting opiine parasitoids for biocontrol of invasive tephritids.

Reproductive and Developmental Biology of Acroclisoides sinicus, a Hyperparasitoid of Scelionid Parasitoids.

Simple SummaryAcroclisoides sinicus is a pteromalid of Asian origin that has recently been detected in Europe and North America. It has been frequently found in association with several scelionid and eupelmid primary parasitoids of hemipteran eggs, including the brown marmorated stink bug Halyomorpha halys, leading us to suspect that A. sinicus is an obligate or facultative hyperparasitoid. Laboratory tests were conducted using pentatomid egg masses (H. halys, Acrosternum heegeri, and Dolycoris baccarum) parasitized by primary parasitoids, including Trissolcus japonicus, Trissolcus mitsukurii, Telenomus sp., Anastatus bifasciatus, and unparasitized H. halys egg masses, to test this hypothesis. Our studies confirmed that A. sinicus is an obligate hyperparasitoid of the pupal stage of scelionid primary parasitoids but not of eupelmid ones, at least under the tested conditions.Acroclisoides sinicus (Hymenoptera: Pteromalidae) was described in 1988 from China, but recent findings in Europe and North America within the framework of Halyomorpha halys (Hemiptera: Pentatomidae) biological control indicate a Holarctic distribution. The few records and fragmented information on A. sinicus are derived from generic observations of other species belonging to the same genus, and its biological and ethological traits are still completely unexplored. It was suspected to be a facultative or obligate hyperparasitoid of many egg parasitoid species (e.g., Scelionidae and Eupelmidae), especially those parasitizing Pentatomidae eggs. Laboratory colonies of A. sinicus were established from specimens collected in the field in Europe and the USA, which allowed us to investigate for the first time the life traits of this somewhat enigmatic species. Our studies confirmed the obligate hyperparasitoid hypothesis for species of Scelionidae but not of Eupelmidae. Laboratory studies revealed that A. sinicus is extremely selective in its host recognition as only the pupal stage of its host species is exploited for parasitization. Taking into consideration its hyperparasitoid habit, the adventive A. sinicus populations in Europe and North America may potentially be severe threats to pentatomid natural control as new components in the trophic chain of pentatomids and their parasitoid guilds.

Egg Parasitoids of Cabbage Caterpillars in Sri Lanka: A Search for Biocontrol Agents

Purpose : Management of cabbage caterpillar complex through augmentative release of egg parasitoids has been suggested considering the current issues in insecticide application, mainly the effect on human health, non-target effects and environmental pollution. Use of local egg parasitoid species is preferred considering the environmental risk associated with the use of exotic species; therefore, this study was conducted to examine the egg parasitoid guild of cabbage caterpillars in Sri Lanka. Research Method : Field survey was conducted during January 2012 to May 2013 in major cabbage growing areas in the mid-country. Eggs of cabbage caterpillars were collected and reared them until the emergence of host larvae or adult parasitoids. Emerged parasitoids were preserved in 70% ethanol, and prepared the microscopic slides upon the dissection of male genitalia. Parasitoids were identified by using taxonomic keys and Trichogramma literature as per the protocol suggested by Natural History museum, London and the identities were confirmed by the taxonomist in Natural history museum in London. Findings : Trichoplusia ni, Spodoptera litura, Crocidolomia pavonana and Plutella xylostella were found as the members of cabbage caterpillar complex. Two egg parasitoid species: Trichogramma chilonis Ishi and Trichogramma achaeae Nagaraja and Nagarkatti were found attacking eggs of cabbage caterpillars. Trichogramma chilonis has been reported previously in Sri Lanka but Trichogramma achaeae is the first country report. T. chilonis was widely distributed and caused for higher level of parasitism than T. achaeae. The highest level of parasitism (67%) by both species was found in Trichoplusia ni eggs which was significantly different from other species. Level of parasitism of caterpillar eggs was significantly varied between pesticide free fields (16.8%) and conventional fields (13.1%). Research Limitation : The study of behavioral characters of these parasitoids is required to assess the suitability as biocontrol agents; as an initial step for augmentative biocontrol, the locally available egg parasitoids were reported in this study. Originality/ Value : These findings would be contributing Sri Lankan agriculture sector to develop the augmentative biocontrol approach to manage the cabbage caterpillar complex and to produce pesticide residues free crop produce.

Exploring the potential for novel associations of generalist parasitoids for biological control of invasive woodboring beetles

Cerambycid and buprestid woodborers are important invasive forest pests. Parasitoids play a unique role in reducing woodborer populations because of their specific adaptations regarding host concealment. We reviewed parasitoid guilds of cerambycid and buprestid woodborers to characterize their life-history traits and macroecological patterns of host use. The parasitoid guilds shift from more specialist endoparasitoids to more generalist ectoparasitoids following the hosts’ ontogeny and the increased concealment of host feeding niche. Larval ectoparasitoids dominate the guilds, and many of them locate hosts through substrate vibration from living hosts, rendering attacked (paralyzed) hosts undetectable by other parasitoids and consequently leading to a rarity of multiparasitism. These characteristics promote novel associations between exotic woodborers and extant larval parasitoids, leading to coexistence and synergistic regulation of host populations by different parasitoids. We provide case studies to propose a framework of optimal use of co-evolved and novel associations for complementary suppression of invasive woodborer populations. We also discuss potential non-target impacts for the use of generalist parasitoids in biological control of invasive cerambycid and buprestid woodborers.

Characteristics of the meconia of European egg parasitoids of Halyomorpha halys

Halyomorpha halys is a severe invasive Asian pest worldwide and classical biological control is foreseen as the most promising control method. Egg parasitoids appear to be the most important natural enemies of this pest, especially the Asian hymenopteran Trissolcus japonicus. In the invaded areas, only a few egg parasitoid species have been able to adopt H. halys as a host. Anastatus bifasciatus is the most common native egg parasitoid of H. halys in Europe, but reaches only low levels of parasitization, while several other native species are only occasionally found. Recently, adventive populations have been found both in the USA and in Europe of T. japonicus, and in Italy of a second Asian species, Trissolcus mitsukurii. Species identification based on morphological traits by specialists or by molecular analysis is a crucial step in the management of biological control programs. The ability to identify the genus or species within a narrow guild of egg parasitoids based on adult emergence holes and meconium features can be a simple and useful method to support management efforts. We present here detailed descriptions of the meconium of the most frequent parasitoid species attacking H. halys in Europe and the characteristics of their emergence holes of the adult wasps.

Loss of consumers constrains phenotypic evolution in the resulting food web.

The loss of biodiversity is altering the structure of ecological networks; however, we are currently in a poor position to predict how these altered communities will affect the evolution of remaining populations. Theory on fitness landscapes provides a framework for predicting how selection alters the evolutionary trajectory and adaptive potential of populations, but often treats the network of interacting populations as a “black box.” Here, we integrate ecological networks and fitness landscapes to examine how changes in food‐web structure shape phenotypic evolution. We conducted a field experiment that removed a guild of larval parasitoids that imposed direct and indirect selection pressures on an insect herbivore. We then measured herbivore survival as a function of three key phenotypic traits to estimate directional, quadratic, and correlational selection gradients in each treatment. We used these selection gradients to characterize the slope and curvature of the fitness landscape to understand the direct and indirect effects of consumer loss on phenotypic evolution. We found that the number of traits under directional selection increased with the removal of larval parasitoids, indicating evolution was more constrained toward a specific combination of traits. Similarly, we found that the removal of larval parasitoids altered the curvature of the fitness landscape in such a way that tended to decrease the evolvability of the traits we measured in the next generation. Our results suggest that the loss of trophic interactions can impose greater constraints on phenotypic evolution. This indicates that the simplification of ecological communities may constrain the adaptive potential of remaining populations to future environmental change.

Discovery of Parasitoids of Anoplophora glabripennis (Coleoptera: Cerambycidae) and Their Seasonal Abundance in China Using Sentinel Host Eggs and Larvae.

Asian longhorned beetle, Anoplophora glabripennis (Motschulsky), is a high-risk invasive forest pest worldwide. We surveyed Asian longhorned beetle parasitoid guilds and their seasonal abundance using field-deployed sentinel host logs infested with Asian longhorned beetle eggs or newly hatched (early-instar) larvae in three different sites of China (Beijing City, Shanghai City, and Jilin Province) from 2015 to 2018. Our survey detected 12 species of hymenopteran parasitoids (four Pteromalidae, three Braconidae, two Eupelmidae, one Eurytomidae, one Ichneumonidae, and one Bethylidae) attacking sentinel Asian longhorned beetle larvae or eggs deployed in these sites. Total parasitism by all the parasitoid species varied with different sites and across different years of the survey (averaging 7-16% in Beijing, 4-11% in Shanghai, and 0-0.2% in Jilin Province). In addition, the seasonal pattern of parasitism also differed among different sites, with parasitism peaking in July in the northern site (Beijing, 19%) and June in the southern site (Shanghai, 16%). Among all the parasitoid species recovered, Oxysychus sp. (Hymenoptera: Pteromalidae) was the most abundant parasitoid species in both Beijing and Shanghai (with 42-66% relative abundance and an average of 6% Asian longhorned beetle parasitism). The second most abundant species was Bracon planitibiae Yang, Cao et Gould (Hymenoptera: Braconidae), which accounted for 35% of the species collected and caused an average of 5% Asian longhorned beetle parasitism. Relevance of our findings to Asian longhorned beetle biocontrol is discussed.

The impact of climate on the winter strategies of insects

The impact of climate on the winter strategies of insects

<i>Aphidius geranii</i> sp. n. (Hymenoptera: Braconidae) from Southeast Europe – a new member of the <i>Aphidius urticae</i> s. str. group

Aphidius geranii Tomanovic and Kavallieratos, sp. n., is described as an additional member of the Aphidius urticae s. str. group from high-mountain habitats of Southeast Europe. The new species was reared from Amphorophora sp./Geranium coeruleatum associations. Parasitoid guilds associated with G. coeruleatum are discussed. Key for identification Aphidius spp. on Geranium plants in Europe is given.

Spatial and seasonal distribution of egg parasitoids of the sharpshooter Tapajosa rubromarginata (Hemiptera: Cicadellidae: Proconiini) on feral Johnson grass and commercial citrus host in Argentina

Hymenopterous egg parasitoids are considered promising biocontrol agents against insect vectors of the bacterium Xylella fastidiosa Wells. We studied the spatial and seasonal occurrence of the egg parasitoid guild of the sharpshooter Tapajosa rubromarginata (Signoret) (Hemiptera: Cicadellidae: Proconiini), a known vector of X. fastidiosa, in a commercial lemon orchard in Tucumán Province, Argentina. Egg masses of T. rubromarginata laid at three different heights were examined for two years, in spring and in summer, in order to determine the specific composition and abundance of its parasitoids. The overall rate of egg parasitoid emergence was about 54%. Fourteen species of parasitoids were obtained from egg masses of this host, nine belonging to the genus Cosmocomoidea Howard (Mymaridae) and the rest to five genera of Trichogrammatidae. The percentage of emerged wasps was higher in citrus than in the lower grassy stratum and it was similar in both seasons. Mymarids were generally more frequent and abundant than trichogrammatids, dominating as egg parasitoids of T. rubromarginata on citrus leaves, whereas trichogrammatids were more frequently found parasitizing egg masses of the same host on Johnson grass leaves. Three species were predominant among all the parasitoids, the trichogrammatid Zagella delicata De Santis and the mymarids Cosmocomoidea annulicornis (Ogloblin) and C. metanotalis (Ogloblin), accounting for about three-quarters of the emerged wasps; the other parasitoid species were occasionally or rarely found in the orchard.

Parasitoid guild and parasitism rate of the obliquebanded leafroller in IPM orchards and adjacent woodlands

The obliquebanded leafroller (OBLR), Choristoneura rosaceana (Harris) [Lepidoptera: Tortricidae], a primary pest in Quebec apple orchards, can be naturally parasitized. Knowing that habitats around crop’s peripheries are reservoirs for natural enemies of pests, the objective of the present investigation was to assess parasitism and parasitoid guild composition associated with the OBLR. The two-year study included orchards under integrated pest management, their edges, and adjacent woodlands. Parasitism was assessed using sentinel OBLR larvae and considered spring, early summer and late summer. Parasitism rates between regions with different vegetation composition were not significantly different. The first year, late summer larvae showed higher parasitism in orchards (27%), compared to edges (7%) and woodlands (11%). The following year, larvae exposed in early summer had higher parasitism rate in edges (28%) compared to orchards and woodlands (17% in both zones). Nineteen parasitoid species parasitized sentinel larvae. The tachinid Actia interrupta (Curran), the most abundant species, represented 28 and 62% of species the first and the second year respectively. Our research demonstrates that natural biological regulation of the OBLR is the result of a highly diversified parasitoid guild and this should be taken into account in any Integrated Pest Management program.

Host acceptance by three native braconid parasitoid species attacking larvae of the Mexican fruit fly, Anastrepha ludens (Diptera, Tephritidae)

We studied the oviposition and host acceptance behavior of three braconid parasitoid species native to Mexico, Doryctobraconcrawfordi (Viereck), Opiushirtus (Fischer), and Utetesanastrephae (Viereck), with potential to be considered as biocontrol agents against tephritid fruit fly pests in the Neotropics. Third instar larvae of Anastrephaludens (Loew), with and without previous parasitization by conspecifics, were simultaneously offered to females of each species, and the individual behavior was video recorded to construct oviposition flow diagrams. The patterns of foraging and host acceptance were similar in the studied species; all rejected mostly parasitized hosts suggesting that this strategy is common in the guild of larval parasitoids attacking Anastrepha spp. The complete searching and host acceptance process took 2.2 ± 0.1 min (mean ± SE) in D.crawfordi, 1.7 ± 0.1 s in U.anastrephae and 1.5 ± 0.1 s in O.hirtus. Notably, because of toxins injected by parasitoid females during oviposition, the parasitized hosts experienced a transient paralysis of variable duration. Hosts attacked by U.anastrephae remained immobile for the shortest time (12.5 ± 1 min) (mean±SE), followed by D.crawfordi (20.5 ± 3.4 min) and O.hirtus (24.1 ± 2 min). Our data revealed a notable discrimination ability in all three species, and that behavioral differences lay mainly in the time of parasitization and in the duration of paralysis experienced by attacked hosts. This suggest that the three species could be valuable as biocontrol agents, but additional studies are necessary to better understand the advantages and limitations of each one as natural enemies of fruit fly pests.

Explaining variations in the diversity of parasitoid assemblages in a biosphere reserve of Mexico: evidence from vegetation, land management and seasonality.

Insect fauna biodiversity in natural protected areas has not been thoroughly studied. Therefore, the aim of this work was to assess whether and how vegetation types, land management and seasonality influence the diversity of Ichneumonidae (Hymenoptera) in the Ría Lagartos Biosphere Reserve (Mexico). A sampling programme was conducted using Malaise traps from 2008 to 2009 in three vegetation types, each with two conservation zones (core and buffer zones). Three seasons were considered: rainy, dry and north-winds (isolated storms from November to February). A total of 336 species were identified. Rarefaction and Generalized Linear Model indicated higher species richness and abundance, respectively, in the buffer zone of the dry forest; possible explanations for this finding include the intermediate disturbance hypothesis, wherein diversity can be higher in sites where disturbance is not very frequent or very intense, and the 'enemies hypothesis', wherein structural complexity and high plant diversity favour increased predators or, in this case, parasitoids. Diversity was higher during the rainy season, which may have been due to the higher availability of resources. Vegetation and management had a positive impact on the Coc (attack cocoons and pupae) and Myc (attack concealed larvae living in the fruiting bodies of mushrooms) parasitoid guilds. Members of the Coc guild are generalist parasitoids, which may be favoured in complex vegetation with a high richness of potential hosts and non-hosts. The Myc guild requires certain environmental conditions that promote fungal growth, such as humidity, that is absent in the other vegetation types of savannah and coastal dune scrubland.

Multi‐scale and antagonist selection on life‐history traits in parasitoids: A community ecology perspective

Abstract Life‐history traits within ecological communities can be influenced by regional environmental conditions (external filters) and community‐wide density‐dependent processes (internal filters). While traits in a regional context may converge to a narrow range of values because of environmental filtering, species belonging to a guild may present contrasting traits as a means of niche differentiation, allowing coexistence whilst exploiting the same resources. To disentangle the role of external and internal filters on phenotypic diversity within ecological communities, we examined the patterns of life‐history trait variation within a guild of insect parasitoids during two successive years across three contrasted regions in relation to several ecological factors. By combining a mean‐field approach and an analysis of phenotypic variance across organizational levels (from individual to guild), we showed that the patterns of life‐history trait variation across regions are consistent with local adaptation or adaptive phenotypic plasticity while the patterns of phenotypic variation within regions suggested how coexistence modulates life‐history traits expression through niche differentiation. Within a given region, phenotypic pattern of parasitoid life‐history traits may also arise from bottom‐up effects of trophic webs: insect host species could also control parasitoid life‐history traits in nature. Our results also showed that parasitoid life‐history traits presented contrasting variation patterns according to the sampling year, suggesting temporal variations in evolutionary and ecological dynamics of parasitoid species. The application of such trait‐based studies to insect parasitoids has the potential to provide further insight on how agricultural environments contribute to differential diversification among natural enemies guilds, highlighting the main role of agricultural landscape management for organisms'responses. A plain language summary is available for this article.

Exposure to genetically engineered olive fly (Bactrocera oleae) has no negative impact on three non-target organisms

Bactrocera oleae (Diptera: Tephritidae) remains a major pest of olive fruit production worldwide. Current pest management programs largely depend on chemical insecticides, resulting in high economic and environmental costs. Alternative pest control approaches are therefore highly desirable. We have created a conditional female-specific self-limiting strain of B. oleae (OX3097D-Bol) that could be applied for sustainable pest control. OX3097D-Bol olive fly carries a fluorescent marker (DsRed2) for identification and a self-limiting genetic trait that is repressed by tetracycline. In the absence of tetracycline, the tetracycline transactivator (tTAV) accumulates, resulting in female death at larvae and early pupal stages. The aim of this study was to evaluate the impact of genetically engineered OX3097D-Bol olive fly on three non-target organisms that either predate or parasitize olive flies, one from the guild of parasitoids (Psyttalia concolor) and two from the guild of predators (Pardosa spider species and the rove beetle Aleochara bilineata). No significant negative effect was observed on life history parameters, mortality and reproductive capacity of the non-target organisms studied. These results suggest that potential exposure to DsRed2 and tTAV gene products (e.g. mRNA and encoded proteins) would have a negligible impact on on-target organisms in the guilds or predators and parasitoids.

Identification and characterization of bacterial symbionts in three species of filth fly parasitoids.

Facultative bacterial symbionts are widespread among insects and have diverse effects on their biology. Here, we focused on bacterial symbionts of three ecologically and economically important filth flies parasitoid species-Spalangia cameroni, Spalangia endius and Muscidifurax raptor. Both Spalangia species harbored a Sodalis bacterium that is closely related to Sodalis praecaptivus (a free-living bacterium) and to Sodalis symbionts of weevils. This is the only case of Sodalis infection in the important order Hymenoptera. We also found, for the first time in this parasitoid guild, a Rickettsia infecting the two Spalangia spp., albeit in much higher prevalence in S. cameroni. Molecular and phylogenetic analyses revealed that it is closely related to Rickettsia felis and other Rickettsia species from the 'transitional' group. All three parasitoid species harbored Wolbachia. Using multi-locus sequence typing, we found that M. raptor harbors a single Wolbachia strain whereas the Spalangia spp. have multiple strains. By controlled crossings, we found that Wolbachia infection in S. endius causes incomplete cytoplasmic incompatibility and increased longevity, thereby promoting Wolbachia's spread. In contrast, no effects of Wolbachia on the reproduction and longevity of M. raptor were found. This study underscores the diversity and nature of symbiotic interactions between microbes and insects.

Effect of Diachasmimorpha longicaudata releases on the native parasitoid guild attacking Anastrepha spp. larvae in disturbed zones of Chiapas, Mexico

We evaluated the effect of augmentative releases of Diachasmimorpha longicaudata (Ashmead), on the native parasitoid guild of Anastrepha spp. over a two year period in zones adjacent to mango commercial orchards in Chiapas, Mexico. We chose two 15 ha working zones, 15 km apart, harbouring fruit fly hosts of varying densities without chemical control. In 2013, parasitoids were released in zone “A” while zone “B” served as control. In 2014 zones were exchanged. As expected, releases of D. longicaudata significantly increased total parasitism, from around 0.5–5% to over 22%, but annual parasitism by native parasitoids was only significantly affected in zone “A”. The numbers of native parasitoids were higher in zone “A” in both years, and diversity (H′) was not affected by D. longicaudata releases in both zones. Our results suggest that releases of D. longicaudata affect the relative abundance but not the species richness of native parasitoids.