Cadmium exposure through the food chain reduces the parasitic fitness of Chouioia cunea to Hyphantria cunea pupae: An ecotoxicological risk to pest control.

The toxicity of heavy metals on various trophic levels along the food chain has been extensively investigated, but no studies have focused on parasitic natural enemy insects. Herein, we constructed a food chain consisting of soil-Fraxinus mandshurica seedlings-Hyphantria cunea pupae-Chouioia cunea to analyze the effects of Cd exposure through food chain on the fitness of parasitic natural enemy insects and its corresponding mechanism. The results showed that the transfer of Cd between F. mandshurica leaves and H. cunea pupae and between H. cunea pupae and C. cunea was a bio-minimization effect. After parasitizing Cd-accumulated pupa, the number of offspring larvae, and the number, individual size (body weight, body length, abdomen length) and life span of offspring adults decreased significantly, while the duration of embryo development extended significantly. The contents of malondialdehyde and H2O2 in Cd-exposed offspring wasps increased significantly, accompanied by a significantly decrease in antioxidant capacity. The cellular immunity parameters significantly decreased in Cd-accumulated pupae, including the number of hemocytes, melanization activity and the expression level of cellular immunity genes (e.g. Hemolin-1 and PPO1). The humoral immunity disorder was found in the Cd-accumulated pupae, as evidenced by that the expression level of immune recognition gene (PGRP-SA), signal transduction genes (IMD, Dorsal, and Tube), as well as all antimicrobial peptide genes (e.g. Lysozym and Attacin) decreased significantly. Cd exposure decreased the content of glucose, trehalose, amino acid, and free fatty acid in H. cunea pupae. The expression of Hk2 in glycolysis pathway and the expression of Idh2, Idh3, Cs, and OGDH in TCA cycle pathway were significantly down-regulated in Cd-accumulated pupae. Taken together, exposure to Cd through the food chain causes oxidative damage on the offspring wasps and disrupts energy metabolism of the host insect, ultimately reducing the parasitic fitness of C. cunea to H. cunea pupae.

60Co-γ Radiation Alters Developmental Stages of Zeugodacus cucurbitae (Diptera: Tephritidae) Through Apoptosis Pathways Gene Expression.

Radiation is considered as a promising insect pest control strategy for minimizing postharvest yield losses. Among various techniques, irradiation is a method of choice as it induces lethal biochemical or molecular changes that cause a downstream cascade of abrupt physiological abnormalities at the cellular level. In this study, we evaluated the effect of 60Co-γ radiation on various developmental stages of Zeugodacus cucurbitae Coquillett and subsequent carry-over effects on the progeny. For this purpose, we treated eggs with 30- and 50-Gy radiation doses of 60Co-γ. We found that radiation significantly affected cellular antioxidants, insect morphology, and gene expression profiles. Our results indicate that in response to various doses of irradiation reactive oxygen species, catalase, peroxidase, and superoxide dismutase activities were increased along with a significant increase in the malondialdehyde (MDA) content. We observed higher mortality rates during the pupal stage of the insects that hatched from irradiated eggs (50 Gy). Furthermore, the life span of the adults was reduced in response to 50 Gy radiation. The negative effects carried over to the next generation were marked by significantly lower fecundity in the F1 generation of the irradiation groups as compared to control. The radiation induced morphological abnormalities at the pupal, as well as the adult, stages. Furthermore, variations in the gene expression following irradiation are discussed. Taken together, our results signify the utility of 60Co-γ radiation for fruit fly postharvest management.

Effect of Drosophila suzukii on Blueberry VOCs: Chemical Cues for a Pupal Parasitoid, Trichopria anastrephae.

Biocontrol agents such as parasitic wasps use long-range volatiles and host-associated cues from lower trophic levels to find their hosts. However, this chemical landscape may be altered by the invasion of exotic insect species. The spotted-wing drosophila (SWD), Drosophila suzukii (Diptera: Drosophilidae), is a highly polyphagous fruit pest native to eastern Asia and recently arrived in South America. Our study aimed to characterize the effect of SWD attack on the volatile organic compounds (VOCs) of blueberries, a common host fruit, and to correlate these odor changes with the olfactory-mediated behavioral response of resident populations of Trichopria anastrephae parasitoids, here reported for the first time in Uruguay. Using fruit VOC chemical characterization followed by multivariate analyses of the odor blends of blueberries attacked by SWD, we showed that the development of SWD immature stages inside the fruit generates a different odor profile to that from control fruits (physically damaged and free of damage). These differences can be explained by the diversity, frequency, and amounts of fruit VOCs. The behavioral response of T. anastrephae in Y-tube bioassays showed that female wasps were significantly attracted to volatiles from SWD-attacked blueberries when tested against both clean air and undamaged blueberries. Therefore, T. anastrephae females can use chemical cues from SWD-infested fruits, which may lead to a successful location of their insect host. Since resident parasitoids are able to locate this novel potential host, biological control programs using local populations may be plausible as a strategy for control of SWD.

Identification of functionally distinct macrophage subpopulations in Drosophila.

Vertebrate macrophages are a highly heterogeneous cell population, but while Drosophila blood is dominated by a macrophage-like lineage (plasmatocytes), until very recently these cells were considered to represent a homogeneous population. Here, we present our identification of enhancer elements labelling plasmatocyte subpopulations, which vary in abundance across development. These subpopulations exhibit functional differences compared to the overall population, including more potent injury responses and differential localisation and dynamics in pupae and adults. Our enhancer analysis identified candidate genes regulating plasmatocyte behaviour: pan-plasmatocyte expression of one such gene (Calnexin14D) improves wound responses, causing the overall population to resemble more closely the subpopulation marked by the Calnexin14D-associated enhancer. Finally, we show that exposure to increased levels of apoptotic cell death modulates subpopulation cell numbers. Taken together this demonstrates macrophage heterogeneity in Drosophila, identifies mechanisms involved in subpopulation specification and function and facilitates the use of Drosophila to study macrophage heterogeneity in vivo.

Influence of Perfluorobutanoic Acid (PFBA) on the Developmental Cycle and Damage Potential of the Beet Armyworm Spodoptera exigua (Hübner) (Insecta: Lepidoptera: Noctuidae).

Perfluorobutanoic acid (PFBA), one of the short-chain replacement perfluoroalkyl substances, has been shown to accumulate in plants. The potential of PFBA to modulate the developmental cycle of the beet armyworm, Spodoptera exigua, a polyphagous pest, was investigated. Second-instar larvae were fed with PFBA-spiked artificial diets and leaves from soybean plants grown with PFBA-spiked irrigation water. Spiked PFBA concentrations were 200 µg/kg for the artificial diet, whereas 405 to 15,190 ng/kg accumulated in the soybean leaves. The larvae fed with the PFBA-spiked diet showed a significant increase in weight gain compared with the controls over a 7-day exposure period. A similar weight gain trend was observed with larvae fed with the PFBA-containing soybean leaves, with the dose-response data fitting into a Brain-Cousens hormesis model with a 57% stimulation over controls. The artificial diet treatments showed 66.7% metamorphosed larva to pupa at 9 days after exposure (dpe) compared with 33.3% of the controls. The adult emergence at 16-dpe followed a similar trend with 57.7% and 33.3%, respectively, for the exposed and control groups. The duration of transition from larvae to adults was more symmetrical and 0.5 day faster for the exposed groups over controls. The beet armyworm caused more damage on leaves from the PFBA exposed plants in a nonmonotonic dose-response manner. The results suggest PFBA may have a stimulatory impact on some hormonal signaling pathways at low doses.

A re-evaluation of silk measurement by the cecropia caterpillar (Hyalophora cecropia) during cocoon construction reveals use of a silk odometer that is temporally regulated.

The late 5th instar caterpillar of the cecropia silk moth (Hyalophora cecropia) spins a silken cocoon with a distinct, multilayered architecture. The cocoon construction program, first described by the seminal work of Van der Kloot and Williams, consists of a highly ordered sequence of events. We perform behavioral experiments to re-evaluate the original cecropia work, which hypothesized that the length of silk that passes through the spinneret controls the orderly execution of each of the discrete events of cocoon spinning. We confirm and extend by three-dimensional scanning and quantitative measurements of silk weights that if cocoon construction is interrupted, upon re-spinning, the caterpillar continues the cocoon program from where it left off. We also confirm and extend by quantitative measurements of silk weights that cecropia caterpillars will not bypass any of the sections of the cocoon during the construction process, even if presented with a pre-spun section of a cocoon spun by another caterpillar. Blocking silk output inhibits caterpillars from performing normal spinning behaviors used for cocoon construction. Surprisingly, unblocking silk output 24-hr later did not restart the cocoon construction program, suggesting the involvement of a temporally-defined interval timer. We confirm with surgical reductions of the silk glands that it is the length of silk itself that matters, rather than the total amount of silk extracted by individuals. We used scanning electron microscopy to directly show that either mono- or dual-filament silk (i.e., equal silk lengths but which vary in their total amount of silk extracted) can be used to construct equivalent cocoons of normal size and that contain the relevant layers. We propose that our findings, taken together with the results of prior studies, strongly support the hypothesis that the caterpillar uses a silk "odometer" to measure the length of silk extracted during cocoon construction but does so in a temporally regulated manner. We further postulate that our examination of the anatomy of the silk spinning apparatus and ablating spinneret sensory output provides evidence that silk length measurement occurs upstream of output from the spinneret.

Cladistic analysis of the genus Bruggmanniella Tavares (Diptera, Cecicomyiidae, Asphondyliini) with evolutionary inferences on the gall inducer-host plant association and description of a new Brazilian species.

In this study, we present a phylogenetic analysis of the genus Bruggmanniella Tavares based on morphological features. Cladistic analyses were conducted using 57 characters from 26 species. All species of Bruggmanniella except for B. byrsonimae were selected as ingroup and the genera Asphondylia Loew, Bruggmannia Tavares, Illiciomyia Tokuda, Parazalepidota Maia, Pseudasphondylia Monzen, Schizomyia Kieffer, and Lopesia Rübsaamen as outgroup. We used characters from larvae, pupae, adults, and galls. The results of this study supported Bruggmanniella as the sister group of Pseudasphondylia. Bruggmanniella actinodaphnes Tokuda and Yukawa and B. cinnamomi Tokuda and Yukawa have been moved to genus Pseudasphondylia (Pseudasphondylia actinodaphnes (Tokuda and Yukawa) comb. nov. and Pseudasphondylia cinnamomi (Tokuda and Yukawa) comb. nov.). The new genus Odontokeros gen. nov. has been erected for the single species Odontokeros brevipes (Lin, Yang & Tokuda) comb. nov. In addition, we described a new Brazilian species, Bruggmanniella miconia Garcia, Lamas and Urso-Guimarães sp. nov. Identification keys to the New World species of Bruggmanniella are presented.

The Taiman Transcriptional Coactivator Engages Toll Signals to Promote Apoptosis and Intertissue Invasion in Drosophila.

The Drosophila Taiman (Tai) protein is homologous to the human steroid-receptor coactivators SRC1-3 and activates transcription in complex with the 20-hydroxyecdysone (20E) receptor (EcR). Tai has roles in intestinal homeostasis, germline maintenance, cell motility, and proliferation through interactions with EcR and the coactivator Yorkie (Yki). Tai also promotes invasion of tumor cells in adjacent organs, but this pro-invasive mechanism is undefined. Here, we show that Tai expression transforms sessile pupal wing cells into an invasive mass that penetrates the adjacent thorax during a period of high 20E. Candidate analysis confirms a reliance on elements of the 20E and Hippo pathways, such as Yki and the Yki-Tai target dilp8. Screening the Tai-induced wing transcriptome detects enrichment for innate immune factors, including the Spätzle (Spz) family of secreted Toll ligands that induce apoptosis during cell competition. Tai-expressing wing cells induce immune signaling and apoptosis among adjacent thoracic cells, and genetic reduction of spz, Toll, or the rpr/hid/grim pro-apoptotic factors each suppresses invasion, suggesting an intercellular Spz-Toll circuit supports killing-mediated invasion. Modeling these interactions in larval epithelia confirms that Tai kills neighboring cells via a mechanism involving Toll, Spz factors, and the Spz inhibitor Necrotic. Tai-expressing cells evade death signals by repressing the immune deficiency (IMD) pathway, which operates in parallel to Toll to control nuclear factor κB (NF-κB) activity and independently regulates JNK activity. In sum, these findings suggest that Tai promotes competitive cell killing via Spz-Toll and that this killing mechanism supports pathologic intertissue invasion in Drosophila.

Exploring the Role of Insulin Signaling in Relative Growth: A Case Study on Wing-Body Scaling in Lepidoptera.

Adult forms emerge from the relative growth of the body and its parts. Each appendage and organ has a unique pattern of growth that influences the size and shape it attains. This produces adult size relationships referred to as static allometries, which have received a great amount of attention in evolutionary and developmental biology. However, many questions remain unanswered, for example: What sorts of developmental processes coordinate growth? And how do these processes change given variation in body size? It has become increasingly clear that nutrition is one of the strongest influences on size relationships. In insects, nutrition acts via insulin/TOR signaling to facilitate inter- and intra-specific variation in body size and appendage size. Yet, the mechanism by which insulin signaling influences the scaling of growth remains unclear. Here we will discuss the potential roles of insulin signaling in wing-body scaling in Lepidoptera. We analyzed the growth of wings in animals reared on different diet qualities that induce a range of body sizes not normally present in our laboratory populations. By growing wings in tissue culture, we survey how perturbation and stimulation of insulin/TOR signaling influences wing growth. To conclude, we will discuss the implications of our findings for the development and evolution of organismal form.

Meta-analysis of the role of entomopathogenic and unspecialized fungal endophytes as plant bodyguards.

Herbaceous plants harbour species-rich communities of asymptomatic endophytic fungi. Although some of these endophytes are entomopathogenic, many are not, and remarkably little is known about how the presence of these fungi in plant tissues affects phytophagous insects. Here we show through a meta-analysis that both entomopathogenic and nonentomopathogenic endophytes have a negative effect on insect herbivores. Growth and performance of polyphagous and sucking insects are reduced by nonentomopathogenic endophytes, but monophages are unaffected, likely because the latter are better adapted to secondary metabolites produced or induced by the fungi. Furthermore, studies using excised leaves report weaker effects than those with intact plants, likely caused by chemical changes being masked by leaf excision. Most surprisingly, endophyte infection of seeds produces the greatest effect on insect herbivores in subsequent mature plants, even though the usual mode of fungal transmission is infection of leaves by airborne spores. We conclude that these ubiquitous hidden fungi may be important bodyguards of plants. However, in order to fully understand their roles in plant protection, we must be aware that minor differences in experimental design can lead to contradictory results.

Longer life span is associated with elevated immune activity in a seasonally polyphenic butterfly.

Seasonal polyphenism constitutes a specific type of phenotypic plasticity in which short-lived organisms produce different phenotypes in different times of the year. Seasonal generations of such species frequently differ in their overall lifespan and in the values of traits closely related to fitness. Seasonal polyphenisms provide thus excellent, albeit underused model systems for studying trade-offs between life-history traits. Here, we compare immunological parameters between the two generations of the European map butterfly (Araschnia levana), a well-known example of a seasonally polyphenic species. To reveal possible costs of immune defence, we also examine the concurrent differences in several life-history traits. Both in laboratory experiments and in the field, last instar larvae heading towards the diapause (overwintering) had higher levels of both phenoloxidase (PO) activity and lytic activity than directly developing individuals. These results suggest that individuals from the diapausing generation with much longer juvenile (pupal) period invest more in their immune system than those from the short-living directly developing generation. The revealed negative correlation between pupal mass and PO activity may be one of the reasons why, in this species, the diapausing generation has a smaller body size than the directly developing generation. Immunological parameters may thus well mediate trade-offs between body size-related traits.

Isaria fumosorosea-based zero-valent iron nanoparticles affect the growth and survival of sweet potato whitefly, Bemisia tabaci (Gennadius).

BACKGROUND: Nanoparticles can be used for effective pest management as a combined formulation of metal and some other material that has proven efficacy against a given pest. This study reports the synthesis, characterization and efficacy of Isaria fumosorosea-based zero-valent iron (ZVI) nanoparticles against sweet potato whitefly Bemisia tabaci (Gennadius). RESULTS: The I. fumosorosea-ZVI nanoparticles showed a characteristic surface plasmon absorption band at 470 nm during UV-visible spectroscopy. The scanning electron micrographs of nanoparticles showed spherical shaped nanoparticles with sizes ranging between 1.71 and 3.0 µm. The EDX analysis showed the characteristic peak of iron at 0.6 and 6.8 KeV. The XRD analysis showed characteristic peaks at 44.72°, 65.070°, 82.339° and 82.65°. The bioassay results indicated that the percentage of larval mortality of B. tabaci challenged with I. fumosorosea ZVI nanoparticles was both concentration and age dependent. Isaria fumosorosea ZVI nanoparticles showed high pathogenicity against second and third instar nymphs, and pupae with LC50 values of 19.17, 26.10 and 37.71 ppm, respectively. The LT50 was lowest for second instar nymphs (3.15 days) and highest for pupae (4.22 days) when inoculated with a concentration of 50 ppm. CONCLUSION: Isaria fumosorosea ZVI nanoparticles can be an eco-friendly tool for effective B. tabaci management. © 2019 Society of Chemical Industry.

Competition for Space Induces Cell Elimination through Compaction-Driven ERK Downregulation.

The plasticity of developing tissues relies on the adjustment of cell survival and growth rate to environmental cues. This includes the effect of mechanical cues on cell survival. Accordingly, compaction of an epithelium can lead to cell extrusion and cell death. This process was proposed to contribute to tissue homeostasis but also to facilitate the expansion of pretumoral cells through the compaction and elimination of the neighboring healthy cells. However, we know very little about the pathways that can trigger apoptosis upon tissue deformation, and the contribution of compaction-driven death to clone expansion has never been assessed in vivo. Using the Drosophila pupal notum and a new live sensor of ERK, we show first that tissue compaction induces cell elimination through the downregulation of epidermal growth factor receptor/extracellular signal regulated kinase (EGFR/ERK) pathway and the upregulation of the pro-apoptotic protein Hid. Those results suggest that the sensitivity of EGFR/ERK pathway to mechanics could play a more general role in the fine tuning of cell elimination during morphogenesis and tissue homeostasis. Second, we assessed in vivo the contribution of compaction-driven death to pretumoral cell expansion. We found that the activation of the oncogene Ras in clones can downregulate ERK and activate apoptosis in the neighboring cells through their compaction, which eventually contributes to Ras clone expansion. The mechanical modulation of EGFR/ERK during growth-mediated competition for space may contribute to tumor progression.

Oviposition of fruit flies (Diptera: Tephritidae) and its relation with the pericarp of citrus fruits / Oviposição de moscas-das-frutas (Diptera: Tephritidae) e sua relação com o pericarpo de frutos cítricos

Abstract Fruit flies (Diptera: Tephritidae) represent a threat to fruit growing worldwide, mainly the citrus culture, however, biological studies show that fruit flies are not perfectly adapted to this host. This study investigated oviposition of Anastrepha fraterculus (Wiedemann, 1830) and Ceratitis capitata (Wiedemann, 1824) and its relation with the pericarp of citrus fruits. We evaluated the relationship between depth of oviposition of A. fraterculus and C. capitata and epicarp thickness of orange [Citrus sinensis (L.) Osbeck)] 'Navelina' and tangerine [C. reticulata (L.)] 'Clemenules' and the influence of fruit mesocarp of tangerine 'Clemenules' on oviposition of these species. The study was conducted under controlled conditions of temperature (25 ± 2 °C), relative humidity (70 ± 10% RH) and photophase (12 h). A. fraterculus and C. capitata laid their eggs in the flavedo region of orange 'Navelina' and between the albedo and flavedo of tangerine 'Clemenules'. When fruits with mesocarp exposed were offered, there was no oviposition by both fruit fly species. The results show that epicarp thickness of citrus fruits did not influence oviposition of A. fraterculus and C. capitata as oviposition did not occur only in the presence of the mesocarp, suggesting that other factors are involved in oviposition of these species.

Resumo As moscas-das-frutas (Diptera: Tephritidae) representam um risco à fruticultura mundial, especialmente na cultura dos citros, entretanto estudos biológicos demonstram que as moscas-das-frutas não estão perfeitamente adaptadas à estes hospedeiros. Este estudo investigou a oviposição de Anastrepha fraterculus (Wiedemann, 1830) e Ceratitis capitata (Wiedemann, 1824) e sua relação com o pericarpo de frutos cítricos. Foi avaliada a relação entre a profundidade de oviposição de A. fraterculus e de C. capitata e a espessura do epicarpo dos frutos de laranjeira [Citrus sinensis (L.) Osbeck)] 'Navelina' e tangerineira [C. reticulata (L.)] 'Clemenules' e a influência do mesocarpo de frutos de tangerineira 'Clemenules' na oviposição destas espécies. O estudo foi conduzido em condições controladas de temperatura (25 ± 2 °C), umidade relativa (70 ± 10%) e fotofase (12 horas). A. fraterculus e C. capitata depositaram ovos no flavedo de frutos de laranjeira 'Navelina' e entre o flavedo e o albedo de frutos de tangerineira 'Clemenules'. Quando oferecido frutos com mesocarpo exposto, não houve oviposição por ambas as espécies de mosca. Os resultados demonstram que a espessura do epicarpo de frutos cítricos não influenciou a oviposição de A. fraterculus e de C. capitata, a qual não ocorreu na presença apenas do mesocarpo, sugerindo que outros fatores estão envolvidos na oviposição por estas espécies.

Spodoptera litura-mediated chemical defense is differentially modulated in older and younger systemic leaves of Solanum lycopersicum.

MAIN CONCLUSION: Metabolite profiling, biochemical assays, and transcript analysis revealed differential modulation of specific induced defense responses in local, older, and younger systemic leaves in Solanum lycopersicum upon Spodoptera litura herbivory. Plants reconfigure their metabolome upon herbivory to induce production of defense metabolites involved in both direct and indirect defenses against insect herbivores. Herbivory mediated leaf-to-leaf systemic induction pattern of primary and non-volatile secondary metabolites is not well studied in tomato. Here, we show that, in cultivated tomato Solanum lycopersicum herbivory by generalist insect, Spodoptera litura results in differential alteration of primary metabolites, majorly sugars and amino acids and specific secondary metabolites in local, younger, and older systemic leaves. Cluster analysis of 55 metabolites identified by GC-MS showed correlation between local and younger systemic leaves. Re-allocation of primary metabolites like glucose and amino acids from the local to systemic leaf was observed. Secondary metabolites chlorogenic acid, caffeic acid, and catechin were significantly induced during herbivory in systemic leaves. Among specific secondary metabolites, chlorogenic acid and catechin significantly inhibits S. litura larval growth in all stages. Local leaf exhibited increased lignin accumulation upon herbivory. Differential alteration of induced defense responses like reactive oxygen species, polyphenol oxidase activity, proteinase inhibitor, cell wall metabolites, and lignin accumulation was observed in systemic leaves. The metabolite alteration also resulted in increased defense in systemic leaves. Thus, comparative analysis of metabolites in local and systemic leaves of tomato revealed a constant re-allocation of primary metabolites to systemic leaves and differential induction of secondary metabolites and induced defenses upon herbivory.

Parasitism of Two Spodoptera spp. by Microplitis prodeniae (Hymenoptera: Braconidae).

Early instar larvae of the tobacco cutworm Spodoptera litura (Lepidoptera: Noctuidae) and the beet armyworm Spodoptera exigua (Lepidoptera: Noctuidae) are recognized hosts of the parasitic wasp Microplitis prodeniae Rao and Kurian (Hymenoptera: Braconidae), although M. prodeniae has previously been regarded as monophagous. In this study, we found the immature period and longevity of M. prodeniae developing in S. exigua was similar to that in S. litura. It was shown that the development time of M. prodeniae in S. exigua was 15.1 ± 0.3 d, not significantly different from 15.0 ± 0.2 d in S. litura. The parasitism rate of M. prodeniae attacking S. exigua was significantly lower than on S. litura (65.48 ± 2.29 and 43.83 ± 2.20%, respectively), whilst the female ratio of the wasp's offspring was not significantly different when developing on the two species. M. prodeniae females prefer to oviposit on the second- and third-instar host larvae of S. exigua, rather than other instars. The effects of development of M. prodeniae on two important lepidopterous pests are discussed.

Radiation of Bactrocera dorsalis (Diptera: Tephritidae) Eggs to Improve the Mass Rearing of Diachasmimorpha longicaudata (Hymenoptera: Braconidae).

This study explored the potential for Bactrocera dorsalis (Hendel) (Diptera: Tephritidae) larvae hatched from irradiated eggs as hosts for Diachasmimorpha longicaudata (Ashmead) (Hymenoptera: Braconidae). B. dorsalis eggs of three different ages (12-, 24-, and 36-h old) were analyzed for hatchability, pupation rate, pupal weight, emergence rate, and sex ratio after exposure to different doses of radiation (5 and 10 Gy) at different dose rates (1 and 6 Gy/min). For the eggs of different ages exposed to radiation, only the hatchability and pupal weight of 36-h-old eggs exposed to the dose rate of 1 Gy/min were not affected; therefore, 6 Gy/min was not suitable for irradiating eggs. The viability of the parents and progenies of D. longicaudata when the parents were reared from 36-h-old eggs irradiated at nine different doses (0, 5, 10, 15, 20, 25, 30, 35, and 40 Gy) under laboratory conditions were investigated. The emergence percentage, sex ratio, and longevity of parasitoids developed from irradiated eggs were similar to those reared from nonirradiated hosts. A significant increase in larva mortality was observed for the eggs irradiated at doses above 25 Gy, and no redundant adult flies emerged at doses above 15 Gy. Hence, for B. dorsalis eggs to be applied in the mass rearing of D. longicaudata, the age of 36 h and a dose of 20-25 Gy are the optimal parameters. The results reveal that hosts and parasitoids need not be separated, enabling a reduction in cost, labor, and time and resulting in an improved mass rearing procedure for D. longicaudata.

A New Gall Midge Species of Asphondylia (Diptera: Cecidomyiidae) Inducing Flower Galls on Clinopodium nepeta (Lamiaceae) From Europe, Its Phenology, and Associated Fungi.

A new gall midge, Asphondylia nepetae sp. n. Viggiani (Diptera: Cecidomyiidae), causing flower gall on Clinopodium nepeta (L.) Kuntze (Lamiaceae), is described from Europe. The morphological characteristics of adult, larvae, and pupa are described and illustrated. Molecular approach (by sequencing 28S-D2, ITS2, and COI) confirmed that A. nepetae is a distinct species. The development of the gall is always associated with the presence of the fungus Botryosphaeria dothidea (Moug.: Fr.) Ces. and De Not. (Botryosphaeriales: Botryosphaeriaceae). The new species can complete several generations per year, on the flowers of the same host plant and its adults emerge from late spring to autumn. Pupae overwinter inside peculiar flower galls in a state of quiescence. The impact of the pest is highly variable with a percentage of flowers infested that ranged between 3 and 57.5% in the sampled years. Insect mortality was, at least in part, due to parasitoids that attack the young stages of the midge. Among them, the dominant species was Sigmophora brevicornis (Panzer) (Chalcidoidea: Eulophidae).

Phylogeny of the genus Stephomyia Tavares, 1916 (Diptera: Cecidomyiidae) / Filogenia do gênero Stephomyia Tavares, 1916 (Diptera: Cecidomyiidae)

Abstract Stephomyia Tavares, 1916 comprises seven species, all Neotropical: S. clavata (Tavares, 1920); S. epeugeniae Gagné, 1994; S. espiralis Maia, 1993; S. mina Maia, 1993; S. rotundifoliorum Maia, 1993; S. tetralobae Maia, 1993; and S. eugeniae (Felt, 1913). In the present study, a cladistic analysis based upon adult, pupa, larva and gall morphological characters as well as host plant data is carried out in order to discuss the monophyly of the genus and the relationships among the known species. The Stephomyia monophyly was supported by eight synapomorphies: five homoplastic characters and three non-homoplastic characters. Analyzes showed S. clavata with great instability within the genus, probably due to lack of larva, pupa and female data, so S. clavata was deactivated in analyze. The topology found was (S. mina ((S. eugeniae + S. epeugeniae) (S. tetralobae (S. rotundifoliorum + S. espiralis)))).

Resumo Stephomyia Tavares, 1916 compreende sete espécies, todas neotropicais: S. clavata (Tavares, 1920); S. epeugeniae Gagné, 1994; S. espiralis Maia, 1993; S. mina Maia, 1993; S. rotundifoliorum Maia, 1993; S. tetralobae Maia, 1993 e S. eugeniae (Felt, 1913). Neste estudo, uma análise cladística baseada em caracteres morfológicos dos adultos, pupa, larva e galha, bem como na informação das plantas hospedeiras é realizada e a monofilia do gênero e as relações entre as espécies conhecidas são discutidas. A monofilia de Stephomyia foi suportada por oito sinapomorfias: cinco caracteres homoplásticos e três não homoplásticos. Análises mostraram uma grande instabilidade de S. clavata dentro do gênero, provavelmente devido à falta de informações sobre a larva, a pupa e a fêmea, o que resultou em desativação na análise. A topologia encontrada foi (S. mina ((S. eugeniae + S. epeugeniae) (S. tetralobae (S. rotundifoliorum + S. espiralis)))).

Do mothers really know best? Complexities in testing the preference-performance hypothesis in polyphagous frugivorous fruit flies.

The preference-performance hypothesis (PPH) has widely been used to explain host exploitation patterns by phytophagous insects. However, this hypothesis often fails in the case of polyphagous species when compared with specialists. One explanation, validated by the information-processing hypothesis (IPH), considers that polyphagous insects are unable to process a large array of cues, which hinders females from distinguishing between high- and low- quality hosts. Here we analyzed Anastrepha ludens female host preference and offspring performance, and tested if neuronal limitations could possibly play a role in the incapacity of the polyphagous A. ludens to make 'accurate decisions' and therefore partially explain mismatches related to PPH. Results testing the PPH by correlating female preference to six naturally occurring hosts and its offspring outcomes show that A. ludens females oviposited greater proportions of eggs on fruit according to hierarchical preferences. Infestation level was low in white sapote, the preferential and seemingly putative ancestral host, likely due to sapote defence mechanisms. Pupal weight and adult size were lower when A. ludens larvae developed in guava (conditional host that was artificially infested) and peach, a lower ranked host compared with 'Marsh' grapefruit, white sapote, and 'Manila' mango (three preferred hosts). Larvae reared in 'Manzano' pepper, a low-ranked host, performed better than in peach and guava. Results testing the IPH, show that polyphagous A. ludens females were less accurate when discerning between a non natural host (guava) when compared with a preferred, natural host (grapefruit): error rate was significantly higher, number of oviposited fruit in a 6-h period was extremely low, time searching and ovipositing took longer, and pupae recovery was extremely low. Our findings indicate that both hypotheses tested are complementary and help better understand host use by A. ludens. However, we also discuss the complexity of polyphagy considering other factors such as plant resistance/defence mechanisms which are not fully addressed in both theories tested.