Compatibility of Entomopathogenic Nematodes with Chemical Insecticides for the Control of Drosophila suzukii (Diptera: Drosophilidae).

The spotted-wing drosophila, Drosophila suzukii (Matsumura) (Diptera: Drosophilidae), is a pest that reduces the productivity of small fruits. Entomopathogenic nematodes (EPNs) and chemical insecticides can suppress this pest, but the compatibility of the two approaches together requires further examination. This laboratory study evaluated the compatibility of Steinernema brazilense IBCBn 06, S. carpocapsae IBCBn 02, Heterorhabditis amazonensis IBCBn 24, and H. bacteriophora HB with ten chemical insecticides registered for managing D. suzukii pupae. In the first study, most insecticides at the recommended rate did not reduce the viability (% of living infective juveniles (IJs)) of S. braziliense and both Heterorhabditis species. The viability of S. carpocapsae was lowered by exposure to spinetoram, malathion, abamectin, azadirachtin, deltamethrin, lambda-cyhalothrin, malathion, and spinetoram after 48 h. During infectivity bioassays, phosmet was compatible with all the EPNs, causing minimal changes in infectivity (% pupal mortality) and efficiency relative to EPN-only controls, whereas lambda-cyhalothrin generally reduced infectivity of EPNs on D. suzukii pupae the most, with a 53, 75, 57, and 13% reduction in infectivity efficiency among H. bacteriophora, H. amazonensis, S. carpocapsae, and S. brazilense, respectively. The second study compared pupal mortality caused by the two most compatible nematode species and five insecticides in various combinations. Both Heterorhabditis species caused 78-79% mortality among D. suzukii pupae when used alone, and were tested in combination with spinetoram, malathion, azadirachtin, phosmet, or novaluron at a one-quarter rate. Notably, H. bacteriophora caused 79% mortality on D. suzukii pupae when used alone, and 89% mortality when combined with spinetoram, showing an additive effect. Novaluron drastically reduced the number of progeny IJs when combined with H. amazonensis by 270 IJs and H. bacteriophora by 218. Any adult flies that emerged from EPN-insecticide-treated pupae had a shorter lifespan than from untreated pupae. The combined use of Heterorhabditis and compatible chemical insecticides was promising, except for novaluron.

The Potential of Plant-Based Biorational Products for the Drosophila suzukii Control: Current Status, Opportunities, and Limitations.

Drosophila suzukii (Matsumura) (Diptera: Drosophilidae) is an invasive species that causes serious damage to soft-skinned fruits. The use of plant-based biorational insecticides (plant extracts and essential oils) to control this pest has grown extensively. We conducted a systematic review and meta-analysis to examine the current status, trends, and perspectives of these studies, with a focus on the plant families and major compounds used as insecticides to control D. suzukii. The first article in this research field was published in 2015, and there has been exponential growth in subsequent years. Thirty-six botanical families were studied in these articles, with a prevalent interest in Myrtaceae and Lamiaceae plant species. The major constituents of these plant-based biorational molecules belong to monoterpenoids, followed by monoterpenes, benzene derivatives, and others. Geranial was the most frequent major constituent of these plant-based compounds. Our analysis revealed a few crucial consequences of the bias provided by the investigations using plant-based biorational insecticides for controlling D. suzukii. Firstly, there is a major focus on the pest species, with little or no attention paid to undesired effects on non-target beneficial organisms (e.g., pollinator bees, predators; parasitoids) and non-target pests. Secondly, the poor knowledge of how these plant-based biorational insecticides act on target and non-target organisms. Finally, there is a need to assess the efficacy of these substances under field conditions. Thus, attention is needed to address these gaps so that plant-based biorational insecticides can become a viable pest management tool for controlling D. suzukii.

Assessing Natural Incidence of Resident Pupal Parasitoids on the Drosophila suzukii (Diptera: Drosophilidae) Population in Non-crop Fruits.

Drosophila suzukii (Matsumura) (Diptera: Drosophilidae), world-renowned as spotted-wing drosophila, is an invasive pest mainly affecting healthy, soft and stone fruit crops throughout Argentinian fruit-growing regions. Natural environments overgrown by exotic feral host plants apparently favour D. suzukii proliferation. This is common in the subtropical northwestern Argentina's berry-producing region. An assemblage of resident parasitoid species has been associated with D. suzukii in crop and non-crop areas of Tucumán, the Argentina's leading berries producer and exporter. Consequently, the hypothesis that the combined action of two pupal parasitoid species, Pachycrepoideus vindemiae Rondani (Hymenoptera: Pteromalidae) and Trichopria anastrephae Lima (Hymenoptera: Diapriidae), occurring in non-crop fruit areas, has a significant impact on D. suzukii natural regulation in such invaded habitats was tested. A survey of D. suzukii puparia from both feral peach [Prunus persica (L.) Batsch] (Rosaceae) and guava (Psydium guajava L.) (Myrtaceae) fallen fruits and soil surrounding them was performed in a wilderness area of Tucumán. Abundance of D. suzukii and associated parasitoids, and parasitism levels were assessed. Whole of 3437 D. suzukii puparia were recovered; 78% and 22% were surveyed from fruits and soil underneath the fruit, respectively. Tested fruits are important D. suzukii multiplying hosts. Both P. vindemiae and T. anastrephae accounted for 99.8% of total parasitoid individuals. Pupal parasitoids contribute to the D. suzukii natural mortality, as they killed a quarter of all puparia. Mostly T. anastrephae foraged on host puparia located in the fruit and P. vindemiae in both microhabitats. This information supports an augmentative biological control strategy in non-crop areas.

The Population Dynamics and Parasitism Rates of Ceratitis capitata, Anastrepha fraterculus, and Drosophila suzukii in Non-Crop Hosts: Implications for the Management of Pest Fruit Flies.

Understanding the seasonal dynamics inherent to non-crop host-fruit fly-parasitoid interactions is vitally important for implementing eco-friendly pest control strategies. This study assessed the abundance and seasonal infestation levels of three pest fly species, Ceratitis capitata (Wiedemann), Anastrepha fraterculus (Wiedemann), Drosophila suzukii (Matsumura), as well as the related saprophytic drosophilids, and their natural parasitism in a disturbed wild habitat characterized by non-crop hosts in northwestern Argentina over 40 months. Juglans australis Griseb (walnut), Citrus aurantium L. (sour orange), Eriobotrya japonica (Thunb.) Lindley (loquat), Prunus persica (L.) Batsch (peach), and Psydium guajava L. (guava) were sampled throughout their fruiting seasons. Fruits were collected from both the tree canopies and the ground. The most abundant puparia was A. fraterculus, followed by C. capitata and D. suzukii. Drosophila species from the D. melanogaster group were highly abundant only in fallen fruits. Spatiotemporal overlaps of different host fruit availability provided suitable sources for pest proliferation throughout the year. The populations of both invasive pests peaked from December to January, and were related to the highest ripe peach availability, whereas the A. fraterculus population peaked from February to April, overlapping with the guava fruiting period. The three pest fly species were parasitized mainly by three generalist resident parasitoids, which are potential biocontrol agents to use within an integrated pest management approach.

Survey on Drosophila suzukii and Ceratitis capitata (Diptera: Drosophilidae, Tephritidae) and Associated Eucoilinae Species (Hymenoptera: Figitidae) in Northwestern Argentina. First Record of Dicerataspis grenadensis and Leptopilina boulardi as Parasitoids of D. suzukii.

The Southeast Asian-native Drosophila suzukii (Matsumura) (Diptera: Drosophilidae), also known as "spotted-wing Drosophila," is one of the most globally invasive agricultural species. Although D. suzukii is a pest spread throughout all the Argentinian fruit-growing regions, few information has been published on its impact on local fruit production. Parasitoid species associated with D. suzukii in Argentina belong to Pteromalidae (Chalcidoidea), Diapriidae (Diaprioidea), both attacking host pupae, and Figitidae (Cynipoidea), which attack host larvae. Nine Eucoilinae (Figitidae) species, belonging to Dicerataspis, Dieucoila, Euxestophaga, Ganaspis, Hexacola, and Leptopilina genera, have been associated with D. suzukii in Argentina. Ceratitis capitata (Wiedemann), commonly known as "medfly," is native to Africa and has a worldwide distribution, covering many tropical, subtropical, and temperate regions. In Argentina, C. capitata has been associated with several native hymenopterous parasitoids belonging to Braconidae (Ichneumonioidea), Eulophidae (Chalcidoidea), Pteromalidae, Diapriidae, and Figitidae families. Only two eucoline species, Ganaspis pelleranoi (Brèthes) and Leptopilina haywardi (Blanchard) have been related to medfly in Argentina. We report new trophic associations between the parasitoids Dicerataspis grenadensis Ashmead and Leptopilina boulardi (Barbotin, Carton and Kelner-Pillault) and D. suzukii, and between the parasitoid Odontosema albinerve Kieffer and C. capitata, after surveys conducted in Tucumán, northwestern Argentina. An annotated checklist and a taxonomic key of Eucoilinae associated with both invasive pests, in Argentina, are also provided.

Alphitobius diaperinus (Coleoptera: Tenebrionidae) susceptibility to Cunila angustifolia essential oil.

The lesser mealworm, Alphitobius diaperinus (Panzer), is an insect that lives in poultry houses, and high infestations may cause economic losses to producers. The control of this insect is usually done with insecticides; however, many of these chemicals have no effect on lesser mealworm. Therefore, control alternatives are needed. The aim of this study was to evaluate the influence of Cunila angustifolia (Benth) oil on larvae and adults of A. diaperinus. In vitro tests used larvae and adults of A. diaperinus distributed in petri dishes with 0, 1, 5, and 10% of oil in a single dose. In vivo tests were performed in poultry houses with five treatments: 0, 5, and 10% and chemical insecticide (cypermethrin) in a single application, and a group with 5% of oil applied twice 15 d apart. In vitro, oil bioactivity showed an efficacy of 100% both for larvae and adults, when tested at concentrations of 5 and 10%. A reduced number of larvae were observed using 1% of oil; however, it was not effective against adults as compared with the control group. In vivo, the oil effectiveness against lesser mealworm was verified by larva and adult reduction in all concentrations compared with control (0%) throughout the experiments, with better efficacy when used at 5% with two applications. Therefore, we concluded that the oil of C. angustifolia has larvicidal and insecticidal effect against A. diaperinus larvae and adults, in vitro and in vivo.

Implications of the Niche Partitioning and Coexistence of Two Resident Parasitoids for Drosophila suzukii Management in Non-Crop Areas.

Understanding the mechanisms associated with the coexistence of competing parasitoid species is critical in approaching any biological control strategy against the globally invasive pest spotted-wing drosophila (=SWD), Drosophila suzukii (Matsumura). This study assessed the coexistence of two resident pupal parasitoids, Trichopria anastrephae Lima and Pachycrepoideus vindemiae Rondani, in SWD-infested fruit, in disturbed wild vegetation areas of Tucumán, northwestern Argentina, based on niche segregation. Drosophilid puparia were collected between December/2016 and April/2017 from three different pupation microhabitats in fallen feral peach and guava. These microhabitats were "inside flesh (mesocarp)", "outside flesh", but associated with the fruit, and "soil", i.e., puparia buried close to fruit. Saprophytic drosophilid puparia (=SD) belonging to the Drosophila melanogaster group and SWD were found in all tested microhabitats. SD predominated in both inside and outside flesh, whereas SWD in soil. Both parasitoids attacked SWD puparia. However, T. anastrephae emerged mainly from SD puparia primarily in the inside flesh, whereas P. vindemiae mostly foraged SWD puparia in less competitive microhabitats, such as in the soil or outside the flesh. Divergence in host choice and spatial patterns of same-resource preferences between both parasitoids may mediate their coexistence in non-crop environments. Given this scenario, both parasitoids have potential as SWD biocontrol agents.

Pathogenicity and Virulence of Different Concentrations of Brazilian Isolates of Entomopathogenic Nematodes Against Drosophila suzukii.

The invasive pest Drosophila suzukii (Matsumura) (Diptera: Drosophilidae) was recently recorded in Brazil and constitutes a threat to fruit growing, mainly for small, soft fruits. Recent advances in research on ways of controlling D. suzukii involve the use of entomopathogenic nematodes (EPNs). In this context, the objective of this study was to evaluate the pathogenicity and virulence of four isolates in different concentrations against D. suzukii pupae. The EPN isolates used in trials were Steinernema brazilense IBCBn 06, S. carpocapsae IBCBn 02, Heterorhabditis bacteriophora HB, and H. amazonensis IBCBn 24. Both H. amazonensis IBCBn 24 and H. bacteriophora HB were effective in controlling D. suzukii as they caused a mortality rate of 86.25% and 80.0%, and virulence of 549.75 IJs/pupae and 787.75 IJs/pupae in the concentrations of 1800 IJs/ml and 5400 IJs/ml, respectively. The lowest lethal concentrations (LC50) of juveniles were found in host pupae with 771.63 IJs/ml of H. bacteriophora HB and 1115.49 IJs/ml of H. amazonensis IBCBn 24. Results showed that both EPNs, H. amazonensis IBCBn 24 and H. bacteriophora HB, could be promising eco-friendly biological agents to control D. suzukii.

Medfly Population Suppression through Augmentative Release of an Introduced Parasitoid in an Irrigated Multi-Fruit Orchard of Central-Western Argentina.

Biological control through the augmentative release of parasitoids is an important complementary tool that may be incorporated into other strategies for the eradication/eco-friendly control of pest fruit flies. However, not much information is available on the effectiveness of fruit fly parasitoids as biocontrol agents in semi-arid and temperate fruit-growing regions. Therefore, this study evaluated the effect of augmentative releases of the larval parasitoid Diachasmimorpha longicaudata (Ashmead) on Ceratitis capitata (Wiedemann) (medfly) populations over two fruit seasons (2013 and 2014) on a 10 ha irrigated fruit farm in San Juan province, central-western Argentina. The parasitoids were mass reared on irradiated medfly larvae of the Vienna-8 temperature-sensitive lethal genetic sexing strain. About 1692 (±108) parasitoids/ha were released per each of the 13 periods throughout each fruit season. Another similar farm was chosen as a control of non-parasitoid release. The numbers of captured adult flies in food-baited traps and of recovered fly puparia from sentinel fruits were considered the main variables to analyze the effect of parasitoid release on fly population suppression using a generalized least squares model. The results showed a significant decrease (p < 0.05) in the medfly population on the parasitoid release farm when compared to the Control farm, demonstrating the effectiveness of augmentative biological control using this exotic parasitoid. Thus, D. longicaudata could be used in combination with other medfly suppression strategies in the fruit production valleys of San Juan.

Drosophila suzukii Management in Latin America: Current Status and Perspectives.

Spotted-wing drosophila, Drosophila suzukii Matsumura, was first established in Latin America in Mexico in 2011. The vinegar fly has since been detected in 296 municipalities in Argentina, Brazil, Chile, Mexico, and Uruguay. Drosophila suzukii is polyphagous and is found on 64 host plants in 25 families in Latin America, with most hosts also exotic species. In Latin America, D. suzukii is attacked by 14 species of parasitoid wasps in the families Diapriidae, Figitidae, and Pteromalidae, which are promising native parasitoids for control of the pest. This article analyzes results from studies on monitoring, biological, chemical, and cultural control, and sterile insect techniques to provide a basis for the development of area-wide and sustainable D. suzukii management programs in Latin America. The review examines how D. suzukii has been managed in Latin America and how research conducted in this region can contribute to management of the species in other parts of the world.

Natural Parasitism Influences Biological Control Strategies Against Both Global Invasive Pests Ceratitis capitata (Diptera: Tephritidae) and Drosophila suzukii (Diptera: Drosophilidae), and the Neotropical-Native Pest Anastrepha fraterculus (Diptera: Tephritidae).

Ceratitis capitata (Wiedemann) and Drosophila suzukii (Matsumura) are two severe invasive pests widespread in all Argentinean fruit-producing regions. Both coexist with the Neotropical pest Anastrepha fraterculus (Wiedemann) in northern Argentina. The northwestern region shelters major soft fruit and Citrus producing and exporting industries, which are heavily affected by these dipterans. Eco-friendly strategies are under assessment in Argentina. This study mainly assessed D. suzukii, C. capitata, and A. fraterculus temporal abundance variations and their natural parasitism levels on a 1.5-ha-patch of feral peach trees within a disturbed secondary subtropical rainforest of northwestern Argentina. Fly puparia were mainly collected from the soil under fallen peach. Sampling was performed over three peach fruiting seasons. The most abundant pest species was C. capitata. Drosophila suzukii was only found in the last collecting period, but outnumbered A. fraterculus. Natural parasitism distinctly affected the temporal abundance of these dipterans: it significantly depressed C. capitata abundance in last sampling weeks, it did not substantially affect D. suzukii abundance, but it increased synchronously with the increase in the A. fraterculus abundance. Parasitism on C. capitata was mostly exerted by a combination of both a cosmopolitan pupal and a native larval parasitoid, while A. fraterculus was mainly parasitized by two indigenous larval parasitoids. Only three resident pupal parasitoids were associated with D. suzukii, of which the cosmopolitan Pachycrepoideus vindemiae Rondani (Hymenoptera: Pteromalidae) was the most significant. Data on the resident parasitoid impact are relevant for designing biocontrol strategies in noncrop habitats.

Effectiveness of Steinernema rarum PAM 25 (Rhabditida: Steinernematidae) Against Drosophila suzukii (Diptera: Drosophilidae).

Drosophila suzukii (Matsumura 1931) represents one of the main pests of small fruits. The use of biological agents is very promising for insect control. In the present study, the nematode Steinernema rarum PAM 25 was evaluated for the control of D. suzukii pupae, this species has not been evaluated previously. First, we evaluated the pathogenicity of S. rarum PAM 25 at the concentration of 1,000 infective juveniles (IJs) inoculated into D. suzukii pupae. In the second bioassay, we evaluated the influence of 1,500; 2,000; 2,500; 3,000; 4,000 IJs/ml nematode concentration and temperature on D. suzukii mortality. In the third bioassay, we evaluated the influence of the isolate S. rarum PAM 25 on D. suzukii adult lifespan following pupal infection, using the concentrations with the highest mortality rate of pupae at each temperature as determined in the second experiment. The S. rarum PAM 25 isolate is pathogenic to D. suzukii. The most effective temperature for S. rarum PAM 25 activity was 14°C at a concentration of 4,000 IJs/ml. Adults infected with S. rarum PAM 25 showed a significant reduction in longevity. The results confirmed the potential of S. rarum PAM 25 for the control of D. suzukii.

Natural Areas of Cerrado Foster Wasp (Hymenoptera) Diversity in Human Modified Landscapes.

Land use changes from native vegetation to agriculture, livestock grazing, and urban development are among the main problems related to biodiversity loss worldwide. In this paper we evaluate how land use changes (eucalypt plantation and pasture) affect the richness and assemblage of wasps (Braconidae, Ichneumonidae, Pompilidae, and Vespidae), in comparison with nearby areas with native vegetation in the Cerrado. Specimens were collected at six points, with two Malaise traps at each location. The collections were performed monthly for 10 d, for 12 mo. A total of 773 hymenopterans of the selected groups were collected, representing 253 species or morphospecies. Richness of the families Ichneumonidae and Pompilidae between the areas did not present significant differences. For the families Braconidae and Vespidae, the richness was greater in the eucalypt plantation and pasture areas compared to the native area. Species composition in the native habitat was different from either of the managed habitats in the studied environment. Furthermore, the composition of wasps in native areas varied less throughout the sampling campaigns when compared with the pasture and eucalyptus sites. In native areas, 85 exclusive morphospecies were found. Thus, changes in land use may cause changes in the composition of wasp species, since areas with native vegetation presented more heterogeneous and stable environments than the other land uses. The maintenance of native areas, even if close to planted forest and/or pasture areas, could be the best way to combine forest productivity with biodiversity conservation.

Effectiveness of Entomopathogenic Nematodes Against Ceratitis capitata (Diptera: Tephritidae) Pupae and Nematode Compatibility with Chemical Insecticides.

The Mediterranean fruit fly Ceratitis capitata (Wiedemann, 1824) (Diptera: Tephritidae) is among the main pests of fruit crops worldwide. Biological control using entomopathogenic nematodes (EPNs) may be an alternative to suppress populations of this pest. Thus, the aim of this study was to evaluate the pathogenicity and virulence of six EPN isolates (Heterorhabditis bacteriophora HB, H. amazonensis IBCB-n24, Steinernema carpocapsae IBCB-n02, S. rarum PAM-25, S. glaseri IBCB-n47, and S. brazilense IBCB-n06) against C. capitata pupae. The compatibility of EPNs with different chemical insecticides that are registered for management of C. capitata was also assessed. Isolates of H. bacteriophora HB and S. brazilense IBCB-n06 at a concentration of 1,000 infective juveniles (IJ)/ml proved to be most pathogenic to C. capitata (70 and 80% mortality, respectively). In contrast, the isolates H. amazonensis IBCB-n24, Steinernema carpocapsae IBCB-n02, S. rarum PAM-25, S. glaseri IBCB-n47 provided pupal mortality of less than 60%. Bioassays to determine lethal concentrations indicated that concentrations of 600 IJ/ml (H. bacteriophora HB) and 1,000 IJ/ml (S. brazilense IBCB-n06) showed the highest virulence against C. capitata pupae. In contrast, the highest numbers of IJs emerged at concentrations of 1,200 and 200 IJ/ml. In compatibility bioassays, malathion, spinetoram, phosmet, acetamiprid, and novaluron were considered compatible with and harmless (Class 1) to H. bacteriophora HB and S. brazilense IBCB-n06, according to IOBC/WPRS. This information is important for implementing integrated management programs for C. capitata, using biological control with EPNs, whether alone or in combination with chemical insecticides.

First transcriptome of the Neotropical pest Euschistus heros (Hemiptera: Pentatomidae) with dissection of its siRNA machinery.

Over the past few years, the use of RNA interference (RNAi) for insect pest management has attracted considerable interest in academia and industry as a pest-specific and environment-friendly strategy for pest control. For the success of this technique, the presence of core RNAi genes and a functional silencing machinery is essential. Therefore, the aim of this study was to test whether the Neotropical brown stinkbug Euschistus heros has the main RNAi core genes and whether the supply of dsRNA could generate an efficient gene silencing response. To do this, total mRNA of all developmental stages was sequenced on an Illumina platform, followed by a de novo assembly, gene annotation and RNAi-related gene identification. Once RNAi-related genes were identified, nuclease activities in hemolymph were investigated through an ex vivo assay. To test the functionality of the siRNA machinery, E. heros adults were microinjected with ~28 ng per mg of insect of a dsRNA targeting the V-ATPase-A gene. Mortality, relative transcript levels of V-ATPase-A, and the expression of the genes involved in the siRNA machinery, Dicer-2 (DCR-2) and Argonaute 2 (AGO-2), were analyzed. Transcriptome sequencing generated more than 126 million sequenced reads, and these were annotated in approximately 80,000 contigs. The search of RNAi-related genes resulted in 47 genes involved in the three major RNAi pathways, with the absence of sid-like homologous. Although ex vivo incubation of dsRNA in E. heros hemolymph showed rapid degradation, there was 35% mortality at 4 days after treatment and a significant reduction in V-ATPase-A gene expression. These results indicated that although sid-like genes are lacking, the dsRNA uptake mechanism was very efficient. Also, 2-fold and 4-fold overexpression of DCR-2 and AGO-2, respectively, after dsRNA supply indicated the activation of the siRNA machinery. Consequently, E. heros has proven to be sensitive to RNAi upon injection of dsRNA into its hemocoel. We believe that this finding together with a publically available transcriptome and the validation of a responsive RNAi machinery provide a starting point for future field applications against one of the most important soybean pests in South America.

Some Aspects of the Biology of Trichopria anastrephae (Hymenoptera: Diapriidae), a Resident Parasitoid Attacking Drosophila suzukii (Diptera: Drosophilidae) in Brazil.

Spotted-wing Drosophila, Drosophila suzukii (Matsumura, 1931), is an economic pest of thin-skinned fruit crops. Its control has commonly been carried out through chemical methods. However, given the need to develop safer and environmentally friendly management alternatives, the pupal endoparasitoid Trichopria anastrephae Lima stands out as a potential biological control agent. However, the lack of information on the mass rearing of this parasitoid limits its use. Thus, the objective of our study was to provide information that is useful for rearing T. anastrephae using D. suzukii as a host. The effects of pupal age, exposure time, and pupal density on the parasitism rate were examined, as was the effect of honey provision for extending adult parasitoid longevity. Exposing 15 12-h-old pupae per female for 24 h resulted in higher parasitism rates and a greater number of emerged parasitoids. Males and females of T. anastrephae fed with pure honey (100%) or honey diluted to 50% in water lived longer compared to those fed 10% honey, no food, or only water.

Toxicities of Insecticidal Toxic Baits to Control Ceratitis capitata (Diptera: Tephritidae): Implications for Field Management.

Ceratitis capitata (Wiedemann, 1824) is a significant insect pest of fruits produced worldwide and is capable of causing direct and indirect damage to fruit. Chemical control is the most frequently used management strategy, mainly involving organophosphate insecticides. However, the frequent use of this chemical group has resulted in unacceptable chemical residues on fruits. In this study, the toxicity of 18 insecticides was evaluated in adults and larvae of C. capitata in a laboratory. The organophosphate insecticides chlorpyrifos (Lorsban 480BR), phosmet (Imidan 500WP), and malathion (Malathion 1000EC); the spinosyns spinetoram (Delegate 250WG) and spinosad (Tracer); and the pyrethroid alpha-cypermethrin (Fastac 100SC) caused high mortality (>80%) in C. capitata adults in topical application bioassays and by ingestion when mixed with Biofruit 5% food lures. However, the insecticides chlorfenapyr (Pirate), spinetoram and chlorpyrifos produced a significant reduction in larval infestation of the fruits (67, 74, and 84% larval mortality, respectively). Insecticides based on spinosyns, alpha-cypermethrin, and cyantraniliprole are alternatives that can replace organophosphates in the management of C. capitata in the field.

Insecticide Toxicity to Drosophila suzukii (Diptera: Drosophilidae) parasitoids: Trichopria anastrephae (Hymenoptera: Diapriidae) and Pachycrepoideus vindemmiae (Hymenoptera: Pteromalidae).

Drosophila suzukii (Matsumura) is an important pest of small fruits, which has been causing significant damage to commercial crops in North America, Europe, and South America. This pest is mainly controlled with insecticide applications because of its highly biotic potential and polyphagy. However, studies conducted in crops infested by D. suzukii have shown that this species is attacked by parasitoids that may serve as effective biological controls for this pest. The aim of the current study is to assess the lethal time (LT10 and LT50) and parasitism potential of exposed adults (F0): sex ratio and longevity (F1) of Trichopria anastrephae Lima and Pachycrepoideus vindemmiae (Rondani) when exposed to dry residues of different commercial insecticides. Abamectin, acetamiprid, thiamethoxam, malathion, phosmet, deltamethrin, spinetoram, and spinosad were evaluated. Pachycrepoideus vindemmiae was more sensitive to insecticides than T. anastrephae, showing higher mortality rates in a shorter period of time, as well as a significant reduction in parasitism. Spinosyns (spinosad and spinetoram) and abamectin caused high P. vindemmiae mortality rates, but were harmless to T. anastrephae. Neonicotinoids, organophosphates, and pyrethroids caused high mortality rates regardless of the species. Treatments did not affect D. suzukii offspring longevity and sex ratio (F1). The current study provides information needed for the implementation of D. suzukii management programs focused on the conservation of natural enemies.

Toxicities and Residual Effect of Spinosad and Alpha-Cypermethrin-Based Baits to Replace Malathion for Ceratitis capitata (Diptera: Tephritidae) Control.

Ceratitis capitata (Wiedemann, 1824) is the main insect pest of fruits worldwide. The objective of this study was to evaluate the toxicity and residual effects of the ready-to-use toxic baits Success 0.02CB (0.24 g of active ingredient [a.i.] per liter of spinosad) and Gelsura (6 g of a.i./liter of alpha-cypermethrin) and to compare them with other food lures containing spinosad and malathion mixed with hydrolyzed protein (Biofruit 5% and Flyral 1.25%), Anamed without dilution or sugarcane molasses (7%) against adult C. capitata in laboratory and greenhouse trials. Ceratitis capitata adults were highly susceptible to all toxic bait formulations (mortality > 80%) until 96 h after exposure. The lowest LT50 (hours) of toxic baits were 2.32 (Gelsura at 4,000 mg/liter), 4.26 (Gelsura at 2,000 mg/liter), 4.28 (Anamed + malathion) and 4.89 (sugarcane molasses + malathion), while formulations containing spinosad (Biofruit, Flyral, Anamed and Success 0.02CB) showed LT50 of approximately 11 h. Without rain, Gelsura (2,000 mg/liter) and all spinosad formulations provided mortality superior to 80% 14 d after application. Gelsura and Anamed + spinosad showed higher resistance to a 5-mm simulated rain, similar to Anamed + malathion, while the other formulations had its efficacy decreased. All toxic baits were effective on adult C. capitata in residual experiments without rain while Anamed + spinosad caused high adult mortality after 5 to 25 mm rains. Gelsura and Anamed + spinosad can be used to replace toxic baits containing malathion for C. capitata population management.