Larval Parasitoid Research Articles

Releases of the parasitoid Pachycrepoideus vindemmiae for augmentative biological control of spotted wing drosophila, Drosophila suzukii

Spotted wing drosophila, Drosophila suzukii, is native to East Asia but has become a major pest of soft-skinned fruit crops in its invaded range in the Americas, Europe and North Africa. Control efforts are complicated by the seasonal movement of D. suzukii into crops from non-crop or untreated-crop habitats. Biological control may help to suppress D. suzukii populations. However, surveys have found that few parasitoid species attack D. suzukii in North America and Europe, with low levels of parasitism by the pupal parasitoids Trichopria drosophilae and Pachycrepoideus vindemmiae and little or no parasitism by larval parasitoids. Augmentation of these resident pupal parasitoids may be a sustainable tool for D. suzukii management. Most augmentation efforts to date have focused on T. drosophilae, although P. vindemmiae is the more abundant and widespread species in North America. In this study, we tested whether augmentative releases of P. vindemmiae could help control D. suzukii in caneberry hoop houses in Minnesota, Oregon and California. Results were inconsistent. Most trials showed no detectable post-release effects on parasitism or D. suzukii levels, although one trial in Oregon did show elevated parasitism levels in release plots. Larger releases of P. vindemmiae may be needed when D. suzukii numbers are high, or to overcome the effects of suboptimal conditions and/or dispersal.

Parasitoids of Dasiops (Diptera: Lonchaeidae) in sweet granadilla orchards in an Andean forest of Peru

ABSTRACT We report hymenopteran larval and pupal parasitoids of the Dasiops species in sweet granadilla (Passiflora ligularis J.) orchards in a Peruvian Andean forest. Flower bud and fruit samples infested by Dasiops were collected in three orchards from Oxapampa (Pasco, Peru). In addition, we exposed non-parasitized Dasiops pupae at ground level to verify the presence of pupal parasitoids. We identified Utetes anastrephae (Viereck) and Opius sp. (Hymenoptera: Braconidae) on flower buds infested b.y Dasiops inedulis Steyskal. However, Aganaspis pelleranoi (Brèthes) (Hymenoptera: Figitidae) emerged from D. frieseni pupae reared from unripe fruits. Also, the pupal parasitoids Pachycrepoideus vindemmiae (Rondani) (Hymenoptera: Pteromalidae) and Coptera sp. (Hymenoptera: Diapriidae) emerged from pupae of both D. inedulis and D. frieseni exposed to parasitism at ground level. Our findings shed new light into new interactions for species in the genus Dasiops and their larval and pupal parasitoids in sweet granadilla agroecosystems from the Neotropical region.

Study of mating effect, hosts range and competition with the parasitoid Bracon hebetor on some behavioral and biological aspects of larval parasitoid Goniosus sp

Laboratory studies was conducted to investigate effect of mating behavior on egg laying, host selection and competition with Bracon hebetor. The results showed that no differences in mating and egg laying behavior between mated and unmated females. number of egg laying were 90.67 egg per female of unmated and mated females respectively. However unmated female produce only males progeny.The parasitoid showed response to the larvae of different lepidopterous insects such as. Mediterranean flour moth, potato tuber warm, greater wax moth, tomato leafminer, Angoumois Grain Moth and lesser date moth. The parasitoid did not respond to the larvae of Corn stem borer and cotton bollworm (tomato fruitworm) .The results of competition study between the parasite Goniozus sp and B. hebetor indicates that the first parasite was more competitive and parasitism on the larvae of the host where the percentage of parasitism was 72.22% of the total larvae, while, the percentage of parasitism was 27.77% for the parasite B.hebetor.

Exogenous Application of Gallic Acid Induces the Direct Defense of Tea Plant Against Ectropis obliqua Caterpillars.

Gallic acid (GA), an important polyphenolic compound in the plant, is a well-known antioxidant, antihyperglycemic, and anti-lipid peroxidative agent. Recently, GA treatment exhibited ameliorative effects on plants in response to some abiotic stresses. However, the elicitation effect of GA on plant defense against herbivorous insects has not yet been reported. In this study, we found that the exogenous application of GA induced the direct defense of tea plant (Camellia sinensis) against tea geometrid (Ectropis obliqua) larvae, through activating jasmonic acid (JA) signaling and phenylpropanoid pathways. These signaling cascades resulted in the efficient induction of several defensive compounds. Among them, astragalin, naringenin, and epigallocatechin-3-gallate were the three of the most active anti-feeding compounds. However, the exogenous GA treatment did not affect the preference of E. obliqua female moths and larval parasitoid Apanteles sp. Our study suggests that GA may serve as an elicitor that triggers a direct defense response against tea geometrid larvae in tea plants. This study will help to deepen the understanding of the interaction between plants and phytophagous insects and also provide theoretical and technical guidance for the development of plant defense elicitors.

Synergistic control of Callosobruchus maculatus Fab. (Coleoptera: Chrysomelidae) by releases of an oophagous and a larval parasitoid in experimental cowpea storage systems

Synergistic control of Callosobruchus maculatus Fab. (Coleoptera: Chrysomelidae) by releases of an oophagous and a larval parasitoid in experimental cowpea storage systems

A Coordinated Sampling and Identification Methodology for Larval Parasitoids of Spotted-Wing Drosophila.

We provide recommendations for sampling and identification of introduced larval parasitoids of spotted-wing drosophila, Drosophila suzukii (Matsumura) (Diptera: Drosophilidae). These parasitoids are either under consideration for importation (aka classical) biological control introductions, or their adventive (presumed to have been accidentally introduced) populations have recently been discovered in North America and Europe. Within the context of the ecology of D. suzukii and its parasitoids, we discuss advantages and disadvantages of estimating larval parasitism levels using different methods, including naturally collected fruit samples and sentinel baits. For most situations, we recommend repeated sampling of naturally occurring fruit rather than using sentinel baits to monitor seasonal dynamics of host plant-Drosophila-parasitoid associations. We describe how to separate Drosophilidae puparia from host fruit material in order to accurately estimate parasitism levels and establish host-parasitoid associations. We provide instructions for identification of emerging parasitoids and include a key to the common families of parasitoids of D. suzukii. We anticipate that the guidelines for methodology and interpretation of results that we provide here will form the basis for a large, multi-research team sampling effort in the coming years to characterize the biological control and nontarget impacts of accidentally and intentionally introduced larval parasitoids of D. suzukii in several regions of the world.

Seasonal activity of oil palm leaf webworm, Acria meyricki Shashank and Ramamurthy and its natural enemies in oil palm-cocoa intercropping system and their management in oil palm

The pest was active during October to March. The population density ranged from 0.31 to 2.31 larvae/frond and 0.05 to 9.35 larvae/frond during first and second study periods respectively. The larval parasitoid, Dolichogenidea hyposidrae Wilkinson (Hymenoptera: Braconidae) was recorded to the tune of 7.14 to 98.21% and 2.66 to 95.0% during the first and second study periods respectively. Level of parasitism by pupal parasitoid, Brachymeria albotibialis (Ashmead) (Hymenoptera: Chalcididae) was 8.62 to 64.0%. In oil palm-cocoa intercropping system, lower pest density, lower pest damage and high level of parasitism by natural enemies were recorded. Insecticides viz., deltamethrin, lambda cyhalothrin, chlorantraniliprole, thiodicarb and fipronil were found effective in managing this pest under severe conditions in oil palm gardens.

OUP accepted manuscript

Born in the backwoods of rural Mississippi to an illiterate sharecropper, W. Joe Lewis graduated from Mississippi State University at the age of twenty-four with a Ph.D. in entomology. He immediately accepted a research position with the USDA–Agricultural Research Service, which resulted in a forty-year career, culminating with the highest professional grade for a USDA scientist, acknowledging his meritorious service. During those four decades, he also held joint faculty appointments with the University of Georgia and University of Florida. Lewis earned three degrees in entomology from Mississippi State University within a rapid span of seven years (B.S., 1964; M.S., 1965; Ph.D., 1967). His USDA career had numerous research firsts: isolation and identification of the kairomones for larval and egg parasitoids; demonstration of a parasitoid to use kairomones to enhance its searching ability in the field; development of a laboratory system for oriented in-flight behavioral studies of parasitoids; demonstration of the key role that associative learning plays in parasitoid responses to chemical and/or visual host cues; discovery that plants, in response to herbivore feeding damage, can actively emit information-rich chemical distress signals that are used by a parasitoid to locate and attack the herbivore; and demonstration that plant signals can be herbivore-specific and selectively used by parasitoids. Additionally, Lewis led the formulation and successful demonstration, using cotton production as a model, of the economic and environmental benefits of a fundamental shift to a total system approach to sustainable pest management.

The parasitoid complex of diamondback moth, Plutella xylostella (Linnaeus) (Lepidoptera: Plutellidae), in Canada: impact and status

Abstract Diamondback moth, Plutella xylostella (Linnaeus) (Lepidoptera: Plutellidae), a globally important pest of Brassicaceae crops, migrates into all provinces of Canada annually. Life tables were used to determine the mortality levels contributed by the parasitoid complexes associated with diamondback moth in British Columbia, Ontario, Prince Edward Island, and insular Newfoundland. Overall, diamondback moth populations showed high generational mortality (> 90%) in all provinces, although parasitism levels were generally low. The net reproductive rate of increase in diamondback moth was less than 1.0 (populations declined) in both years in British Columbia and in each of two years in Newfoundland and Ontario, but it was greater than 1.0 in all three years in Prince Edward Island. Lower parasitism levels were found in Prince Edward Island (3.0–6.3%) compared with other provinces (8.4–17.6%, except one year in British Columbia). Diadegma insulare was the main larval parasitoid found; it was present in all provinces. Microplitis plutellae was present in all provinces except British Columbia. Oomyzus sokolowskii was found in British Columbia and Ontario. The parasitoid community documented from sentinel sampling was less diverse than that found through destructive sampling. Hypotheses are provided to explain the presence of major parasitoids. Increasing larval parasitism would have the largest effect on diamondback moth population growth in Canada.

Effect of Adult Nutrition at Different Concentrations on Reproduction and Longevity of <i>Bracon brevicornis</i>, Larval Parasitoid of Coconut Black-Headed Caterpillar

Coconut black-headed caterpillar (<i>Opisina arenosella</i>) or BHC is one of the main coconut palm defoliators in many Asian countries, including Malaysia, where it was discovered in 2017. Since then, an effort has been made to manage the pest by the use of larval parasitoids, started with a study on the effects of sucrose diet on reproduction, longevity and parasitism of a naturally occurring parasitoid known as <i>Bracon brevicornis</i> (Hymenoptera: Braconidae). The aim of this study was to determine the optimal sucrose concentration for improving its rearing technique. Two experiments were conducted, i.e., a) reproductive performance study; and b) longevity study. In each study, different sucrose concentrations were tested on mated females in five (5) replications. Feeding on 20% sucrose concentration resulted in significantly (P<0.05) highest fecundity (82.4 ± 0.9), hatchability (100%), pupation, fertility (82.7%) and longest reproductive period (12.8 ± 0.3 days) of <i>B. brevicornis</i> among treatments. Meanwhile, 40% sucrose was able to prolong its adults’ lifespan (20.6 days). Adults fed on 20% sucrose had the highest parasitism (33.4±0.6 host larvae), despite the fact that 30% sucrose had no statistically significant difference. Thus, this study suggested that 20% sucrose could be suitable to increase fertility and parasitism by <i>B. brevicornis</i>. However, additional research on its effect on behaviours is necessary to acquire a better knowledge of its efficiency in the field.

Crop diversification for sustainable management of leaf webworm, Nausinoe geometralis Guenee of Jasmine (Jasminum sambac L.)

A field trial to investigate the effect of diversifying crops in jasmine ecosystem to manage leaf webworm incidence, revealed that there was a significant reduction in the pest incidence and infestation in intercropped plots as compared to jasmine sole crop. The data indicated the supremacy of marigold in reducing the incidence of the pest as well as attracting more natural enemy population, bagging the credit of eco-feast crop. Marigold recorded significantly the lowest mean incidence of 15.58%, followed by onion (16.03%) and coriander (16.43%) compared to jasmine as sole crop (2.17%). The population of natural enemies viz., coccinellids, chrysopids, preying mantises and spiders were more recorded in marigold intercropped jasmine with 8.70, 3.60, 4.40, 5.30 nos/five plants respectively. Moreover, the emergence of the larval parasitoids, Bracon brevicornis and Phanerotoma hendecasiella were more encountered in jasmine intercropped with marigold than sole jasmine crop. The pest defender ratio was highest in jasmine + marigold (1:3.50) and the order falls as jasmine + coriander (1:3.05) and jasmine + gingelly (1:2.34).

Rapid Spread of an Introduced Parasitoid for Biological Control of Emerald Ash Borer (Coleoptera: Buprestidae) in Maryland.

Emerald ash borer (Agrilus planipennis Fairmaire (Coleoptera: Buprestidae)), an invasive phloem-feeding beetle native to Asia, has devastated North American ash forests since its detection in Michigan, United States in 2002. As the emerald ash borer has continued to spread, the potential for successful long-term management hinges upon the release, establishment, and spread of introduced larval and egg parasitoids for biological control. Here, we focus on the establishment and evidence for spatial spread of introduced larval parasitoid, Spathius agrili Yang and Spathius galinae Belokobylskij & Strazanac (Hymenoptera: Braconidae) in the state of Maryland. To assess each species, we analyzed historical release and recovery data and resampled previous release sites and nonrelease sites for establishment. We found little evidence of establishment or spread for S. agrili, despite a comparatively large number of release locations, events, and individuals. By contrast, despite much lower propagule pressure and shorter history of releases, we detected multiple established populations of S. galinae at release sites and at sites up to 90 km from the nearest release point approximately 3 yr after its most current release. Our findings show that S. galinae has established and spread rapidly following field releases whereas its congener, S. agrili has not. Although it may still be too early to evaluate the level of population control and ash protection afforded by S. galinae, these findings indicate the need for continued investment in S. galinae for emerald ash borer classical biological control efforts.

Siricid Parasitoids (Hymenoptera: Ichneumonidae) From Eastern White Pine and Associated Pine Species in Southern Appalachia

Siricid Parasitoids (Hymenoptera: Ichneumonidae) From Eastern White Pine and Associated Pine Species in Southern Appalachia

Natural parasitization of Cotesia spp. and Bracon spp. on Spodoptera litura Fab. in castor crop

The larval stage of Spodoptera litura Fab. is more prone to parasitism. Larval parasitoids such as braconids belongs to family Braconidae of order Hymenoptera acts as Ecto parasitoids. Braconids have wide host range and successful biocontrol agent recommended for the control of lepidopteran larvae in many crops and stored grains. The present study on parasitization of braconids on S. litura was conducted under laboratory conditions. The larva of S. litura collected from castor crop from various locations near by Nagpur, Maharashtra, India and reared on castor leaves under laboratory conditions. The larvae were parasitized by two parasitoids namely, Cotesia spp. and Bracon spp. The study revealed that the field collected larva of S. litura when reared on castor leaves showed an average parasitization of 11% and 4.3% by Cotesia spp. and Bracon spp. respectively.

The Larval food-plants of Apochima diaphanaria ssp. rjabovi (Wehrli, 1936) (Lepidoptera: Geometridae) and its new larval parasitoid Drino imberbis (Wiedemann, 1830) record

The larval food plant of the Apochima diaphanaria ssp. rjabovi (Wehrli, 1936) in the Geometridae family has not been known until now. In this study, the medicinal plants Ferula haussknechtii H. Wolff ex Rech.f., Prangos uloptera DC. (Apiaceae) and Rheum ribes L. (Polygonaceae) species are identified for the first time as larval food plants of Apochima diaphanaria ssp. rjabovi. In addition, Drino imberbis (Wiedemann, 1830) (Diptera, Tachinidae) species is recorded as the first larval parasitoid of Apochima diaphanaria ssp. rjabovi. Pictures of the habitat, larva, pupa and adult individual of this moth subspecies, as well as pictures of the pupa and the adult individual of the larval parasitoid are present in the study.

Spread and phenology of Spathius galinae and Tetrastichus planipennisi, recently introduced for biocontrol of emerald ash borer (Coleoptera: Buprestidae) in the northeastern United States

Emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), is an invasive wood-boring pest of ash trees (Fraxinus spp.) in the United States. It is responsible for catastrophic decline of ash in urban and forested ecosystems, resulting in millions of dollars in economic losses. Biological control is one of the most promising management options available to reduce A. planipennis spread and impact. From 2015 to 2017, two larval parasitoids from the native range of A. planipennis, Spathius galinae Belokobylskij & Strazenac (Hymenoptera: Braconidae) and Tetrastichus planipennisi Yang (Hymenoptera: Eulophidae), were released in forested areas in New York and Connecticut. The purpose of this study was to measure the spread and seasonal phenology of these introduced parasitoids. From May to September 2020, sentinel ash logs containing EAB larvae were deployed in naturally occurring A. planipennis infested trees at each release site and at 2 km intervals up to 14 km away from the release site. Logs were replaced every two weeks and the parasitization rate was recorded. Each month, three trees from each release area were also cut and debarked to record A. planipennis infestation levels, natural parasitization rates, and A. planipennis and parasitoid phenology. We observed that both S. galinae and T. planipennisi emerged from the logs first deployed from the end of May to early June. Parasitization peaked in late July and mid-August, with sentinel logs deployed at each distance producing both species throughout the summer until mid-September. Both S. galinae and T. planipennisi were detected 14 km away from the release sites, the greatest distance away from the release sites sampled. Debarked trees produced similar seasonal patterns of parasitism. Our results indicate that the classical biological control program initiated several years ago has successfully produced a self-sustaining population of both S. galinae and T. planipennisi, which have been spreading widely and attacking the borer throughout the growing season. These findings strongly suggest that future release efforts may allow for wider temporal release windows and larger strategic spacing of release points across geographic regions.

Courtship behavior and identification of a sex pheromone in Ibalia leucospoides (Hymenoptera: Ibaliidae), a larval parasitoid of Sirex noctilio (Hymenoptera: Siricidae).

BackgroundIbalia leucospoides (Hymenoptera: Ibaliidae) is a larval parasitoid that has been widely introduced as a biological control agent for the invasive woodwasp,Sirex noctilio (Hymenoptera: Siricidae) in the Southern Hemisphere. In this study, the courtship behavior and identificaion of sex pheromones are described for I. leucospoides under laboratory conditions.MethodsFor courtship behavior, both sexes were observed in a wire mesh observation cylinder (75 cm length ×10 cm diameter) for 15 minutes. The female body washes were analyzed using Gas Chromatography- Electroantennographic Detection (GC-EAD). Then the EAD-active compounds were tentatively identified using GC-Mass Spectrometry (GC-MS) and examined in olfactometer assays.ResultsThe courtship behavior included rhythmic lateral movements, mounting, head-nodding cycles in males, and wing-fanning in females. GC-EAD analysis of female body washes with male antennae revealed seven compounds which elicited antennal responses, four of which are straight-chain alkanes (C23, C25, C26, and C27). The identities of these alkanes were confirmed by matching the retention times, mass spectra, and male antennal activity to those of commercially obtained chemicals. In olfactometer assays, a blend of the four straight-chain alkanes was attractive to I. leucospoides males, and there was no response to blends that lacked any of these four compounds. Female body wash was no more attractive than the four-component blend. The ratios of EAD-active components differ between hydrocarbon profiles from males and females.ConclusionThis study is the first investigation of cuticular hydrocarbons in the family Ibaliidae. It provides evidence that the ubiquitous alkanes (C23, C25, C26, and C27) in sex-specific ratios attract I. leucospoides males.

Phylogeny of gracillariid leaf-mining moths: evolution of larval behaviour inferred from phylogenomic and Sanger data.

Gracillariidae is the most taxonomically diverse cosmopolitan leaf-mining moth family, consisting of nearly 2000 named species in 105 described genera, classified into eight extant subfamilies. The majority of gracillariid species are internal plant feeders as larvae, creating mines and galls in plant tissue. Despite their diversity and ecological adaptations, their phylogenetic relationships, especially among subfamilies, remain uncertain. Genomic data (83 taxa, 589 loci) were integrated with Sanger data (130 taxa, 22 loci), to reconstruct a phylogeny of Gracillariidae. Based on analyses of both datasets combined and analyzed separately, monophyly of Gracillariidae and all its subfamilies, monophyly of the clade "LAMPO" (subfamilies: Lithocolletinae, Acrocercopinae, Marmarinae, Phyllocnistinae, and Oecophyllembiinae) and relationships of its subclade "AMO" (subfamilies: Acrocercopinae, Marmarinae, and Oecophyllembiinae) were strongly supported. A sister-group relationship of Ornixolinae to the remainder of the family, and a monophyletic leaf roller lineage (Callicercops Vári + Parornichinae) + Gracillariinae, as sister to the "LAMPO" clade were supported by the most likely tree. Dating analyses indicate a mid-Cretaceous (105.3 Ma) origin of the family, followed by a rapid diversification into the nine subfamilies predating the Cretaceous-Palaeogene extinction. We hypothesize that advanced larval behaviours, such as making keeled or tentiform blotch mines, rolling leaves and galling, allowed gracillariids to better avoid larval parasitoids allowing them to further diversify. Finally, we stabilize the classification by formally re-establishing the subfamily ranks of Marmarinae stat.rev., Oecophyllembiinae stat.rev. and Parornichinae stat.rev., and erect a new subfamily, Callicercopinae Li, Ohshima and Kawahara to accommodate the enigmatic genus Callicercops.

Parasitoids of Tuta absoluta (Meyrick) in open field tomato crop in Iraq

The tomato leaf miner, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), is an invasive pest in Iraq, that represents a global threat to commercial tomato production, in both open field and greenhouse. Field survey was conducted to identify parasitoids of T. absoluta in tomato open field in three sites: Suweera, Azeezia and Kut in Wasit province, central Iraq during the 2019 cropping season. Five hymenopterans parasitoid species were identified on T. absoluta as: two egg parasitoids Trichogramma pintoi Voegele (Trichogrammatidae) and Telenomus sp. (Platygastridae); two larval parasitoids Habrobracon concolorans Marshall (Braconidae) and Closterocerus sp. (Eulophidae), and one parasitoid of pupa, Proconura sp. (Chalcididae). The present study reports the first record of these parasitoids of T. absoluta on tomato open field in Iraq.

Delayed Response after Learning Associated with Oviposition Experience in the Larval Parasitoid, Cotesia kariyai (Hymenoptera: Braconidae)

Delayed Response after Learning Associated with Oviposition Experience in the Larval Parasitoid, Cotesia kariyai (Hymenoptera: Braconidae)