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The lineage G1 of Ganaspis brasiliensis is a larval parasitoid of the worldwide pest Drosophila suzukii and one of its most effective natural enemies in the native area. Because of its high degree of host specificity, G. brasiliensis G1 is considered a suitable species for introduction in areas invaded by D. suzukii following a classical biological control approach. Indeed, the release of the parasitoid is currently implemented in the USA and Italy. G1 females attack only host larvae developing in ripening fresh fruits on the plant and not larvae that develop in decaying fruits. To date, virtually no information is available on the cues regulating the foraging behavior of G1. In this study, we therefore aimed to find out whether chemical cues are exploited by G1 females to: (i) locate host fruits; (ii) locate suitable host larvae within infested fruit; (iii) discriminate between infested fresh fruits and infested rotting ones. We used a model system composed of blueberries and D. suzukii tested in two-choice olfactometer bioassays (with D. suzukii-infested fruits, healthy fruits, and pure air as odor targets), followed by the collection and the characterization of volatile organic compounds (VOCs) released by the tested targets. The results showed a clear time-dependent choice made by G1 females of infested versus healthy fruits related to the concomitant development of D. suzukii larvae and fruit degradation. Attraction to infested fruits was recorded during the early stages of infestation, followed by a repellent phase coinciding with fruits largely degraded by larval feeding. We found that the attractiveness of G. brasiliensis G1 towards fruits infested by young larvae was associated with the detection of VOCs released by the infested blueberries, and host’s cuticular hydrocarbons. Conversely, the repellence of older and deteriorated fruits hosting developed D. suzukii larvae was associated with the detection of a fermentation compound produced by microorganisms likely carried inside the fruit by the flies. The response of G1 females to the temporal dynamics of chemical cues emitted by the fruit–host larvae complex was consistent with the high degree of specificity of the parasitoid towards the ripening host fruits and towards D. suzukii.

The spotted or bean pod borer, Maruca vitrata Fabricius is an important pest of major pulses and vegetable legumes in India and are mostly managed by chemical pesticides. Exploring other alternative management tools, here, we carried out on the availability of parasitoids and its genetic variation to control this major pest. Totally, four larval parasitoids viz., Bassus sp., Trathala flavoorbitalis Cameron, Phanerotoma hendecasisella Cameron and an undetermined Braconid wasp were recorded on M. vitrata larva. The occurrence of P. hendecasisella was reported for the first time from Tamil Nadu, India. The Bassus sp. was found to be dominant with the parasitism of 3.0 to 12.7% in different pulses and total parasitism of four parasitoids was maximum in pigeonpea (16.1%). Total parasitism had a positive relationship with number of webbings on cowpea. The larval parasitoids Bassus sp. and braconid wasp (undetermined) yielded specific fragments (~800 bp) with mitochondrial COI primer. Presence of Wolbachia was confirmed in all four larval parasitoids with the amplicons size between 600 and 650 bp. The results clearly indicate the close proximity of Bassus sp. on M. vitrata than other parasitoids studied, and suggestfor further insights on suitability, mass culturing and development for sustainable management of this insect pest. [ABSTRACT FROM AUTHOR]

[Display omitted] • Ganaspis brasiliensis G1 is a larval parasitoid highly specific to Drosophila suzukii. • G. brasiliensis G1 females attack only young host larvae in ripening fruits. • VOCs from blueberries infested by young host larvae attract G1 females. • VOCs from blueberries deteriorated by developing host larvae are repellent to G1 females. • VOCs emitted by uninfested ripe fruits are not attractive towards G1 females. The lineage G1 of Ganaspis brasiliensis is a larval parasitoid of the worldwide pest Drosophila suzukii and one of its most effective natural enemies in the native area. Because of its high degree of host specificity, G. brasiliensis G1 is considered a suitable species for introduction in areas invaded by D. suzukii following a classical biological control approach. Indeed, the release of the parasitoid is currently implemented in the USA and Italy. G1 females attack only host larvae developing in ripening fresh fruits on the plant and not larvae that develop in decaying fruits. To date, virtually no information is available on the cues regulating the foraging behavior of G1. In this study, we therefore aimed to find out whether chemical cues are exploited by G1 females to: (i) locate host fruits; (ii) locate suitable host larvae within infested fruit; (iii) discriminate between infested fresh fruits and infested rotting ones. We used a model system composed of blueberries and D. suzukii tested in two-choice olfactometer bioassays (with D. suzukii -infested fruits, healthy fruits, and pure air as odor targets), followed by the collection and the characterization of volatile organic compounds (VOCs) released by the tested targets. The results showed a clear time-dependent choice made by G1 females of infested versus healthy fruits related to the concomitant development of D. suzukii larvae and fruit degradation. Attraction to infested fruits was recorded during the early stages of infestation, followed by a repellent phase coinciding with fruits largely degraded by larval feeding. We found that the attractiveness of G. brasiliensis G1 towards fruits infested by young larvae was associated with the detection of VOCs released by the infested blueberries, and host's cuticular hydrocarbons. Conversely, the repellence of older and deteriorated fruits hosting developed D. suzukii larvae was associated with the detection of a fermentation compound produced by microorganisms likely carried inside the fruit by the flies. The response of G1 females to the temporal dynamics of chemical cues emitted by the fruit–host larvae complex was consistent with the high degree of specificity of the parasitoid towards the ripening host fruits and towards D. suzukii. [ABSTRACT FROM AUTHOR]

BACKGROUND: Habrobracon hebetor (Hymenoptera: Braconidae) is a gregarious ectoparasitoid that attacks the larvae of several species of pyralid and noctuid moths. The reproduction and population dynamics of parasitoids in general are affected by host deprivation. However, how host deprivation affects H. hebetor is unknown. The effect of host deprivation on the parental generation, life table parameters, and the paralysis rate of the F1 generation of H. hebetor were evaluated using the agestage, two-sex life table under laboratory conditions. RESULTS: The results indicated that the greatest longevity and the least lifetime fecundity of the F0 generation occurred after 19 days of host deprivation (PW-20 treatment). The life table parameters (intrinsic rate of increase, r; finite rate of increase, λ; and net reproductive rate, R0) and the paralysis rate parameters (net paralysis rate, C0; transformation rate, Qp; stable paralysis rate, ψ; and finite paralysis rate, ω) of F1 individuals after PW-20 treatment were significantly higher than those of individuals subjected to the control treatment (no host deprivation). However, no difference was detected between the two host deprivation treatments: host deprivation after 1 day of host contact and immediate host deprivation (PW treatment). CONCLUSION: Our results demonstrated that the effectiveness of H. hebetor did not decrease even during host deprivation for 19 days. Meanwhile, it was observed that mass rearing of the parasitoid could be improved by providing 10 individuals of 5th instar larvae of Ephestia elutella (Lepidoptera: Pyralidae) with a 20% honey-water solution. [ABSTRACT FROM AUTHOR]

This study assesses the feasibility of using natural enemies for the control of Acanthoscelides obtectus Say and Zabrotes subfasciatus Boheman (Coleoptera: Chrysomelidae), key pests of stored dried beans, Phaseolus vulgaris L. (Fabales: Fabaceae). The predatory mites Blattisocius tarsalis Berlese (Acari: Ascidae) and Amblyseius swirskii Athias-Henriot (Acari: Phytoseiidae) were able to prey on A. obtectus eggs, reducing the bruchid population by more than 60% under both controlled and warehouse conditions. Therefore, they show good potential as biological agents for controlling this pest. The larval parasitoids Anisopteromalus calandrae Howard and Lariophagus distinguendus Förster (Hymenoptera: Pteromalidae) were both moderately effective (34–38% reduction) at suppressing A. obtectus populations, but when A. calandrae was combined with B. tarsalis, a significant improvement in control efficacy (81% reduction in emergence) was observed. Therefore, the release of A. calandrae combined with B. tarsalis seems to be a promising strategy for controlling A. obtectus. Neither B. tarsalis nor A. swirskii were able to prey on Z. subfasciatus eggs. Only the parasitoid A. calandrae was moderately effective (39% reduction) at supressing Z. subfasciatus populations. Further testing is needed to identify other natural enemies that can complement the action of A. calandrae in reducing Z. subfasciatus populations. [ABSTRACT FROM AUTHOR]

The spotted wing drosophila, Drosophila suzukii (Matsumura) (Diptera Drosophilidae), is considered one of the world's most important pests on berries because of the direct damage it causes. Thus, inclusion of biological control agents is being explored as part of the IPM program. There are two species of larval parasitoids of Drosophila spp. currently registered in Mexico: Leptopilina boulardi (Barbotin, Carton et Keiner-Pillault) (Hymenoptera Figitidae) and Ganaspis brasiliensis (Ihering) (Hymenoptera Figitidae), but the response of D. suzukii against the attack of these parasitoids is unknown. The objective of this study was to determine if Mexican populations of L. boulardi and G. brasiliensis could parasitize and complete their development on D. suzukii; as well as determining if there is a preference to parasite either D. suzukii or Drosophila melanogaster Meigen. In laboratory tests, both species succeeded in parasitizing D. suzukii, and even though the larvae did not complete their development, they killed the host. Additionally, in choice test, both species had a 2:1 ratio of preference for using D. melanogaster as a host rather than D. suzukii. Although neither of the parasitoids complete their development on D. suzukii, they could contribute to pest management since they cause death by oviposition and could maintain their populations on D. melanogaster, since both drosophilid species are present in the field. [ABSTRACT FROM AUTHOR]

The cereal leafminer, Syringopais temperatella Lederer (Lepidoptera: Scythridae) is an important pest in barley and wheat in Northern Cyprus. This study was carried out to identify the larval parasitoids and to determine the parasitism rate of S. temperatella. These studies were conducted in 42 cereal fields of 18 villages in Lefkoşa, Girne, Güzelyurt, Gazimağusa and İskele townships in 2012-2013 years, and 1567 and 862 larvae were collected in the two years, respectively. Larvae were kept inside boxes covered with nets in the laboratory at 25±1◦C and 65±5% r.h. Following pupation, adult moths and parasitoids were obtained and percentage of parasitized larvae was determined. At the end of the study, Bracon (Habrobracon) stabilis (Wesmael) (Braconidae) and Agathis gracilenta Tobias (Braconidae) species from Hymenoptera order were obtained. Bracon stabilis (93.4%) was determined as widespread and in higher level. A. gracilenta was identified for the first time as larval parasitoid of S. temperatella and also for Northern Cyprus and Cyprus Island. The average parasitism rate in cereal fields was 34.8-18.1% in Güzelyurt, 31.8-12.2% in İskele, 21.0-8.4% in Girne, 16.2-5.4% in Lefkoşa and, 9.5-1.8% in Gazimağusa townships in 2012-2013 years, respectively [ABSTRACT FROM AUTHOR]

The native parasitoids Necremnus tutae Ribes & Bernardo and N. cosmopterix Ribes & Bernardo (Hymenoptera: Eulophidae) are potential biocontrol agents of the exotic tomato pest Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) in Europe. We investigated the functional response of parasitoid females to different densities of 3rd-instar host larvae (from 3 to 40 hosts offered), as well as some life history traits (longevity, lifetime fecundity, parasitism and host-feeding rate) of N. tutae and N. cosmopterix. In functional response experiments, the rate of attack of both parasitoids was positively correlated with host density, N. tutae and N. cosmopterix showing type III and type II functional response, respectively; the latter species exhibited a higher maximum estimated host-killing rate than the former. Both parasitoids showed high fecundity (> 50 eggs) during their lifetime. The potential application of N. tutae and N. cosmopterix in conservation biological control of T. absoluta is discussed. [ABSTRACT FROM AUTHOR]

Larval parasitoids can substantially reduce the population density of the pollen beetle [Brassicogethes aeneus (Fabricius), syn. Meligethes aeneus (Fabricius)]. The most abundant tersilochine parasitoids of pollen beetle are Tersilochus heterocerus, Phradis interstitialis and P. morionellus. The main activity of these parasitoids was observed in the period shortly before flowering to full flowering of oilseed rape. Insecticide applications during this period may have negative effects on parasitoids. In the present study, the effects of the insecticides Biscaya (a.i. thiacloprid), Mavrik (a.i. tau-fluvalinate) and Karate Zeon (a.i. lambda-cyhalothrin) applied during the bud or flowering stage of winter oilseed rape on parasitization of pollen beetle larvae by T. heterocerus were studied in 12 field trials at different locations in Germany in 2013-2015. The effects on parasitism by Phradis spp. were assessed in 2015. Parasitism of pollen beetle larvae by T. heterocerus was found in all field trials in all experimental years, but in most trials not before full flowering. Maximum percentage of parasitized larvae at different locations ranged between 3.4 and 16.8% in 2013, 8.3 and 22.4% in 2014 and from 11.1 to 29.1% in 2015. Levels of parasitism were not significantly different between the untreated control and insecticide treatments within each location. In contrast to T. heterocerus, Phradis spp. was not detected at all locations and not before flowering declining. In field trials at Lucklum and Puch, the maximum level of parasitism by Phradis spp. was 9.4 and 18.3%, respectively. No significant effect of insecticide application on parasitism by Phradis spp. was observed between the treatments. The results of this study showed that the insecticides used in the field trials did not affect parasitization of pollen beetle larvae by T. heterocerus and Phradis spp., regardless whether applied at the bud stage, at the beginning of flowering or full flowering. [ABSTRACT FROM AUTHOR]

Venturia canescens and Habrobracon hebetor are cosmopolitan parasitoids found in large numbers in food processing facilities in northeastern Spain and in many other countries. These parasitoids attack larvae of pyralid moths, which are important pests of stored products and food industries worldwide. In this study, we evaluated the performance of these two parasitoids when offered single or combined populations of Plodia interpunctella and Ephestia kuehniella, since these can occur together in storehouses. We tested the parasitoid’s performance in small cages under laboratory conditions and small experimental storerooms (≈ 30 m3). In the laboratory, the two parasitoids were able to reduce pyralid populations by more than 37% over a 48-h period (40-44% for E. kuehniella, 37-41% of P. interpunctella and 53-55% of both hosts when offered together). Similar results were obtained in small storerooms after 10 days: a > 35% reduction in pyralid populations also was obtained when host species were offered either singly (E. kuehniella or P. interpunctella) or in combination (E. kuehniella + P. interpunctella) (35-57% for E. kuehniella, 40-54% of P. interpunctella and 41-46% of both hosts when offered together). Parasitism was consistently good from June through November (mean temperatures from 18 to 28 °C and 9.5 to 15 h of daylight). Therefore, both parasitoids, single or in combination, can be efficient biological control agents of these two pyralid moths when infesting stored food facilities. [ABSTRACT FROM AUTHOR]

The Asian spotted wing drosophila, Drosophila suzukii, has recently become a serious pest of soft fruits in Europe. Classical biological control through the introduction of larval parasitoids from its native range in Asia is presently being considered. However, host specificity of potential biological control agents has to be determined to avoid releasing species that may have unintended non-target impacts. Larvae of six different European non-target fly species and the target D. suzukii were exposed either on diet or blueberries to three Asian larval parasitoids, Asobara japonica, Leptopilina japonica, and Ganaspis cf. brasiliensis, and one European species, Leptopilina heterotoma. Asobara japonica showed the lowest specificity, attacking and developing in all Drosophilidae. Leptopilina japonica successfully parasitized two non-target Drosophilidae, D. melanogaster and D. subobscura, with one singly progeny emerging from D. immigrans. Ganaspis cf. brasiliensis had the highest level of specificity but variations occurred between two geographical populations tested. A Japanese population was strictly specific to D. suzukii, whereas another population from China parasitized D. suzukii, D. melanogaster and sporadically D. subobscura. The European L. heterotoma successfully developed in D. melanogaster, D. subobscura and occasionally in D. immigrans, but nearly all eggs and larvae in D. suzukii were encapsulated. These results show that Ganaspis cf. brasiliensis is the species with the highest potential for biological control, but more studies are needed on its taxonomic status and the existence of biotypes or cryptic species varying in their specificity before field releases can be conducted in Europe. [ABSTRACT FROM AUTHOR]

Larval parasitoids of the leaf miner genus Liriomyza were studied in six provinces of southern Thailand, Songkhla, Phatthalung, Nakhon Si Thammarat, Trang, Satun and Pattani, from April 2000- March 2001. Two families of hymenopteran parasitoids, Eulophidae and Braconidae, were found. The eulophid included Asecodes sp. nr. notandus (Sivestri), Cirrospilus ambiguus Hanssan & LaSalle, Hemiptarsenus variconis (Girault), Neochrysocharis formosa (Westwood) and Quadrastichus sp. nr. liriomyzae Hanssan & LaSalle. There was only one braconid species, Opius dissitus (Muesebeck). Among these, A. sp. nr. notandus was found in highest frequency while H. variconis had the widest range of host plants. The parasitoids were found on 14 host plant species. Vigna sesquipedalis was able to be used by all six species of parasitoids. It was also the host plant most often used by the parasitoids in this study.

Factors affecting overwintering mortality in the Mediterranean corn stalk borer, Sesamia nonagrioides Lefebvre (Lepidoptera: Noctuidae), were investigated under field conditions in the southeast Mediterranean region of Turkey. During two consecutive years larvae and pupae were sampled from December to April in maize plots sown on three different dates. Field-collected larvae and pupae were reared and the emerged parasitoids were recorded. An effect of sowing date on total numbers of S. nonagrioides was found with reduced populations in the early sown plots. Larval parasitism did not significantly affect overwintering mortality. Habrobracon hebetor (Say) (Hymenoptera: Braconidae) caused 11% parasitism and was found only in the first year of the study. Pupal parasitoids were predominantly Ichneumon sarcitorius caucasicus Meyer, Barichneumon sp. and Pimpla spuria Gravenhorst (Hymenoptera: Ichneumonidae) and the parasitism level was 11% in both years of the study. [ABSTRACT FROM AUTHOR]

Abstract: The pressure to attain sustainable primary production necessitates that novel alternatives to issues such as pest management are researched and developed. Given this context we tracked (using Malaise traps) the changes in diversity and abundance of native wasp parasitoids (belonging to the superfamily Ichneumonoidea, comprising the families Ichneumonidae and Braconidae) in three field trials comprising mixed plantings of Eucalyptus and/or Acacia. Our aim was to examine the influences of time since planting (determines architectural complexity), tree species composition and presence/absence of understorey vegetation (i.e. vegetational complexity) on populations of Ichneumonoidea. In the trial referred to as “GES1” the diversity of wasps increased from 10 to 37 morphospecies in the 3 years following planting; over this time some of the trees were estimated to have undergone an approximate 2.7-fold increase in height. In the plantings comprising Eucalyptus and/or Acacia in the proportions 10:90, 38:62 or 100:0, respectively (“GES2”), there was a tendency for Ichneumonoidea to be more abundant in arboreta in which the composition of Eucalyptus and Acacia was more closely matched (i.e. 38:62 eucalypts to acacias) compared to arboreta in which trees of one or other of the two genera dominated (i.e. 10:90 and 100:0 eucalypts to acacia). We also report a tendency for Ichneumonoidea to be less abundant in the halves of the third planting (“GES3”) where understorey vegetation had been killed with herbicide. Our results were in accordance with the general ecological principle that greater habitat complexity favours greater species diversity. We suggest that increasing the vegetational complexity of commercial Eucalyptus plantations in ways that favour desired species of Ichneumonoidea could be a means of enhancing the biological control of incipient populations of pest insects. [Copyright &y& Elsevier]

1. Interspecific competition among parasitoids may play a key role in the community dynamics of tritrophic plant–herbivore–parasitoid systems and has important implications for management of herbivorous insect pests. 2. A model system was used to explore the outcome of interspecific competition between parasitoids that differ in host specificity. The system included the lepidopteran pest Heliothis virescens, the generalist parasitoid Cotesia marginiventris, and two specialist parasitoids, Microplitis croceipes and Cardiochiles nigriceps. 3. The generalist, C. marginiventris, dominated intrinsic competition when given an 8-h developmental head start over C. nigriceps or when its oviposition was simultaneous with that of M. croceipes. Microplitis croceipes and especially C. nigriceps larvae prevailed when they were allowed to oviposit prior to C. marginiventris. 4. Rates of host mortality prior to parasitoid emergence varied with parasitoid species composition and with the order of oviposition. 5. Implications for integrated pest management and the adaptive significance of competition as related to host specialisation are discussed. [ABSTRACT FROM AUTHOR]

Leafminter of the genus Liriomyza are important pests of agricultural crops. In the mid-1990s three polyphagous new world species have been accidently introduced into South-East Asia. Different aspects of the biology of one species, Liriomyza sativae Blanchard, were studied during the period May 2000?–?July 2001 in Hanoi province in northern Vietnam on longbean, soybean, tomato, potato and cucumber. Trapping of adults and counting of larvae in mines showed that in May?–?June the generation time was approximately 15 days. This was supported by laboratory studies at constant temperature. The generation time was about 25?–?30 days in October?–?November and about 20 days in the spring season (February?–?May), based on adult trapping. In an unsprayed field, more than 50% of all mines contained parasitized larvae about 2 months after transplanting. Use of insecticides had little effect, indicating resistance in the leafminers. [ABSTRACT FROM AUTHOR]

We compared the foraging strategies of two key braconid endoparasitoids of the tobacco budworm (Heliothis virescens Fab.), Cardiochiles nigriceps Vier. and Microplitis croceipes Cresson, that differ in host and habitat range but otherwise share comparable, overlapping niches. The most important host-location cues by far for both species were materials associated with damaged plants. Both species demonstrated a significant preference for volatiles released from plants damaged by H. virescens larvae over those released from undamaged tobacco and cotton plants. In choice experiments with damaged tobacco versus cotton, M. croceipes showed a significant preference for cotton plants. In contrast, C. nigriceps preferred damaged tobacco plants. Plant compounds provoked a strong response even when released from systemically induced plants (from which damaged leaves, host, and host by-products were removed). C. nigriceps appears to have a much keener ability to locate hosts over long distances than M. croceipes. This observation may be related to the highly specialized nature of this parasitoid. The possible adaptive significance of the foraging behaviors of these two parasitoids is discussed. [ABSTRACT FROM AUTHOR]

Interspecific competition between the 3 principal larval parasitoids of the pine sawfly, Neodiprion sertifer, is of common occurrence when total larval parasitism, and hence multiple attack rates, are high. At the intrinsic level, the ectoparasitoid Exenterus abruptorius is superior to the 2 endoparasitoids, Lophyroplectus luteator and Lamachus eques, respectively, whereas L. luteator is superior to L. eques only. During mass outbreaks of the host competition between Exenterus and Lophyroplectus is most intense, whilst Lamachus fails to build up in the presence of its 2 competitors (Fig. 1). However, due to its superior host finding ability, Lamachus dominates in areas of low host densities where the 2 other species are less efficient (Table 1). L. luteator frequently sustains heavy losses in direct competition with E. abruptorius, but these can be largely compensated in the next generation because its fertility is about 5-times higher than that of Exenterus. [ABSTRACT FROM AUTHOR]

• Adult parasitoids freely searched for hosts under up to 150 cm of chickpeas. • Parasitoids kept bruchid populations below 10% that of the control. • Parasitoid wasps can be an alternative to pesticides for controlling C. chinensis. In this study, two predatory mites and two parasitoid wasps were evaluated for their effectiveness in controlling Callosobruchus chinensis (Coleoptera: Chrysomelidae), a common pest in stored chickpeas. The predatory mite Amblyseius swirskii (Acari: Phytoseiidae) preyed on the bruchid's eggs but did not consume a large amount; the mite Blattisocius tarsalis (Acari: Ascidae) did not consume C. chinensis eggs. However, the larval parasitoids Anisopteromalus calandrae and Lariophagus distinguendus (Hymenoptera: Pteromalidae) were effective at reducing the bruchid's larval population, producing mortality rates above 90% in controlled conditions (28 ± 2 °C, 75 ± 5% relative humidity [RH]). In tubes of 20-cm diameter filled with 9–35 kg of chickpeas, both parasitoids were able to parasitize the host at depths of 40, 100, and 150 cm, even when larvae were offered simultaneously at all depths. This indicates that parasitoids will probably be able to locate hosts at least at 150 cm of distance in a storage facility. A. calandrae was similarly effective at reducing the bruchid population at different parasitoid-to-host ratios (1:7, 1:15, 1:30, and 1:60). Moreover, A. calandrae efficiently reduced C. chinensis populations when released in 25-kg commercial polypropylene bags of chickpeas in simulated warehouse conditions (27 ± 2 °C and 65 ± 4% RH). This is the first time that A. calandrae and L. distinguendus are shown to be effective biological control agents for the integrated management of C. chinensis in stored chickpeas and can be an alternative to the application of pesticides for maintaining low bruchid population levels. [ABSTRACT FROM AUTHOR]

Background: Habrobracon hebetor (Hymenoptera: Braconidae) is a gregarious ectoparasitoid that attacks the larvae of several species of pyralid and noctuid moths. The reproduction and population dynamics of parasitoids in general are affected by host deprivation. However, how host deprivation affects H. hebetor is unknown. The effect of host deprivation on the parental generation, life table parameters, and the paralysis rate of the F 1 generation of H. hebetor were evaluated using the age-stage, two-sex life table under laboratory conditions., Results: The results indicated that the greatest longevity and the least lifetime fecundity of the F 0 generation occurred after 19 days of host deprivation (PW-20 treatment). The life table parameters (intrinsic rate of increase, r; finite rate of increase, λ; and net reproductive rate, R 0 ) and the paralysis rate parameters (net paralysis rate, C 0 ; transformation rate, Q p ; stable paralysis rate, ψ; and finite paralysis rate, ω) of F 1 individuals after PW-20 treatment were significantly higher than those of individuals subjected to the control treatment (no host deprivation). However, no difference was detected between the two host deprivation treatments: host deprivation after 1 day of host contact and immediate host deprivation (PW treatment)., Conclusion: Our results demonstrated that the effectiveness of H. hebetor did not decrease even during host deprivation for 19 days. Meanwhile, it was observed that mass rearing of the parasitoid could be improved by providing 10 individuals of 5th instar larvae of Ephestia elutella (Lepidoptera: Pyralidae) with a 20% honey-water solution. © 2020 Society of Chemical Industry., (© 2020 Society of Chemical Industry.)

Summary 1. Competition between parasitoid species may be a key factor in the community dynamics of plant–herbivore-parasitoid systems and is an important consideration in the selection and management of effective biological control agents. 2. Interspecific competition can occur between adult parasitoids searching for hosts (extrinsic competition) and between multiple parasitoid larvae developing within a single host individual (intrinsic competition). A model system comprising the lepidopteran pest Heliothis virescens and two key hymenopteran endoparasitoids, Microplitis croceipes and Cardiochiles nigriceps, was employed to explore parasitoid host-location strategies and the consequences of intrinsic and extrinsic competitive interactions between parasitoid species. 3. The less specialised of the two parasitoids, M. croceipes, was found to have a shorter hatching time and to dominate intrinsic competition, except when its oviposition followed that of the more specialised parasitoid, C. nigriceps, by 16 h or more. This interval corresponded to the differential in hatching time between the two species. 4. Cardiochiles nigriceps, however, displayed superior host-searching efficiency that may compensate for its disadvantage in intrinsic competition. This parasitoid was more effective at detecting host infestation sites via airborne odours and at locating and attacking early instar host larvae than was M. croceipes. [ABSTRACT FROM AUTHOR]