Cotesia Glomerata Research Articles

The effect of maternal factors of Cotesia glomerata (Braconidae) on its larval competitor Hyposoter ebeninus (Ichneumonidae)

The effect of maternal factors of Cotesia glomerata (Braconidae) on its larval competitor Hyposoter ebeninus (Ichneumonidae)

A Comprehensive Review of Insect Pest Management in Muga Silkworm (Antheraea assamensis Helfer): Current Scenario and Future Prospects

Muga silkworm (Antheraea assamensis Helfer), renowned for its natural production of prized golden silk, is native to Assam and adjacent regions in North-Eastern India. However, outdoor rearing of Muga silkworms exposes them to environmental fluctuations year-round, resulting in significant crop losses due to insect pests. Notably, pre-seed crops (Aherua and Jarua) and seed crops (Chotua and Bhodia) experience significantly higher losses compare to commercial crops (Jethua and Kotia). This paper presents a thorough analysis of insect pests impacting Muga silkworm rearing, classified according to activity periods and intensity of attacks. Primary insect pests include Exorista sorbillans (Uzi fly), Apanteles glomeratus (Brachonid fly), ants and wasps. Uzi fly inflicts damage during winter (November to February), primarily affecting 4th and 5th instar Muga larvae, leading to substantial losses during cocoon harvest in March-April, jeopardizing seed production for subsequent Jethua (April-May) commercial crops. Apanteles glomeratus and ants pose threats during summer. Vespa orientalis (wasp) causes damage to late instars from April to September. Chemical control methods are discouraged due to their adverse effects on silkworms. Therefore, urgent research into environmentally sustainable pest management strategies tailored to Muga rearing's specific needs and limitations are warranted. This review synthesizes detailed descriptions of identified pests, challenges in insect pest management, and discusses various mitigation strategies, offering insights into the biology of major insect pests affecting Muga silkworms and evaluating the effectiveness of different pest management approaches.

Crop species diversity levels with attract and reward strategies to enhance Pieris brassicae parasitism rate by Cotesia glomerata in strip intercropping

Abstract Crop diversification through inter‐ and mixed cropping practices has been shown to enhance conservation biological control of herbivorous pest insects. However, distinct cropping practices are usually tested independently, which makes assessing the relative impact of specific measures difficult. We assessed parasitism rates of released large cabbage white (Pieris brassicae) caterpillars by parasitoids on white cabbage (Brassica oleracea) plants in six different cropping systems: four different strip‐cropping designs, a pixel cropping design and a monoculture. These cropping designs differed in the number of crops included, the use of parasitoid‐attractive cultivars in concurrence with a cash cultivar, the use of nectar‐providing crops for adult parasitoids and the spatial arrangement of the crops. Parasitism rate by the main P. brassicae parasitoid Cotesia glomerata was enhanced by strip cropping of white cabbage with wheat, and even further enhanced by the inclusion of four more main crops. Contrastingly, C. glomerata parasitism rate was lower in the most intensive crop mixture, that is pixel cropping, than in any of the strip‐cropping designs. The use of attractive cultivars or rewarding floral resources within a strip‐cropping set‐up did not significantly further enhance C. glomerata parasitism rate. Synthesis and applications: Our results show that increasing the number of crops in the agroecosystem enhances parasitism rates, whereas the additional inclusion of more subtle measures to attract or reward parasitoids shows mostly marginal effects. We argue that strip cropping can readily be employed as (part of a) pest control strategy, but trait‐based measures still need further development. How to implement attract and/or reward strategies in large‐scale agricultural systems should be further evaluated in the context of crop diversification schemes. Read the free Plain Language Summary for this article on the Journal blog.

Impact of Various Brassica species on The Developmental Response of Pieris brassicae (Linnaeus) (Lepidoptera: Pieridae), Its Extent of Damage, And Report of Its Biocontrol Agent In District Rajouri of Pir Panjal Region of Himalaya

Cole crops are globally consumed as vegetables and are important sources of our dietary requirements, but they are infested by an array of pests, specifically the large white butterfly, Pieris brassicae (L). It is a critical global pest of cruciferous vegetable crops. We investigated the consequences of diverse cruciferous vegetables on the fitness of P. brassicae under laboratory conditions in 2021-22, to survive, develop, and reproduce under laboratory conditions, the extent of damage, and the report of the biocontrol agent, Cotesia glomerata (L). Under laboratory conditions, the effect of radish (Raphanus sativus), cabbage (Brassica oleracea var. capitata), and cauliflower (Brassica oleracea var. botrytis) on P. brassicae health were assessed by studying survival time, total development time, and mortality. Development time from hatching of eggs to adult emergence was longest on radish (32.6±0.84 days) and shortest on cabbage (25.0±1.41 days). In addition, the higher hatching percentage (96%), lower larval death, and higher yield of adults in cabbage indicated the fact of cabbage being the most appropriate food for P. brassicae. Life tables were dominant tools for analyzing and comprehending various aspects of an insect population's growth, survival, and reproduction. Furthermore, the crop loss was a function of pest population and the information on crop losses would serve as a guide for research programmes in crop improvement. The resistance to certain insecticides and the methods used to manage this insect pest on vegetable products in general required extensive research including biocontrol. We report the endoparasitoids C. glomerata (L) as a biocontrol agent against P. brassicae in district Rajouri which is the first record from the area which, therefore, warrants the essentiality of having a compact insect pest management plan that can relieve the dependency of destructive chemical control methods.

Oviposition fluids from adult wasps mediate interspecific competition between parasitoid larvae

Abstract Parasitoid wasp larvae engage in intense interspecific competition when sharing a host insect, with lethal consequences for the losers. Larval parasitoid competition is generally thought to be resolved by physical traits, such as enlarged mandibles. Although solitary parasitoid larvae are typically superior competitors against gregarious larvae, such physical traits are unlikely to be effective against large numbers of competitors. Larval competition may instead be mediated by maternal factors that increase the survival of offspring facing interspecific competition, thus increasing parental fitness. When laying eggs inside a host, many female parasitoids also inject oviposition fluids that are known to suppress host immune responses, permitting successful offspring development. We explored whether the oviposition fluids of two wasp species in the genus Cotesia (Cotesia rubecula, a strong competitor that almost always wins interspecific competition against a weaker competitor, Cotesia glomerata) might also represent maternal factors that improve the interspecific competitive ability of their offspring. We demonstrate that injections of both venom and calyx fluid from C. rubecula can inhibit egg hatching and larval development of C. glomerata. Venom from C. rubecula decreased C. glomerata egg development by 2.7 times, and calyx fluid injections caused deformities in 23% of developing C. glomerata. In contrast, reciprocal injections of the oviposition fluids from C. glomerata did not inhibit the development of C. rubecula. Our results show that maternal factors can improve the interspecific competitive ability of parasitoid larvae, challenging the previous assumptions that larval competition was resolved primarily through physical combat or larval secretions.

Native natural enemies of plant pests in Slovenia with an emphasis on species suitable for mass rearing.

In Slovenia, only the native natural enemies of plant pests that are on the EPPO Positive List of biological control agents can be used in agricultural production to control plant pests. The List of native species of organisms for biological control, which is an important part of the Regulations on biological control, currently includes a total of 35 species of beneficial insects and mites and entomopathogenic nematodes. Compared to the number of species on the first list that was established in 2006, the number of beneficial species that Slovenian growers of food and ornamental plants can currently use in everyday practice has doubled. This is the result of intensive professional and research work in the investigation of the occurrence and distribution of natural enemy species in Slovenia, which has been systematically supported by the state for many years. Natural enemy species, which are an integral part of the EPPO Positive List of biological control agents, can be included on the list of native biological control species via a special procedure. However, many natural enemy species that are not yet included on the EPPO Positive List have been identified in the period 2007-2022. In this paper, we list 75 such species and we present 5 candidates (Cotesia glomerata [L.], Diadegma semiclausum [Hellen], Anisopteromalus calandrae [Howard], Neochrysocharis formosa [Westwood] and Kampimodromus aberrans [Oudemans]) that, in our opinion, have high potential as biological controls and will be suitable in the future for mass rearing and use in augmentative biological control.

Parasitism causes changes in caterpillar odours and associated bacterial communities with consequences for host-location by a hyperparasitoid.

Microorganisms living in and on macroorganisms may produce microbial volatile compounds (mVOCs) that characterise organismal odours. The mVOCs might thereby provide a reliable cue to carnivorous enemies in locating their host or prey. Parasitism by parasitoid wasps might alter the microbiome of their caterpillar host, affecting organismal odours and interactions with insects of higher trophic levels such as hyperparasitoids. Hyperparasitoids parasitise larvae or pupae of parasitoids, which are often concealed or inconspicuous. Odours of parasitised caterpillars aid them to locate their host, but the origin of these odours and its relationship to the caterpillar microbiome are unknown. Here, we analysed the odours and microbiome of the large cabbage white caterpillar Pieris brassicae in relation to parasitism by its endoparasitoid Cotesia glomerata. We identified how bacterial presence in and on the caterpillars is correlated with caterpillar odours and tested the attractiveness of parasitised and unparasitised caterpillars to the hyperparasitoid Baryscapus galactopus. We manipulated the presence of the external microbiome and the transient internal microbiome of caterpillars to identify the microbial origin of odours. We found that parasitism by C. glomerata led to the production of five characteristic volatile products and significantly affected the internal and external microbiome of the caterpillar, which were both found to have a significant correlation with caterpillar odours. The preference of the hyperparasitoid was correlated with the presence of the external microbiome. Likely, the changes in external microbiome and body odour after parasitism were driven by the resident internal microbiome of caterpillars, where the bacterium Wolbachia sp. was only present after parasitism. Micro-injection of Wolbachia in unparasitised caterpillars increased hyperparasitoid attraction to the caterpillars compared to untreated caterpillars, while no differences were found compared to parasitised caterpillars. In conclusion, our results indicate that host-parasite interactions can affect multi-trophic interactions and hyperparasitoid olfaction through alterations of the microbiome.

Plant species with higher chemical defences enhance herbivore cellular immunity with differential effectiveness against two parasitoid species

Abstract Insect herbivores simultaneously experience bottom‐up effects of plant defensive chemistry and the top‐down effects of natural enemies. At the intersection of these effects are herbivore immune systems, herbivore traits that have largely been overlooked in studies of plant‐insect interactions. Most previous studies have demonstrated compromised immunity of herbivores that feed on plants with higher defensive chemistry. Many studies have used embedded microfilaments or silica beads as proxies for parasitoid eggs. Yet, parasitoids may evade or suppress host immune responses by injecting venom and calyx fluid, or through modifications of their egg surface structure, necessitating studies that include all three trophic levels to obtain a complete picture of how plant traits may modulate herbivore immunity. Here, we examined the effect of host plant species that differ in glucosinolate (anti‐herbivore compounds produced by plants in the Brassicaceae) concentrations on the immune status of an herbivore and its consequences for two species of parasitoids with different life history traits. We found that larvae of the butterfly Pieris rapae that fed on field mustard Brassica rapa, which contain 52‐fold higher glucosinolate concentrations than collards B. oleracea, attained lower body weights and experienced prolonged development to adulthood. Yet, caterpillars that fed on B. rapa had enhanced cellular immunity, as measured by total and differential haemocyte counts as well as melanization capacity, compared to larvae that fed on B. oleracea. In turn, the likelihood that at least some eggs in clutches of the gregarious endoparasitoid Cotesia glomerata would be encapsulated, leading to a reduction in brood size, were three times greater when their host caterpillars fed on B. rapa compared to B. oleracea. Interestingly, eggs of the solitary endoparasitoid Cotesia rubecula were rarely encapsulated irrespective of the host plant on which their host caterpillar fed. Therefore, our results suggest that plant defence metabolites can influence the expression of herbivore immunity, but the effectiveness of this response strongly depends on the identity of the parasitoid and its ability to evade the caterpillar immune response, and possibly the evolution of these trophic interactions in non‐native systems. Read the free Plain Language Summary for this article on the Journal blog.

Intraspecific plant variation and nonhost herbivores affect parasitoid host location behaviour

Parasitoids need to find their hosts in patchy environments that differ in profitability. To maximize foraging efficiency, parasitoids use volatile information of plants on which their hosts feed. The blend of plant volatiles emitted is affected by genetic variation in plants and by the herbivore species feeding on the plant. How parasitoids deal with variation in plant volatiles induced by host or nonhost herbivores on various plant genotypes in a plant stand is unclear. In a wind tunnel, we examined foraging behaviour of the parasitoid Cotesia glomerata in mixes of white cabbage cultivars with host ( Pieris brassicae ) and nonhost herbivores ( Mamestra brassicae or Delia radicum ). We specifically studied the efficiency of parasitoids in locating a host-infested plant when having to pass three other plants that varied in volatile emission by cultivar and herbivore identity. We show that foraging decisions of C. glomerata are affected by the apparency of volatile cues from upwind host-infested plants. We found that parasitoids flew over the first three plants more often when the last plant was a host-infested attractive cultivar and the first three plants were a less attractive cultivar, regardless of the presence of host or nonhost herbivores. Furthermore, parasitoids spent more time on the first three plants if these were infested with host or nonhost larvae, and this effect was stronger when the first three plants were of the attractive cultivar. Our results suggest that parasitoids may more easily locate host herbivores on plant genotypes with more apparent volatile information. However, host location efficiency is affected by the contrast with other plumes of plant volatiles derived from genotypic variation in plants and induction of volatiles by nonhost herbivores. Apparency of information on upwind patches influences patch residence time and patch choice and is an important component of optimal foraging in parasitoids. • Foraging decisions by Cotesia glomerata are affected by the apparency of information. • Profitability of upwind patches affects foraging decisions on the current patch. • Nonhost herbivores with traits similar to the host reduced host location efficiency. • Established parasitoid cultivar preferences are nuanced in complex plant mixtures.

Response of Parasitic Wasp Cotesia glomerata L. (Hymenoptera: Braconidae) to Cabbage Plants of Two Varieties: Olfactory Spectra of Males and Females.

The parasitoid Cotesia glomerata L. (Hymenoptera: Braconidae) oviposits in larvae of the large cabbage white butterfly (Pieris brassicae L.). Many parasitoids are attracted by volatile organic compounds (VOCs) emitted by the plant that the host insects feed on. The objectives of the study were to identify the VOCs in leaves of two varieties of cabbage (white cabbage, Brassica oleracea var. capitata f. alba and cauliflower, B. oleracea var. botrytis) damaged by P. brassicae caterpillars which elicit antennal responses of C. glomerata, and characterize the olfactory spectra of females and males. Leaf extracts were analyzed by using gas chromatography equipped with an electroantennographic detector (GC-EAD) and GC-mass spectrometry. In total, 32 olfactory-active compounds for C. glomerata in cauliflower and 24 in white cabbage were revealed. The females perceived more compounds than males. Hexan-1-ol, (E)-3-hexen-1-ol, (E)-2-octenal, benzylcianide, tetradecanal, and two unidentified compounds elicited EAG responses in females but not in males. Females were more sensitive to (E)-3-hexenal, (Z)-3-hexenal, and pentadecenal, whereas males showed higher sensitivity to (Z)-3-hexenyl butanoate, heptanal, (Δ)-2-pentenal, (E)-2-hexenol, and octanal. The olfactory spectrum of C. glomerata was expanded from 18 to 41 VOCs emitted by different varieties of cabbage damaged by P. brassicae caterpillars. Eight EAG-active VOCs were common for all cabbage varieties. In tritrophic interactions, benzylcyanide can serve as an important signal for C. glomerata females indicating damage of cabbage caused by P. brassicae caterpillars. The data are useful for development of a push-pull strategy for P. brassicae control, based on parasitoid behavior regulation by VOCs.

Parasitoids affect plant responses through their host Pieris brassicae, but not for the benefit of their own performance

Abstract Upon parasitism, many parasitoids inject symbiotic viruses and venom into their host. Thereby, they modify the hosts physiology including its saliva composition and, in turn, plant perception of herbivory. It has been hypothesised that parasitoids manipulate plant responses to increase their host performance and maximise their own fitness. However, it is still unclear whether parasitoids are under selective pressure to increase plant quality or whether indirect changes in plants due to parasitism are a by‐product of the physiological changes induced in their host. We tested whether the parasitoids Hyposoter ebeninus and Cotesia glomerata manipulate induced plant responses through the host Pieris brassicae caterpillars to increase their own performance. During their entire lifespan, parasitised herbivores were fed with leaf material of Brassica oleracea plants that were left untreated or continuously exposed to feeding by either unparasitised, conspecific or heterospecific parasitised caterpillars. We measured the development time, weight, clutch size and mortality of parasitoids that emerged from caterpillars as proxy for their performance. Both parasitoid species did not perform significantly better when their host was fed with leaves from plants continuously induced by a conspecific parasitoid relative to unparasitised caterpillars. However, parasitoid species asymmetrically affected each other's performance through plant‐mediated interactions. Our results do not support the hypothesis of parasitoids manipulating plant responses for their own benefit, suggesting that indirect plant‐mediated interactions among parasitoids may be a by‐product of host manipulation. However, our work confirms the significance of parasitoid‐induced plant‐mediated interactions in insect communities that to date are still understudied.

Identity of wasp parasitoids (Hymenoptera) attacking Pieris brassicae (Linnaeus, 1758) (Lepidoptera: Pieridae) in South Africa

The alien invasive large cabbage white, Pieris brassicae (Linnaeus, 1758) (Pieridae), although introduced into South Africa more than 27 years ago, has not dramatically expanded its distribution, possibly because it is effectively attacked by two parasitoid wasp species. Even though there is a cohort of parasitoid species associated with P. brassicae in the Northern Hemisphere, these are the only two recorded parasitoids in South Africa. We determine these parasitoid wasps as Cotesia glomerata (Linnaeus, 1758) (Braconidae: Microgastrinae) and Pteromalus puparum (Linnaeus, 1758) (Pteromalidae), and provide high resolution images and DNA barcodes to facilitate their recognition. This is the first record of C. glomerata from the Afrotropical region.

Effects of oviposition in a non‐host species on foraging behaviour of the parasitoid Cotesia glomerata

Abstract Parasitoids lay their eggs in or on a host, usually another insect. During foraging, parasitoids can encounter insects that differ in terms of host suitability and quality. At one extreme end of this spectrum are non‐hosts that are unsuitable for offspring development. Non‐hosts are generally ignored but parasitization does occur and occasionally also results in egg deposition. Here, the authors investigate how oviposition in a non‐host influences subsequent foraging behaviour of a parasitoid and whether this is mediated by learning. The study system consists of the endoparasitoid Cotesia glomerata and the presumed non‐host caterpillar Mamestra brassicae. In the presence of Pieris brassicae hosts and/or their traces (frass), C. glomerata inserted its ovipositor into M. brassicae caterpillars. Eggs were deposited, but all eggs disappeared within 96 h, confirming the non‐host status of M. brassicae. In contrast to the expectation, there was no memory retention after oviposition in a non‐host and parasitoids did not alter their behaviour with respect to non‐host contacts and ovipositions. Instead, C. glomerata became more motivated to forage on a non‐host infested leaf. The authors propose that egg deposition in non‐hosts by C. glomerata might be due to their high egg load, which is thought to make parasitoids less selective on host quality, especially when they have few reproductive opportunities. In such cases, fitness costs to individual females are low. Egg deposition in non‐hosts might ultimately lead to host range expansion if parasitoids overcome the defence response of non‐hosts over evolutionary time.

Parasitism by endoparasitoid wasps alters the internal but not the external microbiome in host caterpillars

BackgroundThe microbiome of many insects consists of a diverse community of microorganisms that can play critical roles in the functioning and overall health of their hosts. Although the microbial communities of insects have been studied thoroughly over the past decade, little is still known about how biotic interactions affect the microbial community structure in and on the bodies of insects. In insects that are attacked by parasites or parasitoids, it can be expected that the microbiome of the host insect is affected by the presence of these parasitic organisms that develop in close association with their host. In this study, we used high-throughput amplicon sequencing targeting both bacteria and fungi to test the hypothesis that parasitism by the endoparasitoid Cotesia glomerata affected the microbiome of its host Pieris brassicae. Healthy and parasitized caterpillars were collected from both natural populations and a laboratory culture.ResultsSignificant differences in bacterial community structure were found between field-collected caterpillars and laboratory-reared caterpillars, and between the external and the internal microbiome of the caterpillars. Parasitism significantly altered the internal microbiome of caterpillars, but not the external microbiome. The internal microbiome of all parasitized caterpillars and of the parasitoid larvae in the caterpillar hosts was dominated by a Wolbachia strain, which was completely absent in healthy caterpillars, suggesting that the strain was transferred to the caterpillars during oviposition by the parasitoids.ConclusionWe conclude that biotic interactions such as parasitism have pronounced effects on the microbiome of an insect host and possibly affect interactions with higher-order insects.

Memory extinction and spontaneous recovery shaping parasitoid foraging behavior.

Animals can alter their foraging behavior through associative learning, where an encounter with an essential resource (e.g., food or a reproductive opportunity) is associated with nearby environmental cues (e.g., volatiles). This can subsequently improve the animal’s foraging efficiency. However, when these associated cues are encountered again, the anticipated resource is not always present. Such an unrewarding experience, also called a memory-extinction experience, can change an animal’s response to the associated cues. Although some studies are available on the mechanisms of this process, they rarely focus on cues and rewards that are relevant in an animal’s natural habitat. In this study, we tested the effect of different types of ecologically relevant memory-extinction experiences on the conditioned plant volatile preferences of the parasitic wasp Cotesia glomerata that uses these cues to locate its caterpillar hosts. These extinction experiences consisted of contact with only host traces (frass and silk), contact with nonhost traces, or oviposition in a nonhost near host traces, on the conditioned plant species. Our results show that the lack of oviposition, after contacting host traces, led to the temporary alteration of the conditioned plant volatile preference in C. glomerata, but this effect was plant species-specific. These results provide novel insights into how ecologically relevant memory-extinction experiences can fine-tune an animal’s foraging behavior. This fine-tuning of learned behavior can be beneficial when the lack of finding a resource accurately predicts current, but not future foraging opportunities. Such continuous reevaluation of obtained information helps animals to prevent maladaptive foraging behavior.

A Chromosome-Level Genome Assembly of the Parasitoid Wasp, Cotesia glomerata (Hymenoptera: Braconidae).

Hymenopterans make up about 20% of all animal species, but most are poorly known and lack high-quality genomic resources. One group of important, yet understudied hymenopterans are parasitoid wasps in the family Braconidae. Among this understudied group is the genus Cotesia, a clade of ~1,000 species routinely used in studies of physiology, ecology, biological control, and genetics. However, our ability to understand these organisms has been hindered by a lack of genomic resources. We helped bridge this gap by generating a high-quality genome assembly for the parasitoid wasp, Cotesia glomerata (Braconidae; Microgastrinae). We generated this assembly using multiple sequencing technologies, including Oxford Nanopore, whole-genome shotgun sequencing, and 3D chromatin contact information (HiC). Our assembly is one of the most contiguous, complete, and publicly available hymenopteran genomes, represented by 3,355 scaffolds with a scaffold N50 of ~28 Mb and a BUSCO score of ~99%. Given the genome sizes found in closely related species, our genome assembly was ~50% larger than expected, which was apparently induced by runaway amplification of 3 types of repetitive elements: simple repeats, long terminal repeats, and long interspersed nuclear elements. This assembly is another step forward for genomics across this hyperdiverse, yet understudied order of insects. The assembled genomic data and metadata files are publicly available via Figshare (https://doi.org/10.6084/m9.figshare.13010549).

Multi-camera field monitoring reveals costs of learning for parasitoid foraging behaviour.

Dynamic conditions in nature have led to the evolution of behavioural traits that allow animals to use information on local circumstances and adjust their behaviour accordingly, for example through learning. Although learning can improve foraging efficiency, the learned information can become unreliable as the environment continues to change. This could lead to potential fitness costs when memories holding such unreliable information persist. Indeed, persistent unreliable memory was found to reduce the foraging efficiency of the parasitoid Cotesia glomerata under laboratory conditions.Here, we evaluated the effect of such persistent unreliable memory on the foraging behaviour of C. glomerata in the field. This is a critical step in studies of foraging theory, since animal behaviour evolved under the complex conditions present in nature.Existing methods provide little detail on how parasitoids interact with their environment in the field, therefore we developed a novel multi‐camera system that allowed us to trace parasitoid foraging behaviour in detail. With this multi‐camera system, we studied how persistent unreliable memory affected the foraging behaviour of C. glomerata when these memories led parasitoids to plants infested with non‐host caterpillars in a semi‐field set‐up.Our results demonstrate that persistent unreliable memory can lead to maladaptive foraging behaviour in C. glomerata under field conditions and increased the likelihood of oviposition in the non‐host caterpillar Mamestra brassica. Furthermore, these time‐ and egg‐related costs can be context dependent, since they rely on the plant species used.These results provide us with new insight on how animals use previously obtained information in naturally complex and dynamic foraging situations and confirm that costs and benefits of learning depend on the environment animals forage in. Although behavioural studies of small animals in natural habitats remain challenging, novel methods such as our multi‐camera system contribute to understanding the nuances of animal foraging behaviour.

Environmentally acquired chemical camouflage affects Pieris brassicae L. host plant selection and orientation behaviour of a larval parasitoid

Environmentally acquired chemical camouflage is a phenomenon, where a plant growing close to a strong volatile organic compound (VOC) emitter will adsorb and re-emit the VOCs produced by the neighbouring plant. The re-emitted volatile bouquet may resemble more the VOC composition of the neighbour than plant’s own typical odour, and thus act as chemical camouflage against insect detection, potentially simultaneously providing associational resistance towards herbivory. We exposed a pest-sensitive horticultural crop, Brassica oleracea var. italica (broccoli) cv. Lucky, to the volatiles emitted by Rhododendron tomentosum [RT] twigs and assessed the host selection by ovipositing females and larval instars of the major caterpillar pest Pieris brassicae between RT-exposed and control plants. Potential impact of RT exposure on herbivore natural enemies was studied using behavioural tests with a parasitoid wasp Cotesia glomerata. P. brassicae females laid significantly less eggs and egg clusters were fewer on RT-exposed plants at both night-time (6 °C) and daytime (22 °C) temperatures. Larvae preferred leaves from control plants over RT-exposed plants at both temperatures. Preceding RT-exposure did not disturb orientation of parasitoid wasp Cotesia glomerata females towards B. oleracea plants damaged by its host P. brassicae. However, host-damaged control plants were favoured by the parasitoid over RT-exposed, host-damaged plants. Our results suggest that companion plant based chemical camouflage as a mechanism of pest suppression could be developed as an additional tool for the integrated pest management toolbox in agriculture.

Population dynamics and parasitoid complex of Archips rosana (L.) (Lepidoptera: Tortricidae) in Western Turkey

The rose tortrix moth, Archips rosana (L.) (Lepidoptera: Tortricidae), is a pest that causes serious crop losses in apple orchards throughout the world. In this study, the population dynamics of A. rosana and its associated parasitoids were investigated in two provinces of Western Turkey (Denizli and Usak) in 2018 and 2019. A total of 318 egg masses, 300 larvae, and 129 pupae were collected from the survey areas. Although no parasitoids were detected in egg masses, ten parasitoid species belonging to Braconidae, Chalcididae, and Ichneumonidae (Hymenoptera), and Tachinidae (Diptera), were reared from the samples of larvae and pupae. Phytodietus astutus (Gravenhorst) (Ichneumonidae) was the most abundant parasitoid species, with a relative abundance of 35.1%, followed by Itoplectus maculator (Fabricius) (Ichneumonidae) represented by 27% of the recovered parasitoids. Moreover, P. astutus and Scambus inanis (Schrank) (Ichneumonidae) reared from the samples are the first records from Turkey, while Cotesia glomerata (L.) (Braconidae), Exochus sp.(Ichneumonidae), and Nemorilla maculosa (Meigen) (Tachinidae) are the first records from A. rosana. Using pheromone traps in the apple orchards, the first adult of A. rosana was caught on May 24 in Civril (Denizli) and on May 30 in Sivasli (Usak) in 2019

Defense Traits and Tolerance Strategies of Plants against Herbivores

Plants exposes to various types of biotic and abiotic stresses. It received various signals called Herbivore-associated molecular patterns (HAMPs) and induces defence mechanism against insects. Defense system, by this plant mitigates the adverse effects of herbivore, consisting of various morphological, biochemical, and molecular mechanisms. The trichomes, epidermis, cuticle, and bark tissues are important physical barriers to herbivores. Various secondary metabolites reduces digestibility in insect. The cysteine protease overexpression in maize retard the growth of S. frugiperda. In Arabidopsis, release of green-leaf volatiles by overexpression of hpl gene increases, which increases attraction of parasitoid Cotesia glomerata that increases mortality of larva of Pieris rapae. The application of plant hormones like JA, SA, and Ethylene etc. also induces defence system in the plant against insect. However, the exact defensive mechanism is still not understood. Studying the level of molecular mechanism of induced resistance against insect could be an important tool for the pest management.