Parasitism Rates Research Articles

Biological reinforcement learning simulation for natural enemy -host behavior: Exploring deep learning algorithms for population dynamics

This study introduces a simulation of biological reinforcement learning to explore the behavior of natural enemies in the presence of host pests, aiming to analyze the population dynamics between natural enemies and insect pests within an ecological context. The simulation leverages on Q-learning, a reinforcement learning algorithm, to model the decision-making processes of both parasitoids/predators and pests, thereby assessing the impact of varying parasitism and predation rates on pest population growth. Simulation parameters, such as episode count, duration in months, steps, learning rate, and discount factor, were set arbitrarily. Environmental and reward matrices, representing climatic conditions, crop availability, and the rewards for different actions, were established for each month. Initial Q-tables for parasitoids/predators and pests, along with population arrays, were used to track population dynamics.•The simulation, illustrated through the Aphid-Ladybird beetle interaction case study over multiple episodes, includes a sensitivity analysis to evaluate the effects of different predation rates.•Findings reveal detailed population dynamics, phase relationships between predator and pest populations, and the significant influence of predation rates.•These insights contribute to a deeper understanding of ecological systems and inform potential pest management strategies.

Variable Rates of Parasitism on Ornate Box Turtles (Terrapene ornata) in Eastern Kansas by the Chelonian-Specific Ectoparasite Cistudinomyia cistudinis

Variable Rates of Parasitism on Ornate Box Turtles (Terrapene ornata) in Eastern Kansas by the Chelonian-Specific Ectoparasite Cistudinomyia cistudinis

An Effective Fluorescent Marker for Tracking the Dispersal of Small Insects with Field Evidence of Mark-Release-Recapture of Trissolcus japonicus.

Understanding insect dispersal helps us predict the spread of insect pests and their natural enemies. Dispersal can be studied by marking, releasing, and recapturing insects, known as mark-release-recapture (MRR). MRR techniques should be convenient, economical, and persistent. Currently, there are limited options for marking small parasitoids that do not impact their fitness and dispersal ability. We evaluated commercially available fluorescent markers used in forensics. These fluorophores can easily be detected by ultraviolet (UV) light, requiring minimal costs and labor to process the marked specimens. This fluorophore marking technique was evaluated with the pest Drosophila suzukii and three parasitoids: Trissolcus japonicus, Pachycrepoideus vindemiae, Ganaspis brasiliensis (=G. kimorum). We evaluated the persistence of the marks on all the insects over time and examined the parasitoids for impacts on longevity, parasitism, locomotor activity, and flight take-off. The green fluorophore marker persisted for over 20 days on all four species. Marking generally did not consistently reduce the survival, parasitism rate, locomotor activity, or take-off of the parasitoids tested. Marked T. japonicus were recaptured in the field up to 100 m away from the release point and three weeks after release, indicating that this technique is a viable method for studying parasitoid dispersal.

Morphological and biological characteristics of Eriborus sp. (Hymenoptera: Ichneumonidae), a parasitoid wasp of Cydalima perspectalis (Lepidoptera: Crambidae).

The box tree moth (BTM), Cydalima perspectalis Walker, is a pest that infests various plants within the Buxus genus. Although a specific parasitoid wasp species associated with the BTM has been observed in the Republic of Korea, no research on this species has been published. Here, we describe the fundamental morphological and biological characteristics of this parasitoid. We have identified the wasp as belonging to the genus Eriborus (Hymenoptera: Ichneumonidae: Campopleginae). Eriborus sp. parasitizes within the living host body, with 1 wasp emerging from each host. The parasitism rate observed in collected BTM populations was 33.1%. The emergence rate was 87.1%, with all emerging adults being females, resulting in a sex ratio of 0. The pupal period avg 9.5 days, and the adult lifespan avg 10.5 days. Eriborus sp. parasitized BTM larvae from the first to the fourth instar and reproduced by thelytokous parthenogenesis. Eriborus sp. exhibited morphological differences compared with previously reported Eriborus species in Korea, particularly in the length of the ovipositor sheath. Additionally, the proportion of the highest similarity in nucleotide sequences of mitochondrial cytochrome oxidase I DNA was only 94.53%, rendering species identification using GenBank's mt cytochrome c oxidase 1 DNA sequences unfeasible. These data suggest that Eriborus sp. could be used as a biological control agent for managing BTM infestations.

Attracting Scelionidae egg parasitoids to enhance stink bug egg parasitisation in soybean crops using methyl salicylate and (E,E)-α-farnesene.

Plant volatile organic compounds (VOCs) play a crucial role in mediating interactions between plants, herbivores and natural enemies. Among these VOCs, methyl salicylate and (E,E)-α-farnesene are emitted as herbivore-induced plant volatiles (HIPVs) by soybean plants in response to feeding by the brown stink bug Eushistus heros. These HIPVs function as synomones, influencing the foraging behaviour of the egg parasitoid, Telenomus podisi, the main natural enemy of E. heros, one of the major soybean pests in Brazil. Laboratory experiments showed that two soybean cultivars, BRS 7580 and BRS 7880, produced similar qualitative blends of HIPVs, with methyl salicylate, (E,E)-α-farnesene and (Z)-3-hexenyl acetate being produced by both cultivars. Soybean cultivar BRS 7580 produced a significant lower amount of HIPVs compared to BRS 7880 but this difference did not affect the attractiveness of the egg parasitoid Telenomus podisi. Field experiments using these two cultivars and synthetic applications of methyl salicylate and (E,E)-α-farnesene showed a substantial increase in egg parasitism in all treated areas. Parasitism rates ranged from 50% to 80% in areas where these HIPVs were deployed, compared to only 10% in untreated control areas. The egg parasitoid Telenomus podisi demonstrated an adept ability in recognising between HIPVs in soybean blends, even in the presence of significant quantitative differences. The results from the field experiment showed the potential of HIPVs in attracting natural enemies to specific target areas within fields. (E,E)-α-Farnesene showed an improved action during the later stages of soybean growth, notably at R6. In addition, this volatile attracted other families of natural enemies. © 2024 Society of Chemical Industry.

Differential responses of Meloidogyne spp. to Pasteuria isolates over crop cycles

In the present study examining the interaction between Meloidogyne spp. and Pasteuria isolates over three crop cycles, significant differences were observed in eggmass production, root galling, plant root weight, endospore production, and parasitism rates. Higher eggmass production was noted in the Meloidogyne blend treatment, whereas M. incognita showed a marked decline after the third cycle. Root galling varied significantly with nematode populations and Pasteuria isolates, showing notable interaction effects (P0.01). The Meloidogyne blend treatment exhibited the highest gall rating, while M. javanica and M. incognita treatments with Pp3 and PpEcu isolates resulted in lower galling. Fresh root weights of tomato plants differed significantly in the presence of Meloidogyne spp. and Pasteuria isolates, with significant interactions observed (P0.05). Greater root weights were recorded in M. javanica and M. incognita treatments with Pp3 and PpEcu isolates. The production of Pasteuria endospores in Meloidogyne females also showed significant variability across crop cycles (P0.01), with M. incognita and PpEcu treatments yielding the highest endospore numbers. Moreover, parasitism of Meloidogyne females by Pasteuria was significantly influenced by nematode population and isolate presence (P0.01). Higher numbers of infected M. incognita females were found in PpEcu treatments. Final female populations of Meloidogyne spp. varied significantly under Pasteuria influence, with the Meloidogyne blend treatment showing the highest population and M. incognita under PpEcu the lowest. The results highlight the complex interactions between nematodes and the bacteria, emphasizing the potential of Pasteuria isolates to influence various aspects of Meloidogyne spp. development.

Odorant-binding protein CrufOBP1 in Cotesia ruficrus females plays a pivotal role in the detection of Spodoptera frugiperda larvae

Cotesia ruficrus presents a promising local natural enemy for controlling the invasive fall armyworm Spodoptera frugiperda in China. However, the mechanisms underlying how C. ruficrus locates its target pest remain unclear. In this study, we analyzed the expression patterns of 18 CrufOBPs across different developmental stages of C. ruficrus, and found that CrufOBP1 exhibited consistent and high expression levels in female adults. CrufOBP1 transcript was predominantly localized in sensilla placodea and sensilla trichodea on the antennae. Additionally, we confirmed the binding properties of CrufOBP1 protein to various cuticular compounds of S. frugiperda larvae. Subsequent electroantennogram and behavioral assays revealed that 1-(2-hydroxy-5-methylphenyl)-ethanone attracted female C. ruficrus, consequently increased the parasitism rate. However, upon silencing CrufOBP1, females exhibited reduced attraction towards 1-(2-hydroxy-5-methylphenyl)-ethanone, indicating the crucial role of CrufOBP1 in the chemoreception of C. ruficrus. These findings shed light on the kairomone-based mechanism employed by C. ruficrus to locate S. frugiperda larvae and hold a promise for the development of environmentally friendly pest management strategies.

Lack of impact of Wolbachia on foraging behavior and morphological characteristics of the parasitoid wasp, Habrobracon hebetor (Braconidae)

Wolbachia are the most widespread intracellular alphaproteobacteria in insects with a variety of phenoptypic effects on the fitness and reproduction of their host, but much less is known about how these bacteria affect host behavior. In this study, we asked whether Wolbachia affects the foraging behavior of the parasitoid wasp Habrobracon hebetor (Hym.: Braconidae), an important biological control agent of many lepidopteran larvae. To test this, we analyzed the functional and numerical responses of Wolbachia-infected and uninfected (tetracycline cured) wasps, as well as morphological parameters. Functional response analysis showed Holling type II responses in both the Wolbachia-infected and uninfected females. The handling time and searching efficiency of Wolbachia-infected and uninfected females were similar, although the estimated maximum parasitism rate was shorter in infected females. Regardless of Wolbachia infection status, there was a negative non-linear relationship between the number of larvae parasitized by a female and an increase in the host density, reflecting a decrease in the total number of eggs laid. Our results also showed that Wolbachia had no effect on morphological traits of the parasitoid wasp. Together, these results suggest that Wolbachia which are prevalent in H. hebetor have limited impact on foraging behavior and morphology.

Studies of certain parameters affecting two parasitoid species, Trichogramma evanescens Westwood and Trichogrammatoidea bactrae Nagaraja (Hymenoptera: Trichogrammatidae), on egg host, Sitotroga cerealella (Olivier) (Gelechiidae: Lepidoptera)

BackgroundTwo Trichogramma spp., Trichogramma evanescens Westwood and Trichogrammatoidea bactrae Nagaraja (Hymenoptera: Trichogrammatidae), were studied to control one of the most cereal pests attacking various grains, Sitotroga cerealella (Olivier) (Gelechiidae: Lepidoptera). Experiments were carried out to evaluate S. cerealella egg-ages, parasitoids’ emergence time and cold storage host eggs on rearing the two tested parasitoids’ spp.ResultsThe age of S. cerealella eggs had significantly influenced the parasitization and adult emergence rates of the two parasitoid species. Parasitism rate resulted from old host eggs (32 h old) (44.93%) decreased than those of the fresh ones (2 h old) (95.85%). Emergence rate ranged between (62.64–97.85%) for T. evanescens and (62.90–95.54%) for T. bactrae from different S. cerealella egg-ages (0–32 h). Regardless to late emerged parasitoids, their population affected. T. evanescens parasitized rate ranged (73.79–95.06%), which comparatively lower than those of T. bactrae (88.81–96.90%), at parasitoid emerging times (0–64 h), respectively. Emergence times had significantly differences in the emergence rate of T. evanescens and/or T. bactrae. On the other hand, percentage of parasitism of the non-stored S. cerealella eggs was higher than the other cold-stored ones. The emergence rate of adult parasitoids, T. evanescens (66.00–91.16%) and T. bactrae (71.16–94.11%), was decreased at the cold storage durations (5–40 days) increased. In comparison to the tested biological aspects between the two parasitoid species, non-significant differences were recorded, at the three assessment parameters, which include host egg-ages, parasitoid emergence time and cold-stored eggs. Meanwhile, there were significant differences between F1 emerged rates for T. evanescens and T. bactrae obtained at each of the three tested parameters.ConclusionIt was concluded that low emergence time of the parasitoids, T. evanescens and T. bactrae, was relatively more effective when they parasitized the fresh egg-age and less cold storage periods of S. cerealella.

Damage and Entomophagy in Natural Infestations of Spodoptera frugiperda (Lepidoptera: Noctuidae) in Maize Landraces in Oaxaca, Mexico1

Abstract The fall armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), seriously damages maize (Zea mays L.) crops in tropical, subtropical, and temperate zones of Mexico and around the world. This study was conducted to evaluate the damage caused by S. frugiperda to six native maize populations and the natural parasites of S. frugiperda in three localities from Oaxaca, Mexico. Two native maize populations each of the Zapalote Chico, Bolita, and Conico-Chalqueño races were used. Plantings were done at Coatecas Altas, Santa Lucia Miahuatlan, and Villa de Zaachila under a randomized complete block design with four replications. The agroecological conditions of cultivation influenced the damage caused by S. frugiperda and influenced its natural parasitism. The ordered weighted mean damage in the localities was Villa de Zaachila (1.40–4.92) > Coatecas Altas (1.33–4.06) > Santa Lucia Miahuatlan (0.53–1.00). The order of parasitism rates in the localities was Villa de Zaachila (56.16%) ≈ Santa Lucia Miahuatlan (37.59%) > Coatecas Altas (14.27%). Zapalote Chico populations were less damaged by S. frugiperda larvae and flowered earlier than did the Conico-Chalqueño and Bolita populations. Thirteen parasitoid species and nematodes were recorded attacking S. frugiperda. Chelonus insularis Cresson was the most abundant parasitoid species across the locations. Members of 17 families of predators and 12 families of parasitoids also were identified as potential natural enemies of S. frugiperda. The population dynamics of this armyworm were determined by the environmental conditions of the location, maize population, transition from the vegetative to the reproductive stage, and presence of natural enemies, whereas natural parasitism was influenced only by location.

Silicon Fertilization Improves Sunflower Rhizosphere Microbial Community Structure and Reduces Parasitism by Orobanche cumana Wallr.

Sunflower broomrape (Orobanche cumana Wallr.) has severely restricted the development of the sunflower industry in China, and more efficient and convenient control methods are urgently needed. In this experiment, we investigated the effects of N, P and silica fertilizers on the parasitism rate of O. cumana, as well as on the yield of sunflower and native microbial communities in the field. Firstly, pot experiments were conducted to select the most effective fertilization method and to determine the physiological and biochemical indexes of sunflowers. Subsequently, field application studies were carried out to determine the physiological indexes, yield, O. cumana parasitism on sunflower, and the effect on the indigenous microbial community. The results demonstrate that compared with the CNP treatment (Control), the number of parasites under the N1P5 treatment significantly decreased by 66.15%. The exogenous application of silica can significantly reduce the number of O. cumana parasites. The treatments with N1P5 (N/P = 1:5) and available SiO2 content higher than 40 mg/kg (NS2, NS3, SF2 and SF3) significantly increased superoxide dismutase (SOD) activity and decreased malondialdehyde (MDA) content in sunflower leaves. In the field, fertilization significantly decreased the number of O. cumana parasites. The S treatment improved the native microbial community structure and enriched beneficial microorganisms, including Vicinamibacteria and Pyrinomonadaceae. Additionally, applying the S treatment significantly increased sunflower yield by 23.82% and crude protein content by 20.20%. In summary, the application of silicon fertilizer can effectively improve the host microbial community, reduce O. cumana parasitism and improve the yield and quality of sunflower.

Weather Parameter’s Impact on Natural Parasitization by Campoletis chlorideae Uchida in Chickpea Ecosystem - New Alluvial Zone of West Bengal

Background: A major biotic constraint in chickpea (Cicer arietinum L.) production is gram pod borer, Helicoverpa armigera (Hübner). However, the population of this pest is reduced to some extent by a solitary endo-larval parasitoid, Campoletis chlorideae Uchida under field conditions. Climate change has a greater impact on natural enemies’ effectiveness used in field-level pest management. Therefore, the present study was conducted to understand the impact of weather factors on C. chlorideae parasitization rate of H. armigera in chickpea grown in the new alluvial agro-climatic zone of West Bengal. Methods: Chickpea was grown in a randomized complete block design (RCBD) with three replications during Rabi 2017-18, 2018-19 and 2019-2020, at Mondouri farm, Bidhan Chandra Krishi Visawavidayala, Mohanpur, West Bengal. To know the most significant weather parameter which influences C. chlorideae parasitization or parasitoid incidence, H. armigera larvae (2nd instar) collected from the field experiment were reared until cocoon formation and parasitization % was correlated with weather parameters and subsequently subjected to stepwise regression analysis. Result: The larval endo-parasitoid, C. chlorideae marked its first appearance from 3rd SMW after the appearance of H. armigera and its activity was high (68% to 72% parasitization) during the flowering to pod initiation stage and thereafter declined gradually. Among the weather variables, only temperature (maximum and minimum) had a consistent and significant negative correlation with C. chlorideae incidence and was responsible for nearly 50% C. chlorideae incidence. An increase in 1°C temperature results in a decrease of 4% parasitoid incidence. Thus, climate change in the near future will have a considerable influence on the overall survival, development and rate of parasitization of parasitoids.

Direct effects of barley yellow dwarf virus on the performance, parasitoid resistance, and feeding behavior of its vector Sitobion avenae (Hemiptera: Aphididae).

The complex interaction between plant viruses and their insect vectors is the basis for the epidemiology of plant viruses. The 'Vector Manipulation Hypothesis' (VMH) was proposed to demonstrate the evolution of strategies in plant viruses to enhance their transmission to new hosts through direct effects on insect vector behavior and/or physiology. However, the aphid vectors used in previous studies were mostly obtained by feeding on virus-infected plants and as a result, it was difficult to eliminate the confounding effects of infected host plants. Furthermore, the mechanisms of the direct effects of plant viruses on insect vectors have rarely been examined comprehensively. We fed Sitobion avenae on an artificial diet infused with a purified suspension of Barley yellow dwarf virus (BYDV) PAV strain to obtain viruliferous aphids. We then examined their growth and reproduction performance, resistance to the parasitoid Aphidius gifuensis Ashmead, and feeding behavior. The results indicate that (1) viruliferous aphids had a shorter life span and a lower relative growth rate at the nymphal stage; (2) A. gifuensis had a lower parasitism rate, mummification rate, and emergence rate in viruliferous aphids; (3) Viruliferous aphids spent more time on non-probing and salivation behavior and had a shorter total duration of penetration and ingestion compared with healthy conspecifics. These results suggest that plant virus infection may directly alter vector fitness and behavior that improves plant virus transmission, but not vector growth. These findings highlight the mechanisms of VMH and the ecological significance of vector manipulation by plant viruses, and have implications for plant virus disease and vector management. © 2024 Society of Chemical Industry.

Proactive biological control of spotted lanternfly: Parasitism and host feeding behavior of Anastatus orientalis (Hymenoptera: Eupelmidae) on Lycorma delicatula (Hemiptera: Fulgoridae) egg masses

Lycorma delicatula (Hemiptera: Fulgoridae) is a recognized threat to perennial vine, tree crops, and forest ecosystems. Native to China, L. delicatula has invaded eastern Asian countries (The Republic of Korea [i.e., South Korea] and Japan) and is spreading rapidly through the eastern and mid-western regions of the USA. Stablished populations in these regions present a significant incursion threat to California’s multi-billion-dollar perennial crops (e.g., grape and nut production). As a part of a proactive classical biological control program targeting L. delicatula in California, USA, the egg parasitoid, Anastatus orientalis (Hymenoptera: Eupelmidae), is being evaluated for possible use against this pest should it establish in California. In support of this proactive research, the oviposition and host feeding behavior of A. orientalis was investigated. The effect of time exposure (i.e., 48-, 72-, 96-, 168-hours) on the percentage of eggs parasitized by 7-day old female parasitoids previously exposed to L. delicatula egg masses in presence/absence of a conspecific male was also investigated. Parasitism rates were significantly higher after 96 h of exposure time and offspring sex ratio did not change in any of the treatments (i.e., exposure time, presence/absence of a male). In another experiment, mated and unmated female parasitoids of three different ages (i.e., ≤ 24-, 72- and 120 h of age) were digitally video recorded for 24 h while foraging on L. delicatula egg masses and host use behaviors were quantified. Anastatus orientalis females that were 72 h old (mated) and 120 h (mated and unmated) spent significantly more time antennating and probing/ovipositing in L. delicatula egg masses than younger unmated females. An increase in host feeding behavior was always associated with increased oviposition behavior. No detrimental effects of host feeding on rates of parasitism and A. orientalis offspring emergence were detected. This finding confirms that A. orientalis is a concurrent parasitoid and can use the same host egg for feeding and parasitism. Implications of these results on possible rearing and release strategies of A. orientalis as a biological control agent of L. delicatula are discussed.

Making shelter for enemies: parasitoid-induced shelter-building behaviour in Paraponyx stagnalis

ABSTRACT Manipulative parasitoids manipulate the behaviour of their hosts in such a way as to benefit their own offspring. Paraponyx stagnalis Zeller is a leaf case worm caterpillar pest of rice and pupates in cases made out of cut leaf blades. These shelters are typically open-ended tubular cases. Its solitary primary endoparasitoid – Apanteles sp. – triggers changes in the way it sews the cases. The observed changes in the folded leaf shelter may serve various functions for the developing parasitoid, such as minimising the risk of hyperparasitism and predation, and enhancing structural stability. To obtain evidence to support these hypotheses, we (1) documented the morphotype of the cases/puparia constructed by unparasitised and parasitised P. stagnalis larval instars, (2) studied the overall rate of primary parasitism of P. stagnalis by Apanteles sp. and (3) studied the rate of hyperparasitism of primary parasitoids in 10 rice fields of south India. Unlike the unparasitised third-instar host larvae, the parasitised larvae sealed the open ends of the folded leaf shelter with silken threads, affixed the puparium to rice leaves and made small cases. The overall parasitism rate was about 40%. However, the hyperparasitism was between 0.6 and 1%. Though the primary parasitism by Apanteles sp. is considerably higher in all 10 fields, the meagre incidence of hyperparasitism strengthens our hypothesis that the modified puparium construction might be triggered by the primary parasitoid and beneficial for the offspring of the primary parasitoid. Our field observations suggest that future experimental studies can bring mechanical evidence for host manipulation by Apanteles sp.

Intestinal Parasitic Infections and Associated Risk Factors Among Sudanese Psychiatric Patients.

Intestinal parasitic infections (IPIs) are considered to be a major health problem, particularly in the tropical countries, such as Sudan. Due to poor hygiene practices, the psychiatric patients may pick up parasitic infections. Until now, there exists no published data or available information regarding the prevalence rate of intestinal parasitic infections among Sudanese psychiatric patients. Therefore, our present study aimed to determine the prevalence of intestinal parasitic infections and the potential associated risk factors among Sudanese psychiatric patients. A hospital based cross-sectional study was conducted from September 2021 to March 2022. A total of 422 stool samples were randomly collected from psychiatric patients attending the psychiatric section at Kosti Teaching Hospital in the White Nile State of Sudan. Socio-demographic data were gathered using structured questionnaires. All stool samples were examined using different parasitological techniques. The overall prevalence rate of intestinal parasitic infection among psychiatric patients was 120/211 (56.8%) and among non-psychiatric patients 66/211 (31.3%) The prevalence rate of intestinal parasites (IPs) among psychiatric patients were as follows: Entamoeba histolytica (29.9%), Giardia lamblia (19.4%), Entamoeba coli (5.2%), Ascaris lumbricoides (0.9%), Hymenolepis nana (0.9%), and Enterobius vermicularis (0.5%). There was no relationship between intestinal parasitic infection and age, sociodemographic features, sources of drinking water, contact with domestic animals, washing of hands, eating of raw vegetables/meats, or having psychiatric disorders (p > 0.05). Studying the prevalence rate of intestinal parasitic infections among psychiatric patients may help to assess their health condition or status, leading to better psychiatric healthcare services, diagnoses, and treatments.

New parasitoids of Spodoptera frugiperda in Lampung Province, Indonesia

Lampung Province is one of the largest maize producers in Indonesia. The invasion of Spodoptera frugiperda into Indonesia led to damage in maize, thereby impacting production. In the invaded area, native natural enemies also played a role in controlling the population of S. frugiperda. Therefore, the exploration and identification of parasitoids associated with S. frugiperda were necessary to determine potential control strategies. Four species of parasitoids were discovered emerging from S. frugiperda larvae collected from four maize production areas in Lampung Province, Indonesia, i.e. Lampung Timur, Pesawaran, Pringsewu, and Lampung Selatan. The parasitation rate ranges from 3.17 to 4.81%. Morphological observations confirmed that the parasitoids belonged to the genera Senometopia (Diptera: Tachinidae), Eriborus (Hymenoptera: Ichneumonidae), Chelonus (Hymenoptera: Braconidae), and Drino (Palexorista) (Diptera: Tachinidae). Additionally, Cytochrome C Oxidase Subunit I (COI) sequence analysis revealed that the parasitoids were identified as Senometopia illota, Genus nr. Eriborus sp., Chelonus formosanus, and Drino (Pelexorista) sp. Senometopia illota and Genus nr. Eriborus sp. are newly recorded as parasitoids of S. frugiperda. This finding will provide valuable information concerning the global diversity and distribution of parasitoids, including Indonesia, as well as a basis for determining appropriate control strategies for S. frugiperda.

Gastrointestinal Helminths in Wild Felids in the Cerrado and Pantanal: Zoonotic Bioindicators in Important Brazilian Biomes.

Environmental changes in the Brazilian Pantanal and Cerrado facilitate the spread of parasitic diseases in wildlife, with significant implications for public health owing to their zoonotic potential. This study aimed to examine the occurrence and diversity of gastrointestinal parasites in wild felids within these regions to assess their ecological and health impacts. We collected and analyzed helminth-positive samples from 27 wild felids using specific taxonomic keys. Diverse parasitic taxa were detected, including zoonotic helminths, such as Ancylostoma braziliense, Ancylostoma caninum, Ancylostoma pluridentatum, Toxocara cati, Toxocara canis, Dipylidium caninum, Taenia spp., Echinococcus spp., and Spirometra spp. Other nematodes, such as Physaloptera praeputialis and Physaloptera anomala, were identified, along with acanthocephalans from the genus Oncicola and a trematode, Neodiplostomum spp. (potentially the first record of this parasite in wild felids in the Americas). Human encroachment into natural habitats has profound effects on wild populations, influencing parasitic infection rates and patterns. This study underscores the importance of continuous monitoring and research on parasitic infections as a means of safeguarding both wildlife and human populations and highlights the role of wild felids as bioindicators of environmental health.

Nutrients and drought alter tri‐trophic interactions in cool‐temperate forests

Abstract Herbivorous insects are the main consumers in forest ecosystems, and the complexity of trophic interactions varies with resource availability, heterogeneity among feeding guilds and the presence of natural enemies. In this study, we examined tri‐trophic interactions in Nothofagus pumilio (Fagales: Nothofagaceae) Poepp. & Endl. Krasser forests in southern South America. Specifically, we focused on the effect of nitrogen addition and a drought event on levels of insect herbivory by different feeding guilds and the rate of parasitism on leaf miners throughout the growing season (middle and late). Nitrogen (N) addition increased the foliar nitrogen content but had no effect on total damage by arboreal insects. However, the different feeding guilds responded differently to nitrogen addition, and these responses varied between average or dry year and within the growing season. Particularly, miner activity responded positively to nitrogen addition, increasing their incidence towards the late season of the average year. The positive effect of nitrogen addition on miner activity did not cascade up to the trophic level of parasitoids, which varied with the climatic context and the growing season. These results suggest that tri‐trophic interactions were mainly controlled by the climatic context, since consumers and their natural enemy responses were more dependent on the climatic context and growing seasons than on plant quality. Overall, we highlight the role of fluctuating abiotic resources and the heterogeneity within each trophic level in structuring tri‐trophic interactions in forest ecosystems.

OsRCI-1-Mediated GLVs Enhance Rice Resistance to Brown Planthoppers.

Green leaf volatiles (GLVs) play pivotal roles in plant anti-herbivore defense. This study investigated whether the rice 13-lipoxygense gene OsRCI-1 is involved in GLV production and plant defense in rice. The overexpression of OsRCI-1 (oeRCI lines) in rice resulted in increased wound-induced levels of two prominent GLVs, cis-3-hexen-1-ol and cis-3-hexenal. In a previous study, we found that the overexpression of OsRCI-1 reduced the colonization by the rice brown planthopper (BPH, Nilaparvata lugens) but increased the attractiveness to the egg parasitoid Anagrus nilaparvatae compared to wild-type (WT) plants. This study found that when cis-3-hexen-1-ol, but not cis-3-hexenal, was added to WT plants, it could change the BPH's colonization preference, i.e., more BPHs preferred to colonize the oeRCI lines. The exogenous application of cis-3-hexen-1-ol or cis-3-hexenal to BPH-infested WT plants could weaken or overturn the preference of A. nilaparvatae for oeRCI lines. However, field experiments revealed that only cis-3-hexenal was attractive to the parasitoid and increased the parasitism rates of BPH eggs. These results indicate that OsRCI-1 is involved in rice GLV production and therefore modulates both direct and indirect defense in rice.