Control Agents Research Articles

Optimizing Delegation in Collaborative Human-AI Hybrid Teams

When humans and autonomous systems operate together as what we refer to as a hybrid team, we of course wish to ensure the team operates successfully and effectively. We refer to team members as agents. In our proposed framework, we address the case of hybrid teams in which, at any time, only one team member (the control agent) is authorized to act as control for the team. To determine the best selection of a control agent, we propose the addition of an AI manager (via Reinforcement Learning) which learns as an outside observer of the team. The manager learns a model of behavior linking observations of agent performance and the environment/world the team is operating in, and from these observations makes the most desirable selection of a control agent. From our review of current state of the art, we present a novel manager model for oversight of hybrid teams by our support for diverse agents and decision-maker operations across multiple time steps and decisions. In our model, we restrict the manager’s task by introducing a set of constraints. The manager constraints indicate acceptable team operation, so a violation occurs if the team enters a condition which is unacceptable and requires manager intervention. To ensure minimal added complexity or potential inefficiency for the team, the manager should attempt to minimize the number of times the team reaches a constraint violation and requires subsequent manager intervention. Therefore, our manager is optimizing its selection of authorized agents to boost overall team performance while minimizing the frequency of manager intervention. We demonstrate our manager’s performance in a simulated driving scenario representing the case of a hybrid team of agents composed of a human driver and autonomous driving system. We perform experiments for our driving scenario with interfering vehicles, indicating the need for collision avoidance and proper speed control. Our results indicate a positive impact on our manager, with some cases resulting in increased team performance up to \(\approx 187\%\) that of the best solo agent performance.

Isolation and characterization of halophilic Bacillus thuringiensis from local Egyptian sites and their potential against Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae)

Abstract Background Bacillus thuringiensis (Bt) serves as a peculiar soil microbe that is Gram-positive, rod-shaped, spore-forming, and aerobic facultative. It endures across a range of conditions and has been demonstrated to be an effective biological pest control agent against several insect pests. The main objective of the study is to isolate and recognize Bt bacteria from saline environments in Egyptian soil for biological surveillance uses. Results Isolates three, four, five, ten, eleven, twelve, and thirteen were found to be moderately tolerant, while isolate eight showed highly tolerant, but isolate six was found to be borderline extreme halophile. On the other hand, the other isolates showed extreme halophiles. To find out the presence of crystals, a scanning electron microscope was carried out and the result showed that the crystals ranged from spherical to bi-pyramidal spherical. Molecular analysis was carried out using universal primers to confirm the presence of cry genes. The results showed that 84.6% of the isolates contain cry seven and eight, whereas cry one and four are distributed by 92.3%. Cry two genes were found to be 100 percent in all tested and isolated cultures. Cry genes were present and distribution among isolated was detected using gene-specific primers. cry3Ba1 and cry8B showed the lowest and equal distribution among the isolates, while the cry2Ab2gene frequency distribution was (84.6%) among isolated cultures. Around six cry genes were found to be absent in all isolated cultures. The bioinsecticidal activity and bioassays were carried out to check the potential effect of halophilic Bt isolates against 1st instar larvae of the Fall Armyworm (FAW) Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae). Mortality was calculated after infecting S. frugiperda with thirteen Bt isolates. The most virulent Bt isolate was isolate 7, followed by isolate 10, with LC50 values of 9.542 × 107 spores/ml and 1.289 × 108 spores/ml, respectively, after 72 h. Morphological traits of the larvae were carried out, to check the effect of Bt isolates as a biological control against the FAW. Conclusion To protect and enhance the sustainability of field crops and vegetables, especially in new high salinity lands, from disease-causing insects such as FAW, it is necessary to identify new strains of Bt from these saline lands. In this field, local isolates of Bt from several regions in Egypt known for their high levels of salinity were documented and showed an effective bioinsecticide on FAW larvae.

Testing the efficacy of Trichogramma ostriniae (Hymenoptera: Trichogrammatidae) as a inundative biological control agent in Western Nebraska.

The western bean cutworm (Striacosta albicosta) is a primary pest of corn and dry edible bean, for which control measures are often warranted. Inundative releases of Trichogramma ostriniae have been used to control lepidopterous pests, such as the European corn borer (Ostrinia nubilalis), in eastern North America (e.g., New York, Virginia). However, no prior field studies have assessed T. ostriniae as a biological control agent in the North American Great Plains. Objectives for this study were (i) to determine the suitability of S. albicosta as a host for T. ostriniae and (ii) to assess the feasibility of T. ostriniae as a biological control agent of S. albicosta in Nebraska corn and dry edible bean fields. Dispersal and parasitism were monitored with yellow sticky cards and sentinel egg masses (O. nubilalis, S. albicosta, and Ephestia kuehniella) at 36 locations surrounding a central release point. Trichogramma ostriniae adults tended to be concentrated near the point of release. However, egg parasitism was so low that the minimum rates of T. ostriniae needed for effective control could not be determined. Our evidence indicates that the low parasitism measured in this study may indicate low suitability of T. ostriniae to Western Nebraska and, possibly, the Great Plains.

Curcuma longa essential oil as an acaricidal agent for the control of cattle ectoparasitic tick - Rhipicephalus (Boophilus) annulatus.

well known for its insecticidal, anti-inflammatory, antioxidant, anticancer, anti-rheumatic and antibiotic properties, Turmeric (Curcuma longa L.) Essential oil (EO), is effective in repelling and controlling many different pest species. The present study evaluates in vitro efficacy of turmeric EO against ectoparasitic tick, Rhipicephalus (Boophilus)annulatus collected from their natural host, domesticated cows. Repellency and toxicity of the EO on ectoparasitic ticks was analyzed with petri dish choice bioassay and AIT (Adult immersion test) against adult engorged females and nymphal stages of ticks. The Repellency Concentration (RC50) and Lethal Concentration (LC50) reproductive index, inhibition of oviposition and egg hatchability of treated ticks were estimated. GC-MS analysis identified Ar-turmerone as the major phytochemical, which induces adulticidal and repellant properties of EO. The nymphal stages of the ticks exhibited greater repellency on application of EO than the adult stage. Also, EO induced effective mortality in adult ticks. Further, this lethal concentration is capable of producing a decreased output in reproductive parameters namely, fecundity, % of oviposition and egg hatchability in surviving ticks thereby considerably reducing Rhipicephalus (Boophilus)R(B). annulatus population on its host. This study reveals the potency C. longa EO to be used as an effective pest control agent against R (B). annulatus infestation that can serve as an alternative to synthetic pesticides.

Forming of modern Russian youth’s social representations about maintaining health: condition and problems

The article deals with the study of health maintaining among Russian youth. Based on data from all-Russian surveys and presented in relevant studies, the contradictions between the value perception of health and destructive health practices among young people were found. In this regard, based on the understanding of health conservation as a purposeful activity, in the structure of which the cognitive component plays a significant role, the author underlines to study young people’s ideas about health and health caring in order to realise the reasons of differences between the state of health and the attitude of Russian youth. In this regard, the author conducted a study of the structure of social ideas of young Russians. The theoretical basis of the study was the key provisions of the concept of social representations by S. Moscovici. The empirical basis was the data of the author’s empirical study “Health Saving of Modern Russian Youth: Ideas and Practices”. Based on the results of the study, it was established that the core of modern youth’s social ideas about health conservation are traditional images and ideas that reflect the most characteristic of Russian society and its health conservation culture, but in a limited format. The peripheral zone includes components such as breaking bad habits, well-being, and maintaining emotional stability. The least characteristic of young Russians is the connection between ideas about health and health preservation with institutional practices of clinical examination and preventive examinations, which suggests a decrease in the role of the medical institute as an agent of social control in relation to health in the ideas of the younger generation. Thus, the social ideas of young Russians about health and the practices of its preservation, along with traditional ideas, are distinguished by features, the formation of which, according to the author, is due to the influence of new agents of healthy lifestyle socialization and the online-sources

The impact of humidity on the functional response of Blattisocius Mali (Acari: Blattisociidae) preying on the acarid mite Tyrophagus putrescentiae.

Humidity influences the life table parameters and foraging behaviours of various terrestrial arthropods. The soil mite, Blattisocius mali Oudemans is a potential biological control agent of some acarid mites, moths, and nematodes. In the current study, we investigated the functional response of B. mali preying on the eggs of the mould mite Tyrophagus putrescentiae Schrank (Acari: Acaridae) at different humidity levels between 33% and 92%. To determine the type of functional response, we used logistic regression and a generalized functional response equation suggested by Real. The functional response parameters were estimated using models proposed by Hassell and Cabello et al. Blattisocius mali exhibited Type II functional response at 33% and Type III at other tested humidities (52%, 72%, 82%, and 92%). The potential for prey mortality (α) was the highest, i.e., 0.05923, and the handling time was the shortest, i.e., 0.00463day, at 92% humidity, indicating the highest efficiency of B. mali at this humidity. Our findings revealed that B. mali was more efficient at higher humidity levels as compared to lower humidity levels. Humidity affected the predation rate and might have played an important role in stabilizing the predator-prey system by shifting the functional response with humidity.

Sex-ratio distortion in a weed biological control agent, Ceratapion basicorne (Coleoptera: Brentidae), associated with a species of Rickettsia.

Many endosymbionts of insects have been shown to manipulate and alter their hosts' reproduction with implications for agriculture, disease transmission, and ecological systems. Less studied are the microbiota of classical biological control agents and the implications of inadvertent endosymbionts in laboratory colonies for field establishment and effects on target pests or nontarget organisms. While native-range field populations of agents may have a low incidence of vertically transmitted endosymbionts, quarantine and laboratory rearing of inbred populations may increase this low prevalence to fixation in relatively few generations. Fixation of detrimental endosymbionts in founding biological control agent populations prior to release may have far-reaching effects. Significant female-biased sex-ratio distortion was found within laboratory populations of the weevil Ceratapion basicorne (Illiger), a classical biological control agent that was recently approved for use against yellow starthistle (Centaurea solstitialis L.). This sex-ratio distortion was observed to be vertically inherited and reversible through antibiotic treatment of the host insect. Molecular diagnostics identified a Rickettsia sp. as the only bacterial endosymbiont present in breeding lines with distorted sex ratios and implicated this as the first reported Rickettsia associated with sex-ratio distortion within the superfamily Curculionoidea.

Isolation and identification of antifungal, antibacterial and nematocide agents from marine bacillus gottheilii MSB1.

Pathogenic fungi employ numerous strategies to colonize plants, infect them, reduce crop yield and quality, and cause significant losses in agricultural production. The increasing use of chemical pesticides has led to various ecological and environmental issues, including the emergence of resistant weeds, soil compaction, and water pollution, all negatively impacting agricultural sustainability. Additionally, the extensive development of synthetic fungicides has adverse effects on animal and human health, prompting the exploration of alternative approaches and green strategies for phytopathogen control. Microorganisms living in sponges represent a promising source of novel bioactive secondary metabolites, potentially useful in developing new nematicidal and antimicrobial agents. This study focuses on extracting bioactive compounds from endosymbiotic bacteria associated with the marine sponge Hyrtios erect sp. (collected from NIOF Station, Hurghada, Red Sea, Egypt) using various organic solvents. Bacillus sp. was isolated and identified through 16S rRNA gene sequencing. The biocidal activity of Bacillus gotheilii MSB1 extracts was screened against plant pathogenic bacteria, fungi, and nematodes. The n-butanol extract showed significant potential as a biological fungicide against Alternaria alternata and Fusarium oxysporum. Both n-hexane and ethyl acetate extracts exhibited negative impacts against the plant pathogenic bacteria Erwinia carotovora and Ralstonia solanacearum, whereas the n-butanol extract had a positive effect. Regarding nematicidal activity, ethyl acetate and n-butanol extracts demonstrated in-vitro activity against the root-knot nematode Meloidogyne incognita, which causes serious vegetable crop diseases, but the n-hexane extract showed no positive effects. The findings suggest that bioactive compounds from endosymbiotic bacteria associated with marine sponges, particularly B. gotheilii MSB1, hold significant potential as alternative biological control agents against plant pathogens. The n-butanol extract, in particular, displayed promising biocidal activities against various plant pathogenic fungi, bacteria, and nematodes. These results support further exploration and development of such bioactive compounds as sustainable, environmentally friendly alternatives to synthetic pesticides and fungicides in agricultural practices.

Diversity of Diptera and their parasitoids associated with Inga vera Willd. (1806) (Fabaceae) with new host record in Minas Gerais, Brazil

Diptera belonging to four different families, as well as four associated parasitoids were reared from fruits of Inga vera Willd. (Fabaceae) in Lavras, Minas Gerais, southeast Brazil. We collected 450 fruits from five trees of I. vera between 2020 and 2021 in various localities situated within the University Federal of Lavras. We reared specimens belonging to four different dipteran families: Anastrepha distincta Greene (Tephritidae), Asteromyia sp. (Cecidomyiidae), Drosophila zottii Vilela (Drosophilidae), and Neosilba pendula (Bezzi) (Lonchaeidae). Lopheucoilasp.(Hymenoptera: Figitidae) probably is a parasitoid of N. pendulawhereas Eupelmus sp. (Hymenoptera: Eupelmidae), and two species of Sycophila (Hymenoptera, Eurytomidae) appear to be parasitoids of Asteromyia sp.. We additionally conducted molecular characterization using the DNA barcoding locus for the majority of the species reared in this study. This study provides valuable insights into the biology and ecology of frugivorous flies in Brazil, and sheds light on potential biological control agents, enabling better management practices.

Characterization of autochthone biological control agents for pear protection against the brown spot of pear disease caused by Stemphylium vesicarium

AbstractStemphylium vesicarium is an important phytopathogen for many plant species, that switches between necrotrophic and saprophytic lifestyles. In the last decade, it has severely affected pear production worldwide, causing the so-called brown spot of pears (BSP), which led to the replacement of several pear orchards in northern Italy with consequent important economic losses. In the field, the management of the disease still relies on fungicide application, though several resistant genotypes of the pathogen emerged through the years. In the present study, three different bacterial species have been isolated from an infected orchard and evaluated as potential biological control agents (BCAs) against a local isolate of Stemphylium vesicarium. Two bacterial isolates belonging to the Bacillus genus demonstrated a significant ability to inhibit S. vesicarium growth in vitro, both through direct antagonism and the emission of volatile organic compounds (VOCs). The cell-free supernatant from one of these isolates exhibited a strong biocontrol activity, particularly through compounds extracted in acidic conditions. The protective effectiveness of the two most promising BCAs was further validated on detached pear fruits infected with S. vesicarium. Overall, the findings suggest that these two BCAs have the potential to be developed into a bio-based alternative to fungicides to control BSP, thus contributing to a more sustainable pear production.

Parasitism by Aleiodes ceres Shimbori, 2023 (Hymenoptera: Braconidae) of three species of Spodoptera Guenée, 1852: effects of preferential instar and host diet

AbstractA recently discovered koinobiont parasitoid species, Aleiodes ceres Shimbori, 2023, proved to be a promising biological control agent for larvae of Spodoptera cosmioides (Walker, 1858), S. eridania (Stoll, 1782), and S. frugiperda (J.E. Smith, 1797), all well-known pests that cause critical damage to soybean and corn crops. This study investigated the potential of parasitism by A. ceres in these three species, including different instars (1st, 2nd, 3rd, and 4th instar) and diets (artificial and natural). Parasitism was highest when it occurs in the second instar for all three host species. The egg-to-pupa period of A. ceres was shorter in the second and third instars in relation to the first instar. Parasitism was substantially enhanced by the use of natural diets (soybean and corn leaves) compared with the artificial diet in all three species of the Spodoptera complex, suggesting a possible allelochemical interaction. Based on the results from the three host species, the potential for control of Spodoptera spp. by A. ceres was evident.

Pioneering Innovations in Biological Weed Control: A Comprehensive Review

The biological method of weed control is an effective option. Before implementing bio-agents, there is a need for a better understanding of the mechanisms involved in interactions by multiple agents against weeds. This covers knowledge of how plants integrate and prioritize their responses to multiple attackers. Across the globe, terrestrial ecosystems are known to be characterized by a huge diversity of species and a corresponding diversity of interactions between these species. These include species of different trophic levels of habitats on the same food chain. Plants undoubtedly play significant role as intermediaries in interactions between the insect and microbial populations with which they are involved. Plant interactions brought forth by one species can have cascading impacts on other species, influencing their abundances and the composition of communities. Several research efforts are underway to develop highly effective biological control agents to reliably control a problematic broad spectrum of weeds. Sustainable and ecosystem-compatible weed management for controlling weeds by biological means, such as insects, bio-agents, myco-herbicides and harmful Rhizobacteria. Their interaction with cultural practices and allelochemicals are some biological components of sustainable agriculture. Hence, biological agents enhance efficiency and restrict the detrimental effect of weeds compared to weeds being left alone. The challenge is to identify appropriate microbe/bioagents, which reduce weed growth. Logically, biological weed management is the only way to control weeds in eco-friendly weed management.

Ultrabright and Efficient Green Perovskite Light-Emitting Diodes Enabled by Well-Crystallized Dense CsPbBr3 Nanocubes.

Perovskite light-emitting diodes (PeLEDs) are promising for next-generation high-definition displays. One of the keys to achieving high performance PeLEDs lies in how to fabricate crystalline and dense perovskite films. However, there exist challenges to directly grow well-crystallized CsPbBr3 nanocrystal thin films on transport layers due to low solubility in solvents and fast precipitation of all-inorganic CsPbBr3, and the corresponding bright, efficient, and stable green PeLEDs have rarely been reported. Herein, we report an efficient strategy to prepare well-crystallized and dense CsPbBr3 nanocubes for ultrabright and efficient green PeLEDs. We introduce sulfobetaine zwitterion as crystallization control agent and strontium fluoride nanocrystals as nucleation seeds to grow high-quality CsPbBr3 nanocube films. Eventually, the CsPbBr3 films enable green PeLEDs with a maximum luminance of 162 767 cd m-2 and a champion external quantum efficiency of 21.3% along with a narrow spectral line width of ∼14.7 nm, representing state-of-the-art performances in green PeLEDs.

Using ecological niches to determine potential habitat suitability for Psacothea hilaris (Coleoptera: Cerambycidae) and its natural enemies in China under future climates.

Climate change impacts the distribution of pests and its natural enemies, prompting this study to investigate the dynamics and shifts in distribution under current and future climate conditions. The spatial pattern of Psacothea hilaris (Pascoe) (Coleoptera: Cerambycidae) in China was analyzed, and the MaxEnt model was optimized to predict the potential geographic distribution of P. hilaris and its two natural enemies (Dastarcus helophoroides (Fairmaire) (Coleoptera: Bothrideridae) and Dendrocopos major (Linnaeus) (Piciformes: Picidae)) in China, to further analyze the key environmental factors affecting the survival of P. hilaris and its natural enemies, and to determine the potential of using D. helophoroides and D. major as natural enemies to control P. hilaris. The results showed that the suitable ranges of P. hilaris and natural enemies are expanding under the influence of climate change, and both have migrated to higher latitudes. The potential ranges of D. helophoroides, D. major, and P. hilaris are highly similar. It is noteworthy that the potential range of D. helophoroides completely covers the potential range of P. hilaris. This indicates that D. helophoroides and D. major can be employed as biological control agents to manage P. hilaris populations. This study provides a theoretical framework and empirical evidence for the development of early warning and green control strategies for P. hilaris.

Isolation and Evaluation of Indigenous Isolates of Beauveria bassiana and Synergistic Control of Spodoptera frugiperda with the Parasitoid Microplitis prodeniae

Entomopathogenic fungi (EPFs) are capable of infecting a variety of insect pests and are widely used as biopesticides worldwide. This study intended to isolate indigenous EPFs from cadavers of Protaetia brevitarsis and investigate their effects on the fall armyworm Spodoptera frugiperda (FAW), a globally widespread invasive pest. Morphological and molecular analyses confirmed four native EPF strains all belong to Beauveria bassiana. Pathogenicity tests showed they were virulent toward FAW 1st instar larvae. The application of EPFs either by dipping or spraying significantly increased the larval mortalities compared to the control group, with corrected mortalities ranging from 92% to 73% after dipping in a fungal suspension of 108 conidia/mL, and those ranging from 76% to 35% after spraying with a fungal suspension of 107 conidia/mL. Our findings revealed the infectivity of four strains to FAW larvae significantly changed in a dose- and time-dependent manner. In addition, the combination use of the local B. bassiana strain and parasitoid Microplitis prodeniae resulted in a significantly enhanced S. frugiperda 3rd instar larval mortality compared to a single inoculation with one of them, suggesting an apparent synergistic effect for the joint application of these two biological control agents. The mortality inflicted by B. bassiana was probably promoted by the release of parasitoids, since the parasitoids’ movements and attacks could strengthen the fungal distribution and infection processes. This study underscores the potential of the combination use of EPFs and parasitoids against S. frugiperda early-instar larvae, and provides insights into the consequences of integrating these EPFs into integrated pest management systems.

Virome of red imported fire ants by metagenomic analysis in Guangdong, southern China

The red imported fire ant (RIFA) has made China its habitat for approximately 25 years, but few reports have described the species and amount of virus circulating in it. Researchers are currently exploring viruses associated with RIFAs as potential biological control agents against invasive ants. The present meta-transcriptome analysis revealed the virome of red imported fire ants in Guangdong, southern China, which included 17 viruses, including Solenopsis invicta virus 4-GD (SINV-4) and Guangdong Polycipiviridae ant virus 1 (GPAV1) in the Polycipiviridae family; Solenopsis invicta virus 1-GD (SINV-1), and Guangdong Dicistroviridae ant virus 2-3 (GDAV2-3) in the Dicistroviridae family; Guangdong Iflaviridae ant virus 4-9 (GIAV4-9) in the Iflaviridae family; Guangdong Parvoviridae ant virus 10 (GPAV10) in the Parvoviridae family; and Guangdong ant virus 11-15 (GAV11-15). A total of 15 novel viruses and 2 known viruses were identified in this study. These findings reveal the virome of red imported fire ants in Guangdong Province and present a different result from that of a similar study reported in the United States, providing more choices for potential classical biological control agents against red imported fire ants in China.

Research on Crack Sealing Performance of Polymer Microsphere/Hydrogel Composite System

Owing to their excellent water-absorption and swelling properties, polymer microspheres have been extensively applied as deep profile control agents in oilfields. These microspheres effectively seal large pore-throat channels in reservoirs, optimizing the water-absorption profile. In this study, a composite system was developed, comprising polymer microspheres and polyacrylamide polymers, with the inclusion of a cross-linking agent. The system leverages the synergistic effects of polymer microspheres and other plugging techniques to efficiently seal fractured reservoirs. Results indicate that the composite system exhibits strong blocking and scour resistance due to enhanced network integrity, higher viscosity, and improved elastic strength. Additionally, the composite system demonstrates a notable self-repairing capability, maintaining a high sealing efficiency even after a waterflood breakthrough.

Biocontrol Potential of a Native Trichoderma Collection Against Fusarium oxysporum f. sp. cubense Subtropical Race 4

The Canary Islands lead banana (Musa acuminata) production in the EU. Different fungal pathogens affect this crop in subtropical areas, with Fusarium oxysporum f. sp. cubense subtropical race 4 (Foc-STR4) being the most important in the Canary Islands. With the aim of developing environmentally sustainable techniques for disease control, this study presents the results of the evaluation of the antifungal capacity of a native Trichoderma collection (12 species, 109 isolates) obtained from banana soils. The results demonstrate the diversity of biocontrol genes and the in vitro antagonistic potential of different native Trichoderma species/isolates against two Foc-STR4 strains obtained from plants with Panama disease symptoms. Trichoderma virens (TF18), a dominant species in banana soils in the Canary Islands, showed a high capacity to inhibit the growth of Foc-STR4 in different in vitro assays. Trichoderma atrobrunneum (TF01) showed mycoparasitism capacity through the spiral coil around the hyphae of the pathogen. In addition, the genome analysis of T. atrobrunneum (TF03) showed 69 putative biosynthetic gene clusters, with the notable presence of the trichothecene tri5 gene. Finally, our work demonstrates that the soils of the Canary Islands banana crops are a potential source of environmentally adapted biological control agents to control or reduce the incidence of Foc-STR4.

Female contact sex pheromone recognition in the German cockroach (Blattella germanica) is mediated by two male antennae-enriched sensory neuron membrane proteins.

The German cockroach Blattella germanica is a notorious urban health pest that has developed resistance to multiple pesticides. Thus, novel non-lethal pest control agents are urgently needed. Olfaction interference via disruption of sex pheromone recognition-related genes offers a promising approach. The German cockroach has a unique courtship behavior in which female adults emit contact sex pheromones (CSPs) in response to antennal touching, which subsequently triggers distinctive male sex behavioral responses. Due to the limited volatility of CSPs, the molecular mechanisms underlying their recognition and the specific olfactory pathways activated remain poorly defined. Although the odorant receptor coreceptor (Orco) is critical for most insect olfaction, sensory neuron membrane proteins (SNMPs), in particular SNMP1, also play crucial roles in sex pheromone recognition in moths and flies. While multiple SNMP1 homologs have been identified in multiple insect species, they have yet to be fully functionally characterized in cockroaches. In this study, RNA-interference (RNAi)-mediated knockdown of BgerOrco reduced both the electrophysiology responses and courtship behaviors of males, indicating CSP perception proceeds via an olfaction pathway. Similar RNAi knockdown of BgerSNMP1e and BgerSNMP1d, which are predominantly expressed in male antennae, revealed critical roles in perceiving the major component of the Blattella germanica CSP blend. Unlike BgerSNMP1e, BgerSNMP1d was also found to function in the perception of the minor CSP component. Molecular docking analyses revealed no differences in the binding affinities of BgerSNMP1d for the major and minor CSP components, whereas the binding affinities of BgerSNMP1e displayed clear selectivity for the major component. Our results show that the olfactory pathway is critical for CSP recognition and that two male-enriched SNMP genes, BgerSNMP1e and BgerSNMP1d, are crucial factors mediating the male response to CSP stimulation in German cockroaches. This study lays a foundation for studying the mechanisms of CSP recognition and provides novel molecular targets with potential to be exploited as disruptors of courtship behavior. © 2024 Society of Chemical Industry.

Temperature-Dependent Pupation Depth in the Oriental Fruit Fly Bactrocera dorsalis and Its Implications for Biological Control

The oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae), is a notable agricultural pest that undergoes pupation in the soil. Mortality risk from predation and parasitism decreases as the depth of the pupal location increases from the ground surface, with a one-centimetre increase in depth causing a significant change. Soil properties, such as moisture and hardness, influence pupation depth, but the effect of temperature has not been fully tested. This laboratory study examined whether a biologically important variation in pupation depth (e.g., one centimetre) is caused by naturally experienced temperature variations (20 to 35 °C) in B. dorsalis. The temperature–pupation depth relationship revealed a unimodal pattern, with the deepest pupation occurring at intermediate temperature levels and shallower pupation at the two extreme temperature ranges. Strong quantitative effects were observed, with the highest mean pupation depth of 40.8 mm at 27.5 °C and the lowest mean pupation depth of 15 mm at 35 °C. The observed quantitative effect suggests that temperature can strongly affect pupal mortality from predators and parasitoids by influencing pupation depth. Future studies that reveal the ability of biological control agents to forage underground for pupae at different temperatures are awaited, as this is key information for evaluating the effectiveness of these agents.