Frontiers in insect science最新文献

Honey bees are essential pollinators in global food production, however, their populations are increasingly threatened by insecticides. Protecting bees from these chemical stressors is critical not only for ecosystem stability but also for agricultural sustainability. Natural dietary compounds, such as curcumin (CU) and rosmarinic acid (RA), have demonstrated antioxidant and detoxification-promoting properties in other organisms and may offer a promising approach to enhancing honey bee resilience to pesticide exposure. This study investigates the potential of CU and RA to mitigate pesticide-induced harm in honey bees. In acute toxicity tests, newly emerged bees and foragers were topically exposed to lethal doses of acetamiprid (1.04 µg/bee for newly emerged and 15.3 µg/bee for forager), carbaryl (0.06 µg/bee for newly emerged and 0.51 µg/bee for forager), and flupyradifurone (15.6 µg/bee for newly emerged and 24.1 µg/bee for forager), followed by post-feeding with CU and RA at 50, 100, and 200 ppm for 48h. Additionally, the effects of CU and RA at 100 ppm were tested under chronic oral intoxication through continuous insecticide feeding. CU100 significantly reduced mortality in insecticide-exposed bees, except foragers exposed to acetamiprid, while RA showed variable detoxification effects, with RA100 and RA200 improving survival in carbaryl-exposed bees and RA50 enhancing survival of 0.06 µg/bee for newly emerged bees exposed to flupyradifurone. Chronic toxicity assessments confirmed CU100's superior protective effect over RA100, especially in carbaryl-exposed groups. Gene expression analysis revealed that CU and RA modulated detoxification related genes, enhancing honey bees' resilience by upregulating key detoxification genes in the head and abdomen. These findings suggest that CU and RA offer potential benefits in reducing insecticide toxicity in honey bees. However, further research is needed to assess their effects across different life stages, environmental conditions, and colony dynamics, as well as to elucidate the pathways involved in detoxification gene regulation. A comprehensive understanding of their mechanisms and ecological implications is essential before considering these compounds for practical applications in pollinator health management.

Monochamus saltuarius is an important wood-boring pest of forests and a vector insect for the transmission of Bursaphelenchus xylophilus in China and other East Asian regions. To gain insight into the Mo. saltuarius olfactory system, we characterized the sizes and morphological characteristics of sensilla on antennae, maxillary palps, and labial palps of adults by scanning electron microscopy. Eight types of antennal sensilla were identified on the antennae: Böhm bristles (BBs), sensilla chaetica (SChs, with subtypes SChI and SChII), sensilla trichodea (STs, with subtypes STI, STII and STIII), sensilla auricillica (SAus), sensilla basiconica (SBs, with subtypes SBI and SBII), sensilla grooved peg (SGPs), dome shaped organs (DSOs), and cuticular pores (CPs); among these, BBs, STIs, STIIs, SChIs, and SChIIs may be mechanoreceptors, and STIIIs, SAus, SBIs, SBIIs, SGPs and CPs may be chemoreceptors. Seven sensillum types were identified on maxillary palps and labial palps: BBs, STs (with subtypes STII, and STIII), SChs, sensilla placodea (SPs), sensilla coeloconica (SCos), CPs, and sensilla twig basiconica (STBs, with subtypes STBI, STBII, STBIII, and STBIV), among which BBs, STIIs, and SChs may be mechanoreceptors, and STIIIs, SPs, CPs, STBIs, STBIIs, STBIIIs, and STIVs may be chemoreceptors. DSOs on the antennae and SCos on the palps may be hydroreceptors, and/or thermoreceptors. The types and densities of sensilla increased from the base to the tip of the antennae, and sensilla with chemical-sensing functions were concentrated mostly on the flagellum. Identification of these sensillum types provides a basis for analyzing the mechanisms of host recognition and environmental perception of Mo. saltuarius.

Introduction: The genus Bifidobacterium is a key component of the honey bee gut microbiota, playing a fundamental role in maintaining host health and colony well-being. Alongside other core genera such as Bombilactobacillus, Gilliamella, Lactobacillus, and Snodgrassella, Bifidobacterium contributes to essential functions including nutrient digestion, immune modulation, and protection against pathogens. Among threats to honey bee health, Chalkbrood disease, caused by fungus Ascosphaera apis, remains a major concern due to detrimental effects on colony strength and honey yield.

Materials and methods: We characterized enzymatic activity and carbohydrate assimilation of nine Bifidobacterium strains isolated from the honey bee intestinal tract. In parallel, we assessed antifungal potential against A. apis strains, focusing on volatile organic compounds (VOCs).

Results and discussion: Notably, Bifidobacterium asteroides 3CP-2B exhibited enzymatic capabilities supporting digestive functions and metabolism of sugars potentially harmful to honey bees. This strain showed marked antifungal activity against A. apis, mediated by volatile and non-volatile bioactive metabolites. Among VOCs identified, propanoic acid, ethanol, acetic acid, ethyl propionate, and 1-propanol were the most prominent compounds associated with the antifungal effect.

Spodoptera frugiperda (J.E. Smith), (Noctuidae, Lepidoptera), commonly known as fall armyworm (FAW), is a significant polyphagous pest that can cause considerable damage to various crops. Fundamental research on FAW is crucial and beneficial for creating an integrated management strategy. Lot of literatures are available on web to describe the fitness of FAW via conventional methods that deals the basic biology of FAW. However, there is currently a need to check the fitness for each stage of FAW using an advanced two-sex life table tool, which is crucial for creating efficient control strategies. The proposed study used an age-stage, two-sex life table to examine the lifetable parameters of FAW on four natural hosts: castor beans (Ricinus communis), potatoes (Solanum tuberosum), maize (Zea mays L.), and wheat (Triticum aestivium L.). The findings demonstrated that, despite notable variations in development and reproduction, the FAW completed its life cycle on each of the four studied hosts. The FAW that were fed maize performed at their best, showing shorter immature (egg-pupa) phases, longer lifespans, and better rates of adult reproduction. On maize, female FAW had the highest fecundity (2497.1 eggs/female), while on wheat, it was the lowest (675 eggs/female). With values of 532.8 (offspring individual-1), 0.21d^-1, and 1.23 d^-1, respectively, net reproductive rate, intrinsic rate of increase, and finite rate of increase peaked on maize, while the corresponding parameters were lowest on wheat (94.62 offspring individual^-1, 0.11 d^-1, and 1.12 d^-1, respectively). This study indicates that all host plants can contribute to the development and outbreak of this pest in the absence of its primary host. Therefore, all potential host plants in the area should be thoroughly examined when developing an IPM program against said pest.

The intracellular bacterium Wolbachia pipientis has emerged as a promising tool for controlling mosquito-borne diseases; however, key aspects of its biology remain insufficiently understood, particularly how Wolbachia influences vector competence for certain arboviruses. The main factors implicated are the activation of mosquito antiviral pathways and competition for cellular resources at the viral replication site. Transinfection of Wolbachia strains into vector populations has proven to be an effective strategy for controlling arboviral diseases. Here, we investigate the within-host density and tissue distribution of two naturally occurring Wolbachia strains-wAlbA and wAlbB-n Aedes albopictus from Argentina, where infection patterns diverge from those observed globally. Using quantitative PCR, we assessed symbiont density in ovarian (n = 5) and somatic tissues (n = 5) of adult females, and in adult males across different ages: 0, 5 and 14 days post-emergence (n = 5 per age group). Our results reveal superinfection in ovaries (wAlbA + wAlbB) with similar densities (median relative density _{w AlbA} = 3.78 and median relative density _{w AlbB} = 3.31), but only wAlbB was consistently detected in somatic tissues (median relative density _{w AlbB} = 0.41), suggesting tissue-specific distribution of strains. Additionally, wAlbB density in males remained stable throughout the adult lifespan (median relative density_Time0 = 0.83; median relative density_{time 5} = 1.98; median relative density_{time 14} = 0.66). These findings support the hypothesis that Wolbachia somatic localization is strain-specific and may be under evolutionary selection, with implications for vertical transmission and host fitness. By advancing our understanding of Wolbachia density dynamics in a natural mosquito vector population, this study contributes critical baseline data to inform and optimize Wolbachia-based biocontrol strategies in regions at risk of arboviral outbreaks. Because the wAlbB strain from Ae. albopictus is widely used in replacement techniques, any knowledge of its behavior in natural host populations is valuable.

The broad range of Scolytinae pests sizes and their subtle visual similarities, especially in smaller species, continue to challenge the accuracy of mainstream object detection models. To address these challenges, this paper proposes GIWT-YOLO, a lightweight detection model based on YOLOv11s, specifically tailored for Scolytinae pests detection. (1) We designed a lightweight multi-scale convolution module, GIConv, to improve the model's ability to extract features at different pest scales. This module enhances the accuracy of small-object detection while reducing the computational cost and parameter complexity of the backbone. (2) The WTConv module inspired by wavelet transform is introduced into the backbone. This enlarges the effective receptive field and improves the model's ability to distinguish pests with similar textures. (3) An SE attention mechanism is incorporated between the Neck and Head to enhance the model's focus on key feature regions. Experimental results show that GIWT-YOLO achieves 84.7% in Precision, 88.7% in mAP@50, and 63.4% in mAP@50~95, which are improvements of 2.2%, 4.0%, and 3.1%, respectively, compared to the baseline YOLOv11s. Additionally, the model's parameters and GFLOPs are reduced by 11.3% and 13.4%, respectively. Our proposed model surpasses the state-of-the-art (SOTA) performance in small-sized pest detection while maintaining a lightweight architecture, and its generalization ability has been validated on other public datasets. Our model provides an efficient solution for detecting Scolytinae pests. In future work, we plan to collect additional images of various pest species to expand the dataset, further enhancing the model's applicability to a wider range of pest detection scenarios.

Photoperiod is a critical environmental factor for insect development and physiology, yet little is known about the effects of photoperiodic signals received during photoperiod-sensitive stages on reproductive parameters. The green lacewing, Chrysoperla nipponensis, is a promising candidate for mass rearing in biological control. Photoperiod is the primary environmental factor influencing C. nipponensis reproductive diapause. This study investigates how photoperiodic cues during photoperiod-sensitive stages affect key reproductive parameters such as fecundity, lifespan, oviposition duration, oviposition rate, diapause rate, pre-oviposition period, and lipid content of C. nipponensis. The results showed that short-day conditions (Light:Dark = 9h:15h; L9:D15) during pre-adult stages increase total lipid and triglyceride levels in both third larvae and newly emerged females, thereby enhancing fecundity of female, without reducing lifespan or oviposition. Furthermore, long-day conditions (Light:Dark = 15h:9h; L15:D9) during the pre-adult stage inhibited diapause, while increasing fecundity and extending oviposition duration. Our findings demonstrate that photoperiodic signals during the pre-adult stages significantly affect the reproductive parameters of C. nipponensis, which advances the understanding of photoperiod-dependent reproductive diapause and offers novel insights for optimizing strategies in mass-rearing of natural enemies.

Introduction: The Aedes aegypti constitutes the primary vector for dengue fever, yellow fever, chikungunya, Zika, West Nile, and encephalitis viruses, all of which have impacted One Health (human, animal, and environmental health) significantly. It has been distributed widely in urban settings in Saudi Arabia, particularly in cities like Jeddah and Jizan, a situation that underscores the urgent need for innovative and sustainable vector control strategies. Molecular tools, such as DNA barcoding using mitochondrial markers, have become essential for identifying mosquito species accurately and understanding their role in disease transmission. Such knowledge is vital for informing effective, climate-resilient public health interventions.

Methods: This research focuses on identifying Aedes species in various regions of Saudi Arabia using polymerase chain reaction (PCR) and sequencing techniques, in order to evaluate the molecular diversity of these dengue vectors in Jeddah and Jizan. The study utilizes the cytochrome one oxidase (COI) gene as a molecular marker for phylogenetic analysis to compare the populations of Aedes species.

Results: The findings reveal the presence of significant genetic variation among mosquito populations. In the Jeddah region, the Ae. aegypti types MN299016.1 and KU495081.1 match completely (100%) the respective populations found in Argentina and Australia, with 93.1% (27/29) and 6.9% (2/29) respectively. Meanwhile, the samples from the Jizan region are 100% and 99.6% similar to the Ae. aegypti types MN298998.1, MK300226.1, PP892777.1, and MF043259.1 found in Canada, Kenya, India, and England.

Conclusion: This study underscores the necessity of using molecular techniques in vector surveillance to mitigate the spread of Zoonotic and vector borne diseases in Saudi Arabia. Moreover, these efforts align with the objectives of the Saudi Vision 2030 by promoting environmentally responsive vector surveillance in Jeddah and Jizan, thereby supporting integrated approaches to public health and ecological sustainability.

Over the years, most scholarly published papers have studied vertebrates, despite invertebrates' higher species diversity and number of individuals. This has led to an inaccurate representation of global biodiversity patterns in scientific publications. Furthermore, the bias for studying vertebrates is also evident when comparing studies conducted in the tropics vs. temperate zones. We investigated whether similar taxonomic and geographical biases are maintained in recent years when studying the behavior of Neotropical ants. We searched for papers published between 2015 and 2022 with the words "ant" OR "ants" OR formicidae; tropic* OR neotropic* and behav* AND tropic* OR neotropic*. We found that recently published papers studying ants cover only ~10% of the Neotropical ant species, with a primary focus on economically damaging and/or invasive ants. Our results revealed that studies on ant behavior in the Neotropics are dominated by four species, which represent less than 0.15% of the ant species in the Neotropics, and that 50% of the focal species were mentioned only once or twice in studies regarding behavior. Moreover, recent ant behavior studies cover only approximately 8% of the Neotropical ant biodiversity. We found that the Neotropical countries where most ants have been collected for behavioral studies are Brazil, Panama, and Costa Rica. In contrast, other Central American countries are absent from the recent ant literature. Our results reveal concerning patterns of taxonomic and geographical inequity in the study of Neotropical ant behavior, despite its potential role in managing ant invasions and ensuring effective conservation measures. We highlight the need to broaden behavioral studies in the Neotropics and urge researchers to investigate relatively unknown ant species, and include understudied countries with limited scientific resources to fill this critical gap in current ant research.

Introductiom: Habitat fragmentation alters environmental structure and imposes selective pressures on dispersal-related traits in insect vectors, potentially driving morphological adaptations that enhance flight performance. In this study, weinvestigate how landscape metrics influence the size and shape of the head and wings in two Triatominae species, Triatoma garciabesi and T. guasayana, which present differing ecological strategies. We hypothesize that individuals from more fragmented landscapes exhibit phenotypic shifts associated with enhanced dispersal capacity and increased morphological symmetry.

Methods: To test this, we combined community-based sampling of triatomines with geometric morphometrics and multiscale landscape metrics. We applied geometric morphometrics and generalized linear models (GLM)-based analyses to assess the effects of habitat fragmentation on flight-related morphology.

Results: Our results reveal that T. garciabesi shows increased head asymmetry and narrower wings in highly fragmented landscapes, while T. guasayana exhibits subtle shifts in head shape asymmetry and greater sexual dimorphism. In both species, head and wing sizes tended to be larger in fragmented habitats, especially in females, suggesting differential morphological responses that may reflect species-specific dispersal strategies.

Discussion: Habitat fragmentation differentially affects T. garciabesi and T. guasayana, leading to distinct dispersal syndromes. Triatoma garciabesi shows greater plasticity, highlighting the role of landscape structure in shaping adaptive dispersal traits.