Entomological Research最新文献

The lesser grain borer, Rhyzopertha dominica, is an important pest of various stored products around the world. In this study, the development, survival, reproduction, and life table parameters of R. dominica were investigated on six stored products (angelica, jujube, maize, rice, soybean, and wheat). The developmental time of the immature stage of R. dominica was shortest on wheat (40.20 days) and longest on angelica (67.04 days). The survival rate of the immature stage was highest on wheat (76.33%) and lowest on angelica (41.00%). The fecundity level of R. dominica was highest on wheat (246.05 eggs/female) and lowest on angelica (69.38 eggs/female). The net reproductive rate (R₀) and intrinsic rate of increase (r_m) of R. dominica differed significantly among the six stored products. The highest R₀ of R. dominica was on wheat (68.50), followed by rice (41.28), maize (32.32), soybean (27.17), jujube (23.16), and angelica (20.18); the r_m values showed a similar trend, with values of 0.059, 0.046, 0.042, 0.039, 0.036, and 0.033, respectively. Our results indicate that wheat was the most suitable stored product, whereas angelica was the least suitable, for the feeding, development, and population increase of R. dominica. These findings provide basic information about the occurrence trends and characteristics of R. dominica that will be useful for the control of this pest on different stored products. The physicochemical properties of angelica should be further explored for potential application in the control or integrated management of R. dominica.

Libellula angelina is an endangered dragonfly species that is native to East Asia. Recently, their population has become severely reduced through habitat loss. To protect L. angelina populations, we need to understand which factors determine their distribution and how their potential habitats will change in the future. In this study, the habitat preference of L. angelina was identified through field surveys, and the potential distribution of L. angelina and the impact of integrated climate–land cover changes were simulated using the MaxEnt model. Furthermore, the wetland loss scenario was applied to areas where the current trend in wetland loss will continue in the future. The field survey identified that L. angelina prefers small inland wetlands: permanent freshwater, ponds; permanent rivers, ponds; irrigated land; and estuarine waters. From the MaxEnt results, altitude was the variable with the greatest contribution and distance from wetlands was the most unique variable. MaxEnt described the geographic pattern of occurrences under the current climate well, with few areas requiring any further survey. In the future projection, the potential habitat area was increased by up to 48.8% and 30.6% in the 2050s and 2080s, respectively. However, potential habitat loss was expected if wetlands continue to decline as they have done in the last 20 years. The wetland loss scenario resulted in potential habitat losses of 1.9%–2.3% and 4.5%–6.1% in the 2050s and 2080s, respectively. Therefore, to protect L. angelina populations we must minimize the loss of current populations, secure wetlands and strengthen the connectivity between wetlands.

Mosquitoes (Diptera: Culicidae) are considered to be huge threat among millions of peoples, animals, and other living organisms in the world. Most of the vector borne diseases such as malaria, filariasis, dengue hemorrhagic fever, chikungunya, Japanese encephalitis etc., created huge impact on humans in all over the world. Vector diseases in Kingdom of Saudi Arabia are increasing day by day and their control measures taken through the government sectors for eradicating the vectors helps in controlling the diseases but still more approaches to be implemented or assimilated. Most of the synthetic or chemical based insecticides to control mosquitoes developed resistance among their communities even though they showed their potential in controlling the vector in initial days. Botanical insecticides from plant-based origin such as active compounds, essential oils, green synthesized nanomaterials, and microbial secondary metabolites helps more efficiency in controlling vectors. Mode of action against vectors differs based on its persisting active ingredients, such as larvicidal, pupicidal, adulticidal, oviposition, morphological changes etc. Even though number of research works has been carried out against mosquito species, there is only limited number of studies undergone against mosquito vectors from Saudi Arabia origin. Hence this review will give us the current knowledge on the effectiveness of botanical insecticides against major mosquito vectors from Saudi Arabia. Thus, it gives more significant against medical and veterinary sectors.

The fall armyworm (FAW), Spodoptera frugiperda (Lepidoptera, Noctuidae), has emerged as a highly invasive pest globally in the past decade due to its remarkable migratory capabilities. Magnetic receptors play an important role in the migration and navigation of the animal, but little is known about the molecular mechanism of the magnetic receptors of S. frugiperda (SfMagR). In this study, we successfully cloned the cDNA encoding SfMagR, which has a 396 bp of open reading frame (ORF) encoding 132 amino acids. Phylogenetic analysis revealed a high conservation of magnetic receptors among various animal species, notably demonstrating a 98.4% sequence identity between S. frugiperda and Spodoptera litura, and a 70.3% identity with Homo sapiens, a vertebrate species. Expression analysis conducted across different developmental stages demonstrated SfMagR expression in the egg, larval, and pupal stages of the moth, but exhibited predominate expression in the adult stage, particularly in male adults. Moreover, the tissue expression profile indicated that SfMagR expression primarily occurred within the thorax of the moth, specifically in the thorax excluding the legs and wings. These findings not only provide fundamental data and a molecular foundation for future investigations into the function of SfMagR, but also offer valuable insights for the future management of invasive species.

Chigger mites (Trombiculidae), which are known vectors of Orientia tsutsugamushi, have significantly fewer molecular data available than other known species, with a focus on morphological species identification rather than molecular species identification. However, chigger mites are easily damaged because of small size. In addition, natural variation and adult similarity would interrupt accurate classification and identification. Therefore, in this study, a multiple polymerase chain reaction (PCR) method using the internal transcribed spacer (ITS) region of five frequently occurring species (Euschoengastia koreaensis, Leptotrombidium orientale, Leptotrombidium pallidum, Leptotrombidium palpale, and Leptotrombidium scutellare) among eight species known to mediate the spread of is presented. This is the first report using molecular species identification for the classification method of chigger mites, which was only possible with morphological species identification, and is expected to be used as basic data for vector surveillance.

Entomopathogenic fungi are microorganisms that control the density of host insects in nature; they are being studied as environmentally friendly alternatives to chemical insecticides for controlling insect pests. The main habitat of entomopathogenic fungi is soil, and the correlation between the distribution of entomopathogenic fungi and the physicochemical characteristics of soils planted with different trees, including vine (outdoor, greenhouse, and greenhouse shine musket), apple, peach, and pear, were analyzed. The entomopathogenic fungi of the genera Beauveria, Metarhizium, and Purpureocillium investigated in this study were all found in soil samples from vine-greenhouse, apple, and peach trees. Purpureocillium and Beauveria abundances were positively correlated with soil properties; however, Metarhizium abundances were not correlated with soil properties. The Metarhizium isolates discovered in this study showed pathogenicity to cotton aphids (an agricultural pest) and can be employed as sources for biological studies in the future. This study provides data on the diversity and abundance of entomopathogenic fungi related with soil properties, as well as the molecular, biological, and insecticidal characteristics of Metarhizium isolates.

River ecosystems face growing threats from human-induced stressors, resulting in habitat degradation and biodiversity loss. Crucial to these ecosystems, macroinvertebrates maintain river health and functioning. In this review, we examine the challenges confronting macroinvertebrates, explore restoration strategies and management approaches, and shed light on knowledge gaps and future research directions. Habitat degradation, water pollution, climate change, and invasive species are discussed as key challenges. Various restoration strategies, such as in-stream habitat restoration, flow regime restoration, riparian zone restoration, and connectivity restoration, are evaluated for macroinvertebrate conservation. Integrated catchment management, adaptive management, community-based management, monitoring, and policy integration are highlighted as essential management approaches, and knowledge gaps in long-term monitoring, innovative restoration techniques, climate change resilience, and policy incorporation are identified as areas calling for further research. Ultimately, a proactive, adaptable, and cooperative approach to river management will ensure macroinvertebrate conservation and sustainable river ecosystems.

Cotesia plutellae, an endoparasitoid wasp is the natural enemy against the diamondback moth, Plutella xylostella. Successful parasitization of C. plutellae requires maternal factors such as polydnavirus, venom proteins, and ovary proteins into the host, protecting their eggs from the host's immune system. To identify the immune-related genes from the venom glands, we analyzed the transcriptome of venom glands via RNA-seq. RNA-seq analysis reveals that 39,207 transcripts were identified. Totally 106 immune-related genes such as peptidoglycan-recognition proteins, serpins, spätzles, phenoloxidase, defensin, and calreticulin, etc. were identified and classified into pathogen recognition, immune signal modulation, Toll pathway, IMD pathway, effectors, and other immune genes, depending on their biological functions. These results suggest that the transcriptome of the venom glands of C. plutellae can expand the understanding of insect immune response.

The melon fruit fly, Zeugodacus cucurbitae (Coquillett), is an important polyphagous pest that damages to various agricultural crops, whose distribution has become global as a result of human activity. In this study, we investigated the fecundity, pre-oviposition and oviposition periods, and the longevity of adult Z. cucurbitae at various constant temperatures ranging from 15 to 35.2°C. One newly emerged one virgin female and two males of Z. cucurbitae were used, and the longevity of both sexes and the fecundity of the females were examined daily. The longevity of female Z. cucurbitae ranged from 183.8 days at 15.0°C to 30.8 days at 35.2°C, and the maximum fecundity per female was 1204 eggs at 24.5°C. The lower development threshold (LDT) and thermal constant (K) of females were estimated as 14.8°C and 781.13 degree-days, respectively. Female reproduction was modeled using a two-phase oviposition model. Oviposition was estimated using females in the oviposition phase, which had a complete pre-oviposition phase. The oviposition model consisted of two reproductive components (total fecundity and age-specific cumulative oviposition rate during oviposition) and a survival component (age-specific survival rate). The daily egg production of Z. cucurbitae was estimated in relation to adult age and temperature.

Scrub typhus, transmitted through chigger mite bites, is a febrile disease associated with agricultural activities and primarily occurs in autumn. To address the increasing number of cases with scrub typhus over the past 3 years, we analyzed activity, visit history, and occupation data of 12,462 cases reported to the Korea Disease Control and Prevention Agency (KDCA) between January 2019 and December 2021. We examined changes in incidence and general characteristics by visualizing the incidence and eschar bite locations using population data and a geographic information system. Gyeongsangnam-do had the highest overall incidence rate (22.7%), followed by Jeollanam-do (19.0%) and Jeollabuk-do (11.2%), during the study period. However, when considering the incidence rate per 100,000 people, Jeollanam-do had the highest number of cases at 129.1, followed by Gyeongsangnam-do (85.1 cases) and Jeollabuk-do (78.1 cases). Most cases were women (61.0%) in their 70s (28.4%), and the highest incidence occurred in the agricultural worker group during autumn (October–December). Bites occurred most frequently in the abdomen (18.1%), and fever (79.2%) and muscle pain (49.8%) were the main symptoms. We also found a positive correlation (r = 0.848) between chigger mite populations and disease outbreaks over 3 years. In conclusion, it is crucial to provide education on identifying the habitats of chigger mites and rodents (vectors), as well as the appropriate application of repellents. Promoting awareness and preventive measures against infectious diseases is of utmost importance for rural areas and the general public who frequently come into contact with natural environments.