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- P-ISSN2765-2203
- E-ISSN2765-2211
- KCI Candidate
Abstract
Forensic entomology is a field of study that includes the succession of insects attracted to and found on cadavers. One of its main focusses is estimating post-mortem interval (PMI) based on the growth stage of insects found in and around human cadavers. In many countries, the diversity of insect occurrence is studied in relation to the environmental conditions a cadaver may be exposed to or the effects of different clothes. In this study, changes in the decomposition process and differences in insect succession were investigated by comparing skinned and intact water deer carcasses. Five orders, 15 families, and 21 species of insects were identified, most of which were Dipteran and Coleopteran. The skinned carcass decomposed more rapidly than the intact carcass, which was linked to differences in insect succession. The difference in the decomposition rate and insect succession according to the external conditions of the carcass can be used as basic data for estimating the PMI of the carcass and setting the forensic entomological indicator species.
Abstract
Harmful pet insects, if not controlled, can negatively affect people, plants and their surrounding environment. In Vietnam, all crops are regularly impacted by pest insects. In serious cases, crops can be totally destroyed by insect pests. Harmful insects that damage crops often grow fast and increase rapidly. Therefore, research on insects is crucial for managing pests, protecting crops, and forecasting pest situation in the following years. This study aimed to collect data regarding changes of pests on rice and corn as two main crops in four provinces in Red River Delta of Vietnam, including Thai Binh, Nam Dinh, Ha Nam, and Hung Yen, from 2018 to 2022. Primary data were collected from reports of government agencies and official statistics. Based on these data, this study evaluated changes of pest insects in five years, discussed reasons for such changes and response methods, and forecasted pest’s behavior in the following years. Significant findings of this study include the fact that Vietnam has to face many difficulties to develop its agricultural sector. For insect management, an essential action is to do ground surveys to gather all related data including weather data, pesticide data, crop yield, and product quality. This information is meaningful for finding out causes of changes, understanding relationships between insects and surrounding factors, and predicting the situation in the following years.
Abstract
The study investigated species diversity, relative abundance, and decline of flying insects and plants within a fragmented forest in the Federal University of Technology Akure (FUTA), Ondo State, Nigeria. It is known that habitat fragmentation can reduce biodiversity. Thus, it is important to perform comprehensive assessments to understand implications of the habitat fragmentation for flora and fauna. Species richness and abundance of flying insects and plants across fragmented forest patches were quantified using field surveys and taxonomic identification. This study revealed shifts in species diversity, with fragmented areas exhibiting reduced biodiversity compared to contiguous forest ecosystems. Flying insects crucial for ecosystem functioning and pollination services demonstrated decreased species richness and relative abundance within fragmented habitats. This decline was attributed to habitat loss, altered microclimates, and limited movement pathways known to hinder insect dispersal. Similarly, plant species richness and abundance showed decline in fragmented forest due to disrupted mutualistic interactions with pollinators, altered nutrient cycling, and increased competition among plant species. This study underscores the importance of maintaining intact forest habitats to sustain healthy ecosystems and preserve biodiversity. Effective conservation strategies should focus on habitat connectivity, reforestation efforts, and protection of essential ecological corridors to mitigate effects of fragmentation. In conclusion, this investigation provides empirical evidence for effects of habitat fragmentation on flying insects and plants in a forest ecosystem in FUTA Akure, Nigeria. Findings emphasize an urgency of adopting conservation measures to safeguard these invaluable components of biodiversity and ecosystem stability in the face of ongoing habitat loss and fragmentation.
Abstract
The analysis of seven islands in Gogunsan archipelago, Korea with insect fauna and vascular plant flora was carried out based on a field survey conducted in May, July, and September. As a result, a total of 2,817 insect individuals including 264 species and 315 taxa of vascular plant were recorded. Bangchukdo the largest island among the seven islands showed the largest number both insect species and plant taxa. The similarity analysis suggested that the nearness of each island strongly affected the insect fauna and vascular plant flora on each island. In addition, there was significant correlation between the areas of each island and the numbers of insect species (Spearman’s correlation coefficient=0.857, P-value=0.014). In the future, the results of this study can be used as data related to island ecology and conservation.
Abstract
In this study, the distribution, bait preference, hosts, symbionts, habitat status, and cytochrome c oxidase subunit-I sequences of the ant Linepithema humile were analyzed. This species habitat comprised approximately 1.5 km along stone crevices, flower gardens, roadsides, and container yards in the vicinity of Busan station, Korea. Feeding activity of this species was confirmed in 9 species of 7 families of plants. Which was approximately 14% of total flora (63 species of 37 families) in the studied area. Particularly, it was observed that Dendranthema indicum and Camellia japonica were the most frequently visited. Further, we verified that they interacted with four species of aphids. We identified 22 species of ants (17 genera, 4 subfamilies) inhabiting the Busan station area, including L. humile, Tetramorium tsushimae, Nylanderia flavipes and the alien species Paratrechina longicornis. In areas where L. humile was the dominant species, the habitat of local native ants was reduced by approximately 30%. Bait preference was ranked in the following order: jelly, water with glucose (25%), and yogurt, with the highest preference for baits containing sugar and protein. The 630-bp cytochrome c oxidase subunit-I sequences of the local L. humile populations were 99% identical to those of L. humile in the National Center for Biotechnology Information database, and the Argentine ants that invaded Korea had a sequence identical to that of other invasive populations from China, Japan, and New Zealand. As L. humile rapidly increases due to domestic adaptation, continuous monitoring and control strategy for eradication are needed to protect domestic biodiversity.
Abstract
This study was performed to assess Protaetia brevitarsis larva excrement as an organic fertilizer for corn cultivation. Furthermore, the study investigated insect communities in each treatment. In 2009, the corn growth rate was worst in soil treated with P. brevitarsis larva excrement and in 2010, the corn growth rate was worst in untreated soil. From the outcome of the study, P. brevitarsis larva excrement could be utilized as organic fertilizer for corn cultivation.
Abstract
Living modified organisms (LMOs) are managed by seven government agencies according to their use in South Korea. The Ministry of Environment is responsible for LMOs used for environmental remediation. This study aimed to develop guidelines for assessing potential risks posed by transgenic plants used for remediation to insect ecosystems by investigating arthropod communities in sunflower fields. A total of 2,350 insects and spiders belonging to 134 species of 10 orders and 71 families were collected from sunflower fields over four growth stages ranging from anthesis to seed maturity. At the R3 phase of flower-bud formation, Chironomidae sp. of a decomposer insect guild presented the highest density, while Apis mellifera of a pollinator guild was the most abundant in the R5.8 phase of flowering. During the R7 seed-filling phase and the R9 phase of seed maturity, herbivorous Pochazia shantungensis predominated. During the R9 phase, richness and diversity indices of arthropod communities were distinctly lower whereas their dominance indices were significantly higher than those at other phases. In addition, the composition of arthropod communities was strongly correlated not only with the sampling date, but also with the sampling method depending on the growth stage of sunflowers. Our results suggest that appropriate sampling timing and methods should be considered in advance and that long-term field trials that cover a variety of environmental conditions should be carried out to evaluate potential risks to insect ecosystems.
Abstract
Recently, pest-resistant living modified (LM) crops developed using RNA interference (RNAi) technology have been imported into South Korea. However, the potential adverse effects of unintentionally released RNAi-based LM crops on non-target species have not yet been reported. Coccinella septempunctata, which feeds on aphids, is an important natural enemy insect which can be exposed to the double-stranded RNA (dsRNA) produced by RNAi-based LM plants. To assess the risk of ingestion of Snf7 dsRNA by C. septempunctata, we first identified the species through morphological analysis of collected insects. A method for species identification at the gene level was developed using a specific C. septempunctata 12S rRNA. Furthermore, an experimental model was devised to assess the risk of Snf7 dsRNA ingestion in C. septempunctata. Snf7 dsRNA was mass-purified using an effective dsRNA synthesis method and its presence in C. septempunctata was confirmed after treatment with purified Snf7 dsRNA. Finally, the survival rate, development time, and dry weight of Snf7 dsRNA-treated C. septempunctata were compared with those of GFP and vATPase A dsRNA control treatments, and no risk was found. This study illustrates an effective Snf7 dsRNA synthesis method, as well as a high-concentration domestic insect risk assessment method which uses dsRNA to assess the risk of unintentional released of LM organisms against non-target species.
Abstract
The dung beetle, Gymnopleurus mopsus (Coleoptera: Scarabaeidae), is one of endangered species in South Korea. It was last recorded in 1971. To restore this species, we introduced G. mopsus populations from eastern and southern regions of Mongolia in July 2019 and August 2019, respectively. One of the main tasks for the restoration of endangered insects is to develop breeding techniques to eventually incorporate these insects into the restoration system. In a series of laboratory experiments, we investigated effects of short-term hibernation periods on life-history traits of G. mopsus. Adult G. mopsus that had hibernated for 30, 60, and 90 days had lower survival rates than adults that had hibernated for 120 days. We also compared developmental time of these four experimental groups and found a significant difference in the egg - phase. However, the duration of hibernation did not affect the fecundity, brood-ball size, or body size of F1 adults. Follow-up studies are currently being conducted to further investigate the effect of a short-term hibernation period on population growth of G. mopsus under laboratory conditions.
Abstract
Bacterial symbionts are common across insects, including ants (Hymenoptera: Formicidae). Reproduction-manipulating endosymbionts, such as Wolbachia, Spiroplasma, Rickettsia, and Cardinium, are closely associated with many aspects of host-insect life. In addition, phage WO plays an essential role in the phenotypic effects of Wolbachia. Although endosymbionts are possible biological control agents, there is a lack of knowledge of their rate of infection of ants in Korea. We tested a range of Korean ant species for the presence of Wolbachia, Spiroplasma, Rickettsia, Cardinium, and phage WO by extracting DNA from the ants and using specific primer sets to test the status of infections. In addition, the mitochondrial cytochrome c oxidase I (COI) gene of the host ants was amplified to confirm the molecular identification and phylogenetic relationship between the hosts. We found that infection with Wolbachia (29.6% of species) is relatively common when compared with that of other endosymbionts. Only one species was infected with Spiroplasma. Infection with Rickettsia and Cardinium was not detected in the examined ants. Most Wolbachia in ants were infected with phage WO. Although the phenotypic effects of endosymbionts in ants are still unknown, this first survey of endosymbionts in Korea is the first step toward the use of reproduction-manipulating endosymbionts.