The economic contribution of the pollinators is often estimated in order to understand the importance of the pollinator population, particularly insects. Also declining of the pollinator population would be a potential threat to food production which in turn affects nutritional security negatively. Unlike the economic contribution in terms of currency, seldom the contribution has been addressed in terms of nutrients. In the present paper, we estimated the contribution of pollinator population in the micronutrients viz. minerals and vitamins supply of the country. A higher pollinator dependency than present global average was noted in connection with all minerals deemed nutritionally important and most of the vitamins. Pollinator-dependent (PD) crops provide a substantial share of micronutrients to the population, especially with regard to vitamins C and E and elements iron. A positive trend was found in the PD supply of all micronutrients over the last 30 years in Korea, but the rate of increment was somewhat lower for vitamins C and K as well as folate.
Global Symposium GS2: Frontiers in Insect Biotechnology
Insects are the most diversified organisms in the world. They are vital to the functioning of the ecosystem and biosphere, and neither of these systems can operate effectively without insect interactions. Insects are regularly subjected to stressors related to increasing anthropogenic activities, including chemicals and climatic changes that induce major stresses. Depending on the species and the particular stress affecting it, insect populations respond by increasing or decreasing in numbers. Researchers have assessed the responses of insect populations to various direct and indirect environmental stresses. Some insect populations increase, while others decline. The reponses were determined by the particular environmental stress, the insect species, and he stage at which they were exposed to the stress.
A prostaglandin (PG), PGE2, mediates both cellular and humoral immune responses of insects. Spodoptera exigua (Lepidoptera: Noctuidae) biosynthesizes PGE2 by an unknown enzyme. This study predicted the enzyme, which is a novel membrane-bound prostaglandin E synthase-2 (mPGES-2). The transcriptional expression analysis showed the mPGES-2 is inducible to immune challenge. After RNA interference (RNAi), the hemocyte nodulation and expression of eleven antimicrobial peptides were significantly impaired. The RNAi effect was rescued by addition of PGE2 suggesting that mPGES-2 is crucial for immune responses mediated by PGE2.
Insect structural cuticular proteins (CPs) play a major role in determining the diverse physical properties of the cuticle as a result of interactions/cross-linking among themselves and with chitin. CP genes compose a large gene family and have been classified more than ten distinct families based on the presence of unique amino acid sequence motifs. In this study, we performed RNAi-based functional analysis of eleven genes (TcCPLCP1-11) in Tribolium castaneum, which belong to CPLCP (Cuticular Proteins of Low Complexity, Proline rich) cuticular protein family. RNAi for TcCPLCP7-11 caused lethal pupal-adult molting defects and/or abnormal cuticle morphology in the resulting adults. Ultrastructural defects of the cuticles from TcCPLCP7-11-deficient insects by TEM are also discussed.
Plant essential oils (EOs) exhibit an array of biological activities against insect pests. However, their negative influences on the pheromonal activity of azuki bean beetle (ABB), Callosobruchus chinensis L., the field-to-storage pest of legumes, have not received research attentions. We evaluated the effects of three EOs and their two major components on the attractiveness of male ABBS to synthetic homofarnesal (2E- : 2Z-homofarnesal = 6:4) using Y-tube olfactometry in laboratory and rocket traps in the semi-open vinyl house. The tested EOs of Illicium verum, Croton anisatum and Gaultheria fragrantissima as well as the major components, trans-anethole and methyl salicylate ascertained significant negative effect against homofarnesal both in Y-tube olfactometry and in semi-open vinyl house tracing out a new opportunity of integrating them in ABB management programs both in field and storage.
Phospholipase A2 (PLA2) hydrolyzes fatty acids from phospholipids at sn-2 position. Two immune-associated PLA2s are known in Spodoptera exigua. Both are calcium-independent cellular PLA2 (iPLA2A and iPLA2B). These iPLA2s are inducible to immune challenge using different epitopes such as virus, Gram+, Gram- bacteria, and fungi. However, their expression profiles are different between these two iPLA2s. Especially, immune challenge with Gram+ bacteria and fungi significantly up-regulated these iPLA2 expression, suggesting their expression under Toll signal pathway. RNA interferences of Toll or IMD signal components are being investigated.
Eicosanoids play crucial roles in mediating insect immune responses. PLA2 releases arachidonic acid (AA) from phospholipids (PLs) and AA is usually used for biosynthesis of eicosanoids. However, AA is little (less than 0.05%) detected in insect PLs. In contrast, insect PLs have a lot of other C18 PUFAs (linoleic acid and linolenic acid). A new hypothesis is that AA is synthesized from C18 precursor by subsequent desaturation and elongation reactions. We predicted several fatty acyl desaturases (DESs) from Spodoptera exigua. Some specific DES inhibitors inhibited eicosanoid-mediated immune responses. Subsequent AA precursor analysis suggests that AA may be synthesized from linolenic acid via the omega-6 pathway.
The entomopathogenic bacteria Xenorhabdus/Photorhabdus inhibit insect immune responses by inhibiting eicosanoid biosynthesis. Especially, the bacterial secondary metabolites inhibit PLA2 that release eicosanoid biosynthesis precursors. Some organic extracts of the bacteria-cultured broth possessed PLA2 inhibitory activity. This study used butanol to extract the metabolites and showed that the extract possessed potent inhibitory activity against insect immunity. The inhibition was reversed by the addition of eicosanoid biosynthesis precursor, suggesting PLA2 inhibition. Furthermore, sub-fractionation of the butanol extract separated the secondary metabolites and the fractions exhibited differential PLA2 inhibition. The active fractions appeared to contain novel compounds that are not known in PLA2 inhibition of these bacteria.
Insulin/IGF signaling (IIS) regulates different physiological processes such as metabolism, trehalose level, growth, and reproduction. Four IIS components are identified from the bean pod borer, Maruca vitrata (Lepidoptera: Crambidae). RNA interference (RNAi) of insulin receptor (InR), Forkhead Box O (FOXO), Target of Rapamycin (TOR) or Akt led to ovary dysfunction. Especially, the RNAi treatment significantly reduced the stem cell division in the germarium. However, an addition of a porcine insulin stimulated the cell division. Immature diets significantly influenced on the ovarian stem cell development.
Gelechioidea is the superfamily that contains diverse groups comprising over 16,000 species in worldwide. It was estimated that only 25% of the species diversity of the Gelechioidea has been described. In this study, DNA barcoding was assessed based on cytochrome c oxidase subunit I (COI) for the 154 morphologically identified Korean gelechioids. The results of three molecular species delimitation methods were consistent for 72% with their morphological identifications. Based on molecular operational taxonomic unit (MOTU) estimation, we discussed on discordant groups including barcode sharing pairs and cryptic species.
Entomological data can provide valuable information for crime scene investigation especially in postmortem interval (PMI) estimation. This study aimed to establish the candidate species for forensic indicator-to-be. Cadaveric beetles of 48 species belonging to 13 families were retrieved, collated and interpreted from the biological recording data that had been obtained from 45 animal dead bodies between 2016 and 2017. Twelve species including Onthophagus fodiens, Creophilus maxillosus, and Platydracus paganus were observed in higher frequencies (>50%, p<0.05) during animal decomposition. However, the communities of cadaveric beetles differ in their species composition by different localities, suggesting the comprehensive understanding of local α-diversity should be important for forensic entomology.
Family Nitidulidae is the second largest family in Cucujoidea which includes ten subfamilies. Because of their morphological and biological diversity, the phylogenetic relationship within Nitidulidae is one of the most debated topics among Cucujoidea phylogeny and yet, is still open to many questions. To recover the internal relationship of Nitidulidae, we performed ML and BI analyses that targeted on five gene regions (COI, 28s, CAD, H3, Wingless) for 73 taxa. We include 67 ingroups containing nine of the ten currently recognized subfamilies of Nitidulidae and 6 outgroups. The phylogenetic results suggest followings i) Subfamilial status of Prometopinae is reconfirmed; ii) Epuraeinae is paraphyletic with inclusion of Calonecrinae; iii) Nitidulinae is paraphyletic with inclusion of Meligethinae and Cillaeinae. In addition, the generic relationships within Nitidulinae and the evolutionary history of their feeding behaviors are also briefly discussed.
Evolutionary relationship between ovipositior and oviposition behaviour in insect is an intriguing yet poorly understood topic. Gigantic member of phytophagan, the subfamily Cerambycinae provide us a unique opportunity to understand the topic because they have diversified but specialized host plants, oviposition strategies and ovipositors. The evolutionary pathway of these traits is totally unknown because no robust internal phylogeny of Cerambycinae has been studied. Here we construct a multi-locus phylogeny of Cerambycinae (134 taxa, 9 gene regions, 5211bp) focusing on wide range of oviposition site, host plant and ovipositor length. Ancestral state reconstruction analyses show some general trends in cerambycine evolution: i) host plant use evolved from stressed broad leaved trees to conifers and herbaceus plants; ii) oviposition site evolved from bark crevice to wood fissure or plant surface; iii) extremely shortened and elongated ovipositor independently evolved at least four times, respectively. Correlated evolution test show that ovipositor length and oviposition strategy evolved with very strong correlation, while any of other two traits did. This study unveils the complex evolutionary history of ovipositor, oviposition site, host plant use and their correlation within Cerambycinae for the first time.
The genus Aphidius is one of the largest groups of aphid parasitoids. Aphidius colemani is most common and commercially available for the aphid control. Recently, the mummies of Rhopalosiphum padi were collected from barley banker plants in Yecheon. Nucleotide sequence analysis identified its parasitoid as A. transcaspicus, which is morphologically similar to A. colemani. Interspecific variation of both COI and ITS2 between two species was 5.13 and 10.73%, respectively. Intraspecific variations of both COI and ITS2 of A. transcaspicus was 1.85 and 4.96%, respectively. We assume the barley banker plants for A. colemani were contaminated by A. transcaspicus. Thus, precise identification of natural enemies is required for more effective pest control.
Genus Trissolcus are considered as most effective natural enemy for control Pentatomid pests. Trissolcus japonicus (Ashmead) is native egg parasitoid of the brown marmorated stink bug, Halyomorpha halys (Stål) (Hemiptera: Pentatomidae) in Palearctic region. Nevertheless, identification of Palearctic Trissolcus species are still controversial because of morphological homogeneity such as Trissolcus semistriatus (Nees, 1834) and Trissolcus Kozlovi Ryakhovskii, 1975. This study reassessed Korean Trissolcus species diversity and provided DNA barcoding data using mitochondrial cytochrome c oxidase subunit I (COI) gene for 11 Korean Trissolcus species.
The subfamily Mirinae, commonly called plant bug, represents the largest group in Heteroptera, and is also one of the most important groups economically, containing many insect pests as well as predators that can be used as biological control agent in agriculture. However, the monophyletic and phylogenetic relationships of each group within Mirinae are not understood to date, due to a lack of phylogenetic analysis. In this talk, the first comprehensive phylogenetic analyses of the subfamily Mirinae are presented, based on total-evidence data. Major questions raised based on results of this study are discussed: (i) Is each tribe in Mirinae a monophyletic?; (ii) Which tribes or genera are related or not related? (iii) Are these complexes monophyletic?; and (vi) Which characters are nonhomoplacious or homoplacious, and Which are supported in each group?
Mirinae is the most diverse subfamily within the family Miridae (Hemiptera: Heteroptera), and includes more than 4,000 species. In Korea, mirids were first recorded from Jeju Island in the mid-1960s. Since that study, numerous plant bug species from the Korean peninsula have been newly recognized and described. Previously, 101 species of Mirini were recorded from Korean peninsula. In this study, we provide an additional information of Mirini in Korea with a description of new species and new records.
The family Cicadellidae (Hemiptera: Auchenorrhyncha) is one of the largest insect families, and contains approximately 22,000 described species. All members of this group are phytophagous, therefore, many of them are known as insect pests. Additionally, some species can transfer some pathogens such as viruses and phytoplasmas to plants as a vector. Macropsis (Cicadellidae: Macropsinae) is one of the largest groups in Cicadellidae, and has a world distribution. Among them, M. mendax and M. fuscula are famous for a vector associated with phytoplasma disease in Europe (Elm yellow, Rubus stunt disease). In Korea, three Macropsis species have been recorded to date. In this talk, genus Macropsis is reviewed from Korea. Morphological information such as diagnoses and descriptions of genitalia and the key to Macropsis are presented.
Subfamily Asopinae (Heteroptera: Pentatomidae) is known to have a unique behaviour among congeners of the family Pentatomidae. Their predatory behavior towards Lepidoptera and Coleoptera larvae has been numerously studied as some of the species have been used as biological control agents against insect pests. In this presentation a morphological taxonomical revision of the Korean Asopinae is made. New records and the first key from Korea are presented together with illustrations of all their habitus. Their possible role as Biological control agents in Korea is also discussed.
밤은 임산물 중 가장 중요한 품목 중 하나이며, 최근 복숭아명나방에 대한 피해가 급증하고 있는 상태이다. 2017년 11월 21일, 부여군에 위치한 밤 주산단지 내 밤나무 50그루를 무작위로 선정하고 각 나무별로 땅으로 낙과한 밤송이 5개를 무작위로 채집하여 복숭아명나방의 피해과와 개체수를 확인하였다. 그 결과 95% 신뢰수준에서 복숭아명 나방과 그에 의한 피해과 수는 통계적으로 집중분포를 보였으며, 밤알 수는 임의 분포하였다. 복숭아명나방은 밤알 수와 95% 수준에서 통계적으로 역 상관관계를 보여 상대적으로 큰 밤알이 선호됨을 알 수 있었고 피해과 수와는 정 상관관계를 보여 피해과가 많으면 개체수도 많이 존재하는 경향을 보였다. 이러한 결과들은 복숭아명나방의 방제전략을 구축하는데 있어 기본적인 자료로 사용될 수 있고 고려되어야 할 사항들이다.