Insect Natural Enemies Research Articles

Leveraging Biotic Interaction Knowledge Graph and Network Analysis to Uncover Insect Vectors of Plant Virus

Background: Insect vectors spread 80% of plant viruses, causing major agricultural production losses. Direct insect vector identification is difficult due to a wide range of hosts, limited detection methods, and high PCR costs and expertise. Currently, a biodiversity database named Global Biotic Interaction (GloBI) provides an opportunity to identify virus vectors using its data. Objective: This study aims to build an insect vector search engine that can construct an virus-insect-plant interaction knowledge graph, identify insect vectors using network analysis, and extend knowledge about identified insect vectors. Methods: We leverage GloBI data to construct a graph that shows the complex relationships between insects, viruses, and plants. We identify insect vectors using interaction analysis and taxonomy analysis, then combine them into a final score. In interaction analysis, we propose Targeted Node Centric-Degree Centrality (TNC-DC) which finds insects with many directly and indirectly connections to the virus. Finally, we integrate Wikidata, DBPedia, and NCBIOntology to provide comprehensive information about insect vectors in the knowledge extension stage. Results: The interaction graph for each test virus was created. At the test stage, interaction and taxonomic analysis achieved 0.80 precision. TNC-DC succeeded in overcoming the failure of the original degree centrality which always got bees in the prediction results. During knowledge extension stage, we succeeded in finding the natural enemy of the Bemisia Tabaci (an insect vector of Pepper Yellow Leaf Curl Virus). Furthermore, an insect vector search engine is developed. The search engine provides network analysis insights, insect vector common names, photos, descriptions, natural enemies, other species, and relevant publications about the predicted insect vector. Conclusion: An insect vector search engine correctly identified virus vectors using GloBI data, TNC-DC, and entity embedding. Average precision was 0.80 in precision tests. There is a note that some insects are best in the first-to-five order. Keywords: Knowledge Graph, Network Analysis, Degree Centrality, Entity Embedding, Insect Vector

High-quality genome of the zoophytophagous stink bug, Nesidiocoris tenuis, informs their food habit adaptation.

The zoophytophagous stink bug, Nesidiocoris tenuis, is a promising natural enemy of micro-pests such as whiteflies and thrips. This bug possesses both phytophagous and entomophagous food habits, enabling it to obtain nutrition from both plants and insects. This trait allows us to maintain its population density in agricultural fields by introducing insectary plants, even when the pest prey density is extremely low. However, if the bugs' population becomes too dense, they can sometimes damage crop plants. This dual character seems to arise from the food preferences and chemosensation of this predator. To understand the genomic landscape of N. tenuis, we examined the whole genome sequence of a commercially available Japanese strain. We used long-read sequencing and Hi-C analysis to assemble the genome at the chromosomal level. We then conducted a comparative analysis of the genome with previously reported genomes of phytophagous and hematophagous stink bugs to focus on the genetic factors contributing to this species' herbivorous and carnivorous tendencies. Our findings suggest that the gustatory gene set plays a pivotal role in adapting to food habits, making it a promising target for selective breeding. Furthermore, we identified the whole genomes of microorganisms symbiotic with this species through genomic analysis. We believe that our results shed light on the food habit adaptations of N. tenuis and will accelerate breeding efforts based on new breeding techniques for natural enemy insects, including genomics and genome editing.

The comparison of species diversity and abundance of insect natural enemies in the domesticated species of cotton using the yellow pan trap method.

India is the world's largest cotton producer and the only country that grows all four cultivated cotton species. There have been very few studies on the diversity and abundance of natural enemies of cotton insect pests in these cultivated cotton species. Therefore, the current study (2016-2018) was conducted to assess the diversity and abundance of natural enemies that cultivated cotton species harbour. Phule Dhanwantari, Suraj, Suvin, RCH-2, and DCH-32 were the five genotypes used in the study, each with a distinct genetic background. Using the adiv 2.0.1 and vegan R packages, we identified significant differences in natural enemies in terms of species diversity, richness, evenness, and abundance. Analysis of Similarity (ANOSIM) and Non-metric Multidimensional Scaling (NMDS) indicated substantial differences in the natural enemy community structure among the examined genotypes. A total of 17,279 natural enemies were collected and identified across genotypes from seven predatory families and five parasitoid families. The percentage share of these natural enemy families across genotypes and years, in descending order, is Coccinellidae (28.23%) < Tachinidae (19.23%) < Braconidae (12.68%) < Chrysopidae (11.65%) < Chalcididae (9.41%) < Aphelinidae (6.33%) < Pentatomidae (3.29%) < Ichneumonidae (2.37%) < Syrphidae (2.33%) < Vespidae (1.81%) < Asilidae (1.79%) < Geocoridae (0.89%). Coccinellidae, Tachinidae, Braconidae, Chrysopidae, Chalcididae, and Aphelinidae are the six major families that account for more than 85% of all recorded natural enemies. These six families have a higher percentage share in Phule Dhanwantary (90%) compared to the other genotypes. The conservation and better utilization of these natural enemies are crucial for the ecological and safe management of insect pests in the cotton ecosystem.

Pengaruh bentuk morfologi bunga tanaman refugia terhadap ketertarikan serangga polinator dan musuh alami Ordo Hymenoptera

The refugia plant is a flowering plant that functions as a shelter and food source for natural enemy insects and pollinator insects. The number of natural enemy insects and pollinators visiting plants is due to differences in morphological characters, flower color, nectar, flowering time and aroma. insects like small flowers, open petals, easy-to-reach pollen locations and also a longer flowering time. Randomized Block Design (RBD) with 4 replications and 8 treatments of flower types, namely Cosmos caudatus, Zinna elegans, Melampodium divaricatum, Tegestes erecta, Cucumis sativus L., Bassica rapa, Solanum melongena L., Lycopersicum esculentum Mill. The results showed that the percentage of Melampodium divaricatum Produced the percentage of parasitoid insects from the Chalcidade family is 17% and Braconidae 16?. Most of the visitors to C. caudatus flowers are parasitoid insects from the Braconidae family, 18%. In Zinnia sp flowers, parasitoid insect visits from the Pompilidae family were 19%. T. erecta flowers that visit pollinator insects from the family Apidae 23%. In the type of horticultural flower, namely C. sativus , the largest in the predatory insect family Ampulicidae is 25%. , whereas in the flowers of the B. rapa family Barconidae 39%, S. melongena L. Ichenumonidae and Braconidae 33% , L. esculentum Mill. Icneumonidae as much as 38% of these insects as parasitoids. Best treatment for M. divaricatum flowers with open flower types, pollen location outside, crown diameter 23.44 mm, base diameter 11.48 mm, flower tube length 5.22 mm, flowering time 24.25 days.

Long-insert sequence capture detects high copy numbers in a defence-related beta-glucosidase gene βglu-1 with large variations in white spruce but not Norway spruce

Conifers are long-lived and slow-evolving, thus requiring effective defences against their fast-evolving insect natural enemies. The copy number variation (CNV) of two key acetophenone biosynthesis genes Ugt5/Ugt5b and βglu-1 may provide a plausible mechanism underlying the constitutively variable defence in white spruce (Picea glauca) against its primary defoliator, spruce budworm. This study develops a long-insert sequence capture probe set (Picea_hung_p1.0) for quantifying copy number of βglu-1-like, Ugt5-like genes and single-copy genes on 38 Norway spruce (Picea abies) and 40 P. glauca individuals from eight and nine provenances across Europe and North America respectively. We developed local assemblies (Piabi_c1.0 and Pigla_c.1.0), full-length transcriptomes (PIAB_v1 and PIGL_v1), and gene models to characterise the diversity of βglu-1 and Ugt5 genes. We observed very large copy numbers of βglu-1, with up to 381 copies in a single P. glauca individual. We observed among-provenance CNV of βglu-1 in P. glauca but not P. abies. Ugt5b was predominantly single-copy in both species. This study generates critical hypotheses for testing the emergence and mechanism of extreme CNV, the dosage effect on phenotype, and the varying copy number of genes with the same pathway. We demonstrate new approaches to overcome experimental challenges in genomic research in conifer defences.

Inocellia (Amurinocellia) calida (Raphidioptera, Inocelliidae) was first observed as a predator of Monochamussaltuarius (Coleoptera, Cerambycidae) in China, the vector of Bursaphelenchusxylophilus (Aphelenchida, Aphelenchoididae).

Monochamussaltuarius Gebler (Coleoptera, Cerambycidae) serves as the primary carrier of Bursaphelenchusxylophilus (Steiner & Buhrer) (Aphelenchida, Aphelenchoididae) in the middle-temperate zone of China. Pine wilt disease caused by B.xylophilus leads to serious losses to pine forestry around the world. It is necessary to study the biological control of M.saltuarius to effectively prevent the further spread of B.xylophilus. To explore the insect resources that act as natural enemies of M.saltuarius, investigations were conducted on natural enemy insects by splitting Pinuskoraiensis Siebold & Zucc (Pinales, Pinaceae) damaged by M.saltuarius and dissecting their trunks in Yingpan Village, Fushun County, Fushun City, Liaoning Province, China, in 2023. A larva of Inocellia (Amurinocellia) calida (H. Aspöck & U. Aspöck) (Raphidioptera, Inocelliidae) was discovered in the trunk of an infested P.koraiensis. Additionally, the feeding habits of I.calida were preliminarily examined under indoor conditions and a description of its morphological characteristics was provided. When placed in an indoor environment, the I.calida larva began pupating after a period of 21 days, during which time it consumed and attacked a total of 23 M.saltuarius larvae. Ultimately, after a pupal period of ten days, the I.calida larva emerged successfully as an adult. This discovery marks the first recorded presence of I.calida in Liaoning Province and the first documentation of I.calida in China, serving as a natural predatory enemy of M.saltuarius.

Insect pollinator and natural enemy communities in green roof and ground-level urban habitats

Insect pollinator and natural enemy communities in green roof and ground-level urban habitats

Analysis of gut microbiota of ladybug beetle (Harmonia axyridis) after feeding on different artificial diets

BackgroundHarmonia axyridis is an effective natural enemy insect to a variety of phloem-sucking pests and Lepidopteran larvae, such as aphids, scabies, and phylloxera, while its industrial production is limited due to unmature artificial diet. Insect intestinal microbiota affect host development and reproduction. The aim of this study is to understand intestinal microbiota composition of H. axyridis and screen effective probiotics on artificial diet. Considering the role of the components and composition of the diet on the structure and composition of the intestinal microbiome, four kinds of diets were set up: (1) aphid; (2) basic diet; (3) basic diet + glucose; (4) basic diet + trehalose. The gut microbiota of H. axyridis was detected after feeding on different diets.ResultsResults showed that the gut microbiota between artificial diet group and aphid groups were far apart, while the basic and glucose groups were clearly clustered. Besides, the glucose group and trehalose group had one unique phylum, Cryptophyta and Candidatus Saccharibacteria, respectively. The highest abundance of Proteobacteria was found in the aphid diet. The highest abundance of Firmicutes was found in the basic diet. However, the addition of glucose or trehalose alleviated the change. In addition, the relative abundance of Enterobacter, Klebsiella, Enterobacteriaceae_unclassified, Enterobacteriales_unclassified and Serratia in the aphid group was higher than other groups. Moreover, the function of gut genes in each group also showed clear differences.ConclusionThese results have offered a strong link between artificial diets and gut microbes, and also have provided a theoretical basis for the screening of synergistic probiotics in artificial diet.

Impact of Climate Change on the Habitat Suitability of Monochamus saltuarius Gebler (Coleoptera; Cerambycidae) and Its Natural Enemies in China

The longicorn beetle Monochamus saltuarius (Coleoptera; Cerambycidae) is an insect vector that transmits the pine wood nematode Bursaphelenchus xylophilus, a serious issue in pine forests in China, Japan, and South Korea. Dastarcus helophoroides and Scleroderma guani are effective in controlling M. saltuarius. However, the application of these parasites for the direct control of vector insects requires detailed analyses of the suitability of the selected natural enemies in potential pest areas, particularly under climate change. Based on species distribution records as well as the current and projected climate change trends up to 2050, we utilized an optimized Maxent algorithm to predict the potential distribution patterns of M. saltuarius and its natural enemies in China. Furthermore, we estimated Schoener’s D to quantify the overlap in adaptability between M. saltuarius and its natural enemies. The potentially suitable areas predicted under the current climate conditions were concentrated mainly in northeast and north China. Additional suitable areas were detected in central, eastern, northwestern, and southwestern China. Under future climate conditions, the suitable range of M. saltuarius gradually shifted southward, with a tendency to expand into high-altitude and colder regions, such as Sichuan, Qinghai, and Tibet. The potential distribution of the natural enemies D. helophoroides and S. guani continued to expand under climate change. A comparison of the appropriate habitats of M. saltuarius and natural enemy insects indicated that D. helophoroides is more suitable for initial biological control in north, northeast, and central China as well as certain northwest and coastal regions. S. guani could be prioritized for nationwide release, while joint control using both species may be effective in Liaoning, Hebei, and Tianjin provinces. These analyses demonstrate that future climate change is likely to exert adverse effects on the potential distribution of M. saltuarius but is favorable for the potential distributions of natural enemies. This study offers important insights into the effective control of M. saltuarius and provides an experimental basis for the utilization of natural enemies according to the characteristics of different regions.

Diversity Of Insect Pests And Natural Enemies In Green Bean (Vigna Radiata) Plantations In Lakekun Village, Kobalima District, East Malaka

This research was conducted in Lakekun Village, Kobalima District, Malaka Regency from May to July 2023, aiming to determine the types of insect pests and natural enemies in mung beans. Data collection was carried out using direct observation techniques on mung bean plants and sampling using several traps. The types of traps used were pitfall trap, swepnet, yellow sticky trap, swing net and light trap. Sampling was done diagonally to determine the sample unit. The number of observation plots in the field is 3 observation plots. in 1 plot there are 5 sample units and a total of 3 observation plots there are 15 aub plots observed. Insect pests found on mung bean in the research location have three roles, namely as pests, predators and parasitoids. Species that act as pests consist of Artherigona exigua, Nezara viridula L, Aphis craccivora, Halyomopha halys, Riptortus linearis, Adoretus sp. and Gralliclava horrens. Insects that act as predators consist of Menochilus sexmaculatus, Coccinella transversalis, Orthhetrum sabina, Iscunara senegalensis. While insects that act as parasitoids are Tiphia femorata. The highest population found at the research site was Aphis craccivora which amounted to 315 individuals and the lowest population was Graliclava horrens with a total of 7 individuals. The value of the diversity index in mung bean plants is classified as moderate, namely 1.89.&#x0D; Keywords: diversity, insects, mung bean, identification.

Mutagenesis of Odorant Receptor Coreceptor Orco Reveals the Odorant-Detected Behavior of the Predator Eupeodes corollae.

The successful mating of the hoverfly and the search for prey aphids are of great significance for biological control and are usually mediated by chemical cues. The odorant receptor co-receptor (Orco) genes play a crucial role in the process of insect odor perception. However, the function of Orco in the mating and prey-seeking behaviors of the hoverfly remains relatively unexplored. In this study, we characterized the Orco gene from the hoverfly, Eupeodes corollae, a natural enemy insect. We used the CRISPR/Cas9 technique to knock out the Orco gene of E. corollae, and the EcorOrco-/- homozygous mutant was verified by the genotype analysis. Fluorescence in situ hybridization showed that the antennal ORN of EcorOrco-/- mutant lack Orco staining. Electroantennogram (EAG) results showed that the adult mutant almost lost the electrophysiological response to 15 odorants from three types. The two-way choice assay and the glass Y-tube olfactometer indicated that both the larvae and adults of hoverflies lost their behavioral preference to the aphid alarm pheromone (E)-β-farnesene (EBF). In addition, the mating assay results showed a significant decrease in the mating rate of males following the knock out of the EcorOrco gene. Although the mating of females was not affected, the amount of eggs being laid and the hatching rate of the eggs were significantly reduced. These results indicated that the EcorOrco gene was not only involved in the detection of semiochemicals in hoverflies but also plays a pivotal role in the development of eggs. In conclusion, our results expand the comprehension of the chemoreceptive mechanisms in the hoverflies and offers valuable insights for the advancement of more sophisticated pest management strategies.

Suppression of weed and insect populations by living and straw mulches in sesame (Sesamum indicum L.)

In order to evaluate the effect of different weed management treatments on weeds, pest and natural enemies populations in sesame (Sesamum indicum L.), a 2-year study was conducted in East Azarbaijan, Iran in 2020–2021. The study was conducted based on randomized complete block design with four replications. The weed management treatments consisted of trifluralin use (960 g ai ha−1), wheat straw mulch (WSM), living mulches of fenugreek (Trigonella foenum-graecum L.) (FLM), bitter vetch (Vicia ervilia L.) (VLM), calendula (Calendula officinalis L.) (CLM) and one-time hand weeding (OHW). The effect of weed management treatment was significant on densities of insect pests, natural enemies and weed and also weed biomass and sesame seed yield. The lowest densities of insect pests including Myzus persicae, Brevicoryne brassicae, Helicoverpa armigera and Spodoptera exigua were observed in CLM treatment. Also, the highest densities of natural enemies Coccinella septompunctata, Coccinella undecimpunctata and Orius niger were observed in CLM treatment. The highest reductions in grass (51.0%), broadleaf (72.0%), and total (62.6%) weed biomasses and highest seed yield (1456 kg ha−1) were obtained in OHW. The seed yields in CLM and WSM treatments were not significantly different with trifluralin treatment and could be recommended in sustainable production of sesame.

Diptera Pests Occurring on Vegetable Crops in Poland

Abstract In Poland, the share of Diptera in the species composition of the harmful entomofauna occurring on vegetable crops ranges from 20 to 25%. They occur on all vegetables grown in Poland (over 80 species and botanical varieties). Since the systematic registration of pests inhabiting crops in Poland in 1919, over 70 species of flies have been listed as pests of vegetable plants. Species from three families dominate in terms of population and numbers: Anthomyiidae with 12 species (Delia radicum, on early and late cultivars of cruciferous vegetables, mainly broccoli, cauliflower, white cabbage, kohlrabi, and radishes; Delia platura occurs annually on bean and cucumber; Delia antiqua on onion and garlic; and Pegomya hyoscyami on beetroot), Cecidomyiidae with 10 species (two species dominate, Contarinia nasturtii and Dasineura napi, on cruciferous vegetables), and Agromyzidae with 23 species (Liriomyza bryoniae on cucumbers, tomatoes, and peppers, and Phytomyza gymnostoma on leeks). Short-term, gradational occurrence of some dominant species was found, including Botanophila gnava (lettuce), Chamaepsila rosae (carrot, parsley), Delia platura (asparagus, bean), Delia radicum (broccoli, cauliflower, kohlrabi, radishes, white cabbage), Phytomyza gymnostoma (leek), Oscinella frit (corn), and Suillia lurida (garlic). However, they did not affect the level of plant production in the following years of cultivation. Apart from phytophagous species, taxa with a different trophic structure are common. These are copro-, necro-, sapro-, and zoophagous species. The most numerous were flies from the Drosophilidae family (Drosophila busckii, Drosophila limbata, Scaptomyza pallida, Fanniidae (Fannia canicularis, Fannia scalaris), Heleomyzidae (Tephrochlamys tarsalis), and Muscidae (Muscina levida, Muscina stabulans, Phaonia trimaculata). Natural enemies of insects play an important role in vegetable agrocenoses. Species belonging to the order of Coleoptera beetles (Carabidae and Staphylinidae), Syrphidae, Tachinidae, and Muscidae, mainly Phaonia trimaculata larvae, play the most important role in reducing the number of Diptera. In addition, the number of phytophages is limited by other organisms, e.g., Diplopoda, Nematoda, Arachnida, and pathogens of viral, bacterial, and fungal origin.

Regulation of forkhead box O transcription factor by insulin signaling pathway controls the reproductive diapause of the lady beetle, Coccinella septempunctata

In biological control programs, knowledge about diapause regulation in natural enemy insects provides important insight for improving long-term storage, transportation, and field adoption of these biological control agents. As a natural predator of agricultural pests, the lady beetle Coccinella septempunctata has been commercially mass-cultured and widely employed in pest management. In some insects, insulin signaling, in conjunction with the downstream transcription factor Forkhead box O (FoxO), are master regulators of multiple physiological processes involved in diapause, but it is unclear whether insulin signaling and FoxO affect the diapause of C. septempunctata. In this study, we use a combination of approaches to demonstrate that insulin signaling and FoxO mediate the diapause response in C. septempunctata. In diapausing beetles, application of exogenous insulin and knocking down expression of CsFoxo with RNA interference (RNAi) both rescued beetles from developmental arrest. In non-diapausing beetles, knocking down expression of the insulin receptor (CsInR) with RNA interference (RNAi) arrested ovarian development and decreased juvenile hormone (JH) content to levels comparable to the diapause state. Taken together, these results suggest that a shutdown of insulin signaling prompts the activation of the downstream FoxO gene, leading to the diapause phenotype.

Keragaman Serangga Hama dan Musuh Alami Lahan Pertanian Padi Organik (Oryza Sativa L) Desa Rowosari Kecamatan Sumberjambe Kabupaten Jember

The application of organic rice farming systems is a solution to the negative impacts of using chemicals in the application of conventional farming systems. Organic rice cultivation cannot be separated from the presence of insect pests that attack cultivated plants. Naturally, in an ecosystem that is still good, natural enemies are already present in nature without human intervention. The existence of natural enemies in a field can suppress the existing population of insect pests, so that their presence is very helpful in maintaining the balance of the existing insect pest populations. The stability of insect populations in an agricultural ecosystem is largely determined by the high diversity of insect pests and natural enemies found in a field. Thus there is a need for research on the diversity of insect pests and natural enemies as information about which insect families are found on organic rice farming land in Rowosari Village, as well as a consideration for farmers in applying appropriate control methods. This study used yellow pan trap, sweep net and vacuum cleaner insect monitoring tools. The research was conducted on 3 observation plots in the organic rice fields of Tani Jaya II Group, Rowosari Village, Sumberjambe District, Jember Regency. Observations were made 10 times from the vegetative phase to the generative phase of rice aged 7 to 77 days after planting. Observational data were then identified and then analyzed using the Shanon-Wiener Diversity Index (H), Evenness Evenness Index (E), Simpson Dominance Index (D), and Margalef Species Richness Index (R). The results showed that there were 7 families of Pest Insects found on organic rice farming in Rowosari Village, including Pyralidae, Alydidae, Grylidae, Cicadellidae, Chrysomelidae, Acrididae, and Nymphalidae. Natural Enemy Insects found were 9 families including Coccinellidea, Coenagrionidae, Gomphidae, Penttomidae, Meoidae, Miridae, Ichneumonidae, Staphylinidae, and Sciomyzidae. Neutral insects found were as many as 4 families, including Muscidae, Vespidae, Tephritidae, and Drosophilidae. The population of insect pests and natural enemies of organic rice farming land in Rowosari Village is quite balanced with a Diversity Index (H') of 2.32 and Species Richness Index (R) of 2.98, Evenness index (E') of 0.77 which is in the almost even and Dominance (D) 0.13 which means not dominating.

Influence of Silicic Acid Foliar Spray on the Incidence of Sucking Insect Pests and their Natural Enemies in Rapeseed

Silicon induces resistance in various crops against insect pests of diverse feeding guilds, including hemipterans, through upregulation of plant defense mechanisms along with maintenance of plant physiological processes. The present investigation to study the effect of silicon in the form of silicic acid (SA) against major sucking insect pests (Lipaphis erysimi and Bagrada hilaris) and natural enemies (Coccinella transversalis and Episyrphus balteatus) in rapeseed revealed that the foliar application of SA @ 0.4% thrice at 30, 40 and 50 days after sowing significantly reduced the colonization of L. erysimi as against non-significant effect on the population of B. hilaris. Three sprays of SA @ 0.4% significantly increased the population of C. transversalis without any significant effect on E. balteatus population. The silicon content of the rapeseed grains was also found to be significantly enhanced (0.32%) with 3 sprays of SA @ 0.4%.

Arthropods discovered on refugio flowering plants in Mangifera indica plantation

Abstract. Windriyanti W, Rahmadhini N, Fernando I, Kusuma RM. 2023. Arthropods discovered on refugio flowering plants in Mangifera indica plantation. Biodiversitas 24: 4747-4754. The diversity of Refugio flowering plants with different ways of flowering phenology provides alternative food sources for arthropods. Insects are the largest class of arthropods, most of which are ecological services that function as natural enemies and pollinators. Insects require an energy source over a long-term period to promote a stable and healthy population. The use of flowering plants as refugia can maximize the role of insects as ecological services in agroecosystems by providing natural enemies and pollinators with a source of food and shelter. The refugia plants used in this study were sunflowers (Helianthus annuus), king’s salad (Cosmos caudatus), Peruvian zinnia (Zinnia peruviana), Tridax procumbens (Asteraceae), and Alternanthera sessilis (Amaranthaceae) with hedgerow and insectary bank planting patterns. Data collection and periodic direct observation (scan sampling) were conducted by transects. Observed parameters included species composition and population of arthropods in two different agro-systems, monoculture and polyculture. Identification results showed 8 orders, including 44 morphospecies, belonging to 25 families. Arthropod abundance in the on-season of the refugia was found in 1422 individuals. Ecological engineering is a habitat manipulation technology using refugia plants that has increased the composition and population of natural enemy insects and pollinators.

Checklist of insect pests and natural enemies associated with groundnut (Arachis hypogaea L.) ecosystem in Anaimalai tract of Tamil Nadu

Fixed and roving surveys were conducted at Coconut Research Station, Aliyarnagar and Anaimalai tract of Coimbatore district, Tamil Nadu to study the insect pests and natural enemy complex of groundnut ecosystem. Results of the study revealed the occurrence of 32 species of insect pests and 13 species of natural enemies. Among the insect pests, only five viz., Helicoverpa armigera, Spodoptera litura, Scirtothrips dorsalis, Empoasca kerri and Aphis craccivora were considered as major pests. Nine insect pests were considered as minor, while 18 were noticed as spot occurrence. The leafminer, Liriomyza trifolii population was noticed only during kharif season. Among the 13 species of natural enemies, coccinellid beetles viz., Coccinella transversalis and Cheilomenes sexmaculatus were dominant.

Impact of planting distances to arthropods abundance on kangkong

Kangkong (Ipomoea reptans Poir) is the favourite green vegetable especially most of Asian people. The important factors affecting production of kangkong is the planting distance. The optimal planting distance create an ideal microhabitat around crop and potential to suppress development of insect pests. The research purpose is to study the impact of planting distance to arthropods abundance on kangkong. The research was conducted in Somba Opu District, Gowa Regency, South Sulawesi from February to May 2020. The arthropods identification was carried out at the Pest Laboratory, Department of Plant Pest and Diseases, Faculty of Agriculture, Hasanuddin University Makassar. The study was conducted in four treatments of planting distance, P1= 5 cm x 5 cm; P2 = 5 cm x 10 cm, P3 = 5 cm x 15 cm and P4 = the seeds was spread (without planting distance), respectively. Each treatment was repeated four times, the arthropods was caught by pitfall trap. The sampling method used the diagonal pattern. Observation of arthropods began when the kangkong 7 days after planting with interval 7 days until harvest. The arthropods results divided into two group (insect pest and natural enemies) showed that: 1) the highest number of insect pests in the pitfall trap was found in treatment P4 (Valanga sp. 1.25 individual); 2) the highest natural enemies number from Hymenoptera (Formicidae); and 3) the highest harvest number in the treatment P1 (13.1 kg) and the lowest in P4 (11.3 kg). Conclusion of the research: grasshopper Valanga sp. (Orthoptera: Acrididae) as the dominan insect pest in P4 (1.25 individual). Dominant arthropods as natural enemies in the kangkong field as Formicidae in P3 (14.5 individual). The highest harvest in kangkong field at P1 (13.1 kg) and the lowest in P4 (11.3 kg).

The relationship between vector insect populations, natural enemies, and disease incidence of tungro virus during wet and dry seasons

Abstract. Hutasoit RT, Jihad M, Listihani L, Selangga DGW. 2023. The relationship between vector insect populations, natural enemies, and disease incidence of tungro virus during wet and dry seasons. Biodiversitas 24: 4001-4007. Tungro virus is one of the most prevalent viruses affecting rice plants. The tungro virus is frequently found in rice plantations because its green planthopper vector is always present. This study aimed to determine the relationship between the population density of green planthoppers and its natural enemies with the incidence of tungro disease during the rainy and dry seasons in Lanrang, Sidenreng Rappang, South Sulawesi. The research method employed was field monitoring of the population density of green planthoppers, natural enemies, and the incidence of tungro disease. The presence of the tungro virus was confirmed by the molecular method using RTSV and RTBV-specific primers. The results showed three types of tungro vector insects: Nephotettix virescens, Nephotettix nigropictus, and Recilia dorsalis. Nephotettix virescens was the dominant vector insect, with the highest population in March and August of 101 and 51 individuals, respectively. During the dry season, the high population of the three vector insects in August was followed by a high incidence of tungro disease in September, reaching 29.38%. Symptoms of yellow leaves have been confirmed by molecular methods, which indicated that the infection was caused by RTSV and RTBV, as evidenced by the amplification of DNA bands measuring 787 bp and 1400 bp. Data on the population of vector insects and the incidence of tungro disease indicated the importance of determining the ideal time to plant to avoid the plant's susceptible phase during the peak vector population between March and August. The dominant natural enemies found during the observations included Araneus inustus, Tetragnatha maxillosa, Agriocnemis pygmaea, and Menochilus sexmaculatus. Increasing the population of natural enemies could suppress the population of vector insects.