Arthropod Predators Research Articles

Short‐Term Grasslands in Agriculture Support Both Natural Enemy and Phytophagous Arthropod Populations

ABSTRACTSimplified agricultural land with high chemical input is increasingly replacing natural habitats in many parts of the world. This loss and fragmentation of natural areas may have profound impacts on an array of wildlife, including predatory arthropods that provide natural biocontrol of agricultural pests. There is increasing interest in utilising short‐term seminatural habitat restoration in agricultural systems to support populations of beneficial organisms. We assessed the impact of two types of short‐term set‐asides on the diversity and abundance/activity density of phytophagous and predatory arthropods. We found that flower‐enhanced set‐asides supported higher abundances of both phytophagous and predatory arthropods compared to control crop fields. In addition, we found that both set‐aside types (flower enhanced and traditional) supported a more active and diverse community of beneficial predatory carabid beetles, with particularly strong trends in set‐asides supplemented with flowering plants. These results suggest that small‐scale, temporary, seminatural habitats in agricultural systems provide support for a diverse and abundant community of both beneficial and phytophagous arthropods.

Spider (Araneae: Araneomorphae) diversity in Annaba Province, Northeastern Algeria

Spiders, as predatory arthropods, play essential roles in ecosystem equilibrium and serve as bioindicators. To contribute to the understanding of spider diversity in northeast Algeria (Annaba province), a survey of spider fauna was conducted in both forest and urban sites over two consecutive years using the "hand collecting" method. A total of 879 adult spiders (681 females and 198 males) were identified, representing 25 families and 67 species. The Salticid Plexippus paykulli (Audouin, 1826) was the most abundant species, with 127 specimens collected. The most abundant families were Salticidae and Araneidae, with counts of 171 and 139 individuals, respectively. The Shannon-Weaver index varied from 2.17 to 3.68 bits across the different sites, while evenness values ranged from 0.60 to 0.75. This study significantly expanded the known spider species in Annaba province from 96 to 138.

Myrmecophily among mesostigmatid mites

AbstractAnt nests are biodiversity hot spots, concentrating resources from a wide area that can be exploited by other organisms, known as myrmecophiles. The mite order Mesostigmata includes a wide range of lineages that have become myrmecophiles with many species reliant on ant nests for at least part of their development. The nature of the associations is quite variable, including predators of smaller arthropods in the nest (close to the ancestral lifestyle of these mites), scavengers, kleptoparasites, parasites, and parasitoids. A few mite species show extreme modifications of morphological and/or developmental patterns, others show almost none. Some host specificity is common but one-on-one host specialization is rare or poorly tested. Phoresy on the ants is common, but the target ant caste varies with the goal of phoresy. In general, the diversity of mesostigmatid mites in the nest of a given ant species is affected by habitat conditions along with a range of life history characteristics of the ants, including factors such as body size, colony size, colony founding mode, social parasitism, and nest density. Unfortunately, the life history of the majority of mites associated with ants is still unknown.

Terrestrial generalist predators have larger isotopic niches but rely less on aquatic prey at a natural compared to a post-mining lakeshore

The flooded pits from former opencast mining (post-mining lakes) are young aquatic ecosystems often with low primary productivity due to the high acidity. The limited availability of nutrients and simplified aquatic food webs in these artificial lakes may affect the matter fluxes towards food webs in adjacent terrestrial habitats. To understand the impact of emerging prey from a post-mining lake on terrestrial food webs and associated arthropod communities, we compared the emergence and activity of arthropods as well as the isotopic niches of generalist predators and their potential prey between lakeshores of a post-mining and a natural lake. We used aquatic and terrestrial emergence tents to sample potential prey that emerged locally (Collembola and Diptera) and pitfall traps to sample terrestrial arthropod predators (Carabidae and Araneae) from lakeshores. Community and stable isotope (δ13C and δ15N) analyses were performed to compare diversity and isotopic niches of generalist arthropod predators between the natural and post-mining lakeshores. The number of emerging aquatic and terrestrial prey did not differ significantly between lakes, but the δ15N values of aquatic emerging dipterans differed between the two lakes. Predator community diversity did not differ significantly between lakeshores, but generalist predator species from the natural lakeshore generally had larger isotopic niche sizes than the same species at the post-mining lakeshore indicating a more diverse diet. Additional estimates of diet composition suggest that predators at the natural lakeshore utilized aquatic prey to a lesser degree than at the post-mining lake, but still had a more diverse diet.

Evidence at the landscape level links high predator/pest ratios to biocontrol services against aphids

Compared with external environment interferences, the interaction between arthropod natural enemies and pests is the key inherent driver determining the strength of biocontrol services. However, the extent to which this effect can suppress pests is still inconclusive. We combined two complementary experiments to determine how variation in an assemblage of generalist arthropod predators modified the level of biocontrol services for suppression of a key aphid pest in cotton fields. Using generalized linear mixed effect models (GLMM) and path analysis, we clarified the causal relationship between predator/aphid ratios (PAR) and (1) the resulting biocontrol services index (BSI) and (2) the aphid population growth index (APGI) as seen in field predator exclusion trials. We also measured the effect of PAR on APGI in more commercial cotton fields. Our results, at landscape level, indicate that when PAR values increased one unit, BSI values improved 34.1 %, and reduced aphid population growth 28.3 % (the standardized effect coefficient in path analysis) during two weeks in field cage-exclusion trials. The effect of high predator/aphid ratios on reducing the aphid population growth rates was also significant in more commercial cotton fields, which were sampled over a longer time interval (4 weeks). Our study confirmed that there was a causal relationship between the natural enemy/pest ratio and the level of biological pest control services for predators and aphid population growth in crop fields. PAR values (predator/aphid ratios) can, therefore, be used to predict the level of biocontrol services in this context instead of relying on more labor-intensive cage exclusion studies.

Effects of sown and spontaneous inter-row vegetation on weeds and beneficial arthropods in vineyards

The intensification of crop management has resulted in a decline of biodiversity in the last decades, in particular through habitat loss, fragmentation and degradation. Semi-natural habitats within agricultural landscapes such as hedges, grasslands or herbaceous field margins, provide resources and refuge to beneficial arthropods. In vineyards, extensively used inter-row vegetation may be functionally equivalent to such semi-natural habitats and sowing of plant species rich in floral resources may improve habitat functions. In this study, three types of vineyard inter-row vegetation treatments were compared in 15 vineyards of South-eastern France: (1) sowing a high-diversity seed mixture (HD) with a high number of nectariferous plant species, (2) spontaneous vegetation, and (3) tilled inter-rows. We monitored the inter-row vegetation including problematic weeds, the abundance of beneficial arthropods, and the predation of sentinel prey. The invasive weedy grass species Cynodon dactylon showed a lower cover in HD inter-rows than in spontaneous vegetation, whereas no differences were found for the invasive herb Erigeron sumatrensis. Both weed species were still best controlled in tilled inter-rows. Beneficial arthropods were less abundant in tilled than in spontaneously vegetated and sown inter-rows. Day predation was higher in HD inter-rows than in spontaneous vegetation although no significant differences were found for observed predators. Over all treatments, plant species richness, flower and grass cover had a positive influence on several beneficial arthropod groups. Our results highlight the positive effects of species-rich inter-row vegetation on weed control, beneficial arthropod abundance and predation but also showed that further research is needed to improve the efficiency beyond services already provided by spontaneous vegetation.

To pool or not to pool: Pooled metabarcoding does not affect estimates of prey diversity in spider gut content analysis

Abstract Gut content metabarcoding has provided important insights into the food web ecology of spiders, the most dominant terrestrial arthropod predators. In small invertebrates, like spiders, gut content analysis is often performed on whole body DNA extracts of individual predators, from which prey sequences are selectively enriched and sequenced. Since many spider species are generalist predators, large numbers of samples comprising individual spider specimens must be analysed to recover an exhaustive image of a spider species' prey spectrum, which is costly and time‐consuming. Pooled processing of bulk samples of multiple specimens has been suggested to reduce the necessary workload and cost while still recovering a representative estimate of the prey diversity. However, it is still unclear if pooling approaches lead to bias in recovering the prey spectrum and if the results are comparable with data from individually processed spiders. Here, we test the effects of metabarcoding pooled spider gut content on the recovered taxonomic diversity and composition of prey. Using a newly adapted primer pair, which efficiently enriches COI barcode sequences of diverse arthropod prey groups while suppressing spider amplification, we test if pooling leads to reduced taxonomic diversity or skewed estimates of prey composition. Our results show that pooling and individual processing recover highly correlated taxonomic diversity and composition of prey. The only exception are very rare prey items which were less well recovered by pooling. Our results support pooling as a cost‐effective and time‐efficient approach to recover the diet of generalist predators for population‐level studies of spider trophic interactions.

Farmed crickets (Orthoptera: Gryllidae) raised with dermestids (Coleoptera: Dermestidae) suffer from reduced and delayed growth, but not enough to explain reports of dramatic yield loss.

The mass production of insects for food and feed is an expanding North American industry. Facilities that mass rear insects are at risk of pest infestations because the optimal environmental conditions for rearing beneficial species may also support the development of pest species. Here, we present the first recorded results detailing the interactions between dermestids and farmed crickets. Cricket farms have reported extremely low harvest yield during heavy dermestid infestations, but the exact reasons for this low yield are unknown. Many dermestid larvae are covered in dense, detachable, barbed setae called hastisetae, which are used by the larvae as an active trapping system against arthropod predators. We designed a series of experiments to test the hypotheses that a dermestid pest of cricket farms, black larder beetle (Dermestes ater DeGeer (Coleoptera: Dermestidae)), may be directly impacting Gryllodes sigillatus Walker (Orthoptera: Gryllidae) yield through the physical effects of hastisetae ingestion and/or indirectly impacting cricket yield through competition for fishmeal, a primary source of protein in conventional cricket feed. Our predictions that G. sigillatus life history and survival would be negatively affected by dermestids were largely refuted. Females fed infested diets grew less mass, but not smaller body size, compared to females fed uninfested diets. We also found that while G. sigillatus experienced delayed growth early in life after living with dermestids, they were able to tolerate living with, and consuming, dermestid larvae. We discuss how these findings have led to new hypotheses concerning how dermestid infestations drive reductions in cricket farm yield.

Influence of Insecticide Application on Pollinators and Predatory Arthropods in Watermelon Agroecosystem

This study, conducted from January to April 2021 in Kandavara village, Karnataka, examined the effects of various insecticides on honeybees, spiders, and coccinellids in watermelon crops. Using a randomized complete block design, watermelon plants were treated with insecticides when pest populations reached economic thresholds. Honeybee foraging activity and populations of spiders and coccinellids were monitored before treatment and at 3,7 and 10 days post-application. Results showed that untreated control plots consistently had the highest activity of all beneficial insects. Among the insecticides tested, Spinosad 45 SC was the least harmful, with relatively higher levels of honeybee and natural enemy activity. In contrast, Imidacloprid 17.8 SL and Acephate 75 SP were the most detrimental, resulting in significantly lower activity levels for honeybees, spiders, and coccinellids. These findings highlight the importance of selecting insecticides that minimize harm to beneficial insects, emphasizing the need for integrated pest management practices that balance effective pest control with the preservation of essential ecosystem services.

Semiochemical-baited traps as a new method supplementing light traps for faunistic and ecological studies of Macroheterocera (Lepidoptera)

Attractivity and selectivity of two types of traps with synthetic, long-lasting, bisexual generic attractants were compared to conventional light traps to promote their wider use, as an easy-to-use standardised method for entomology. The targeted herbivorous Macroheterocera species playing important role in ecosystems as food source for higher trophic levels (e.g. predatory arthropods, birds and mammals), while other hand they can cause significant economic loss in agriculture. Data on their population dynamic and composition of their assemblages are necessary for both nature conservation and efficient pest management. Light- and semiochemical-baited traps with semisynthetic- (SBL = the acronym stands for semisynthetic bisexual lure) and synthetic lures (FLO = the acronym stands for floral lure of synthetic floral compounds) were used in species rich area of West Ukraine, and in all 10,926 lepidopterans trapped were identified. The attractivity of the light trap was highest with 252 species caught, while traps with semiochemicals captured 132 species including 28 exclusively caught only by them. The qualitative selectivity of light vs. semiochemical-baited traps differed considering both taxa and habitat preferences in such a way that they completed each-other. Differences in quantitative selectivity were also proved even in case of pest species. The parameters of methods varied depending on the phenological phases of the studied assemblages. Considering the revealed attractivity and selectivity, the parallel use of the two methods can offer improved reliable data for conservation biology and pest management.

Material composition and mechanical properties of the venom-injecting forcipules in centipedes

BackgroundCentipedes are terrestrial and predatory arthropods that possess an evolutionary transformed pair of appendages used for venom injection—the forcipules. Many arthropods incorporate reinforcing elements into the cuticle of their piercing or biting structures to enhance hardness, elasticity or resistance to wear and structural failure. Given their frequent exposure to high mechanical stress, we hypothesise that the cuticle of the centipede forcipule might be mechanically reinforced. With a combination of imaging, analytical techniques and mechanical testing, we explore the centipede forcipule in detail to shed light on its morphology and performance. Additionally, we compare these data to characteristics of the locomotory leg to infer evolutionary processes.ResultsWe examined sclerotization patterns using confocal laser-scanning microscopy based on autofluorescence properties of the cuticle (forcipule and leg) and elemental composition by energy-dispersive X-ray spectroscopy in representative species from all five centipede lineages. These experiments revealed gradually increasing sclerotization towards the forcipular tarsungulum and a stronger sclerotization of joints in taxa with condensed podomeres. Depending on the species, calcium, zinc or chlorine are present with a higher concentration towards the distal tarsungulum. Interestingly, these characteristics are more or less mirrored in the locomotory leg’s pretarsal claw in Epimorpha. To understand how incorporated elements affect mechanical properties, we tested resistance to structural failure, hardness (H) and Young’s modulus (E) in two representative species, one with high zinc and one with high calcium content. Both species, however, exhibit similar properties and no differences in mechanical stress the forcipule can withstand.ConclusionsOur study reveals similarities in the material composition and properties of the forcipules in centipedes. The forcipules transformed from an elongated leg-like appearance into rigid piercing structures. Our data supports their serial homology to the locomotory leg and that the forcipule’s tarsungulum is a fusion of tarsus and pretarsal claw. Calcium or zinc incorporation leads to comparable mechanical properties like in piercing structures of chelicerates and insects, but the elemental incorporation does not increase H and E in centipedes, suggesting that centipedes followed their own pathways in the evolutionary transformation of piercing tools.

Arthropod activity density and predation are supported by mixed cropping of maize with common sainfoin (Onobrychis viciifolia) and reduced tillage

AbstractMixed cropping with legumes may mitigate negative impacts of maize, Zea mays L. (Poaceae), production on arthropods by providing additional habitat structures and food resources. Still, knowledge about effects of less common legume partner crops for mixed cropping of maize is scarce. Activity density of epigeic predatory arthropods and proxies for ecosystem functions related to biological pest control were assessed on an experimental field. Plots of mixed cropping of maize and sainfoin, Onobrychis viciifolia Scop. (Fabaceae), and respective single plant species (plot size: 6 × 5 m; n = 48) differed in combination of the seed rate of each partner crop and tillage treatment. Using the “rapid ecosystem function assessment” approach in each plot on three occasions, we tested whether the activity density of generalist arthropod predators and their associated ecosystem functions can be promoted by mixed cropping of maize with sainfoin. Our data show that, compared with tilled maize as a pure culture, mixed cropping can increase activity density of generalist arthropod predators and insect predation potential but effects were limited to strip‐tilled cropping systems and partly depended on sampling date. Thus, from an ecological viewpoint, mixed cropping of sainfoin and maize in strip‐till systems offers the possibility to promote predatory insects and their potential for pest regulation. However, this system is inherently more prone to weed occurrence. Competition effects between cropping partners and weeds may reduce yields and hence lead to trade‐offs between enhancement of arthropods and economic viability.

Spatial and Temporal Variation in the Antagonistic and Mutualistic Interactions among Seed Predator Arthropods, Seed-Dispersing Birds, and the Spanish Juniper.

Plants interact with both antagonistic and mutualistic animals during reproduction, with the outcomes of these interactions significantly influencing plant reproductive success, population dynamics, and the evolution of plant traits. Here, we investigated the spatial and temporal variations in the interactions between Juniperus thurifera, its seed-dispersing birds, and three specific arthropod species that attack the fleshy cones during the predispersal period. We assessed how plant traits affect levels of cone damage by arthropods and seed dispersal by birds, the occurrence of competition among arthropod species, and the impact of seed predators on the activity of frugivores. Plant traits, cone damage by arthropods, and seed dispersal by birds showed spatiotemporal variability. Fluctuation in cone abundance was the leading factor determining damage by arthropods and bird dispersal with a secondary role of cone traits. Large crops satiated predispersal seed predators, although the amount of frugivory did not increase significantly, suggesting a potential satiation of bird dispersers. Crop size and cone traits at individual trees determined preferences by seed predator species and the foraging activity of bird dispersers. Competition among arthropods increased during years of low cone production, and seed predators sometimes negatively affected bird frugivory. High supra-annual variations in cone production appear to be a key evolutionary mechanism enhancing J. thurifera reproductive success. This strategy reduces the impact of specialized seed predators during years of high seed production, despite the potential drawback of satiating seed dispersers.

The diversity and ecological roles of insects and arachnids in arabica coffee (Coffea arabica) plantation in Palasari, Bandung Regency

Keanekaragaman komunitas artropoda dapat dijadikan sebagai bioindikator perubahan lingkungan khususnya pada sistem budi daya kopi dengan sistem pengelolaan yang beragam. Sistem pengelolaan lahan yang beragam akan menimbulkan perubahan struktur komunitas dan fungsi ekologis artropoda. Tujuan dari penelitian ini untuk menganalisis keanekaragaman dan peranan serangga dan Arachnida pada perkebunan kopi Arabika di Kabupaten Bandung. Sampel diambil dari perkebunan kopi di Desa Legok Nyenang, Kabupaten Bandung dengan menetapkan lima plot sampel berukuran 100 m2 per plot dengan jarak antar plot sejauh 50 m. Serangga dan Arachnida terestrial diambil menggunakan jaring ayun, perangkap nampan kuning, dan beating sheet. Sampel yang diperoleh diidentifikasi berdasarkan karakter morfologi hingga tingkat morfospesies. Sebanyak 269 jenis serangga (11 ordo dan 98 famili, total 669 individu) dan 23 jenis Aachnida (satu ordo dan 13 famili, total 44 individu) berhasil dikumpulkan dari perkebunan kopi Arabika Palasari. Peran ekologi yang paling beragam adalah fitofag. Spesies fitofag yang dominan adalah Nysius sp. (Hemiptera: Lygaeidae). Musuh alami yang dominan, yaitu parasitoid Megacampsomeris prismatica (Hymenoptera: Scoliidae) dan predator, Tetragnatha sp. (Araneae: Tetragnathidae), sedangkan fungsi ekologis yang jumlahnya paling rendah adalah serangga penyerbuk (Hymenoptera: Apidae). Keanekaragaman jenis serangga dan Arachnida yang ditemukan pada pertanaman kopi di Kabupaten Bandung termasuk dalam kategori tinggi (H' = 5,10), meskipun indeks kemerataan dan dominansinya tergolong rendah. Hasil penelitian ini menunjukkan bahwa pertanaman kopi merupakan ekosistem yang potensial bagi konservasi keanekaragaman hayati serangga dan Arachnida predator sehingga praktik budi daya dan pengelolaan hama harus diarahkan untuk melindungi serangga menguntungkan, seperti musuh alami dan polinator.

Insectivorous birds and bats outperform ants in the top-down regulation of arthropods across strata of a Japanese temperate forest.

Birds, bats and ants are recognised as significant arthropod predators. However, empirical studies reveal inconsistent trends in their relative roles in top-down control across strata. Here, we describe the differences between forest strata in the separate effects of birds, bats and ants on arthropod densities and their cascading effects on plant damage. We implemented a factorial design to exclude vertebrates and ants in both the canopy and understorey. Additionally, we separately excluded birds and bats from the understorey using diurnal and nocturnal exclosures. At the end of the experiments, we collected all arthropods and assessed herbivory damage. Arthropods responded similarly to predator exclusion across forest strata, with a density increase of 81% on trees without vertebrates and 53% without both vertebrates and ants. Additionally, bird exclusion alone led to an 89% increase in arthropod density, while bat exclusion resulted in a 63% increase. Herbivory increased by 42% when vertebrates were excluded and by 35% when both vertebrates and ants were excluded. Bird exclusion alone increased herbivory damage by 28%, while the exclusion of bats showed a detectable but non-significant increase (by 22%). In contrast, ant exclusion had no significant effect on arthropod density or herbivory damage across strata. Our results reveal that the effects of birds and bats on arthropod density and herbivory damage are similar between the forest canopy and understorey in this temperate forest. In addition, ants were not found to be significant predators in our system. Furthermore, birds, bats and ants appeared to exhibit antagonistic relationships in influencing arthropod density. These findings highlight, unprecedentedly, the equal importance of birds and bats in maintaining ecological balance across different strata of a temperate forest.

Flowering zinnia as companion plant increases predatory arthropod abundance and improves yard-long bean yield

Flowering zinnia as companion plant increases predatory arthropod abundance and improves yard-long bean yield

Beyond predator richness: How diversified cropping can enhance pest regulation

AbstractResearch Highlight discussing: Heinen, J.; Dominguez, V.; Aguilera, G.; Malsher, G.; Vesterinen, E.; Roslin, T.; Bommarco, R.; Bartomeus, I. (2024). Diversified cropping strengthens herbivore regulation by providing seasonal resource continuity to predators. Journal of Applied Ecology, https://doi.org/10.1111/1365‐2664.14674. Crop monocultures consist of homogenous agroecosystems highly dependent on pesticides for pest regulation and mineral fertilisation for maintaining plant nutrition, representing the least resilient system. Agricultural diversification practices can increase heterogeneity in agroecosystems, resulting in greater richness of arthropod predators and enhanced ecological services. Among natural enemies of pests, generalist predators are important for pest regulation as they prey on diverse arthropod pests and be present throughout the season. However, since they consume other predators (intraguild predation) and soil fauna, it is uncertain whether enhanced richness of generalist predators translates into improved pest regulation. The study by Heinen et al. examined how diversified crop rotation and organic fertilisation influenced predator–prey interactions throughout the cropping cycle in cereal fields. The predators' diet preference shifted over the growing season, indicating that soil fauna is an important resource for recruitment and maintenance of predators early in the season. Although intraguild predation was considerably high, it decreased across the season in fields with the greatest level of diversification, where predation of pests remained stable. This study demonstrated how diversified cropping is important for providing resource continuity with alternative prey (soil fauna and predators) over crop‐growing season, enhancing predator richness and herbivore regulation.

Resource overlap and infrequent predation on key pests show vulnerability in cotton biological control services

Promoting arthropod biodiversity to increase ecosystem services through ecological intensification is a challenge for agriculture. And recent evidence suggests that standard pesticide applications not only harm natural enemies but may also fail to deliver long-term pest control solutions. To fuel ecological intensification and build predictive frameworks for pest management incorporating estimates of pest abundance, natural enemy abundance and their associated interactions is essential. Within this framework, there is a need to shift the focus from a single pest and predator to consider the community of predatory arthropods that interact with communities of prey. We took a network-based approach to investigate community interactions of predatory arthropods that feed on key pests and alternative prey in cotton over a three-year period. We merged prey activity, generalist predator communities collected from cotton canopies, and reconstructed trophic interactions with DNA detection frequencies estimated from molecular gut content analysis. Overall, many predator diets overlap, resulting in similar foraging patterns on groups of cotton pests. Moreover, predation on key cotton pests, such as stink bugs and white flies, was low. Therefore, ecological intensification that increases specialized arthropod predators within the community should improve biological control service delivery.

Keragaman Arthropoda pada Teknologi Bujangseta di Tanaman Jeruk Siam

Bujangseta is a technology used throughout the year to produce citrus fruits. This technology has economically succeeded in increasing the income of citrus farmers by 23.5%. Sustainable management of bujangseta technology is neede, one of which is maintaining the sustainability of the agroecosystem. A stable agroecosystem ensures the availability of ecosystem services through nutrient cycling and the natural control of pest and disease populations. The stability of agroecosystems is coherent with the high biodiversity of arthropods. This study aims to evaluate the effect of applying the citrus plant bujangseta in Karangwidoro village and Krajan village, Dau District, Malang Regency, East Java, from June to December 2022. The two application methods were light trapping (lighttrap) and pit trap (pitfall glass), and the results were analyzed using a t-test. The diversity index, species richness index, species evenness index, and dominance index were calculated. The results showed that the detrivores of the Collembola group dominated the diversity of arthropods, the primary pest of the Diaphorina citri, and the predatory arthropods of Paederus sp. and Braconidae. Diversity and community structure of arthopods indicated there at significant differences in diversity, dominance, evenness, and species richness in those two locations. Bujangseta in the Krajan has a higher community structure compared to the Karangwidoro, showing that the ecosystem at the Krajan location is better preserved. Keywords: arthropods, bujangseta, citrus, community structure

Manipulating the community structure of arthropods in rice fields with floral resources plants

Abstract Conservation biological control encourages natural enemies to suppress target pests through manipulation of environmental factors that influence natural enemy survival and effectiveness, including microclimates, availability of food for adults and alternative prey, and shelter from adverse environmental conditions. This study aimed to identify selective flowering plants that could be used to manipulate the arthropod community structure in rice fields. Three rice fields (a field without resources of flowering plants, a field with vegetable crop, and a field with ornamental plant) were used in this experiment. The flowering plants included Helianthus sp., Catharanthus roseus, and Cosmos sulphureus while the vegetable plants included eggplant, cucumber, and long beans. Arthropod recording was carried out by direct observation and yellow pan traps from 14 to 98 days after planting. We recorded 33,728 arthropods representing 153 species in 68 families, 13 orders, and 2 classes. The presence of flowering plant significantly affects abundance, species richness, diversity index, and evenness of arthropods both in dry and wet seasons. The rice field surrounded with ornamental plants or vegetables showed the lowest abundance of phytophagous arthropods, the highest abundance of parasitoid and predatory arthropods. Therefore, vegetable crops such as cucumber, long beans and eggplant have great opportunities as refugia in rice fields.