Herbivorous Arthropods Research Articles

Arthropod associates of Kenyan buffelgrass (Cenchrus ciliaris): a field survey for biological control candidates of a globally important invasive grass

Invasive species are the second largest contributor to biodiversity loss and drivers of ecosystem change. Buffelgrass is a C4, perennial grass native to Africa and Asia that was widely introduced across tropical and subtropical rangelands as livestock forage. Buffelgrass reduces native biodiversity and ecosystem stability in its introduced range when it escapes livestock pastures. Understanding the ecology of insects associated with buffelgrass in its native range may provide an understanding of invasion processes and biological control opportunities where buffelgrass has become an invasive challenge. Here, we present the results of a six-year survey of herbivorous arthropods of a native buffelgrass population from Kenya. Buffelgrass was examined for externally and internally feeding insects of vegetative and reproductive tissues. We also categorised buffelgrass detritivores and parasitoids that may use buffelgrass herbivores as hosts. The samples were photographed and Sanger sequenced to identify them to the lowest possible taxonomic ranking. We collected information on sample abundances, phenologies, tissues consumed, and putative diet breadths. We identified 25 morphospecies representing seven orders and 16 families. The putative host plant specialisation was as high as 67% for Diptera. Phenological variation in herbivore presence correlated with seasonal rainfall and provided a guide for when to conduct follow-up biological control agent searches. The most abundant herbivore was a gall midge (Diptera: Cecidomyiidae) that inhabits buffelgrass culms. Additional research should focus on bringing this species into containment where host choice trials can be conducted to determine if it is truly monophagous and assess its impact on buffelgrass growth.

Effects of leaf traits of tropical trees on the abundance and body mass of herbivorous arthropod communities.

In tropical forests, herbivorous arthropods remove between 7% up to 48% of leaf area, which has forced plants to evolve defense strategies. These strategies influence the palatability of leaves. Palatability, which reflects a syndrome of leaf traits, in turn influences both the abundance and the mean body mass not only of particular arthropod taxa but also of the total communities. In this study, we tested two hypotheses: (H1) The abundance of two important chewer guilds ('leaf chewers' and 'rostrum chewers'), dominant components of arthropod communities, is positively related to the palatability of host trees. (H2) Lower palatability leads to an increased mean body mass of chewers (Jarman-Bell principle). Arthropods were collected by fogging the canopies of 90 tropical trees representing 31 species in three plots at 1000 m and three at 2000 m a.s.l. Palatability was assessed by measuring several 'leaf traits' of each host tree and by conducting a feeding trial with the generalist herbivore Gryllus assimilis (Orthoptera, Gryllidae). Leaf traits provided partial support for H1, as abundance of leaf chewers but not of rostrum chewers was positively affected by the experimentally estimated palatability. There was no support for H2 as neither leaf traits nor experimentally estimated palatability affected the mean body mass of leaf chewers. The mean body mass of rostrum chewers was positively related to palatability. Thus, leaf traits and experimentally estimated palatability influenced the abundance and mean body mass of chewing arthropods on the community level. However, the data were not consistent with the Jarman-Bell principle. Overall, our results suggest that the palatability of leaves is not among the dominant factors influencing abundance and mean body mass of the community of chewing arthropod herbivores. If other factors, such as the microclimate, predation or further (a-)biotic interactions are more important has to be analyzed in refined studies.

Epidermal bladder cells as a herbivore defense mechanism

The aerial surfaces of quinoa (Chenopodium quinoa) and common ice plant (Mesembryanthemum crystallinum) are covered with a layer of epidermal bladder cells (EBCs), which are modified non-glandular trichomes previously considered to be key to the extreme salt and drought tolerance of these plants. Here, however, we find that EBCs of these plants play only minor roles, if any, in abiotic stress tolerance and in fact are detrimental under conditions of water deficit. We report that EBCs instead function as deterrents to a broad range of generalist arthropod herbivores, through their combined function of forming both a chemical and a physical barrier, and they also serve a protective function against a phytopathogen. Our study overturns current models that link EBCs to salt and drought tolerance and assigns new functions to these structures that might provide novel possibilities for protecting crops from arthropod pests.

Local provincialism of late Permian plant–arthropod associations in South Cathaysia: Evidence of arthropod-mediated damages in a Wuchiapingian assemblage of South China

The Permian is a pivotal time interval for the evolution of the terrestrial realm while the evolutionary dynamics of both floral and faunal turnover are poorly understood. Fossil evidence of plant–arthropod associations allows us to explore these confusions. In this paper, plant–arthropod interactions from the Wuchiapingian Qinglong plant assemblage in southwestern China are analysed. Fifty-one damage occurrences attributed to 19 damage types (DTs) from six functional feeding groups were recognised, consisting of hole feeding, margin feeding, surface feeding, piercing-and-sucking, oviposition, and galling. Although broadleaved gigantopterid laminae were less abundant than strap-shaped taeniopterid foliage, the former had more DT richness as well as DT frequency (occurrences based on presence-absence data) than those of the latter, indicating that herbivorous arthropods preferentially targeted broadleaved gigantopterid foliage and providing additional support for the apparency hypothesis. To explore the evolutionary dynamics of Permian plant–arthropod associations, data of DT community composition in the Qinglong and seven other Permian assemblages were analyzed using principal component analysis (PCA) and rank-abundance curve (RAC). PCA result shows that the Qinglong plant–arthropod associations displayed a damage-type spectrum with minimal affinity to those in the South China Kayitou and other assemblages, indicating that there was no compositional similarity of plant–arthropod associations in the Qinglong and other ecosystems. This pattern is probably related to different climatic zonation which resulted in local provincialism of plant–arthropod associations. RAC result shows that margin feeding was the dominant feeding modes during the Permian, suggesting there were a relatively high richness of margin-feeding culprits in these ecosystems.

Editorial: Chemical ecology of plant arthropod interactions: how do herbivorous arthropods cope with defence chemicals of their host plants?

Editorial: Chemical ecology of plant arthropod interactions: how do herbivorous arthropods cope with defence chemicals of their host plants?

Fossil leaves reveal drivers of herbivore functional diversity during the Cenozoic

Herbivorous arthropods are the most diverse group of multicellular organisms on Earth. The most discussed drivers of their inordinate taxonomic and functional diversity are high niche availability associated with the diversity of host plants and dense niche packing due to host partitioning among herbivores. However, the relative contributions of these two factors to dynamics in the diversity of herbivores throughout Earth's history remain unresolved. Using fossil data on herbivore-induced leaf damage from across the Cenozoic, we infer quantitative bipartite interaction networks between plants and functional feeding types of herbivores. We fit a general model of diversity to these interaction networks and discover that host partitioning among functional groups of herbivores contributed twice as much to herbivore functional diversity as host diversity. These findings indicate that niche packing primarily shaped the dynamics in the functional diversity of herbivores during the past 66 my. Our study highlights how the fossil record can be used to test fundamental theories of biodiversity and represents a benchmark for assessing the drivers of herbivore functional diversity in modern ecosystems.

Large mammalian herbivores affect arthropod food webs via changes in vegetation characteristics and microclimate

Abstract Large mammalian herbivores are vital components of terrestrial ecosystems, influencing the plants they feed on, but also serving as ecosystem engineers that impact the occurrence and survival of many other organisms. Arthropods are the most abundant and diverse animal group on earth, filling all trophic levels in food webs and facilitating essential ecosystem services. However, the impacts of large herbivores on arthropod communities and the mechanisms via which these impacts are mediated are not fully understood. Here, we experimentally separated the mechanistic pathways whereby large herbivores affect arthropod food webs using a 24‐year manipulative multi‐site field experiment in the Netherlands. We analysed the abundance, biomass and community composition of arthropods in the plant canopy and on the soil surface, both in grazed sites or sites where large herbivores were excluded. We found that the presence of large herbivores resulted in considerable differences in vegetation properties and microclimate which influenced the abundance and biomass of arthropods to varying trophic levels. Large herbivore grazing enhanced the overall abundance and biomass of arthropod herbivores, pollinators, omnivores and soil‐dwelling predators, but reduced that of detritivores, scavengers, parasitoids and canopy predators. Structural equation models revealed that different trophic groups are affected by grazing via different pathways. Specially, large herbivores facilitated herbivores via increasing plant quality and enhanced ground‐dwelling predators via increasing plant diversity. In contrast, plant‐dwelling predators were suppressed via decreased plant quantity, and parasitoids were mainly affected by changes in microclimate conditions. Synthesis. Our results show that large mammalian herbivores play a significant role in shaping grassland arthropod food webs, and that these impacts were independently mediated by multiple aspects of vegetation properties, that is, physical structure, plant diversity, standing crop biomass and leaf nutrient content. Arthropods of different trophic groups responded differently to the large herbivores, and these functional group‐specific responses in turn may have strong cascading effects on numerous ecosystem services.

Interactions between the omnivorous bug Nesidiocoris tenuis (Heteroptera: Miridae) and the tomato pests Helicoverpa armigera (Lepidoptera: Noctuidae) and Phthorimaea absoluta (Lepidoptera: Gelechiidae): predation, phytophagy, and prey preference

Abstract Nesidiocoris tenuis (Reuter) (Heteroptera: Miridae) is a zoophytophagous bug that can derive nutrients from 3 trophic levels: plants, herbivorous arthropods, and other predators. On tomato, besides damaging the plants as they feed, might the mirid also forage on pest species and repel pests. In greenhouse and laboratory experiments, we investigated the functional response of the bug, its prey preference, and its influence on the oviposition potentials of 2 major pest species Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) and Phthorimaea absoluta Meyrick (Lepidoptera: Gelechiidae) on tomato Solanum lycopersicum L. (Solanaceae). Nesidiocoris tenuis showed a Type II functional response to both prey species. The estimated handling time was higher for H. armigera eggs than for P. absoluta yet N. tenuis attack rates did not differ between the 2 prey species. Nesidiocoris tenuis did not show a preference for 1 species when prey eggs were provided in equal proportions. The feeding on tomato plants by N. tenuis did not affect oviposition by the 2 moth species, as neither species showed a preference for clean or N. tenuis-adult-damaged plants and clean or N. tenuis-nymph-damaged plants. This study shows that N. tenuis can prey upon eggs of both moth species as the 3 species co-occur in tomato fields. However, because of the shorter handling time of P. absoluta eggs by the predator and the higher number of eggs laid by H. armigera, the co-occurrence might be less detrimental to the H. armigera populations compared to P. absoluta.

Hybridisation between host races broadens the host range of offspring in Eotetranychus asiaticus (Acari: Tetranychidae).

Host adaptation in herbivorous arthropods is one of the first steps to sympatric speciation, and spider mites (Acari: Tetranychidae) are useful model organisms for studying this phenomenon. Many researchers have studied the process of host adaptation via artificial selection experiments. Recent analyses suggest that hybridisation has diversified host ranges, although empirical evidence is scarce. We explored the host exploitation of two strains of Eotetranychus asiaticus established from Ternstroemia gymnanthera (Pentaphylacaceae) and Japanese cinnamon, Cinnamomum yabunikkei (Lauraceae), and evaluated the effect of hybridisation on offspring host use. Transplant experiments showed that females oviposited and immature mites developed only on their native hosts, suggesting specialisation to the secondary metabolites of each host plant. However, F1 hybrids from reciprocal crosses developed on both host plants (survival rate: 92-100%) with normal female-biased sex ratios. Furthermore, all backcrosses to the parental strains yielded B1 offspring that were also viable on both host plants with normal sex ratios (69-87% and39-92%femalesonT. gymnanthera andC. yabunikkei, respectively). B1 survival rates in interstrain crosses were varied (11-63%) and lower than those in intrastrain crosses (88-93%). We could not detect any reproductive barriers in these experiments, and host preference may be the sole factor determining pre-mating isolation. The survival rates and sex ratios we observed suggest cytochromosome interactions. In conclusion, hybridisation, which results in heterozygotes and recombination, is an underexplored way to provide spider mites with a novel host plant.

Birds and bats enhance cacao yield despite suppressing arthropod mesopredation.

Bird- and bat-mediated biocontrol benefits the productivity of tropical commodity crops such as cacao, but the ecological interactions driving these ecosystem services remain poorly understood. Whereas birds and bats prey on herbivorous arthropods, they may also prey on arthropod mesopredators such as ants, with poorly understood consequences for pest biocontrol. We used a full-factorial experiment excluding birds, bats, and ants to assess their effects on (a) the abundance of multiple arthropod groups; (b) predation pressure on arthropods evaluated through artificial sentinel caterpillars; and (c) cacao yield over 1 year in shaded agroforestry systems of native cacao varieties in Peru. Birds and bats increased cacao yield by 118%, which translates in smallholder benefits of ca. US $959 ha-1 year-1 . Birds and bats decreased predation by ants and other arthropods, but contributed to the control of phytophagous taxa such as aphids and mealybugs. By contrast, ant presence increased the abundance of these sap-sucking insects, with negative impacts for cacao yield. Notably, high abundances of the dominant ant Nylanderia sp., known to attend sap-sucking insects, were associated with lower cacao yield along a distance gradient from the closest forest edge. According to these results, arthropod predation by birds and bats, rather than mesopredation by arthropods, was most responsible for increases in cacao yield. Moving forward, detailed research about their trophic interactions will be necessary to identify the cause of such benefits. Retaining and restoring the large benefits of birds and bats as well as minimizing disservices by other taxa in cacao agroforests can benefit from management schemes that prioritize preservation of shade trees and adjacent forests within agroforestry landscapes.

Two-way plant-mediated interactions between a plant parasitic nematode and a foliar herbivore arthropod

Interactions between belowground and aboveground heterotrophic communities with no direct physical contact can be connected by the plant as a mediator. Plants respond to the attack of herbivores by producing a suite of defensive compounds that can affect the choice and performance of other herbivores. The aim of this study was to determine the impact of one herbivore's activity on the acceptability of that plant to another species of herbivore. Two herbivores were tested; root-knot nematode, Meloidogyne incognita (RKN), a belowground plant-parasitic nematode, and the two-spotted spider mite, Tetranychus urticae (TSSM), an aboveground folivore. We conducted herbivore preference and performance tests on Lima bean (LB) (Phaseolus lunatus cv. Henderson) as an optimal host for TSSM, and tomato (Solanum lycopersicum cv. Rutgers) which is a sub-optimal host for TSSM but optimal host for RKN. We used two-choice glass olfactometers to measure the response of RKN to plants that were exposed to TSSM versus a clean LB plant. RKN infected the clean plants at a significantly greater rate than the TSSM exposed plants. TSSM preference was measured, using leaf discs and two-choice olfactometers containing a RKN infected plant versus a clean plant at different days post-inoculation (DPI) of the RKN. TSSM preferred the clean plants to those with 25-day old RKN infections on LB, but preferred RKN infected tomato plants at 1 DPI. We also tested the effect of the inoculation (1 DPI) of the entomopathogenic nematode (EPN) Steinernema carpocapsae on tomato plants and TSSM preferred the EPN inoculated plants. We carried out a non-choice performance test for TSSM on both LB and tomato on plants inoculated with RKN versus clean plants and observed no effect of RKN exposure on TSSM performance. This research shows that plants can mediate interactions between below and aboveground herbivores that share the same plant.

The adaptation new superior varieties and planting ways to arthropode diversity and rice yields

The impact of climate change is the biggest challenge for the agricultural sector, especially the food crops sub-sector. The research was conducted in Jembrana Bali. The aim was to obtain new high yielding varieties of rice and location-specific adaptive planting methods. The research time April - August 2021. Used a factorial randomized block design. The first factor consists of the type of variety (V) and the second factor is the method of planting (T). The type of variety (V) consists of 3 levels, namely V1=Bioni 63; V2= Inpari 32; and V3 = Inpari 30, while the method of planting (T) consists of 2 levels, namely T1 = direct seed planting, and T2 = transplanting. Data were analyzed using analysis of variance and further test with LSD 5%. The results showed that the treatment of varieties and planting methods had no significant effect on the diversity of carnivorous arthropods. Four types of carnivorous arthropods were found, namely odonata, araneae, coccinellidae, and paederinae with a low species diversity index of 0.4985; 0.5210; 0.5172; 0.4976; 0.5205, and 0.5057 in V1T1; V1T2; V2T1; V2T2; V3T1, and V3T2. Dominant herbivorous arthropods were Scirpophaga incertulas Walker, Cnaphalocrocis medinalis, Nilaparvata lugens Stal, and Leptocorisa oratorius. The highest yield was shown in V1T2 at 9.44 tons/ha. It was concluded that the new high yielding varieties of rice and location-specific adaptive planting methods were Bioni 63 Agritan transplanting. The use of the new high-yielding variety Bioni 63 Agritan also contributed to the reduction in the use of chemical pesticides, with data supporting low yellow rice stem borer attack.The relationship between research results and sustainable agriculture is supports sustainable agriculture.

Multitrophic arthropod diversity mediates tree diversity effects on primary productivity.

Forests sustain 80% of terrestrial biodiversity and provide essential ecosystem services. Biodiversity experiments have demonstrated that plant diversity correlates with both primary productivity and higher trophic diversity. However, whether higher trophic diversity can mediate the effects of plant diversity on productivity remains unclear. Here, using 5 years of data on aboveground herbivorous, predatory and parasitoid arthropods along with tree growth data within a large-scale forest biodiversity experiment in southeast China, we provide evidence of multidirectional enhancement among the diversity of trees and higher trophic groups and tree productivity. We show that the effects of experimentally increased tree species richness were consistently positive for species richness and abundance of herbivores, predators and parasitoids. Richness effects decreased as trophic levels increased for species richness and abundance of all trophic groups. Multitrophic species richness and abundance of arthropods were important mediators of plant diversity effects on tree productivity, suggesting that optimizing forest management for increased carbon capture can be more effective when the diversity of higher trophic groups is promoted in concert with that of trees.

Cyanogenesis, a Plant Defence Strategy against Herbivores.

Plants and phytophagous arthropods have coevolved in a long battle for survival. Plants respond to phytophagous feeders by producing a battery of antiherbivore chemical defences, while herbivores try to adapt to their hosts by attenuating the toxic effect of the defence compounds. Cyanogenic glucosides are a widespread group of defence chemicals that come from cyanogenic plants. Among the non-cyanogenic ones, the Brassicaceae family has evolved an alternative cyanogenic pathway to produce cyanohydrin as a way to expand defences. When a plant tissue is disrupted by an herbivore attack, cyanogenic substrates are brought into contact with degrading enzymes that cause the release of toxic hydrogen cyanide and derived carbonyl compounds. In this review, we focus our attention on the plant metabolic pathways linked to cyanogenesis to generate cyanide. It also highlights the role of cyanogenesis as a key defence mechanism of plants to fight against herbivore arthropods, and we discuss the potential of cyanogenesis-derived molecules as alternative strategies for pest control.

The changing dynamics of ant-tree cholla mutualisms along a desert urbanization gradient.

Urbanization, among the most widespread and multifaceted anthropogenic change drivers, exerts strong influences on a diversity of ecological communities worldwide. We have begun to understand how urbanization affects species diversity, yet we still have limited knowledge about the ways that species interactions are altered by urbanization. We have an especially poor understanding of how urbanization influences stress-buffering mutualisms, despite the high levels of multivariate stress that urban organisms must overcome and the importance of these interactions to the fitness of many organisms. In this study, we investigated the effects of urbanization on a mutualism between tree cholla cacti (Cylindropuntia imbricata) and visiting ants. We first examined how plant size, ant species composition, and ant activity varied on C. imbricata across an urbanization gradient (urban, suburban, wild) in and around Albuquerque, NM. Ant species composition and activity varied significantly across the urbanization gradient, with ant communities from wildlands having the highest activity and the most dissimilar species composition compared to both suburban and urban sites. In contrast, plant size remained constant regardless of site type. We then experimentally assessed how nectar levels influenced ant aggressive encounters with proxy prey (Drosophila melanogaster larvae) on C. imbricata across urban and wild sites. Ants were more likely to discover, attack, and remove proxy prey in wild sites compared to urban sites; they also performed these behaviors more quickly in wild sites. Nectar supplementation had weaker effects on ant aggression than urbanization, but consistently increased the speed at which aggressive behaviors occurred. Future studies that examine nectar quality and herbivorous arthropod abundance may help explain why this strong difference in ant composition and aggression was not associated with lower plant fitness proxies (i.e. size traits). Nevertheless, this study provides unique insight into the growing body of work demonstrating that mutualisms vary significantly across urbanization gradients.

Combining organic fertilisation and perennial crops in the rotation enhances arthropod communities

Single and combined diversification practices in crop fields and their effects on arthropod predators, decomposers and herbivores have mainly been assessed in small plot and cage experiments. In particular, effects of diversification on arthropod predators and their food resources, such as soil fauna, weed seeds and herbivorous prey in entire crop fields across the growing season, remain unclear. We explored how organic fertilisers, with or without the legacy of perennial ley in the crop rotation, and mineral fertiliser without the legacy of perennial ley, affected below- and aboveground communities in 19 spring cereal crop fields. In each field, we determined the abundance of the soil mesofauna, communities of arthropod prey aboveground and of the predator guilds carabids, staphylinids and spiders. We sampled at three crop stages: tillering, heading and ripening. Weed cover and soil characteristics, such as carbon and nitrogen content, were assessed. For most soil mesofauna groups, the combination of organic fertiliser with the legacy of ley gave highest, organic fertiliser with annual crop rotations intermediate, and mineral fertiliser with annual crop rotations the lowest total abundance. Aboveground arthropod prey abundances were similar across treatments. The legacy of ley increased richness of all aboveground arthropod predators. Staphylinid communities’ abundance increased additively as diversification treatments were combined during tillering of the crop. Increasing organic amendments, alongside the reduced disturbances through inclusion of perennial ley in the rotation, led to more abundant communities below- and aboveground as well as more richness in aboveground predator communities.

Inducible Gut-Specific Carboxylesterase SlCOE030 in Polyphagous Pests of Spodoptera litura Conferring Tolerance between Nicotine and Cyantraniliprole

Insecticides tolerance in herbivorous arthropods is associated with preadaptation to host plant allelochemicals. However, how plant secondary metabolites activate detoxifying metabolic genes to develop tolerance remains unclear. Herein, the tolerance of Spodoptera litura larvae to cyantraniliprole was increased after nicotine exposure. An S. litura α esterase, SlCOE030, was predominantly expressed in the midgut and induced after exposure to cyantraniliprole, nicotine, and cyantraniliprole plus nicotine. Drosophila melanogaster with ectopically overexpressed SlCOE030 enhanced cyantraniliprole and nicotine tolerance by 4.91- and 2.12-fold, respectively. Compared to UAS-SlCOE030 and Esg-GAL4 lines, the Esg > SlCOE030 line laid more eggs after nicotine exposure. SlCOE030 knockdown decreased the sensitivity of nicotine-treated S. litura larvae to cyantraniliprole. Metabolism assays indicated that recombinant SlCOE030 protein metabolizes cyantraniliprole. Homology modeling and molecular docking analysis demonstrated that SlCOE030 exhibits effective affinities for cyantraniliprole and nicotine. Thus, insect CarEs may result in the development of cross-tolerance between synthetic insecticides and plant secondary metabolites.

Grazing intensity drives a trophic shift in the diet of common alpine birds

Large mammalian herbivores (LMH) shape vertebrate communities and structure food webs in many terrestrial ecosystems. However, the mechanisms that underlie the effects of LMH on other vertebrates are poorly understood. In France, domestic LMH have grazed alpine and mountain grasslands for thousands of years, profoundly influencing landscapes and wildlife. As LMH modify habitat structure, favour coprophagous insects and compete with herbivorous insects, the diet of insectivorous alpine birds may be deeply influenced by LMH grazing intensity. To investigate this, we sampled common insectivorous birds faeces (water pipit Anthus spinoletta and wheatear Oenanthe oenanthe) in sites characterized by different levels of grazing intensity by domestic and wild herbivores, in the open landscapes of the southern French Alps and the western Pyrenees. We used isotopic discrimination based on nitrogen stable isotope ratios as an indicator of the trophic level of the arthropods found in bird faeces. From isotopic ratios, we found that bird diets shift from mainly herbivorous arthropods at sites of low grazing intensity, to one mainly composed of other groups, such as predatory, detritivorous or coprophagous arthropods, at sites of higher grazing intensity. This result highlights the strong trophic link between LMH and insectivorous birds in open landscapes, contributing to a better understanding of interactions between domestic grazing, an activity that has historically modelled European landscapes, and biodiversity, with particular relevance for landscape management and bird conservation.

Introduction of artificial light at night increases the abundance of predators, scavengers, and parasites in arthropod communities

While recent studies explore the negative impacts of light pollution on arthropods, few studies investigated community-level responses to artificial light. Using an array of landscaping lights and pitfall traps, we track community composition over 15 consecutive days and nights, including a five-night pre-light period, a five-night during-light period, and a five-night post-light period. Our results highlight a trophic-level response to artificial nighttime lighting with shifts in the presence and abundance of predators, scavengers, parasites, and herbivores. We show that associated trophic shifts occurred immediately upon the introduction of artificial light at night and are limited to nocturnal communities. Lastly, trophic levels reverted to their pre-light state, suggesting many short-term changes in communities are likely the result of behavioral shifts. These trophic shifts may become common as light pollution increases, implicating artificial light as a cause of global arthropod community change and highlighting light pollution's role in global herbivorous arthropod decline.

Tritrophic Interactions among Arthropod Natural Enemies, Herbivores and Plants Considering Volatile Blends at Different Scale Levels.

Herbivore-induced plant volatiles (HIPVs) are released by plants upon damaged or disturbance by phytophagous insects. Plants emit HIPV signals not merely in reaction to tissue damage, but also in response to herbivore salivary secretions, oviposition, and excrement. Although certain volatile chemicals are retained in plant tissues and released rapidly upon damaged, others are synthesized de novo in response to herbivore feeding and emitted not only from damaged tissue but also from nearby by undamaged leaves. HIPVs can be used by predators and parasitoids to locate herbivores at different spatial scales. The HIPV-emitting spatial pattern is dynamic and heterogeneous in nature and influenced by the concentration, chemical makeup, breakdown of the emitted mixes and environmental elements (e.g., turbulence, wind and vegetation) which affect the foraging of biocontrol agents. In addition, sensory capability to detect volatiles and the physical ability to move towards the source were also different between natural enemy individuals. The impacts of HIPVs on arthropod natural enemies have been partially studied at spatial scales, that is why the functions of HIPVs is still subject under much debate. In this review, we summarized the current knowledge and loopholes regarding the role of HIPVs in tritrophic interactions at multiple scale levels. Therefore, we contend that closing these loopholes will make it much easier to use HIPVs for sustainable pest management in agriculture.