Nitrogen fertilizer use is crucial for agricultural productivity, but it is costly and poses environmental pollution risks. More importantly, excessive nitrogen application can stimulate population growth in primary consumers. This study investigated the effects of nitrogen fertilizer use on a major rice insect pest in Asia, the brown planthopper Nilaparvata lugens (BPH), and its key natural enemy, the wolf spider Pardosa pseudoannulata. The results demonstrated that nitrogen application treatment significantly enhanced the protein levels by 7-37% and crude fat levels by 11-43% in BPH, with a significant interaction effect across BPH generations. Meanwhile, P. pseudoannulata that consumed nitrogen-enriched BPH exhibited a 29% reduction in consumed weight and a 27% decrease in relative consumption rate. Furthermore, spiders consuming N-enriched BPH displayed a 49% decline in searching efficiency and a 32% extension in handling time. These findings indicate that nitrogen fertilizer not only directly benefits insect pests but may also indirectly exacerbate pest outbreaks by interfering with the behavior and efficacy of natural enemies, thereby weakening their pest control function. Therefore, promoting the rational application of nitrogen fertilizer is essential for conservation biological control on insect pest.

Many insect pests, including the brown planthopper (BPH), undergo windborne migration that is challenging to observe and track. It remains controversial about their migration patterns and largely unknown regarding the underlying genetic basis. By analyzing 360 whole genomes from around the globe, we clarify the genetic sources of worldwide BPHs and illuminate a landscape of BPH migration showing that East Asian populations perform closed-circuit journeys between Indochina and the Far East, while populations of Malay Archipelago and South Asia undergo one-way migration to Indochina. We further find round-trip migration accelerates population differentiation, with highly diverged regions enriching in a gene desert chromosome that is simultaneously the speciation hotspot between BPH and related species. This study not only shows the power of applying genomic approaches to demystify the migration in windborne migrants but also enhances our understanding of how seasonal movements affect speciation and evolution in insects.

Photographs of the type specimens of nine spider species described by Barrion et al. (2013) from Hainan Island, China, considered as valid taxa in this study, are provided. Among them, three new combinations are proposed: Clubiona pandalira (Barrion-Dupo, Barrion & Heong, 2013) comb. nov. (ex Nusatidia Deeleman-Reinhold, 2001); Dictis edwardsi (Barrion, Barrion-Dupo & Heong, 2013) comb. nov. (ex Scytodes Latreille, 1804); and Nesioneta mingshengzhui (Barrion, Barrion-Dupo & Heong, 2013) comb. nov. (ex Meioneta Hull, 1920). Thirty-one new synonyms are proposed and three species are considered as nomina dubia.

Twenty-eight species in 14 genera of the family Lycosidae Sundevall, 1833 are documented from Hainan Island, China, including five new species: Allotrochosina huangi Wang, Li ＆ Zhang, sp. nov.（♂♀）, Al. limu Wang, Li ＆ Zhang, sp. nov.（♂）, Arctosa hainan Wang, Li ＆Zhang, sp. nov.（♂♀）, Ar. tangguoi Wang, Li ＆ Zhang, sp. nov.（♂） and Zoica hainan Wang, Li ＆ Zhang, sp. nov.（♂♀）. Eight new synonyms are proposed: Arctosa danzhounensis Barrion, Barrion-Dupo ＆ Heong, 2012 syn. nov. = Ar. springiosa Yin, Wang, Xie ＆ Peng, 1993; Hippasa sinsiloides Barrion, Barrion-Dupo ＆ Heong, 2012 syn. nov. = H. holmerae Thorell, 1895; Lycosa hawigvittata Barrion, Barrion-Dupo ＆ Heong, 2012 syn. nov. = L. vittata Yin, Bao ＆ Zhang, 1995; Pardosa daxiansongi Barrion, Barrion-Dupo ＆ Heong, 2012 syn. nov. = P. pusiola（Thorell, 1891）; P. tieshinglii Barrion, Barrion-Dupo ＆ Heong, 2012 syn. nov. = P. sumatrana（Thorell, 1890）; P. villarealae Barrion, Barrion-Dupo ＆ Heong, 2012 syn. nov. = P. sumatrana（Thorell, 1890）; Pirata sanya Barrion, Barrion-Dupo ＆ Heong, 2012 syn. nov. = Lysania pygmaea Thorell, 1890; Pirata catindigae Barrion, Barrion-Dupo ＆ Heong, 2012 syn. nov. = Pi. subpiratica（B?senberg ＆ Strand, 1906）. The genus Allotrochosina Roewer, 1960 and the species Wadicosa okinawensis（Tanaka, 1985） are newly recorded from China, and Pardosa aciculifera Chen, Song ＆ Li, 2001 is recorded from Thailand for the first time. Females of Arctosa tridentata Chen ＆ Song, 1999 and Ocyale qiongzhongensis Yin ＆ Peng, 1997 are described for the first time. Morphological illustrations and photos of all species are given.

Ecological engineering (EE) involves the design and management of human systems based on ecological principles to maximize ecosystem services and minimize external inputs. Pest management strategies have been developed but farmer adoption is lacking and unsustainable. EE practices need to be socially acceptable and it requires shifts in social norms of rice farmers. In many countries where pesticides are being marketed as “fast moving consumer goods” (FMCG) it is a big challenge to shift farmers’ loss-averse attitudes. Reforms in pesticide marketing policies are required. An entertainment education TV series was able to reach wider audience to improve farmers’ ecological literacy, shifting beliefs and practices. To sustain adoption of ecologically based practices organizational structures, incentives systems and communication strategies to support the new norms and practices are needed.

Most rice insect pests are exogenous immigrants from either long distances or neighbouring areas. For their management to be economical and sustainable, an area-wide perspective is imperative. Key pests, like the planthoppers and stem borers, are highly dependent on rice for survival and reproduction. They multiply and move from one rice crop to another, sometimes carrying virus diseases such as ragged stunt, grassy stunt and rice stripe from source areas. The planthoppers are r strategists, unable to overwinter in northern China, Japan and Korea, and are known to "migrate" or are displaced by wind from southern China to temperate regions of China, Japan and the Korean peninsula. With adequate faunal biodiversity and biological control ecosystem services in a rice crop, immigrant pests have low chances of survival and growth capacities, and often remain a minor pest. However, when the local ecosystem services are compromised, often by unnecessary insecticide use or extreme weather conditions, such as droughts or floods, the immigrants show high survival and growth rates. Since, 2008 the Rice Bowl of Thailand suffered brown planthopper (BPH) (Nilaparvata lugens Stal) outbreaks for 14 consecutive rice seasons that caused losses of more than USD 200 million. Farmers were routinely applying insecticides as prophylactics and the BPH consequently "escaped" its natural control and populations increased 100 000-fold. Ecological engineering approaches involve practices that will build and restore biodiversity and ecosystem services, and reduce insecticide-induced threats to ecosystem services. An area-wide increase in floral biodiversity in the crop landscape provides shelter, nectar, alternate hosts and pollen (abbreviated as SNAP by Professor Wratten) to conserve the natural enemy fauna. Pioneered in Jin Hua, China with sesame plants grown on the rice bunds, ecological engineering is now practiced in China, the Philippines, Thailand, and Viet Nam, using several flower species. A multi-country, multi-year field trial conducted by scientists of the International Rice Research Institute (IRRI) in collaboration with researchers from Australia, China, Thailand and Viet Nam showed that the growing of flowers on rice bunds as an ecological engineering practice increased profits (by 7.5%), yields (by 5%), biological control (by 45%) and added aesthetic values to the rural landscape. At the same time the ecological engineering practice decreased insecticide use (by 70%), pest densities (by 30%) and farmers' chemical input costs (by 70%). Farmers are adopters and implementers of ecological engineering practices, and to reach and motivate the millions of farmers in Viet Nam, two TV serials developed using entertainment-education principles were launched to promote the establishment of flower strips and to reduce insecticide applications. The TV serials helped farmers to "see" and appreciate the role of parasitoids by linking these (termed locally as "small bees") to widely-known bees. Farmers that viewed the serials decreased their insecticide use by 24%, had 3.3% higher yields, increased their appreciation of parasitoids and gained positive attitudes towards the establishment of flower strips. To achieve sustainable area-wide pest management, ecological engineering practices have to be coupled with rational pesticide management through better pesticide policies, regulations and implementation, accurate pest diagnostics and timely professional advice to farmers. Aside from its proven impacts on pest control and more profitable farming, increasing biodiversity and ecosystem services in rice fields can also contribute towards climate change adaptation and a more resilient environment.

The application of nitrogen (N) fertilizers to agricultural crops is a common practice globally and a crucial component in the current levels of productivity. Excessive N use, however, is costly and damaging to ecosystems. It is recognized that overuse of N fertilizer can promote pest herbivores by enhancing host plant nutritional quality, but less is known of the effects of N on natural enemies of pests via improved quality and availability of prey, and how these may cascade to indirect effects on pests. Here, we explored the effects of N fertilizer on a key egg parasitiod of Nilaparvata lugens (Stål) (Hemiptera: Delphacidae) (brown planthopper, BPH). Application of N to rice plants significantly prolonged the development time of Anagrus flaveolus (Hymenoptera: Mymaridae), increased wing size and decreased fecundity of adult females. Importantly, N application to rice plants significantly decreased the per capita parasitism of BPH eggs by A. flaveolus. Utilizing planthopper prey on N-treated rice plants led to reduced searching efficiency of A. flaveolus. Ultimately, the strength of biological control exerted by A. flaveolus was negatively affected by nitrogen application under field conditions. Parasitoids were able to discriminate between BPH infested rice plants with different levels of nitrogen using visual plant cues. We conclude that N fertilizer use can have profound effects on natural enemy efficiency which potentially increase the dependence on insecticides, another potentially hazardous input.

Nitrogen fertilizers are widely used to maximize crop productivity but are also known to benefit pest insects. Here we show that nitrogen not only increased the egg size of the key pest, brown planthopper (BPH), Nilaparvata lugens Stål, but also benefitted the predatory mirid bug, Cyrtorhinus lividipennis Reuter (Hemiptera: Miridae). Predator nymph survival and development rate, female adult weight, longevity and fecundity were all enhanced. Importantly, however, high nitrogen levels also extended the predator handling time (Th), reducing the number of prey eggs attacked per predator and signalling a weakening of top-down control. We conclude that nitrogen fertilizer can exacerbate pest impact by natural enemy-mediated effects in addition to previously reported direct effects on herbivores. Our results highlighted the need to moderate the use of nitrogen fertilizers to maintain effective biological control of these rice pests to reduce dependence on insecticides, another potentially hazardous input.

The brown planthopper (BPH), Nilaparvata lugens , is a serious migratory rice pest, which is distributed in the broad area of the tropical and temperate Asian-Pacific region. However, we know little about key aspects regarding its evolution such as how they diverged and dispersed worldwide. By resequencing and analyzing 358 BPH genomes from 92 populations across the world, we uncover the genetic relationships among their worldwide populations and the history of their global dispersal. We recovered five genetic groups representing the major population structures. Of these, Australian BPHs were shown large genetic divergence with Asian BPHs; two distinct groups have formed in South and Southeast/East Asia that show strong genetic admixture in the southwest border regions of China and west Thailand with Myanmar; two local populations in Bangladesh and Fujian province of China, respectively, unexpectedly separated with surrounding populations. We also find the genetic similarity and closely phylogenetic relationships between majority of East Asian BPHs and Indo-china peninsula BPHs, indicating that Southeast Asia mainland is the major insect sources and overwintering sites for East Asia. Our study provides important molecular evidence to address BPH evolution and other key aspects of its biology such as insecticides resistance and rice varieties virulence.

Wild and domestic bees are essential for the pollination of crops in home gardens, agroforests and vegetable fields of rice smallholders. However, it remains unclear how rice fields and agroforests affect pollinator communities. We investigated the effects of habitat loss and isolation on four different components of bee diversity: abundance, species richness, functional diversity, and plant-pollinator interactions. Flower-visiting bees were recorded in a lowland rice-based production region on the Philippines. We sampled two different land use systems (agroforests and rice fields) and along a gradient of habitat isolation (isolated rice fields and rice fields connected to agroforests). All components of bee diversity were higher in agroforests than in rice fields. Especially above-ground nesting and long-tongued species were adversely affected by rice field habitats and body sizes decreased with isolation from agroforests. For plant-pollinator interactions we found that plants received less diverse pollinator visits in isolated rice fields. In conclusion, agroforests provide important food and nesting resources for bees that translate into taxonomically and functionally diverse pollinator communities as well as stable pollinator visitation networks. These cultivation systems should therefore be maintained or expanded to ensure pollination services and bio-diversity conservation. On the contrary, rice fields provide habitat for only few generalist bee species and flower visitation is reduced in isolated rice fields, possibly also leading to impaired pollination of wild plants and crops. Connectivity between bee habitats located in rice production areas is probably disrupted even after a few hundred meters and should therefore be promoted by measures like flower strips in rice fields.

Agricultural intensification threatens biodiversity and ecosystem functioning. Promoting ecosystem services, such as biological pest control, could help to reduce pesticide inputs while simultaneously sustaining a high productivity. The highly intensive rice production in Southeast Asia, where more than 20% of the world's rice yield is produced, is challenged by devastating losses each year due to rice hoppers. This poses a great threat to the more than 3.5 billion people depending on rice as staple food. Egg parasitoids are among the most important natural enemies of rice hoppers and might be promoted with effective habitat management. However, empirical studies that focus on the management of parasitoid populations to enhance biological pest control in rice agroecosystems are largely lacking. We therefore analysed the effects of the availability of diverse habitats on hopper parasitoid performance, parasitism rates and pest control services, hypothesising that egg parasitoid abundance and pest control is positively influenced by diverse non-crop areas, which provide food resources as well as retreat areas for the fallow season. We experimentally tested the efficiency and abundance of egg parasitoids of Nilaparvata lugens and Nephotettix spp. in three study sites representing different levels of floral resources over the course of two rice growing seasons. We used mixed effect models to test whether habitat diversity positively influenced parasitoid abundance and subsequently reduces hatching rates of the hopper nymphs. Nephotettix spp. eggs were parasitized by Gonatocerus spp. and Paracentrobia spp. by 92.5%; Nilaparvata lugens eggs were parasitized by Oligosita spp. and Anagrus spp by 93%. In contrast to our hypothesis, we could demonstrate that additional floral resources do not significantly enhance parasitoid abundance and pest control in rice agroecosystems. Up to six times more parasitoids hatched-from the bait plants exposed in the monoculture compared to the non-crop areas (p < 0.05). All parasitoid genera except Anagrus spp. were found in rice fields in triple or quadruple numbers compared to the non-crop habitats (p < 0.05). This was true also during the fallow period (p < 0.05), where only ratoon rice was available to sustain hopper populations. In contrast to our hypotheses and findings from temperate productions systems, we found higher parasitoid abundance during all crop stages and increased hatching rates in the monocultures than in the non-crop habitats. The structural and temporal heterogeneity of rice crops and ratoon rice within the production area seemed to be sufficient to sustain high densities of parasitoid populations. We conclude that ecological intensification schemes should implement asynchronous planting cycles in rice systems to maintain or enhance parasitoids populations and their biocontrol services. In combination with reduced pesticide inputs, these measures might help to avoid yield losses due to rice hoppers in the future.

In a cross-disciplinary project (LEGATO) combining inter- and transdisciplinary methods, we quantify the dependency of rice-dominated socio-ecological systems on ecosystem functions (ESF) and the ecosystem services (ESS) the integrated system provides. In the collaboration of a large team including geo- and bioscientists, economists, political and cultural scientists, the mutual influences of the biological, climate and soil conditions of the agricultural area and its surrounding natural landscape have been analysed. One focus was on sociocultural and economic backgrounds, another on local as well as regional land use intensity and biodiversity, and the potential impacts of future climate and land use change. LEGATO analysed characteristic elements of three service strands defined by the Millennium Ecosystem Assessment (MA): (a) provisioning services: nutrient cycling and crop production; (b) regulating services: biocontrol and pollination; and (c) cultural services: cultural identity and aesthetics. However, in line with much of the current ESS literature, what the MA called supporting services is treated as ESF within LEGATO. As a core output, LEGATO developed generally applicable principles of ecological engineering (EE), suitable for application in the context of future climate and land use change. EE is an emerging discipline, concerned with the design, monitoring and construction of ecosystems and aims at developing strategies to optimise ecosystem services through exploiting natural regulation mechanisms instead of suppressing them. Along these lines LEGATO also aims to create the knowledge base for decision-making for sustainable land management and livelihoods, including the provision of the corresponding governance and management strategies, technologies and system solutions.

Cyrtorhinus lividipennis Reuter (Hemiptera: Miridae) is an important predatory natural enemy of planthopper and leafhopper eggs in Asian rice paddy fields. Cyrtorhinus lividipennis is known to rely largely on herbivore-induced plant volatiles to identify eggs embedded in rice stem tissues for feeding and on pheromones for mating. However, exactly how C. lividipennis decode these chemical information is unclear. In most insects, the odorant-binding proteins (OBPs) and the chemosensory proteins (CSPs) are essential for seeking out food resources and mates. In this study, we identified 10 OBP and 5 CSP genes in C. lividipennis and investigated their expression patterns in various tissues of adult males and females by quantitative real-time PCR (qRT-PCR). Six OBP genes (ClivOBP1, 2, 4, 6, 9, and 10) were mainly expressed in the male antennae, whereas three genes (ClivOBP3, ClivOBP7, and ClivOBP8) had high expression in the female antennae. ClivCSP1 was predominantly expressed in the male antennae. These findings suggest that most ClivOBPs and ClivCSPs are likely involved in food-searching behavior. The recognition of the pheromone molecules provides the basis for further functional studies on the chemoreception system of C. lividipennis.

[Aim] The objective of this research is to analyze and predict the potential geographical distributions of two important mirid predators Tytthus chinensis and Cyrtorhinus lividipennis,of rice planthoppers,and to study the effects of climatic factors on their potential geographical distribution.[Methods] Maximum entropy niche-based modeling (MaxEnt) was used to predict species geographical distributions based on maximum entropy.The distribution records of the two mirid species and a set of environmental predictor variables were used to model the suitable geographical distributions of the two species.[Results] The results showed that the principal geographical distribution areas of T.chinensis were Southeast China,East Asia,Southeast Asia and parts of the Indonesia or within the geographical biomes of the Oriental and Australia.The suitable distribution areas of C.lividipennis were relatively broader in comparison with those of T.chinensis.In addition to the distribution area of T.chinensis,C.lividipennis could possibly survive in Shandong,Hebei,Shaanxi and Yunnan provinces in China,and the Amazon region as well.The suitability of T.chinensis and C.lividipennis was found to be affected significantly by the precipitation in the warmest season and the mean diurnal range.Especially,the precipitation in the warmest season exceeding 500 mm and the mean diurnal range monthly below 10℃ are the more favorable conditions for the distribution of T.chinensis and C.lividipennis.[Conclusion] Our results revealed that the suitable distribution of these two predators is primarily affected by the precipitation in the warmest season and the mean diurnal temperature range monthly.This study provides some important evidence for successful biological control of the two mirids in these potential distribution regions.

High⁃throughput sequencing is a major breakthrough in the development of DNA sequencing technology and provides an unprecedented opportunity for modern biological scientific research, such as the DNA⁃based approach tracking the food chains among predators⁃prey or herbivores⁃host plants trophic interactions in ecosystems. This review illustrates and compares the principles of various types of technology, including the Roche 454, Illumina, and Ion Torrent technologies, and other recent progress. We also summarize studies that have used high⁃throughput sequencing technology to study interactions among generalist predators / herbivores and their prey / hosts. This review could provide new information and novel approaches to exploring molecular trophic interactions and improving our understanding of the prey / host spectrum, prey / host shift, biological control, resource allocation, conservation biology, and ecological restoration.