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Simple Summary: Rice breeding programs have included traditional varieties and wild rice species as sources of resistance to planthoppers and leafhoppers, which are major insect pests of rice in Asia. However, herbivores can adapt to resistance (known as virulence adaptation), sometimes in as little as 2 years. Virulence adaptation is a major obstacle for deploying resistant varieties. This review assesses knowledge of the rates, consequences, and mechanisms of virulence adaptation and on possible strategies to delay adaptation in rice landscapes. The review indicates that virulence is a complex of responses to minor and major resistance factors. Of particular interest are adaptations to major rice resistance genes that are likely governed by corresponding herbivore virulence genes. Evidence suggests that pre-adapted individuals (called forerunners) with these virulence genes occur in planthopper populations at relatively low frequencies but can rapidly build up numbers in response to planted resistant rice. However, gradual shifts in virulence may also occur due to intra- and intergenerational improvements in the herbivores' abilities to detoxify plant defense toxins, or to confound defense response networks. These may involve gradual changes in the expression of genes involved in successful herbivore attacks and may be associated with the herbivores or their endosymbionts. Several research gaps remain. In particular, there is a need for increased attention to practical, ecologically based deployment strategies that delay adaptation. In recent decades, research on developing and deploying resistant rice has accelerated due to the availability of modern molecular tools and, in particular, advances in marker-assisted selection. However, progress in understanding virulence adaptation has been relatively slow. This review tracks patterns in virulence adaptation to resistance genes (particularly Bph1, bph2, Bph3, and bph4) and examines the nature of virulence based on selection experiments, responses by virulent populations to differential rice varieties (i.e., varieties with different resistance genes), and breeding experiments that interpret the genetic mechanisms underlying adaptation. The review proposes that varietal resistance is best regarded as a combination of minor and major resistance traits against which planthoppers develop partial or complete virulence through heritable improvements that are reversable or through evolutionary adaptation, respectively. Agronomic practices, deployment patterns, and herbivore population pressures determine the rates of adaptation, and there is growing evidence that pesticide detoxification mechanisms can accelerate virulence adaptation. Research to delay adaptation has mainly focused on gene pyramiding (i.e., including ≥ two major genes in a variety) and multilines (i.e., including ≥ two resistant varieties in a field or landscape); however, these strategies have not been adequately tested and, if not managed properly, could inadvertently accelerate adaptation compared to sequential deployment. Several research gaps remain and considerable improvements in research methods are required to better understand and manage virulence adaptation. [ABSTRACT FROM AUTHOR]

Simple Summary: Hybrid rice is grown by millions of Asian farmers and has normally higher yields compared to inbred varieties. However, hybrid rice has been associated with high damage from herbivores. This susceptibility could be due to the physiology of the hybrid plant type or due to a limited availability of male sterile parents that are necessary for hybrid seed production. We examined how plant type and breeding affect the relative susceptibilities of hybrid and inbred rice by exposing 32 rice genotypes to the brown planthopper, whitebacked planthopper, and yellow stemborer in controlled environments and field plots. We compared insect fitness on the plants and related this to the type and genetic similarity of genotypes. Despite their diverse origins (China, Colombia, India, and the Philippines), the hybrids and inbreds formed two distinct genetic groups, thereby confounding plant type and phylogeny. Hybrids were generally more susceptible to stemborers but not to planthoppers. Relative herbivore fitness was strongly influenced by plant origin (i.e., breeding program) with one group of related genotypes being relatively susceptible to all three herbivores. Our results indicate that hybrids are not inherently more susceptible than inbreds to insect herbivores and that careful screening with the elimination of the most susceptible genotypes is necessary to reduce herbivore damage to hybrid and inbred rice in Asia. Several studies have reported higher damage from insect herbivores to hybrid compared to inbred (pure line) rice. We used a collection of 20 hybrid and 12 inbred genotypes from diverse origins to test the hypotheses that hybrid rice susceptibility is due to (a) the hybrid plant type and/or (b) rice phylogeny. We challenged the genotypes with Nilaparvata lugans (BPH), Sogatella furcifera (WBPH) and Scirpophaga incertulas (YSB) in greenhouse and screenhouse bioassays and monitored herbivores in field plots. We used single nucleotide polymorphic (SNP) markers to assess genetic similarities between the genotypes and found that the hybrids and inbreds formed two distinct clusters regardless of origin. In the screenhouse, hybrids were more susceptible than inbreds to YSB; however, resistant hybrids and susceptible inbreds were also apparent from both the screenhouse and field plots. Plant biomass was the best predictor of susceptibility to YSB. Plant origin had a greater effect than plant type on susceptibility to BPH and WBPH. WBPH was the most abundant planthopper in the field plots where numbers were highly correlated with planthopper fitness in the greenhouse bioassays. Our results provide evidence that high-yielding hybrids that are relatively resistant to herbivores can be achieved through careful breeding. The avoidance of susceptible genotypes during breeding should remain a key element of integrated rice pest management. [ABSTRACT FROM AUTHOR]

Ecological engineering is defined as the design of ecosystems for the benefit of human society and the environment. In Asia, the ecological engineering of rice fields by establishing vegetation on bunds/levees for natural enemies has recently gained traction; however, its success depends on farmers' willingness to implement changes. We surveyed 291 rice farmers in four regions of the Philippines to assess their bund management practices and willingness to establish bund vegetation that restores rice regulatory ecosystem services for pest management. During pre- and post-open field day (OFD) interviews, we assessed farmers' perceptions of ecological engineering practices and sought their advice concerning bund vegetation. Over 60% of the farmers grew crops or allowed weeds on their bunds. Vegetables were grown as a source of extra food or income, and flowers were grown for pest management. Among the remaining farmers, their willingness to try ecological engineering increased from 36 to 74% after the OFDs. Furthermore, after the OFDs, willing farmers increasingly (from 2.6 to 15%) cited pest management as a reason to grow vegetables on bunds, and farmers almost exclusively focused on growing vegetables rather than flowers to adapt the system. While 46.5% of farmers who grew vegetables on their bunds applied insecticides, only ca 20% indicated that they would do so after the OFDs, if needed. Farmers had differing opinions on how vegetables would be incorporated into their rice farms. This range of options could be encouraged wherever farmers recognize the potential harm from pesticides for biodiversity and the restoration value of a diversified farm habitat. [ABSTRACT FROM AUTHOR]

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The tropical Andes is one of the most biodiverse ecoregions on Earth, exhibiting high levels of species endemism. The tropical Andes is also one of the most vulnerable ecoregions worldwide due to a long history of anthropogenic transformations. One of the major obstacles for generating conservation plans is gaps in knowledge about the status and threats to many groups of Andean biodiversity, especially invertebrates. Focusing on three important beetle groups (i.e., Coleoptera: ground beetles, rove beetles and dung beetles) in the tropical Andes, we performed a systematic review of scientific literature retrieving 50 studies that allowed us to assess the degree of knowledge across the region, disturbance types, and biodiversity metrics used. We found a high representation of studies in Colombia, compared with other Andean countries. We also found a marked bias among taxonomic groups, topics or metrics evaluated, with dung beetles the most represented group, particularly in studies addressing forest conversion using metrics such as species richness or abundance. We reveal large gaps in information on the diversity of ground and rove beetles, and in the use of other diversity metrics. The lack of information across countries makes it difficult to generalize results and points to the need for more research, especially in under‐represented countries such as Bolivia and Venezuela. Including complementary response metrics, such as biomass, functional diversity or ecological functions, will improve the assessment of human impacts on tropical Andean beetle communities and wider ecosystems. [ABSTRACT FROM AUTHOR]