The use of Telenomus remus (Nixon, 1937) (Hymenoptera: Scelionidae) in the management of Spodoptera spp.: potential, challenges and major benefits

Spodoptera frugiperda (Smith, 1797) (Lepidoptera: Noctuidae), also known as fall armyworm (FAW) is a polyphagous pest which can cause significant losses and is considered a global threat to different crops and a risk to food security. Currently, in maize, the pest is predominantly controlled by pesticides or transgenic events. However, the use of biological control agents is considered the most sustainable and preferred method of control, providing high effectiveness. Among the various natural enemies reported for FAW, the egg parasitoid Telenomus remus has gained most interest, and has been mass released against FAW in the Americas for many years. In addition to FAW, other armyworms of the genus Spodoptera often cause high crop damage and may be controlled using T. remus. Among other important aspects, this paper presents a review on T. remus mass rearing techniques, estimated costs of mass production, and release strategies. Due to the recent invasion of FAW in Africa, Asia, and Australia T. remus provides good opportunities for the establishment of an augmentative biological control program, reinforcing sustainable production of major crops such as maize in affected countries.

Breeding for disease resilience: opportunities to manage polymicrobial challenge and improve commercial performance in the pig industry

Disease resilience, defined as an animal’s ability to maintain productive performance in the face of infection, provides opportunities to manage the polymicrobial challenge common in pig production. Disease resilience can deliver a number of benefits, including more sustainable production as well as improved animal health and the potential for reduced antimicrobial use. However, little progress has been made to date in the application of disease resilience in breeding programs due to a number of factors, including (1) confusion around definitions of disease resilience and its component traits disease resistance and tolerance, and (2) the difficulty in characterizing such a complex trait consisting of multiple biological functions and dynamic elements of rates of response and recovery from infection. Accordingly, this review refines the definitions of disease resistance, tolerance, and resilience based on previous studies to help improve the understanding and application of these breeding goals and traits under different scenarios. We also describe and summarize results from a “natural disease challenge model” designed to provide inputs for selection of disease resilience. The next steps for managing polymicrobial challenges faced by the pig industry will include the development of large-scale multi-omics data, new phenotyping technologies, and mathematical and statistical methods adapted to these data. Genome editing to produce pigs resistant to major diseases may complement selection for disease resilience along with continued efforts in the more traditional areas of biosecurity, vaccination and treatment. Altogether genomic approaches provide exciting opportunities for the pig industry to overcome the challenges provided by hard-to-manage diseases as well as new environmental challenges associated with climate change.

Effects of plant growth regulators and growing media on propagation and field establishment of Stevia rebaudiana: a medicinal plant of commerce

Background Stevia rebaudiana is an economically important medicinal plant that has generated interest among the growers and pharmacologists in terms of its industrial or pharmaceutical value. For the mass production of the seedlings, easy and convenient techniques are lacking while, micro propagation was reported promising but still out of reach at farm level. The unavailability of quality planting materials due to non-viable seeds is restricting its mass commercial scale cultivation. The present study was therefore attempted to standardize the plant growth regulators and growing media to standardize the vegetative propagation protocol through cuttings for its mass multiplication in Terai region of West Bengal, India. Methods Growing media (soil, FYM, saw dust and sand) as sole and in combination and growth hormones (IAA, IBA and NAA in different concentration and a commercial formulation i.e. Totoroot© with different exposure time) were compared with control (i.e. sole soil and no hormone treatment, respectively) to standardize the nursery protocol of Stevia. Results Sand used as sole was found the best growing media for survival and growth of cuttings while, cuttings treated with commercial growth hormone formulation for 5 mins was best. Cuttings treated with commercial growth hormone formulation performed significantly better in the field with respect to survival, growth and production of leaves. Conclusion The study recommends the use of sole sand media and commercial growth hormone formulation with 5 mins exposure time for mass nursery production of Stevia cuttings in Terai zone of West Bengal due to their better performance both in the nursery and after transplanting in the field.

Assessment of the optimal frequency of insecticide sprays required to manage fall armyworm (Spodoptera frugiperda J.E Smith) in maize (Zea mays L.) in northern Ghana

Background Insecticide use is an important component of integrated pest management strategies developed for fall armyworm (FAW), Spodoptera frugiperda J.E Smith, control in maize in many African countries. Here, the optimum number of synthetic insecticide and biopesticide applications needed to effectively manage FAW at a minimal cost in maize was studied. Materials and methods A 3 × 4 factorial experiment arranged in a split plot design was used. Insecticides [Neem seed oil (NSO), 3% Azadirachtin); Emastar 112 EC (emamectin benzoate 48 g/L + acetamiprid 64 g/L); Eradicoat (282 g/L Maltodextrin)] were on the main plots, while insecticide spraying regimes [untreated control, spraying once (at VE–V5 maize develoment stage), twice (at VE–V5 and V6–V12 stages), thrice (at VE–V5, V6–V12 and V12–VT stages), four times (at VE–V5, V6–V12, V12–VT and R1–R3 stages)] were on the sub-plots. Results The results showed that larval infestations were generally lower in Emastar 112 EC treated maize than in those sprayed with Eradicoat or NSO. Infestations were higher in the untreated control (no spray) but decreased with increases in number of spray applications in insecticide treated plots. Again, crop damage was low in Emastar 112 EC treated maize. This variable also decreased with an increase in the number of spray applications. Grain yield was significantly affected by the spraying regime only, with this variable being lowest in the untreated control. In both years, yields were at least 1.5-fold higher in maize sprayed twice, thrice or four times compared to the untreated control. Emastar 112 EC had the highest net economic benefits. A single spray of Emastar 112 EC at the VE–V5 maize development stage resulted in maximum profits, while two sprays (i.e., at VE–V5 and V6–V12 stages) were needed for Eradicoat and NSO. Conclusion Hence, synthetic insecticides and biopesticides require different frequency of spray applications for cost effective management of FAW in northern Ghana. These findings are potentially applicable in other sub-Saharan African countries where this pest is present.

The potential cost of regulation of methane and nitrous oxide emissions in U.S. agriculture

Background Most studies on the environmental impacts of agriculture have attempted to measure environmental impacts but have not assessed the ability of the sector to reduce or mitigate such impacts. Only a few studies have examined greenhouse gas emissions from the sector. This paper assesses the ability of states in the U.S. to reduce agricultural emissions of methane and nitrous oxide, two major greenhouse gases (GHGs) with important global warming potential. Methods The analysis evaluates Färe’s PAC (pollution abatement cost) for each state and year, a measure of the potential opportunity costs of subjecting the sector to GHG emissions regulation. We use both hyperbolic and directional distance functions to specify agricultural technology with good and bad outputs. Results and conclusions We find that such regulations might reduce output by an average of about 2%, although the results for individual states vary quite widely.

Areawide management of fall armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae), using selected cover crop plants

Background Fall armyworm, Spodoptera frugiperda (J. E. Smith) is a migratory moth that annually migrates northward each spring from sites in southern Florida and southern Texas. This caterpillar pest feeds on and damages row, turf and vegetable crops in the eastern and central U.S. Before migrating in spring, it feeds on cover crops in central and eastern Florida and expands its populations. Our objective was to use multi-year studies to compare fall armyworm populations that develop in cover crop plants. Methods A series of field experiments and a laboratory feeding study were conducted to compare infestation and feeding and of fall armyworm on different cover crop plants. Field experiments had plots planted with corn (Zea mays L.), sorghum-sudangrass [Sorghum bicolor (L.) Moench], a standard cover crop in Florida, and two alternative cover crops, sunn hemp (Crotalaria juncea L.) and cowpea [Vigna unguiculata (L.) Walpers spp. unguiculata]. Another trial compared populations in sorghum-sudangrass and in mixtures of sorghum-sudangrass with buckwheat (Fagopyrum esculentum Moench) or pearl millet (Cenchrus americanus (L.) Morrone). Fall armyworm larvae were fed and allowed to develop on different sunn hemp germplasm in a laboratory trial. Results Field populations of fall armyworm were highest on corn, followed by sorghum-sudangrass. Sunn hemp and cowpea had larval populations 70–96% less than on sorghum-sudangrass, suggesting replacement of this cover crop with either plant species might help reduce areawide populations of resident or migratory fall armyworm. Larvae collected from cover crop plots had parasitism levels that averaged 30%, with Chelonus insularis (Hymenoptera: Braconidae) emerging as the most commonly-collected species. Larval feeding on different sunn hemp germplasm lines resulted in no difference in weight gain. Conclusions Replacing sorghum-sudangrass with sunn hemp varieties or germplasm should be acceptable as a replacement cover crop for areawide management of fall armyworm.

Genome editing in cultured fishes

With external fertilization, high fecundity, and established methods for propagation and larval rearing for cultured species, fish provide systems well suited to genome-editing procedures. While early experiments utilized zinc-finger nucleases and transcription activator-like effector nucleases (TALENs), most recent ones have used the CRISPR/Cas9 editor, and achieved rates of targeted genomic insertion well above those of classical transgenic methods, with lower frequencies of off-site integration. Genome-editing experiments with cultured fishes have focused on improving growth rate and disease resistance, achievement of reproductive confinement, and other valued traits. As reviewed here, advances in knowledge of key molecular pathways and, in some cases, favorable alterations of phenotype have been achieved. For example, loss-of-function of myostatin, a negative regulator of muscle growth, led to increased muscle mass, greater weight, and greater fillet yield in genome-edited lines of red sea bream, tiger puffer, and Nile tilapia than in their unedited counterparts. The red sea bream line become the first genome-edited animal to reach commercial production. As for all animals, wide adoption of genome-edited fishes will depend upon addressing issues of regulation, consumer acceptance, and breeding infrastructure.

Factors influencing utilization of municipal solid waste compost among urban farmers in western Uganda

Background Effective management of solid waste is one of the most serious environmental problems confronting urban governments in developing countries due to insufficient financial resources and institutional capacity to provide basic solid waste management infrastructure, impoverished urban populations, low rates and coverage of collection, and rising food consumption rates. Composting has been touted as the most economical solution for reducing organic fraction of urban waste volumes while releasing vital nutrients for the soils. However, there is a paucity of information on utilization and associated factors of urban wastes in Uganda. This study aims to assess the level of utilization of Municipal Solid Waste (MSW) compost produced from Clean Development Mechanism (CDM) plants and associated factors among farmers in Fort Portal and Mbarara Municipalities, western Uganda. Methods Data was collected using a cross-sectional survey from 359 and 361 randomly selected farmers in Mbarara and Fort Portal, respectively. A semi-structured questionnaire was employed to collect quantitative data and analyzed statistically using SPSS and STATA statistical programs. Probit model was used to determine factors that influence farmers’ decisions to utilize MSW compost as a soil conditioner. Results The findings revealed a very low level of utilization in both municipalities, 1.7% in Fort Portal and 2.2% in Mbarara. The results indicated that annual farm income, access to other soil conditioners, experience with the use of fertilizers, membership to a farmers’ group and the cost of MSW compost significantly influenced farmers’ decision to use MSW compost. Conclusions The findings call for government investment in policies aimed at increasing the level of utilization of the MSW compost by improving accessibility to soil conditioners, creating opportunities for maximizing household incomes, farmer-to-farmer experience sharing, dissemination of information through extension programmes and other innovative communication approaches, operationalization of farmers’ groups and introduction of subsidy schemes on the price of compost through operational tax waivers in urban areas of Uganda. Finally, to guarantee quality and to improve the adoption of compost generated at the CDM plants, there is a need for research to assess the quality of MSW compost, undertake a supply chain analysis and cost–benefit study and set a price commensurate with the quality, and develop guidelines and rates of application of the MSW compost.

Dynamic guardianship of potato landraces by Andean communities and the genebank of the International Potato Center

Background Potato landraces (Solanum spp.) are not only crucial for food security and sustenance in Andean communities but are also deeply rooted in the local culture. The crop originated in the Andes, and while a great diversity of potato persists, some landraces have been lost. Local communities and the genebank of the International Potato Center (CIP) partnered to re-establish some of these landraces in situ by supplying clean seed potatoes to farmers. Over time, the genebank formalized a repatriation program of potato landraces. Repatriation is the process of returning native germplasm back to its place of origin, allowing a dynamic exchange between ex situ and in situ conditions. So far, no comprehensive description of CIP’s repatriation program, the changes it induced, nor its benefits, has been carried out. Methods We addressed this research gap by analyzing CIP genebank distribution data for repatriated accessions, conducting structured interviews with experts of the repatriation program, and applying duration and benefit analyses to a survey dataset of 301 households. Results Between 1997 and 2020, 14,950 samples, representing 1519 accessions, were distributed to 135 communities in Peru. While most households (56%) abandoned the repatriated material by the fourth year after receiving it, the in situ survival probability of the remaining material stabilized between 36% in year 5 and 18% in year 15. Households where the plot manager was over 60 years old were more likely to grow the repatriated landraces for longer periods of times. While male plot management decreased survival times compared to female plot management, higher levels of education, labor force, wealth, food insecurity, and geographic location in the southern part of Peru were associated with greater survival times. Most farmers reported nutritional and cultural benefits as reasons for maintaining landrace material. Repatriated potatoes enabled farmers to conserve potato diversity, and hence, re-establish and broaden culinary diversity and traditions. Conclusions Our study is the first to apply an economic model to analyze the duration of in situ landrace cultivation by custodian farmers. We provide an evidence base that describes the vast scope of the program and its benefits.

Trends and constraints of utilization of preserved cowpea leaves among households in arid and semi-arid lands in Kenya: a convergent mixed method study

Background As much as local communities have employed traditional techniques of preservation to enhance availability and utilization of cowpea leaves, the efficiency of these techniques in achieving food security need to be established. The current study sought to document trends and constraints of utilization of preserved cowpea leaves in the arid and semi-arid lands (ASALs) in order to overcome of seasonal availability of the vegetable. Method A mixed method convergent design that included household survey of randomly sampled cowpea producing households and focus group discussion and key informant interviews with stakeholders in the ASAL areas of Kitui and Taita Taveta Counties of Kenya was conducted. Results The study found that the utilization of preserved forms of cowpea leaves in the in-season was by 58% of the respondents. Three quarters (73.6%) of the households could not get the vegetables from their own sources during scarcity, whereas 25% did not consume the vegetables at all at such times. The preserved forms of the vegetables was utilized among 24.0% of the households, with significantly (p < 0.05) higher utilization in less arid areas. Households that were involved in commercialization of cowpea leaves and sale of the preserved forms in the open air market had significantly higher likelihood (p < 0.001, OR = 2.47 and p < 0.001, OR = 2.3, respectively) of utilization of the vegetables during scarcity. Emerging themes from the qualitative survey showed that weaknesses in the policy environment, stakeholder interest, marketing and accessibility to proper equipment were the deterrents of traditional preservation of the vegetable. Conclusion In conclusion, the preserved forms of cowpea leaves promoted availability of the vegetable especially in the dry seasons. In as much as there is limited practising of preservation of the vegetables, its availability is enhanced through dehydration and other value-addition techniques among a significant number of the households.