scholarly journals The Effect of Diet Interacting With Temperature on the Development Rate of a Noctuidae Quinoa Pest

2021 ◽  
Author(s):  
Reinaldo Quispe-Tarqui ◽  
Janneth Yujra Pari ◽  
Franz Callizaya Condori ◽  
François Rebaudo
Keyword(s):  
Protein Content ◽  
Pest Control ◽  
Artificial Diet ◽  
Control Strategies ◽  
Development Rate ◽  
Optimal Time ◽  
Significant Damage ◽  
Performance Curves ◽  
Main Driver ◽  
Andean Countries

Abstract The quinoa pest Copitarsia incommoda (Walker, Lepidoptera: Noctuidae) is a cause of significant damage, and it is thus critical for Andean countries to have access to phenological models to maintain production and food safety. These models are key components in pest control strategies in the context of global warming and in the development of sustainable production integrating agroecological concepts. Phenological models are mainly based on outlining the relationship between temperature and development rate. In this study, we investigated the combined effect of protein content within the diet (artificial diet; artificial diet with −20% protein; artificial diet with +20% protein; natural quinoa diet) and temperature (12, 16.9, 19.5, 22.7, 24.6°C) as drivers of the development rate. Our study supports the literature, since temperature was found to be the main driver of the development rate. It highlights the significant role played by protein content and its interaction with temperature (significant effects of temperature, diet, and diet:temperature on development time using GLMs for all foraging life stages). We discuss the implications of such drivers of the development rate for implementing and applying phenological models that may benefit from including factors other than temperature. While performance curves such as development rate curves obtained from laboratory experiments are still a useful basis for phenological development, we also discuss the need to take into account the heterogeneity of the insect response to environmental factors. This is critical if pest control practices are to be deployed at the optimal time.

scholarly journals Silencing of Double-Stranded Ribonuclease Improves Oral RNAi Efficacy in Southern Green Stinkbug Nezara viridula

Insects ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 115
Author(s):  
Rohit Sharma ◽  
Clauvis Nji Tizi Taning ◽  
Guy Smagghe ◽  
Olivier Christiaens
Keyword(s):  
Rna Interference ◽  
Pest Control ◽  
Artificial Diet ◽  
Ex Vivo ◽  
Control Strategies ◽  
Oral Feeding ◽  
Nezara Viridula ◽  
Critical Factors ◽  
Factors Affecting ◽  
Feeding Bioassay

Variability in RNA-interference (RNAi) efficacy among different insect orders poses a big hurdle in the development of RNAi-based pest control strategies. The activity of double-stranded ribonucleases (dsRNases) in the digestive canal of insects can be one of the critical factors affecting oral RNAi efficacy. Here, the involvement of these dsRNases in the southern green stinkbug Nezara viridula was investigated. First, the full sequence of the only dsRNase (NvdsRNase) in the transcriptome of N. viridula was obtained, followed by an oral feeding bioassay to evaluate the effect of NvdsRNase-silencing on oral RNAi efficacy. The NvdsRNase was first silenced in nymphs by NvdsRNase-dsRNA injections, followed by exposure to an artificial diet containing a lethal αCop-specific dsRNA. A significantly higher mortality was observed in the NvdsRNase-silenced nymphs when placed on the dsαCop-containing diet (65%) than in the dsGFP injected and dsαCop fed control (46.67%). Additionally, an ex vivo dsRNA degradation assay showed a higher stability of dsRNA in the saliva and midgut juice of NvdsRNase-silenced adults. These results provide evidence for the involvement of NvdsRNase in the reduction of oral RNAi efficacy in N. viridula. This information will be useful in further improving potential RNAi-based strategies to control this pest.

scholarly journals Effects of Different Water Regimes and Spacing on Insect Pest Infestation and Efficacy of Control Measures in Cucumber (Cucumis sativus)

2019 ◽  
pp. 1-8
Author(s):  
A. A. Oso ◽  
G. O. Awe
Keyword(s):  
Integrated Pest Management ◽  
Pest Management ◽  
Pest Control ◽  
Control Strategies ◽  
Insect Pest ◽  
Cultural Control ◽  
Irrigated Agriculture ◽  
Yield Attributes ◽  
Pest Infestation ◽  
And Control

Aim: Information on the influence of water availability during different seasons of rainfed or irrigated agriculture as it relates to insect pest population build-up in crops could assist in the development of integrated pest management. A study was therefore conducted to investigate effects of spacing, pest infestation and control on cucumber under rainfed and irrigated conditions. Place and Duration of Study: At the Teaching and Research Farm, Ekiti State University, Ado Ekiti, Nigeria during the 2016/2017 rainy and dry seasons. Methodology: The experiment was laid out using randomized complete block design (RCBD) in a split-plot arrangement in five replications, with spacing (60 x 60 cm, 60 x 90 cm and 60 x 120 cm) as the main plot treatments and the sub-plot treatments were different pest control strategies. The pest control strategies include synthetic insecticide (Lambda-cyhalothrin), botanical insecticide (Anogeissus leiocarpus) and control. Growth parameters and yield attributes were recorded. Insect pest occurrence, their build-up and percentage infestation on cucumber and the efficacy of the management strategies were monitored. Results: The results showed that yield was enhanced in irrigated system with the widest spacing of 60 x 120 cm botanical treatment interaction. Bemisia tabaci was the most prominent insect pest attacking cucumber under irrigated system. Conclusion: Other cultural control practices such as the use of trap crops with little or no financial implication should also be added to botanical pesticides as an integrated pest management tactic for effective management and control of the pest.

scholarly journals Silencing cathepsin L expression reduces Myzus persicae protein content and the nutritional value as prey for Coccinella septempunctata

2018 ◽  
Author(s):  
Imran Rauf ◽  
Muhammad Asif ◽  
Imran Amin ◽  
Rubab Zahra Naqvi ◽  
Noroza Umer ◽  
...  
Keyword(s):  
Rna Interference ◽  
Transgenic Plants ◽  
Protein Content ◽  
Pest Control ◽  
Myzus Persicae ◽  
Nutritive Value ◽  
Cathepsin L ◽  
Coccinella Septempunctata ◽  
List Type ◽  
Rnai Construct

AbstractGut-expressed aphid genes, which may be more easily inhibited by RNA interference (RNAi) constructs, are attractive targets for pest control efforts involving transgenic plants. Here we show that expression of cathepsin L, a cysteine protease that functions in aphid guts, can be reduced by expression of an RNAi construct in transgenic tobacco. The effectiveness of this approach is demonstrated by up to 80% adult mortality, reduced fecundity, and delayed nymph production of Myzus persicae (green peach aphids) when cathepsin L expression was reduced by plant-mediated RNAi. Consistent with the function of cathepsin L as a gut protease, M. persicae fed on the RNAi plants had a lower protein content in their bodies and excreted more protein in their honeydew. Larvae of Coccinella septempunctata (seven-spotted ladybugs) grew more slowly on aphids having reduced cathepsin L expression, suggesting that prey insect nutritive value, and not just direct negative effects of the RNAi construct, needs to be considered when producing transgenic plants for RNAi-mediated pest control.HighlightsSilencing expression of cathepsin L by RNA interference reduces protein content of Myzus persicae (green peach aphid) bodies.Honeydew of aphids with cathepsin L silenced contains elevated protein.Cathepsin L is required for efficient protein uptake from phloem sap.Aphids with cathepsin L expression silenced have increased mortality and fewer offspring.Coccinella septempunctata (seven-spotted ladybugs) grow more slowly on aphids with expression of cathepsin L silenced.

scholarly journals Field selectivity of a spinosad-poisoned bait toward target tephritids and non-target insects

2014 ◽  
pp. 11-15 ◽  
Author(s):  
Marco Infusino ◽  
Nino Iannotta ◽  
Stefano Scalercio
Keyword(s):  
Pest Control ◽  
Ceratitis Capitata ◽  
Negative Impact ◽  
Control Strategies ◽  
Field Trials ◽  
Pest Species ◽  
Wild Populations ◽  
Target Species ◽  
Key Points ◽  
Insect Monitoring

One of the key-points in sustainable agriculture is to minimize the amount of pesticides inputs in agro-ecosystems increasing selectivity of active agents on target pests mainly. According to this perspective, control strategies utilising baits receive a growing interest. a spinosad-poisoned sugar-based bait, the so called GF-120 bait, utilised against diptera Tephritidae, recently appeared on the market. The toxicity of spinosad for non-target insects is demonstrated by several authors. However, the amount of pesticide applied is strongly reduced by using it with an attractive food-bait, even if field evidences on the selective attraction of this bait are missing. The aim of this paper is to evaluate the selectivity of GF-120 bait toward target and non-target insects under field conditions, focussing our attention on pollinators. Field trials were performed in a 20 years old olive orchard, where 12 baited and 12 unbaited traps were positioned for insect monitoring. The abundance of the most common orders of insects and target pest species Bactrocera oleae and Ceratitis capitata has been assessed. The main finding of this research is that many pollinators are not attracted by the bait, while target and non-target diptera are significantly attracted by the bait with the exception of Muscidae. The attraction toward a part of non-target diptera should be better explored in order to avoid negative impact on beneficial and non-target species. The need of pest control strategies safer for the environment and the wild populations of non-target organisms seems to be satisfied by the use of this bait.

scholarly journals A survey of plants used by rural small-scale farmers to control pests of cabbage in the Eastern Cape Province, South Africa

2018 ◽  
Vol 2 (1) ◽  
Author(s):  
Nolitha L. Skenjana ◽  
Maxwell A. Poswal
Keyword(s):  
South Africa ◽  
Pest Control ◽  
Control Strategies ◽  
Diamondback Moth ◽  
Botanical Insecticides ◽  
Small Scale ◽  
Eastern Cape Province ◽  
Eastern Cape ◽  
Plant Parts ◽  
Small Scale Farmers

Background: Resource-poor small-scale farmers often cannot afford the high prices of chemical insecticides to control pests on crops; as a result, some use botanical insecticides. Aim: The aim of the study was to document ethnobotanical pest control methods used by rural small-scale farmers to control pests of cabbage in the Eastern Cape Province of South Africa. Setting: 217 rural small-scale crop-producing farmers from 14 towns in the Amathole, Joe Gqabi, Alfred Nzo, Chris Hani and OR Tambo Districts participated in the study. Methods: Questionnaires were administered to consenting farmers between July and November in 2012, using the convenience and stratified purposive sampling techniques. Data collected were subjected to descriptive statistical analysis. Results: The majority of farmers using botanical insecticides were females above the age of 60 years. The farmers identified 23 plants, which they use in their pest control strategies against seven pests of cabbage. The annual herb Tagetes minuta L. (Asteraceae) was cited as the most commonly used herb by 47% of the respondents, followed by Chenopodium ambrosioides L. (Chenopodiceae), Aloe ferox Mills. (Asphodelaceae) and Nicotiana tabacum L. (Solanaceae). Various plant parts were used in combinations or alone in the preparation of formulations mainly against aphids, cutworms and the diamondback moth. Conclusion: The plants, plant parts, combinations and formulations used by farmers in their cabbage pest control strategies need to be scientifically authenticated for efficacy.

scholarly journals Impulsive Biological Pest Control Strategies of the Sugarcane Borer

2012 ◽  
Vol 2012 ◽  
pp. 1-14 ◽  
Author(s):  
Marat Rafikov ◽  
Alfredo Del Sole Lordelo ◽  
Elvira Rafikova
Keyword(s):  
Pest Control ◽  
Floquet Theory ◽  
Control Strategies ◽  
Egg Parasitoid ◽  
Asymptotically Stable ◽  
Biological Pest Control ◽  
Globally Asymptotically Stable ◽  
Larval Stages ◽  
Sugarcane Borer ◽  
Impulsive Release

We propose an impulsive biological pest control of the sugarcane borer (Diatraea saccharalis) by its egg parasitoidTrichogramma galloibased on a mathematical model in which the sugarcane borer is represented by the egg and larval stages, and the parasitoid is considered in terms of the parasitized eggs. By using the Floquet theory and the small amplitude perturbation method, we show that there exists a globally asymptotically stable pest-eradication periodic solution when some conditions hold. The numerical simulations show that the impulsive release of parasitoids provides reliable strategies of the biological pest control of the sugarcane borer.

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