Search results for "Insect pest"
showing 10 items of 15 documents
Complex responses of global insect pests to climate warming
2020
Although it is well known that insects are sensitive to temperature, how they will be affected by ongoing global warming remains uncertain because these responses are multifaceted and ecologically complex. We reviewed the effects of climate warming on 31 globally important phytophagous (plant‐eating) insect pests to determine whether general trends in their responses to warming were detectable. We included four response categories (range expansion, life history, population dynamics, and trophic interactions) in this assessment. For the majority of these species, we identified at least one response to warming that affects the severity of the threat they pose as pests. Among these insect spec…
Toxicity of five Cry proteins against the insect pest Acanthoscelides obtectus (Coleoptera: Chrisomelidae: Bruchinae).
2019
Abstract The beetle Acanthoscelides obtectus (Say) causes severe post-harvest losses in the common bean (Phaseolus vulgaris). Under laboratory conditions, the susceptibility of A. obtectus to five coleopteran-specific Cry toxic proteins from Bacillus thuringiensis (Cry1Ba, Cry1Ia, Cry3Aa, Cry7Ab, and Cry23/37) was evaluated. After 30 days exposure, Cry proteins demonstrated high activity against A. obtectus adults (100% mortality). Proteins showed statistical differences in toxicity parameters compared to the control treatment, but the parameters were similar among them, and indicated that the final toxic effects can be observed after the 24th day. The toxic effects on A. obtectus larvae we…
The genome sequence of the grape phylloxera provides insights into the evolution, adaptation, and invasion routes of an iconic pest
2020
Background: Although native to North America, the invasion of the aphid-like grape phylloxera Daktulosphaira vitifoliae across the globe altered the course of grape cultivation. For the past 150 years, viticulture relied on grafting-resistant North American Vitis species as rootstocks, thereby limiting genetic stocks tolerant to other stressors such as pathogens and climate change. Limited understanding of the insect genetics resulted in successive outbreaks across the globe when rootstocks failed. Here we report the 294-Mb genome of D. vitifoliae as a basic tool to understand host plant manipulation, nutritional endosymbiosis, and enhance global viticulture. Results: Using a combination of…
Insecticidal spectrum and mode of action of the Bacillus thuringiensis Vip3Ca insecticidal protein.
2016
The Vip3Ca protein, discovered in a screening of Spanish collections of Bacillus thuringiensis, was known to be toxic to Chrysodeixis chalcites, Mamestra brassicae and Trichoplusia ni. In the present study, its activity has been tested with additional insect species and we found that Cydia pomonella is moderately susceptible to this protein. Vip3Ca (of approximately 90 kDa) was processed to an approximately 70 kDa protein when incubated with midgut juice in all tested species. The kinetics of proteolysis correlated with the susceptibility of the insect species to Vip3Ca. The activation was faster to slower in the following order: M. brassicae (susceptible), Spodoptera littoralis (moderately…
A Genomic and Proteomic Approach to Identify and Quantify the Expressed Bacillus thuringiensis Proteins in the Supernatant and Parasporal Crystal
2018
The combined analysis of genomic and proteomic data allowed us to determine which cry and vip genes are present in a Bacillus thuringiensis (Bt) isolate and which ones are being expressed. Nine Bt isolates were selected from Spanish collections of Bt based on their vip1 and vip2 gene content. As a first step, nine isolates were analyzed by PCR to select those Bt isolates that contained genes with the lowest similarity to already described vip1 and vip2 genes (isolates E-SE10.2 and O-V84.2). Two selected isolates were subjected to a combined genomic and proteomic analysis. The results showed that the Bt isolate E-SE10.2 codifies for two new vegetative proteins, Vip2Ac-like_1 and Sip1Aa-like_…
What does happen when an insect pest follows its host plant and viceversa?
2015
Invasive species are usually well known but only make up a small percentage of the European’s alien plants and insects. The ways these exotic species interact with our natural and cultural heritage are very complex and even some species considered invasive had and could have positive aspects on some European landscape and culture. A close look at the complicated relationship between non-native and native plants and insects in the Mediterranean areas reveals some unexpected twists in the story. Here are some cases of when aliens can threaten our cultural heritage or being part of it
A Genomic and Proteomic Approach to Identify and Quantify the Expressed
2018
The combined analysis of genomic and proteomic data allowed us to determine which cry and vip genes are present in a Bacillus thuringiensis (Bt) isolate and which ones are being expressed. Nine Bt isolates were selected from Spanish collections of Bt based on their vip1 and vip2 gene content. As a first step, nine isolates were analyzed by PCR to select those Bt isolates that contained genes with the lowest similarity to already described vip1 and vip2 genes (isolates E-SE10.2 and O-V84.2). Two selected isolates were subjected to a combined genomic and proteomic analysis. The results showed that the Bt isolate E-SE10.2 codifies for two new vegetative proteins, Vip2Ac-like_1 and Sip1Aa-like_…
Essential oils from three Algerian medicinal plants (Artemisia campestris, Pulicaria arabica, and Saccocalyx satureioides) as new botanical insectici…
2020
Medicinal and aromatic plants represent an outstanding source of green active ingredients for a broad range of real-world applications. In the present study, we investigated the insecticidal potential of the essential oils obtained from three medicinal and aromatic plants of economic importance in Algeria, Artemisia campestris, Pulicaria arabica, and Saccocalyx satureioides. Gas chromatography coupled with mass spectrometry (GC-MS) was used to study the essential oil chemical compositions. The three essential oils were tested against a mosquito vectoring filariasis and arboviruses, i.e., Culex quinquefasciatus, a fly pest acting also as pathogens vector, Musca domestica, and an agricultural…
Silica Nanoparticles for Insect Pest Control.
2019
To date, control strategies used against insect pest species are based on synthetic insecticide applications. In addition, the efficacy of these treatments could be decreased due to insecticide resistance in insect populations. Also, the irrational use of chemical control strategies has negative consequences of non-target organisms and threatening human health. Designing nanomaterial for pest insect control is a promising alternative to traditional insecticide formulations. In particular, it has been proven that silica nanoparticles have the potential for molecules delivery, release control improvement and also their toxicity as insecticide alone. In this work, we summarized the state of kn…
Susceptibility of Spodoptera frugiperda and S. exigua to Bacillus thuringiensis Vip3Aa insecticidal protein
2011
The Vip3Aa protein is an insecticidal protein secreted by Bacillus thuringiensis during the vegetative stage of growth. The activity of this protein has been tested after different steps/protocols of purification using Spodoptera frugiperda as a control insect. The results showed that the Vip3Aa protoxin was stable and retained full toxicity after being subjected to common biochemical steps used in protein purification. Bioassays with the protoxin in S. frugiperda and S. exigua showed pronounced differences in LC(50) values when mortality was measured at 7 vs. 10d. At 7d most live larvae were arrested in their development. LC(50) values of "functional mortality" (dead larvae plus larvae rem…