scholarly journals Identification of Insect-Deterrent Metabolites from Acremonium masseei strain CICY026, a Saprophytic Fungus from a Sinkhole in Yucatán

2019 ◽  
Vol 7 (12) ◽  
pp. 712
Author(s):  
Ana L. Ruiz-Jiménez ◽  
Esaú Ruiz-Sánchez ◽  
Gabriela Heredia ◽  
Raúl Tapia-Tussell ◽  
Azucena González-Coloma ◽  
...  
Keyword(s):  
Myzus Persicae ◽  
Insect Pests ◽  
Ethyl Acetate Extract ◽  
Rhopalosiphum Padi ◽  
Theoretical Data ◽  
Phytophagous Insects ◽  
Two Dimensional ◽  
New Knowledge ◽  
Bioassay Guided Fractionation ◽  
Control Insect

Micromycetes from unexplored sources represent an opportunity to discover novel natural products to control insect pests. With this aim, a strain of Acremonium masseei CICY026 isolated from a tropical sinkhole was identified, cultured on fermented rice, and its ethyl acetate extract (EAE) was evaluated against three serious phytophagous insects (Bemisia tabaci, Myzus persicae, and Rhopalosiphum padi). DNA from A. masseei CICY026 was used to confirm its identity. EAE caused settling inhibition (SI) of M. persicae and R. padi (67.5% and 75.3%, respectively). Bioassay-guided fractionation of the active EAE led to the isolation of a novel metabolite, named hexahydroacremonintriol (1), and of acremonin A glucoside (2). The structures of 1 and 2 were determined using IR, one- and two-dimensional NMR, HRMS, and confirmed by theoretical data. The aphid M. persicae was noticeably sensitive to 1 and 2 (SI: 55.6% and 67.2%, respectively), whereas R. padi was only slightly affected by 1 (SI: 59%). This new knowledge about mycobiota from these special sinkhole ecosystems will inform the development of new biorational pesticides.

scholarly journals Bioactive Metabolites from the Endophytic Fungus Aspergillus sp. SPH2

2021 ◽  
Vol 7 (2) ◽  
pp. 109
Author(s):  
Viridiana Morales-Sánchez ◽  
Carmen E. Díaz ◽  
Elena Trujillo ◽  
Sonia A. Olmeda ◽  
Felix Valcarcel ◽  
...  
Keyword(s):  
Endophytic Fungus ◽  
Plant Pathogens ◽  
Insect Pests ◽  
Ethyl Acetate Extract ◽  
Rhopalosiphum Padi ◽  
Fungal Growth ◽  
Bioactive Metabolites ◽  
Endemic Plant ◽  
Antifungal Effects ◽  
Aspergillus Sp

In the current study, an ethyl acetate extract from the endophytic fungus Aspergillus sp. SPH2 isolated from the stem parts of the endemic plant Bethencourtia palmensis was screened for its biocontrol properties against plant pathogens (Fusarium moniliforme, Alternaria alternata, and Botrytis cinerea), insect pests (Spodoptera littoralis, Myzus persicae, Rhopalosiphum padi), plant parasites (Meloidogyne javanica), and ticks (Hyalomma lusitanicum). SPH2 gave extracts with strong fungicidal and ixodicidal effects at different fermentation times. The bioguided isolation of these extracts gave compounds 1–3. Mellein (1) showed strong ixodicidal effects and was also fungicidal. This is the first report on the ixodicidal effects of 1. Neoaspergillic acid (2) showed potent antifungal effects. Compound 2 appeared during the exponential phase of the fungal growth while neohydroxyaspergillic acid (3) appeared during the stationary phase, suggesting that 2 is the biosynthetic precursor of 3. The mycotoxin ochratoxin A was not detected under the fermentation conditions used in this work. Therefore, SPH2 could be a potential biotechnological tool for the production of ixodicidal extracts rich in mellein.

The Increasing Need to Control Insect Pests of Oilseed Rape in England

Bee World ◽  
1983 ◽  
Vol 64 (4) ◽  
pp. 163-168 ◽  
Author(s):  
J. B. Free ◽  
A. W. Ferguson ◽  
Susan Winfield
Keyword(s):  
Oilseed Rape ◽  
Insect Pests ◽  
Control Insect

scholarly journals Prevalence of Insects in Traditionally Stored Rice at Farmhouses in Bangladesh

2021 ◽  
pp. 34-44
Keyword(s):  
Storage Time ◽  
Insect Pests ◽  
Sitophilus Oryzae ◽  
Small Farmers ◽  
Plastic Bags ◽  
Rice Moth ◽  
Plastic Bag ◽  
Meal Worm ◽  
Storage Structures ◽  
Control Insect

A survey was conducted to investigate rice storage practices at the farmer’s level and the prevalence of insects’ status through a pretested questionnaire in Mymensingh and Jashore districts, Bangladesh. For seed purposes, large, medium, and small farmers store about 40, 10, and 5 kg, respectively in the Aman season for 7 months whereas in the Boro season large and medium farmers keep about 80 and 20 kg for 5 months. Average storage time was the highest (7 months) for Boro and Aman rice by large and small farmers, respectively for consumption. Eleven storage items namely, Dole, Motka, Tin, Plastic Drum, Gunny Bag, Bamboo Gola, Dhari, Bamboo Auri, Berh, Steel Drum, and Plastic Bag were found. About 57 and 74% of farmers stored rice, among them 47 and 58% used traditional Dole in Jashore and Mymensingh, respectively. Tin and Berh (1%) were the least used storage structures. About 11 and 17%; 3 and 4% of farmers used neem leaf and chemicals especially phostoxin in storage as an insect repellent in these areas, respectively. The use of Plastic Bags increased sharply due to lightweight, availability, and low price, whereas Bamboo Gola, Berh, Motka users decreased remarkably. Relative abundance of the insect species was: Rice Moth Sitotroga cerealla, Rice Weevil Sitophilus oryzae, Red Flour Beetle Tribolium castoreum, and Lesser Meal Worm Alphitobious diaperinus. Maximum insect infestation was found in stored paddy in Dole followed by Motka, and Plastic Bag; and the least amount was observed in Plastic Drum in both regions. Three fourth of the respondents took no measures to control insect pests in stored rice.

Organochlorine and Organophosphorus Residues in Fat of Bovine and Porcine Carcasses Marketed in Ontario, Canada from 1969 to 1981

1983 ◽  
Vol 46 (10) ◽  
pp. 893-900 ◽  
Author(s):  
R. FRANK ◽  
H. E. BRAUN ◽  
G. FLEMING
Keyword(s):  
Insect Pests ◽  
Regression Equations ◽  
Industrial Chemicals ◽  
Organophosphorus Insecticides ◽  
Organochlorine Insecticides ◽  
Maximum Residue Levels ◽  
Order Of Magnitude ◽  
Residue Levels ◽  
Low Levels ◽  
Control Insect

Between 1969 and 1981, 2482 bovine and 554 porcine carcasses were sampled at provincially inspected abattoirs across Ontario. Abdominal fats were composited into 505 bovine and 122 porcine samples for analyses of organochlorine insecticides and industrial chemicals. Mean ∑DDT residues decreased from 257 μg/kg in 1969–70 to 12 μg/kg in 1981 for bovine fats and from 356 μg/kg in 1971–72 to 5 μg/kg in 1981 for porcine fats. Similar decreases in residue levels were observed for PCB. Dieldrin, with lower initial residues (i.e. 33 μg/kg in bovine fat and 12 μg/kg in porcine), decreased an order of magnitude over this same period. All decreases fitted first order logarithmic regression equations. Chloradane and heptachlor epoxide were rarely observed in bovine or porcine fat; however, the incidence in bovine fat increased after 1973 following the removal of aldrin, dieldrin and heptachlor in 1969 for soil insect control and the subsequent increased use of chlordane. Chlordane appeared at low levels (1–2 μg/kg) in bovine fat during the mid 1970s and remained detectable through 1981. Lindane residues in both bovine and porcine fat fluctuated from year to year and appeared to vary with the need to control insect pests. While present (2 to 39 μg/kg) in the early 1970s, lindane residues disappeared by mid 1970 but reappeared in fatty tissues in 1981 (3–13 μg/kg). A limited number of samples were analyzed for organophosphorus insecticides between 1973 and 1980 and residues were occasionally found. In 1981, the analyses became routine and 3.6% of bovine samples were found to contain detectable residues of fenthion; only 2 of 197 bovine samples exceeded the maximum residue levels permitted under the Food and Drug Act.

scholarly journals Considerations for Insect Learning in Integrated Pest Management

2019 ◽  
Vol 19 (4) ◽  
Author(s):  
Catherine M Little ◽  
Thomas W Chapman ◽  
N Kirk Hillier
Keyword(s):  
Integrated Pest Management ◽  
Pest Management ◽  
Cognitive Abilities ◽  
Insect Pests ◽  
Management Strategies ◽  
Pest Species ◽  
Insect Learning ◽  
Local Ecosystem ◽  
Chemical Pesticides ◽  
Control Insect

AbstractThe past 100 yr have seen dramatic philosophical shifts in our approach to controlling or managing pest species. The introduction of integrated pest management in the 1970s resulted in the incorporation of biological and behavioral approaches to preserve ecosystems and reduce reliance on synthetic chemical pesticides. Increased understanding of the local ecosystem, including its structure and the biology of its species, can improve efficacy of integrated pest management strategies. Pest management strategies incorporating insect learning paradigms to control insect pests or to use insects to control other pests can mediate risk to nontarget insects, including pollinators. Although our understanding of insect learning is in its early stages, efforts to integrate insect learning into pest management strategies have been promising. Due to considerable differences in cognitive abilities among insect species, a case-by-case assessment is needed for each potential application of insect learning within a pest management strategy.

scholarly journals Insights into the Toxicity and Degradation Mechanisms of Imidacloprid Via Physicochemical and Microbial Approaches

Toxics ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 65
Author(s):  
Shimei Pang ◽  
Ziqiu Lin ◽  
Yuming Zhang ◽  
Wenping Zhang ◽  
Nasser Alansary ◽  
...  
Keyword(s):  
Large Scale ◽  
Insect Pests ◽  
Point Of View ◽  
Emerging Contaminant ◽  
Human Beings ◽  
Degradation Mechanisms ◽  
The World ◽  
Neonicotinoid Insecticide ◽  
The Central Nervous System ◽  
Control Insect

Imidacloprid is a neonicotinoid insecticide that has been widely used to control insect pests in agricultural fields for decades. It shows insecticidal activity mainly by blocking the normal conduction of the central nervous system in insects. However, in recent years, imidacloprid has been reported to be an emerging contaminant in all parts of the world, and has different toxic effects on a variety of non-target organisms, including human beings, due to its large-scale use. Hence, the removal of imidacloprid from the ecosystem has received widespread attention. Different remediation approaches have been studied to eliminate imidacloprid residues from the environment, such as oxidation, hydrolysis, adsorption, ultrasound, illumination, and biodegradation. In nature, microbial degradation is one of the most important processes controlling the fate of and transformation from imidacloprid use, and from an environmental point of view, it is the most promising means, as it is the most effective, least hazardous, and most environmentally friendly. To date, several imidacloprid-degrading microbes, including Bacillus, Pseudoxanthomonas, Mycobacterium, Rhizobium, Rhodococcus, and Stenotrophomonas, have been characterized for biodegradation. In addition, previous studies have found that many insects and microorganisms have developed resistance genes to and degradation enzymes of imidacloprid. Furthermore, the metabolites and degradation pathways of imidacloprid have been reported. However, reviews of the toxicity and degradation mechanisms of imidacloprid are rare. In this review, the toxicity and degradation mechanisms of imidacloprid are summarized in order to provide a theoretical and practical basis for the remediation of imidacloprid-contaminated environments.

scholarly journals Dual Insecticidal Effects of Adenanthera pavonina Kunitz-Type Inhibitor on Plodia interpunctella is Mediated by Digestive Enzymes Inhibition and Chitin-Binding Properties

Molecules ◽  
2019 ◽  
Vol 24 (23) ◽  
pp. 4344 ◽  
Author(s):  
Caio Fernando Ramalho de Oliveira ◽  
Taylla Michelle de Oliveira Flores ◽  
Marlon Henrique Cardoso ◽  
Karen Garcia Nogueira Oshiro ◽  
Raphael Russi ◽  
...  
Keyword(s):  
Competitive Inhibition ◽  
Insect Pests ◽  
Pupal Stage ◽  
Kinetic Studies ◽  
Plodia Interpunctella ◽  
Docking Studies ◽  
Inhibition Mechanism ◽  
Adenanthera Pavonina ◽  
Enzymes Inhibition ◽  
Control Insect

The Indianmeal moth, Plodia interpunctella, is one of the most damaging pests of stored products. We investigated the insecticidal properties of ApKTI, a Kunitz trypsin inhibitor from Adenanthera pavonina seeds, against P. interpunctella larvae through bioassays with artificial diet. ApKTI-fed larvae showed reduction of up to 88% on larval weight and 75% in survival. Trypsin enzymes extracted from P. interpunctella larvae were inhibited by ApKTI, which also demonstrated capacity to bind to chitin. Kinetic studies revealed a non-competitive inhibition mechanism of ApKTI for trypsin, which were further corroborated by molecular docking studies. Furthermore, we have demonstrated that ApKTI exhibits a hydrophobic pocket near the reactive site loop probably involved in chitin interactions. Taken together, these data suggested that the insecticidal activity of ApKTI for P. interpunctella larvae involves a dual and promiscuous mechanisms biding to two completely different targets. Both processes might impair the P. interpunctella larval digestive process, leading to larvae death before reaching the pupal stage. Further studies are encouraged using ApKTI as a biotechnological tool to control insect pests in field conditions.

scholarly journals Numerical modeling of fluid resonance in narrow gaps of fixed rectangular structures

2019 ◽  
Vol 11 (8) ◽  
pp. 168781401987230
Author(s):  
Ming-ming Liu ◽  
Rui-jia Jin ◽  
Zhen-dong Cui
Keyword(s):  
Free Surface ◽  
Numerical Model ◽  
Stokes Equations ◽  
Theoretical Data ◽  
Numerical Results ◽  
Two Dimensional ◽  
Arbitrary Lagrangian Eulerian ◽  
Fluid Resonance ◽  
Resonance Wave ◽  
Narrow Gaps

A two-dimensional numerical model is developed to investigate the phenomenon of resonance in narrow gaps. Instead of using commonly used Volume of Fluid method to capture the free surface which is sometimes difficult to capture the geometric properties of the geometrically complicated interface, the free surface is traced by using Arbitrary Lagrangian–Eulerian method. The numerical model is based on the two-dimensional Reynolds-Averaged Navier–Stokes equations. The numerical model is validated against wave propagation in wave flume. Comparisons between the numerical results and available theoretical data show satisfactory agreements. Fluid resonance in narrow gaps of fixed rectangular structures are simulated. Numerical results show that resonance wave height and wave frequency for rectangle boxes with sphenoid corners is larger than for rectangle boxes.

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