Eco-friendly Insecticides Research Articles

Venoms yield their secrets

Evolution Venoms can be deadly but, in the right hands, can perform important therapeutic functions. Research into potential drug leads from venoms has, however, been hampered by an inability to study venoms from animals that are small, rare, or difficult to maintain in the laboratory. In a Perspective, Holford et al. highlight recent studies that have used genomics and other omics technologies to study venoms from a wide range of organisms, shedding light on the evolutionary biology of venoms. The work is also providing important leads for the development of therapeutics and eco-friendly insecticides. Science , this issue p. [842][1] [1]: /lookup/doi/10.1126/science.aau7761

Pharmacological and Larvicidal Potential of Green Synthesized Silver Nanoparticles Using Carmona retusa (Vahl) Masam Leaf Extract

Mosquito control is facing a challenge worldwide, due to ineffectiveness of chemical insecticides. Identification of novel and ecofriendly insecticides is the need of the hour. In the present study mosquito control efficacy, antioxidants and anti-cancerous potential of silver nanoparticle conjugated with Carmona retusa (Vahl) Masam nanoparticles. Synthesized nanoparticles had UV absorption maximum at 420 nm, size ranging between 20 and 40 nm based of TEM, has cubic structure, C–H bending and Ag Metal bands. Results show high free radical scavenging ability of C. retusa derived silver nanoparticles as evidenced by DPPH radical and H2O2 radical assay. C. retusa derived nanoparticles produce 80% inhibition in MCF-7 cell line at concentration of 500 μg/ml. High larvicidal activity with LC50 values of 116.681 ppm for Anopheles stephensi, 198.766 ppm for Aedes aegypti, and 83.553 ppm for Culex quinquefasciatus were observed. Based on the findings of the study we suggest that C. retusa plant mediated AgNPs has anticancerous and mosquito larvicidal property and could be bioprospected for drug development and mosquito control.

EVALUATION OF BT LIQUID FORMULATIONS AGAINST GRAM POD BORER, HELICOVERPA ARMIGERA (HUBNER) AND SPOTTED POD BORER, MARUCA VITRATA (GEYER) IN PIGEONPEA

A field experiment was conducted during 2012-15 at Regional Agricultural Research Station, Lam, Guntur district, Andhra Pradesh to evaluate the efficacy of Bt liquid formulations and other biopesticides against gram pod borer, Helicoverpa armigera and spotted pod borer, Maruca vitrata in pigeonpea. There were nine treatments [2 strains of Bt liquid formulations each at two doses, two doses of Beauveria bassiana, neem formulation (azadirachtin 1500 ppm), and chemical check] including untreated control. Pooled analysis of three years data revealed that two sprays of NBAII BtG4 @ 2% at fortnight interval significantly superior over other treatments in suppressing the larval population of H. armigera (3.2 larvae / plant) and M. vitrata (5.9 larvae / plant) on pigeonpea and recorded minimum pod damage (3.7 and 11.4%, respectively) with maximum yield (1565 kg/ha). Further, it was also revealed that all Bt liquid formulations and B. bassiana were safe to natural enemy population viz., spiders and coccinellids existing in pigeonpea ecosystem. It is suggested to utilize biopesticides as ecofriendly insecticides for pigeonpea production.

Toxicity and repellency of essential oil from Evodia lenticellata Huang fruits and its major monoterpenes against three stored-product insects

Toxicity and repellency of essential oil from Evodia lenticellata Huang fruits and its major monoterpenes against three stored-product insects

Larvicidal potency of selected xerophytic plant extracts on Culex pipiens (Diptera: Culicidae)

AbstractChemical insecticides released into the environment may have adverse biological effects. Therefore, there is a need for ecofriendly insecticides for mosquito control. Xerophytic plant extracts that may provide more ecofriendly active component were evaluated against Culex pipiens 4th instars. Plant extracts prepared using different solvents with a Soxhlet apparatus and different concentrations were tested against Culex pipiens larvae. The effects were observed at 24 h and 72 h intervals and LD50 and LD90 values determined. Chloroform (CHCl3) and ethyl acetate (EtOAc) extracts of Althaea ludwigii were the most effective against Cx. pipiens 4th instars, but were highly dependent on extract concentrations and exposure time. Results suggest that A. ludwigii extracts contain bioactive compounds, such as phenols and saponins, that may provide effective Cx. pipiens larval control. However, the extract was found to be toxic to zebrafish larvae, and may be toxic to other aquatic fauna. Further studies to determine the active components and toxicity to other fauna are needed.

Producing armyworm (spodoptera sp.) Bioinsecticide based on cysteine protease of red ginger (zingiber officinale var. Rubrum)

Armyworm (Spodoptera sp.) is highly polyphagous defoliator on various horticulture and grain plants. Various chemical insecticides have been created to control it. There is a need to create an eco-friendly and specific insecticide which only affect armyworm’s nervous system. This research investigates cysteine-protease’s enzyme activity of red ginger (Zingiber officinale var. Rubrum) which is called zingibain. Its catalytic site matches with residue site in armyworm’s body so it can be used as bioinsecticide raw material which meets the criterias above. Fresh red ginger rhizomes were washed and extracted. The juice was then deposited in low temperature and centrifuged to get rid of its starch content. It was filtrated to remove large contaminants and poured into Potassium Phospate buffer. The liquid was then centrifuged again for 30 minutes before collecting the supernatant. Fresh leaves were then dipped into crude ginger protease extract and fed to fourth instar-armyworms. Leaves dipped into non-diluted extract were barely eaten by armyworm while the 50% and 25% dilution was half eaten and most eaten. The crude red ginger extract was not strong enough to kill them although the research showed its enzymatic activity reaches up to 169 PU. It still needs improvement to be produced as commercial bioinsecticide.

The desert wormwood (Artemisia herba-alba) – From Arabian folk medicine to a source of green and effective nanoinsecticides against mosquito vectors

The desert wormwood (Artemisia herba-alba) – From Arabian folk medicine to a source of green and effective nanoinsecticides against mosquito vectors

Larvicidal efficacy of fabricated silver nanoparticles from Butea monosperma flower extract against dengue vector, Aedes aegypti

Development of resistance to synthetic pesticides by mosquitoes, environmental pollution, high operational cost and harmful effects on nontarget organisms had lead to the development of alternative approaches to synthetic pesticides in the vector control strategies. In this study the larvicidal efficacy of fabricated silver nanoparticles from the aqueous flower extract of Butea monosperma has been investigated against the juvenile stages of Aedes aegypti. The green synthesized silver nanoparticles were characterized using UV-Vis spectroscopy, Fourier Transform Infrared spectroscopy, X Ray Diffraction spectroscopy and Scanning Electron Microscopy. Bioassay test was carried out by following the procedure of WHO. Our findings indicate that the silver nanoparticles synthesized from aqueous flower extract of Butea monosperma possess effective larvicidal and pupicidal activity against Aedes aegypti. Hence Butea monosperma could be utilized for developing eco-friendly insecticide as an alternative to synthetic insecticides.

Essential Oils for Myiasis Control: Potentialities for Ecofriendly Insecticides

Essential Oils for Myiasis Control: Potentialities for Ecofriendly Insecticides

Evaluation of novel natural product insecticide from The Egyptian Red Sea coast

The present work aims to collect the most dominant marine soft corals: Sarcophyton glaucum from the Egyptian Red Sea coast, Gulf of Suez, Al- Ain Elsokhna. Evaluating their potential as insecticides and time of exposure against Sitophilus oryzae adults (Coleoptera: curculionidae). Three different solvents (ethanol, chloroform and aqueous extracts of soft corals Sarcophyton glaucum and five concentrations as (20, 200, 500, 1000 and 2000 ppm.) were used in all experiments. Screening analysis of active materials of soft corals Sarcophyton glaucum extracted by ethanol, chloroform and distilled water were terpene, alkaloids and tannins, respectively. The results of this work indicated that the ethanol extracts of Sarcophyton glaucum were achieved the highest mortality rate 100%against adults of S. oryzae at high concentration 2000 ppm. LC50 and LC95 values were recorded as 63.18 and 967.1 ppm. respectively, followed by concentration of ethanol extract at 1000 ppm after 96h. Meanwhile, chloroform achieved high mortality rate at 83.33% . Moreover, LC50 and LC95 were recorded at 166.9 and 3200.0 ppm., respectively. On other hands, mortality percentage by using aqueous extract of S.glaucum was recorded the lowest mortality rate of 63.33%. Moreover, LC50 and LC95 values were recorded 1036.0 and at 5550.0 ppm respectively, . Due to these results, we concluded that effects ethanol extracts from the soft corals Sarcophyton glaucum on S. oryzae had potential insecticidal activity followed by chloroform extract and at last came aqueous extract. Moreover, The mortality percentages were increased by increasing the concentration and time of exposure. These extracts of soft coral S. glaucum may be promising as a novel natural product which could be used as pesticides against S. oryzae adults. So, I would like to recommend these novel products from soft corals to be used, because they are considered eco-friendly insecticides on insects and do not affect on humans, animals and plants and prevent the environmental pollutions

English

English

Insecticidal activity of camphene, zerumbone and α-humulene from Cheilocostus speciosus rhizome essential oil against the Old-World bollworm, Helicoverpa armigera

Insecticidal activity of camphene, zerumbone and α-humulene from Cheilocostus speciosus rhizome essential oil against the Old-World bollworm, Helicoverpa armigera

The crop-residue of fiber hemp cv. Futura 75: from a waste product to a source of botanical insecticides.

In the attempt to exploit the potential of the monoecious fiber hemp cv. Futura 75 in new fields besides textile, cosmetics and food industry, its crop-residue given by leaves and inflorescences was subjected to hydrodistillation to obtain the essential oils. These are niche products representing an ideal candidate for the development of natural insecticides for the control and management of mosquito vectors, houseflies and moth pests. After GC-MS analysis highlighting a safe and legal chemical profile (THC in the range 0.004-0.012% dw), the leaf and inflorescence essential oils were investigated for the insecticidal potential against three insect targets: the larvae of Culex quinquefasciatus and Spodoptera littoralis and the adults of Musca domestica. The essential oil from inflorescences, showing (E)-caryophyllene (21.4%), myrcene (11.3%), cannabidiol (CBD, 11.1%), α-pinene (7.8%), terpinolene (7.6%), and α-humulene (7.1%) as the main components, was more effective than leaf oil against these insects, with LD50 values of 65.8μg/larva on S. littoralis, 122.1μg/adult on M. domestica, and LC50 of 124.5μl/l on C. quinquefasciatus larvae. The hemp essential oil moderately inhibited the acetylcholinesterase (AChE), which is a target enzyme in pesticide science. Overall, these results shed light on the future application of fiber hemp crop-residue for the development of effective, eco-friendly and sustainable insecticides.

Mosquito-larvicidal efficacy of the extract of Musca domestica maggots against Culex pipiens (Diptera: culidae), an important vector of Filariasis

The intolerably high burdens of mosquito-borne diseases will be reduced sustainably through the development of integral eco-friendly alternative insecticides of natural products origin. The need to broaden the global search for such insecticidal lead-agents, especially , those that will be less vulnerable to resistance, was the reason why this bio-assay study was carried out to test Musca domestica maggots against 4th instar larvae of the mosquito Culex pipiens pipiens. The larvicidal bio-assay followed standard World Health Organisation‟s protocols for testing the susceptibility of mosquitoes to larvicides. Larvicidal tests were carried out in a series of extract concentrations ranging from 0.25-4.50 mg/ml, in distilled and tap water media. The results showed that maggot extract possesses significant (P<0.05) larvicidal activities against the mosquito species, in a way akin to those reported for potent plant extracts. The larvicidal activities of the extract was dose dependent; and extract induced significantly higher larval mortality in tap water bio-assay medium than distilled water, except in the 0.25 mg/ml concentration treatment, where the reverse was the case. While, 100% larval mortality was recorded in extract concentration of 2.50 mg/ml in tap water, it took 4.50 mg/ml to kill all exposed larvae in distilled water bio-assay media. The LC50 values of the extract ranged significantly (P<0.05) from 1.57 mg/ml in tap water to 2.26 mg/ml in distilled water. The LC90 equivalents were 2.14 mg/ml and 3.47 mg/ml, respectively. These results suggest that insects may be at-least as promising as the botanicals in our search for eco-friend alternative insecticides.Key words: Bio-assay media, Insect metabolites, Insecticides, Larval mortality, Lethal Concentration and susceptibility.

Clausena anisata and Dysphania ambrosioides essential oils: from ethno-medicine to modern uses as effective insecticides.

Dysphania ambrosioides (L.) Mosyakin & Clemants (Amaranthaceae) and Clausena anisata (Willd.) Hook. f. ex Benth. (Rutaceae) are two aromatic species traditionally used in Cameroon to repel and kill insects. The present work was carried out to substantiate this traditional use and to evaluate the possible incorporation in commercial botanical insecticides of their essential oils (EOs). The EOs were distilled from leaves of C. anisata and aerial parts of D. ambrosioides and analyzed by gas chromatography-mass spectrometry (GC-MS). The insecticidal activity of both EOs was investigated against the filariasis vector, Culex quinquefasciatus, and the housefly, Musca domestica. As possible mode of action, the inhibition of acetylcholinesterase (AChE) by the two EOs was investigated as well. The D. ambrosioides EO was characterized by the monoterpene peroxide ascaridole (61.4%) and the aromatic p-cymene (29.0%), whereas the C. anisata EO was dominated by the phenylpropanoids (E)-anethole (64.6%) and (E)-methyl isoeugenol (16.1%). The C. anisata EO proved to be very toxic to third instar larvae of C. quinquefasciatus showing LC50 of 29.3μl/l, whereas D. ambrosioides EO was more toxic to adults of M. domestica showing a LD50 of 51.7 μg/adult. The mixture of both EOs showed a significant synergistic effect against mosquito larvae with LC50 estimated as 19.3μl/l, whereas this phenomenon was not observed upon application to M. domestica adults (LD50 = 75.9 μg/adult). Of the two EOs, the D. ambrosioides one provided a good inhibition of AChE (IC50 = 77 μg/ml), whereas C. anisata oil was not effective. These findings provide new evidences supporting the ethno-botanical use of these two Cameroonian plants, and their possible application even in synergistic binary blends, to develop new eco-friendly, safe and effective herbal insecticides.

Ligand-binding characterization of simulated β-adrenergic-like octopamine receptor in Schistocerca gregaria via progressive structure simulation

Ligand-binding characterization of simulated β-adrenergic-like octopamine receptor in Schistocerca gregaria via progressive structure simulation

The interaction of the bioinsecticide PA1b (Pea Albumin 1 subunit b) with the insect V-ATPase triggers apoptosis

PA1b (Pea Albumin 1, subunit b) peptide is an entomotoxin, extracted from Legume seeds, with a lethal activity towards several insect pests, such as mosquitoes, some aphids and cereal weevils. This toxin acts by binding to the subunits c and e of the plasma membrane H+-ATPase (V-ATPase) in the insect midgut. In this study, two cereal weevils, the sensitive Sitophilus oryzae strain WAA42, the resistance Sitophilus oryzae strain ISOR3 and the insensitive red flour beetle Tribolium castaneum, were used in biochemical and histological experiments to demonstrate that a PA1b/V-ATPase interaction triggers the apoptosis mechanism, resulting in insect death. Upon intoxication with PA1b, apoptotic bodies are formed in the cells of the insect midgut. In addition, caspase-3 enzyme activity occurs in the midgut of sensitive weevils after intoxication with active PA1b, but not in the midgut of resistant weevils. These biochemical data were confirmed by immuno-histochemical detection of the caspase-3 active form in the midgut of sensitive weevils. Immuno-labelling experiments also revealed that the caspase-3 active form and V-ATPase are close-localized in the insect midgut. The results concerning this unique peptidic V-ATPase inhibitor pave the way for the utilization of PA1b as a promising, more selective and eco-friendly insecticide.

Insecticidal Properties of Essential Oils and Some of Their Constituents on the Turkestan Cockroach (Blattodea: Blattidae).

The Turkestan cockroach, Blatta lateralis (Walker), has become the most important peridomestic species in urban areas of the Southwestern United States. The aim of this study was to evaluate the use of botanical compounds to control this urban pest. We tested the acute toxicity and repellency of six botanical constituents and three essential oils on Turkestan cockroach nymphs. Chemical composition of the essential oils was also determined. Topical and fumigant assays with nymphs showed that thymol was the most toxic essential oil constituent, with a LD50 of 0.34 mg/nymph and a LC50 of 27.6 mg/liter air, respectively. Contact toxicity was also observed in assays with trans-Cinnamaldehyde, eugenol, geraniol, methyl eugenol, and p-Cymene. Methyl eugenol and geraniol had limited fumigant toxicity. The essential oils from red thyme, clove bud, and Java citronella exhibited toxicity against nymphs. Cockroaches avoided fresh dry residues of thymol and essential oils. Chemical analysis of the essential oils confirmed high contents of effective essential oil constituents. Our results demonstrated that essential oils and some of their constituents have potential as eco-friendly insecticides for the management of Turkestan cockroaches.

Lepidopteran HMG-CoA reductase is a potential selective target for pest control.

As a consequence of the negative impacts on the environment of some insecticides, discovery of eco-friendly insecticides and target has received global attention in recent years. Sequence alignment and structural comparison of the rate-limiting enzyme HMG-CoA reductase (HMGR) revealed differences between lepidopteran pests and other organisms, which suggested insect HMGR could be a selective insecticide target candidate. Inhibition of JH biosynthesis in vitro confirmed that HMGR inhibitors showed a potent lethal effect on the lepidopteran pest Manduca sexta, whereas there was little effect on JH biosynthesis in Apis mellifera and Diploptera punctata. The pest control application of these inhibitors demonstrated that they can be insecticide candidates with potent ovicidal activity, larvicidal activity and insect growth regulatory effects. The present study has validated that Lepidopteran HMGR can be a potent selective insecticide target, and the HMGR inhibitors (especially type II statins) could be selective insecticide candidates and lead compounds. Furthermore, we demonstrated that sequence alignment, homology modeling and structural comparison may be useful for determining potential enzymes or receptors which can be eco-friendly pesticide targets.

Cyromazine resistance in a field strain of house flies, Musca domestica L.: Resistance risk assessment and bio-chemical mechanism

Cyromazine resistance in a field strain of house flies, Musca domestica L.: Resistance risk assessment and bio-chemical mechanism