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Food security and biodiversity conservation are threatened by the emergence and spread of pest and pathogens, and thus there is a current need to develop pest management strategies that are sustainable and friendly to the environment and human health. Here, we performed laboratory and field bioassays to evaluate the insecticidal effects of several concentrations of capsaicinoids and glucosinolates (separately and mixed) on an aphid pest (Aphis cytisorum). The capsaicinoids were extracted from the fruits of Capsicum chinense and glucosinolates from the tubers of native Andean crop Tropaeolum tuberosum. We found that both capsaicinoids and glucosinolates have a biocidal effect on A. cytisorum, acting within a fairly short time. Under laboratory conditions, the toxicity of the compounds increased in relation to their concentrations, causing a high percentage of mortality (83−99%) when the aphids were exposed to dilutions of 10% capsaicinoids, 75−100% glucosinolates, or a mixture of 10% capsaicinoids and 90% glucosinolates. The mortality of aphids sprayed in the field with 5% capsaicinoids, 50% glucosinolates, or with a mixture of 5% capsaicinoids and 45% glucosinolates reached 87−97%. Results obtained from laboratory and field experiments were consistent. Our results suggest the potential use of bioinsecticides based on capsaicinoids and/or glucosinolates as an effective alternative to synthetic pesticides.

Stilbenes are constitutively accumulated in grape canes at a high concentration of about 10 g kg DW. Some of these compounds have antimicrobial activity and are involved in grapevine defence in leaves and fruits, acting as phytoalexins. In this work, we studied their insecticidal effects against Spodoptera littoralis larvae by using an extract from grapevine canes containing 27% (w/w) of total stilbenes and the major ones isolated from this extract ( E-piceatannol, E-resveratrol, isohopeaphenol, E- ε-viniferin and E-vitisin B). The stilbenes isolated from the grapevine extract did not show any significant antifeedant effect or acute toxicity, but they did cause chronic mortality to the larvae population of an important polyphagous pest, S. littoralis. The tetramer, E-vitisin B, appeared to be the most effective compound with LC and LC values of 134 and 298 µg cm, respectively. Significant synergic relationships were found between some stilbenes, resulting in a significant increase in the insecticidal efficacy of the mixture of these substances. Taken together, these results suggest that grapevine canes are a good source of active substances for the development of botanical insecticides. [ABSTRACT FROM AUTHOR]

The constant use of chemicals to control pests can cause several problems to the environment andhuman health, accelerate resistance to insect pests and natural enemies mortality. The objective of this study was toestimate the LC50 of neem oil through the effects on mortality and development of larvae of Spodoptera frugiperda(J. E. Smith) (Lepidoptera: Noctuidae). Third instar larvae were individually placed in tubes of rearing containing arectangular portion of maize (Zea mays L.) leaf (variety AL 34) emerged in neem oil solutions at concentrations of0.010; 0.017; 0.077; 0.129; 0.359; 0.599; 1.0%; deltamethrin 25 EC (0.1%) and control (no treatment). Leaves wereimmerged in the treatment solutions for 3 minutes, dried and offered to caterpillars, repeated 20 times in a completelyrandomized design. The evaluations were performed daily by checking the larval and pupal mortality, period (days) ofthe third instar to pupation and pupal period (days), estimating the lethal concentration (LC50) by the Probit method.The neem oil caused 100% mortality of S. frugiperda, at larval or pupal stage, and the LC50 of neem oil of third instarlarvae was 0.213%.

Botanical insecticides have been studied aiming the alternative pest control. The present study investigated the effects of these insecticides on the instantaneous population growth rate (ri) of Aphis gossypii. Botanical insecticides were tested in the following concentrations: Compostonat®, Rotenat-CE® and Neempro (0, 0.50, 0.75, 1.00, 1.25, 1.50 and 1.75%); Natuneem® and Neemseto® (0, 0.25, 0.50, 0.75 and 1.00%) and essential oils of Foeniculum vulgare Mill., Cymbopogom winterianus (L.), Chenopodium ambrosioides L. and Piper aduncum L (0, 0.0125, 0.025, 0.0375 and 0.05%). Cotton leaf discs, CNPA 8H cultivar with 5 cm in diameter were immersed for 30 seconds in products broth and dried for 30 minutes. Eight replicates per concentration were used and each disc was infested with five apterous adult females of A. gossypii uniform in size and confined for 10 days. Compostonat®, Rotenat® and Neempro provided negative ri decreasing A. gossypii population. Natuneem® and Neemseto® and the essential oil of F. vulgare showed positive ri increasing the population. The coefficients of determination (R2) of regression lines ranged from 0.46 to 0.85. The essential oils of C. winterianus, C. ambrosioides and P. aduncum were not statistically significant precluding the establishment of regression lines.Inseticidas botânicos têm sido estudados, visando o controle alternativo de pragas. O presente trabalho objetivou estudar os efeitos desses inseticidas sobre a taxa instantânea de crescimento populacional (ri) de Aphis gossypii. Os inseticidas botânicos foram testados nas seguintes concentrações: Compostonat®, Rotenat-CE® e Neempro (0; 0,50; 0,75; 1,00; 1,25; 1,50 e 1,75%); Nautneem® e Neemseto® (0; 0,25; 0,50; 0,75 e 1,00%); e os óleos essenciais de Foeniculum vulgare Mill., Cymbopogom winterianus (L.), Chenopodium ambrosioides L. e Piper aduncum L. (0; 0,0125; 0,025; 0,0375 e 0,05%). Discos de folhas de algodoeiro, cultivar CNPA 8H, com 5 cm de diâmetro foram imersos por 30 segundos nas caldas dos produtos e secos por 30 minutos. Utilizaram-se oito repetições por concentração, e cada disco foi infestado com cinco fêmeas adultas ápteras de A. gossypii de tamanho uniforme, confinadas durante 10 dias. Compostonat®, Rotenat® e Neempro proporcionaram ri negativas, declinando a população de A. gossypii. Natuneem®, Neemseto® e o óleo essencial de F. vulgare apresentaram ri positivas, aumentando a população. Os coeficientes de determinação (R2) das retas de regressão variaram entre 0,46 a 0,85. Os óleos essenciais de C. winterianus, C. ambrosioides e P. aduncum não apresentaram significância estatística, impossibilitando o estabelecimento das retas de regressão.

Purpose: To investigate contact and fumigant toxicity of the essential oil of Bidens frondosa and its isolated constituents against booklice (Liposcelis bostrychophila). Methods: The essential oil of B. frondosa was obtained by hydro-distillation and analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) with HP-5MS column. The active constituents were purified from the oil by bioactivity-guided fractionation. Contact (impregnated filter paper method) and fumigant toxicity (sealed space) of the oil and its isolates were determined. Results: Thirty-two compounds, representing 98.88 % of the total oil, were determined and the major constituents of the essential oil were caryophyllene oxide (20.50 %), borneol (17.66 %), 4-terpineol (17.26 %), and ß-cedrene (6.94 %). The essential oil displayed fumigant toxicity against booklice, with a median lethal concentration (LC50) of 507.35 µg/L while the isolated constituents, borneol and 4-terpineol, had LC50 values of 2.20 mg/L and 335.24 µg/L against booklice, respectively. The essential oil also exhibited contact toxicity against L. bostrychophila with an LC50 value of 210.73 µg/cm². Borneol, caryophyllene oxide, β-cedrene, and 4-terpineol showed acute toxicity against booklice with LC50 of 98.04, 84.62, 458.79 and 211.35 µg/cm², respectively. Conclusion: The results suggest that the essential oil and its isolates possess potential for cultivation into natural insecticides or fumigants, for control of insects in stored grains. [ABSTRACT FROM AUTHOR]

Research on natural insecticides has intensified with the spread of resistance to chemicals among insects, particularly disease vectors. To evaluate compounds, the World Health Organization (WHO) has published standardized procedures. However, those may be excessively compound-consuming when it comes to assessing the activity of natural extracts and pure compounds isolated in limited amount. As part of our work on the discovery of new mosquito larvicides from Amazonian plants, we developed a compound-saving assay in 5-ml glass tubes instead of WHO larval 100-ml cups. Comparing activity of synthetic and natural chemicals validated the glass tube assay. Raw data, lethal doses that kill 50% (LD50) and 90% (LD90) at 24 and 48 h, were highly correlated (0.68 < R2 < 0.96, P < 0.001, Pearson test) between cups and tubes. It was also established that 10 tubes ( N = 50 larvae) provided the same level of sensitivity as 20 tubes ( N = 100). This method proved suitable for rapid screening of natural extracts and molecules, identifying active compounds using 10 times less material than in the WHO protocol. [ABSTRACT FROM AUTHOR]

Solanaceous plants have a great economic impact in Egypt. These groups of plants include potatoes, tomatoes and eggplants. The new invasive pest of tomatoes, Tuta absoluta (Meyrick) causes the greatest crop losses which can range from 60 to 100%. After its detection in Egypt during the last half of 2009, it spread quickly to all provinces in the country. We aiming to propose a sustainable control program for this devastating pest. In this research we tested three groups of control agents. The first was microbial and natural, the second - plant extracts and the third - chemical insecticides. Our results showed that the impact of T. absoluta can be greatly reduced by the use of sustainable control measures represented by different insecticide groups. Bioassay experiments showed that this devastating pest can be controlled with some compounds that give high mortality rates. Of these compounds, spinosad and Beauveria bassiana, microbial control agents, followed by azadirachtin, gave the best results in controlling T. absoluta. Of the chemical insecticides, lambda-cyhalotrin was the most effective, followed by lufenuron and profenofos. In conclusion we encourage farmers to use microbial and natural control measures in combating the tomato leafminer, T. absoluta, in Integrated Pest Mangement (IPM) programs. [ABSTRACT FROM AUTHOR]

Óleos essenciais de Piper aduncum L. e Piper hispidinervum C.DC. (Piperaceae) foram avaliados quanto ao efeito inseticida em Sitophilus zeamais Motsch. por ação de contato, fumigação e tópica. Na determinação da DL50 e CL50, foi utilizada a análise de Probit. Médias porcentuais de mortalidade dos insetos foram comparadas por meio da análise de regressão linear e superposição das barras do erro padrão. S. zeamais foi mais suscetível ao efeito de contato do óleo de P. hispidinervum em relação ao de P. aduncum, obtendo-se CL50 de 0,51 e 2,87 mL cm- 2 de óleo, respectivamente. Mortalidade próxima a 100% foi obtida nas concentrações de 20 e 30% do óleo de P. hispidinervum. Quanto ao efeito fumigante, a susceptibilidade foi maior no óleo de P. aduncum do que no de P. hispidinervum. Houve diferença significativa entre os óleos somente nas concentrações de 0,1 e 1,0. A DL50 foi semelhante nos dois óleos essenciais por aplicação tópica. No entanto, a mortalidade foi maior com P. aduncum. Óleos essenciais de P. aduncum e P. hispidinervum possuem efeito inseticida em S. zeamais, mas as respostas dependem da concentração e do método de exposição a que o inseto seja submetido.Essential oils of Piper aduncum L. and Piper hispidinervum C. DC. (Piperaceae) were tested against Sitophilus zeamais Motsch. Contact, fumigant toxicity and topical effect were tested. Probit analysis was employed in evaluating the LC50 and LD50 response. Linear regression analysis and superposition of the bars (means error standard) were used for comparison of means percentage mortality. S. zeamais was more susceptible to the contact toxicity of the P. hispidinervum oil than P. aduncum oil with LC50 values of 0.51 and 2.87 mL cm-2 of the oil, respectively. The mortality rate was nearly 100% at P. hispidinervum oil concentrations of 20 and 30%. With respect to the fumigant action, the weevil was more susceptible to the P. aduncum oil than to P. hispidinervum. A significant difference between oils mortality was observed only at 0.1 and 1.0% concentrations. For topical effect, similar values of the LD50 were obtained for essential oils. However, the mortality was higher with P. aduncum. Essential oils of the P. aduncum and P. hispidinervum possess insecticidal effect from S. zeamais, but the responses varied according to concentration of the oils and exposure methods.

Laboratory-reared Lutzomyia longipalpis (Lutz and Neiva 1912) was tested with extracts of two ichthyotoxic plants, known as timbós, used as fishing poison in the Amazon. Phlebotomines, L. longipalpis, and plants, Antonia ovata and Derris amazonica, were collected in the Raposa-Serra do Sol Indian Reserve, a focus of visceral leishmaniasis in the State of Roraima, Brazil. Extracts were prepared from dried leaves of A. ovata and roots of D. amazonica that were percolated in water, filtered and dried out at 50°C. The solid extract obtained was diluted in water at 150, 200 and 250 mg/ml. The solution was blotted in filter paper placed at the bottom of cylindric glass tubes containing sand flies. For each plant extract and dilution, two series of triplicates with 5 male and 5 female specimens of L. longipalpis were used. Mortality was recorded every 2 h during 72 h of exposure. At 72 h the mortality was as high as 80% for extracts of A. ovata (LD50 = 233 mg/ ml), and 100% for D. amazonica (LD50 = 212 mg/ ml) whereas in the control groups maximum mortality never surpassed 13%. Preliminary assays indicated that A. ovata and D. amazonica displayed significant insecticide effect against L. longipalpis.

In this communication we have evaluated the toxic properties of methanol extracts from flowers, peduncles, leaves, petioles and stem bark of Dimorphandra mollis to Apis mellifera workers. Astilbin (5,7,3',4'-tetrahydroxy--2,3-dihydroflavonol-3-beta-O-rhamnoside) has been isolated from peduncles and flowers of this plant in large amounts. Astilbin presented insecticidal activity against confined bees. The results suggest that astilbin reduces the average survival of treated bees.

In the last decades, the entomotoxicity of JBU and its derived peptides became an object of study, due mainly to the ubiquitous interaction of these compounds with different species of insects and their potential as natural insecticides. In this work, we investigated the neurotoxic effects of JBU in Nauphoeta cinerea cockroaches by dissecting pharmacologically the monoaminergic pathways involved. Selective pharmacological modulators for monoaminergic pathways in in vivo and ex vivo experimental models were employed. Thus, the analysis of N. cinerea neurolocomotory behavior demonstrated that JBU (1.5 and 3 μg/g) induces a significant decrease in the exploratory activity. In these assays, pretreatment of animals with phentolamine, SCH23390 or reserpine, interfered significantly with the response of JBU. Using in vivo abductor metathoracic preparations JBU (1.5 μg/g) induced progressive neuromuscular blockade, in 120 min recordings. In this set of experiments, the previous treatment of the animals with phentolamine, SCH23390 or reserpine, completely inhibited JBU-induced neuromuscular blockade. The recordings of spontaneous compound neural action potentials in N. cinerea legs showed that JBU, only in the smallest dose, significantly decreased the number of potentials in 60 min recordings. When the animals were pretreated with phentolamine, SCH23390, or reserpine, but not with mianserin, there was a significant prevention of the JBU-inhibitory responses on the action potentials firing. Meanwhile, the treatment of the animals with mianserin did not affect JBU's inhibitory activity. The data presented in this work strongly suggest that the neurotoxic response of JBU in N. cinerea involves a cross talking between OCTOPAMIN-ergic and DOPAMIN-ergic nerve systems, but not the SEROTONIN-ergic neurotransmission. Further molecular biology studies with expression of insect receptors associated with voltage clamp techniques will help to discriminate the selectivity of JBU over the monoaminergic transmission. [Display omitted] • The entomotoxicity of Jack Bean Ureases involves locomotory deficits in insects; • The entomotoxicity of Jack Bean Ureases induces central and peripheral neurotoxicity; • Jack Bean Urease impairs Nauphoeta cinerea neuromuscular function; • Jack Bean Urease reduce the mechanoreption in Nauphoeta cinerea cockoraches; • The neurotoxic activity must be related to a octopaminergic-dopaminergic transduction. [ABSTRACT FROM AUTHOR]

Copyright of Revista Ibero-Americana de Ciências Ambientais is the property of CBPC - Companhia Brasileira de Producao Cientifica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Plants and herbivores have co-evolved in their natural habitats for about 350 million years, but since the domestication of crops, plant resistance against insects has taken a different turn. With the onset of monoculture-driven modern agriculture, selective pressure on insects to overcome resistances has dramatically increased. Therefore plant breeders have resorted to high-tech tools to continuously create new insect-resistant crops. Efforts in the past 30 years have resulted in elucidation of mechanisms of many effective plant defenses against insect herbivores. Here, we critically appraise these efforts and - with a focus on sap-sucking insects - discuss how these findings have contributed to herbivore-resistant crops. Moreover, in this review we try to assess where future challenges and opportunities lay ahead. Of particular importance will be a mandatory reduction in systemic pesticide usage and thus a greater reliance on alternative methods, such as improved plant genetics for plant resistance to insect herbivores.

The effects of kaolin and diatomaceous earth applied alone and in combinations with sweet orange [ Citrus sinensis (L.) Osbeck] peel essential oil against Rhyzopertha dominica (F.) (Coleoptera: Bostrichidae) and wheat microbial populations were evaluated. Adult beetles reared on durum wheat (cv Simeto) were used to carry out the tests. Five formulations at five application rates were tested. Both insect mortality and progeny production were affected by the treatment, the application rate and the exposure time. C. sinensis essential oil showed a synergistic effect on the mortality of R. dominica , if combined with kaolin, and antagonistic effect when admixed with diatomaceous earth. Yeasts and moulds as well as total mesophilic aerobic bacteria growths were reduced by C. sinensis essential oil applied alone more than the other dusts and dust-essential oil-based treatments. Kaolin admixed with C. sinensis peel essential oil might be a viable alternative to the chemical pesticides commonly used in wheat pest management. [ABSTRACT FROM AUTHOR]

Copyright of Revista Colombiana de Entomología is the property of Universidad del Valle and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The aim of the study was to evaluate the effects of the seeds, exocarp and aril extracts from Trichilia catigua A. Juss. (Meliaceae) against Spodoptera frugiperda and present the phytochemical study carried out with the aril extract of T. catigua . Limonoids were isolated from the aril of T. catigua through chromatographic techniques and their structures were proposed by spectroscopic analysis and comparison with literature data. The effects of the seeds, exocarp and aril extracts from T. catigua against S. frugiperda were evaluated considering as parameters the duration and mortality of the larval phase, in addition to the pupal weight. Phytochemical investigation of the aril extracts of T. catigua has led to the identification of the limonoids 6α-O-acetyl-7-deacetyl-14,15-dihydro-15-oxo-nimocinol ( 1 ), cedrelone ( 2 ) and 6α-O-acetyl-7-deacetylnimocinol ( 3 ). The hexane and CH 2 Cl 2 extracts of the aril showed a high rate of larval mortality (100 and 90%, respectively). In addition, a prolongation of larval phase and a reduction in the pupal weight were observed for insects treated with hexane, CH 2 Cl 2 and methanol extracts of seeds and with CH 2 Cl 2 extract of exocarp of T. catigua., (© 2022 Walter de Gruyter GmbH, Berlin/Boston.)

Pollen beetles, Meligethes spp. (Coleoptera: Nitidulidae), are among the most damaging pests of oilseed rape ( Brassica napus L.). Increasing populations of pyrethroid-resistant pollen beetles coupled with the prohibition of synthetic pest control products in organic farming means that other direct control methods are needed. A laboratory study was therefore conducted to evaluate the effect of natural products, combinations of natural products and additives as well as natural and synthetic insecticides on mortality of pollen beetles. In addition, field trials under both integrated and organic production were conducted to evaluate the efficacy of six natural products, nine combinations of natural products, two synthetic insecticides (integrated-production trials only), two natural insecticides and two additives to reduce pollen beetles. The laboratory trial, using both a curative and preventive approach, showed that two of the eight natural products (lavender oil and stone meal) caused a mortality of over 98% within the first day of application. The other natural products were only partially effective compared with the untreated control. In the field trials, the natural products reduced the number of pollen beetles 1 day after application compared with the untreated control in both trial years and production systems. Promising substances were stone meal, Silico-Sec and liquid manure. Nevertheless, the efficacy was not consistent, and no effect on oilseed rape yield was observed. In spite of this, these products have the potential to control pollen beetles under field conditions with comparable effects to synthetic insecticides. Further research should therefore focus on timing and frequency of applications as well as on the formulation of the natural products to increase the persistency of the products under field conditions. [ABSTRACT FROM AUTHOR]

The plants extract may be compatible with other management tactics, especially with biological control. so the aim of this work was to evaluate the residual effect of several extracts from cedar tree (C) and mahogany tree (M) (bark (C), wood (M) and leaf (F); cecropia tree (I) (bark - C and wood - M) and of the pereiro (P) (bark -C), and its possible effects on the adults of the parasitoid Trichogramma galloi(Zucchi, 1988) (Hymenoptera: Trichogrammatidae). Cards containing parasitised eggs of Diatraea saccharalis(Fabricius, 1794) (Lepidoptera: Crambidae), or containig eggs that would be submitted to the parasitoid were immersed for 30 seconds in the extracts at 5000 μg.mL-1. The number of parasitised eggs and adult emergence of the parasitoid were evaluated. The highest rates of parasitism, up to 60.0%, was obtained by the control treatment, MC, MM, CC and MF, and the treatments that caused a lower percentage of parasitism, IC, IM, PC, CM and CF, respectively. The extracts of different parts of mahogany, which showed a good percentage of parasitism, affected the development of the parasitoid with a low adult emergence. The PC showed a lower parasitism and emergence. In relation to eggs treated four days after parasitism, it was found that the control treatment had a good average in emergency (98.85%), in the same category of treatments IM, CF and CC, respectively. The CC extract was more selective and the PC was the least selective for T. galloi. [ABSTRACT FROM AUTHOR]

Main method to control insect pest is using synthetic insecticides, but the development of insect resistance to this products, the high operational cost, environmental pollution, toxicity to humans and harmful effect on non-target organisms have created the need for developing alternative approaches to control insect pest. Furthermore, the demand for organic crops, especially vegetables for the fresh market, has greatly increased worldwide. The ideal insecticide should control target pests adequately and should be target-specific, rapidly degradable, and low in toxicity to humans and other mammals. Plant essential oils could be an alternative source for insect pest control because they constitute a rich source of bioactive chemicals and are commonly used as flavoring agents in foods. These materials may be applied to food crops shortly before harvest without leaving excessive residues. Moreover, medically safe of these plant derivatives has emphasized also. For these reasons, much effort has been focused on plant essential oils or their constituents as potential sources of insect control agents. In this context, Apiaceae (Umbelliferae) family would rank among the most important families of plants. In the last few years more and more studies on the insecticidal properties of essential oils from Apiaceae family have been published and it seemed worthwhile to compile them. The focus of this review lies on the lethal (ovicidal, larvicidal, pupicidal and adulticidal) and sublethal (antifeedant, repellent, oviposition deterrent, Growth inhibitory and progeny production) activities of plant essential oils and their main components from Apiaceae family. These features indicate that pesticides based on Apiaceae essential oils could be used in a variety of ways to control a large number of pests. It can be concluded that essential oils and phytochemicals isolated from Apiaceae family may be efficacious and safe replacements for conventional synthetic insecticides. [ABSTRACT FROM AUTHOR]

Plants and herbivores have co-evolved in their natural habitats for about 350 million years, but since the domestication of crops, plant resistance against insects has taken a different turn. With the onset of monoculture-driven modern agriculture, selective pressure on insects to overcome resistances has dramatically increased. Therefore plant breeders have resorted to high-tech tools to continuously create new insect-resistant crops. Efforts in the past 30 years have resulted in elucidation of mechanisms of many effective plant defenses against insect herbivores. Here, we critically appraise these efforts and – with a focus on sap-sucking insects – discuss how these findings have contributed to herbivore-resistant crops. Moreover, in this review we try to assess where future challenges and opportunities lay ahead. Of particular importance will be a mandatory reduction in systemic pesticide usage and thus a greater reliance on alternative methods, such as improved plant genetics for plant resistance to insect herbivores. [ABSTRACT FROM AUTHOR]

Natural sources for novel insecticide molecules hold promise in view of their eco-friendly nature, selectivity, and mammalian safety. Recent progress in understanding the biology of insect olfaction and taste offers new strategies for developing selective pest control agents. We have isolated two natural insecticidal molecules from edible roots of Decalepis hamiltonii named Decalesides I and II, which are novel trisaccharides, highly toxic to household insect pests and stored-product insects. We have experimentally shown that insecticidal activity requires contact with tarsi on the legs but is not toxic orally. The insecticidal activity of molecules is lost by hydrolysis, and various sugars modify toxic response, showing that the insecticidal activity is via gustatory sites on the tarsi. Selective toxicity to insects by virtue of their gustatory site of action and the mammalian safety of the new insecticides is inherent in their chemical structure with 1-4 or 1-1 α linkage that is easily hydrolyzed by digestive enzymes of mammals. Decalesides represent a new chemical class of natural insecticides with a unique mode of action targeting tarsal chemosensory/gustatory system of insects. [ABSTRACT FROM AUTHOR]

Copyright of Acta Scientiarum: Agronomy is the property of Universidade Estadual de Maringa and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Because natural product-based pesticides are thought to be more rapidly degradable than synthetic chemicals while having a lower ecotoxicological effect, the interest in these products for pest control has grown substantially. Recently, a new insecticide compound, which is the crude soluble protein extract (CSPE) from the fermentation product of the entomopathogenic fungus (EF) Metarhizium anisopliae (strain EAMa 01/58-Su), has appeared in the literature as a promising insecticide for the control of the Mediterranean fruit fly, Ceratitis capitata. This CSPE has a moderate acute insecticide effect against adults of C. capitata when administered per os at 1 mg of protein/ml, as an exposure time of 8.3 h is necessary to get 50% of mortality. Even though the ingestion of this compound produces serious injuries in the midgut epithelium, it has a very low antifeedant effect on the flies. The effect of sublethal challenges on reproduction of adult flies was studied, and a reduction was found on the female fecundity levels during the first days after the treatment. On the other hand, the sublethal exposure to the CSPE affected neither the egg fertility nor the mortality of the larvae. However, the CSPE did affect the mortality of the pupae from the F1 generation, which suggests that there is a hormetic response from CSPE challenged females. The described sublethal reproductive effects are as important as direct lethal effects in contributing to the total value of the CSPE of the EF M. anisopliae 01/58-Su strain. [ABSTRACT FROM AUTHOR]

The article presents a study on the effect of blastophore yields, fungal biomass, and toxicity of fungal proteins of Metarhizium anisopliae against the insecticidal protein control of Ceratitis capitata adults. Based on results, concentration of nitrogen source influences the production of insecticidal protein and toxicity of the crude soluble protein extract (CSPE). In conclusion, insecticidal effect against C. capitata can be improved through optimization of culture media.

The article presents a study on the use of entomopathogenic fungus Metarhizium anisopliae in controlling the Ceratitis capitata. The researchers gathered Metarhizium anisopliae strain at the University of Cordoba in Cordoba, Spain, and the conodial culture of the insecticidal fungal proteins were prepared using the Adamek's liquid medium. Accordingly, the secreted chemical from the crude soluble protein extract (CSPE) were tested in a diet test. The results have revealed four fungal proteins.

The tree-of-heaven, Ailanthus altissima Swingle (Simaroubaceae), was studied for its potential insecticide activity against the pea aphid, Acyrtosiphon pisum (Harris). First instar aphids were dipped in water solutions of root extract and of leaf extract of A. altissima, and this was followed by bioassay-oriented fractioning of leaf extract (more active in bioassays) with petroleum ether, chloroform, chloroform-methanol, methanol and water, and of chromatographic fractions. The putative active constituent ailanthone, isolated from the plant resulting in the highest aphid mortality, has been assayed as a pure compound in different concentrations, proving to be responsible for the insecticidal activity reported. [ABSTRACT FROM AUTHOR]

Abstract: Carbaryl is currently one of the most commonly used insecticides for the control of the pineapple fruit borer, Strymon megarus (Godart), in commercial pineapple production. To evaluate more sustainable biological alternatives to conventional insecticides, three microbial and one botanical insecticide were studied. Beauveria bassiana, Metarhizium anisopliae, Bacillus thuringiensis (Bt) and a plant extract from Quassia amara were compared with carbaryl in replicated field trials in Costa Rica during 2005 and 2006. In both years of testing, the untreated control received over 50% fruit damage from S. megarus. Bt and carbaryl provided the highest level of control and the lowest level of fruit damage compared to all other treatments. Based on the results of this study, Bt appears to be an acceptable biological alternative to the conventional insecticide (carbaryl) for control of S. megarus on pineapple. In addition, Bt was the least expensive treatment used in this study. [Copyright &y& Elsevier]

BACKGROUND: To reduce pest attack, several bio rational products are allowed for use on organic vegetables in Brazil. This study investigated eight bio rational products applied singly or in combination against Spodoptera eridania Cramer in field plots of cabbage intercropped with coriander. The treatments were applied once a week over a 5 week period, beginning 34 days after transplanting. The evaluations consisted of counting the larvae of S. eridania on the day before and 7 and 21 days after spraying. The damage to leaves and cabbage head, the commercial weight of head and the percentage of head losses were evaluated. RESULTS: Leaf injury in plots treated with Beauveria bassiana and neem oil (Dalneem) yielded scores of 1.3 and 2.5 (scale ranging from 0 to 4) respectively, in comparison with a score of 3.6 from untreated plots. Head weight losses were 6.1, 5.3 and 4.9% with an aqueous extract of neem leaves, neem oil and B. bassiana respectively, compared with 24.6% lost from untreated plots. CONCLUSION: Dalneem, B. bassiana and the extract of neem leaves at 20% exhibited the best performance for control of S. eridania. [ABSTRACT FROM AUTHOR]

Laboratory bioassays were carried out with DEBBM, a new enhanced diatomaceous earth (DE) formulation that contains the plant extract bitterbarkomycin, against adults of Rhyzopertha dominica (F.). Three series of tests were conducted. In the first, R. dominica adults were exposed on wheat treated with DEBBM at three dose rates, 50, 100 and 150 ppm, and mortality was measured after 7 and 14 days of exposure, at three temperatures (20, 25 and 30°C) and 65% R.H. Mortality increased with increasing temperature; at temperatures ≥25°C, after 14 days of exposure, mortality exceeded 98% even at 50 ppm. In the second series of tests, the same doses were assessed at 25°C and at two levels of R.H. (55 and 75%). In this case, relative humidity did not seriously affect the insecticidal effect of DEBBM, at the doses tested. All adults were dead after 14 days of exposure at 55% R.H. at doses ≥100 ppm. In the third test series, 50 and 150 ppm of DEBBM were added to wheat, barley, maize and rice, in order to evaluate the impact of grain type on the effect of this DE. No significant differences were noted in mortality levels among different grains. With the exception of maize, after 14 days of exposure, all adults were dead. This new enhanced DE formulation is shown to be effective at dose rates that are considerably lower in comparison with older DE formulations. [ABSTRACT FROM AUTHOR]

Azadirachtin, refined rape oil and slaked lime - three natural substances with insecticidal potential - were tested under laboratory conditions for their efficacy against larvae and adults of Colorado potato beetle, Leptinotarsa decemlineata, at 15°C, 20°C, and 25°C. General statistical analysis (all developmental stages and all insecticidal substances taken into account) was performed on the results of the mortality rates of the individuals and no statistically significant differences between the temperatures were observed on the fifth day after application. At all temperatures, the influence of insecticidal substances in question as well as the interaction between the insecticidal substance and the developmental stage of the pest on mortality rates were significant. The individual statistical analysis (a specified developmental stage of the pest at a specified temperature) revealed the maximum efficacy of the refined rape oil at 15°C and 20°C, the adults being the most sensitive developmental stage (mortality rate about 90%). Other substances tested were less effective, and in general the mortality rate of either larvae or adults did not exceed 50%. In the case that the efficacy of the refined rape oil in controlling the population of the adults of the Colorado potato beetle is confirmed also in field trials, this could be the basis for a better strategy in controlling the overwintered Colorado potato beetles on potato. [ABSTRACT FROM AUTHOR]

Entomopathogenic fungi are a poorly exploited source of insecticidal proteins, which may be used for the development of new natural insecticides and as alternative molecules for transgenic deployment. The crude soluble protein extracts in Adamek's liquid medium of 25 fungal isolates belonging to the fungal species Metarhizum anisopliae, Beauveria bassiana, Beauveria brongniartii and Scopulariopsis brevicaulis were screened by per os toxicity on Spodoptera littoralis larvae. Whilst extracts from two M. anisopliae and two B. bassiana isolates gave significant mortalities when applied either on alfalfa leaf discs or incorporated into artificial diet, the one from M. anisopliae 01/58-Su isolate was the only most toxic that showed promise for S. littoralis control. In leaf disc assays, this extract exhibited strong dose-related toxic and antifeedant activity against the larvae. At 10, 20 and 40 μg protein/insect, the extract gave 61.3%, 96.6% and 100.0% mortality, respectively, and average survival time of 5.7, 4.3 and 3.1 days respectively. Not only the antifeeding index was dose-related, but it significantly increased over time in a dose-related manner. Longer exposure times led to a dose-related significant increase in larval mortality. The exposure times for 50% mortality were 91.3 h and 62.1 h for 20 and 40 μg protein/insect respectively. The crude extract when exposed to higher temperature or protease treatment lost toxicity, indicating that toxicity was protein mediated. In addition, the liquid medium composition did not influence its insecticidal activity. The effects of the protein extract on midgut cells of second instar larvae of S. littoralis were investigated by using both light and electron microscopy. A progressive bleeding of the midgut epithelium into the gut lumen was observed along with lysis of the epithelium and deterioration of the microvilli. [ABSTRACT FROM AUTHOR]

The efficiency of Tagetes' intercropping and natural extract on Lactuca sativa aphids population dynamic was evaluated. A complete randomized design DCA was used working with the plant as the sampling unit. They were considered three treatments: control (T), Tagetes' intercropping (CI) and crop powdered with Tagetes' natural extract (CP). Data analysis was performed through an ANOVA and Tukey's test, corresponding to essays repeated in time. Control aphids population dynamic was bigger than crop powdered with Tagetes' natural extract, it was the smallest. Intercropping has a middle population. [ABSTRACT FROM AUTHOR]

The insecticidal efficacy of the diatomaceous earth (DE) formulation SilicoSec (Biofa GmbH) against adults and larvae of the confused flour beetle, Tribolium confusum DuVal (Coleoptera: Tenebrionidae) was evaluated in laboratory tests. These tests were conducted at five temperatures, 22°C, 25°C, 27°C, 30°C and 32°C, and two relative humidity levels, 55% and 65%. SilicoSec was applied to three types of product, hard wheat, soft wheat and wheat flour, at four dose rates, 0.25, 0.5, 1 and 1.5 g/kg of each product. In order to assess the influence of larval instar on the efficacy of SilicoSec, the larvae were divided into two groups, young and old larvae, corresponding to 1–3 and 4–7 instar larvae, respectively. Similarly, adults were divided into three different groups, 1, 2 and 7-d old adults, respectively. For both adults and larvae, mortality on wheat or flour treated with SilicoSec increased with the exposure interval and the dose rate. Larvae were more sensitive to DE than adults, given that adults could survive exposure intervals and application rates that were lethal to larvae. The mortality of larvae and adults exposed to SilicoSec increased with increasing temperature. In contrast, the efficacy of SilicoSec notably decreased with the increase of relative humidity from 55% to 65%. Significantly, more adults and larvae were dead in SilicoSec-treated wheat than in treated flour. The efficacy of SilicoSec was substantially affected by the age of the exposed individuals. Young larvae were significantly more sensitive than old ones. Adults became significantly less susceptible to SilicoSec as their age increased from 1 to 2 and to 7 d. [Copyright &y& Elsevier]

The insecticidal efficacy of the diatomaceous earth formulation SilicoSec® (Agrinova GmbH, Germany) against the rice weevil, Sitophilus oryzae (L.) (Coleoptera: Curculionidae) was evaluated on peeled rice, paddy rice, maize and barley in laboratory tests. SilicoSec was applied at five dose rates: 0.125, 0.25, 0.5, 1 and 1.5 g/kg of grain. The treated grains were infested with S. oryzae adults, and the weevil mortality was estimated after 24, 48 h, 7 and 14 d of exposure on treated grain. After the 14 d counts, all the exposed adults were removed and progeny production on treated grains was assessed 45 and 90 d later. Insecticidal efficacy of SilicoSec against the rice weevil was highly affected by grain type, exposure interval and dose rate. In all grains tested, longer exposure intervals increased weevil mortality. The efficacy of SilicoSec on maize was not satisfactory, given that after a 14 d exposure at the highest dose rate the mortality did not exceed 65%. Moreover, progeny production on treated maize was high, regardless of the dose rate. On the other hand, 100% of weevils were dead on barley treated with the two highest dose rates of SilicoSec, after a 7 d exposure. However, a complete suppression of progeny production on treated barley was not achieved, even at the highest dose rate. A satisfactory level of protection was recorded on paddy rice treated with 1 and 1.5 g of SilicoSec/kg. At these two rates, all adults were dead after a 7 d exposure, and no progeny were produced during the 90 d incubation period. In contrast, the mortality on peeled rice treated with 1.5 g of SilicoSec/kg did not reach 100%, even after 14 d of exposure, and a high number of progeny were recorded. [Copyright &y& Elsevier]

According to the European Directive 2009/128/EC and the subsequent provisions activated in member states, conventional pesticides should be progressively replaced by "non-chemical tools and/or measures". The identification of reliable alternatives to pesticides is crucial to achieve this objective. A European project (PURE) was funded to investigate this topic with reference to annual and perennial crops. In this framework, a number of natural insecticides, in particular microbial and botanical ones (Bacillus thuringiensis ssp. kurstaki, Beauveria bassiana, azadirachtin, pyrethrins and spinosad) were selected to test their effectiveness against grape berry moths, the key pests in most European vineyards. Trials were conducted in 2011 and 2012 in two experimental vineyards located in Italy (Tuscany and Veneto regions), following a randomized block design. Additional investigations were carried out in the Veneto region during 2013. Trial results stressed the high performance of spinosad and B. thuringiensis in controlling berry moth densities and the related damage. The use of B. bassiana mixed with B. thuringiensis did not significantly improve the impact of B. thuringiensis alone. Azadirachtin, and especially pyrethrins, proved to be less effective on berry moths than previous insecticides. The use of selected insecticides caused side-effects on a number of secondary pests, in particular leafhoppers. In 2011, densities of Empoasca vitis were higher in spinosad-treated plots probably because of a reduced egg parasitization rate. One year later, the population density of Zygina rhamni was higher in the plots treated with spinosad or pyrethrins. This trend was confirmed on spinosad-treated plots in the last experimental year. At the same time, spinosad and pyrethrins significantly reduced the predatory mite populations compared to other treatments. The use of these insecticides in viticulture is discussed in the framework of organic viticulture and Integrated Pest Management (IPM). [ABSTRACT FROM AUTHOR]

This study evaluated the influence of temperature and relative humidity (RH) on the insecticidal effect of diatomaceous earth (DE) at two concentrations, 500 and 1000 ppm, on wheat, for the control of Cryptolestes ferrugineus (Stephens) (Coleoptera: Cucujidae), Oryzaephilus surinamensis (L.) (Coleoptera: Silvanidae), and Tribolium confusum Jacquelin du Val (Coleoptera: Tenebrionidae). These bioassays were carried out in all combinations of four temperature levels (15, 20, 25, and 30 °C), and two relative humidity levels (55 and 75%). Cryptolestes ferrugineus and O. surinamensis were found to be much more susceptible to the DE-treated wheat than T. confusum, but the increase of the DE dose increased the mortality level for all three species. Although the increase of temperature and the decrease of RH increased insect mortality in some of the combinations tested, the reverse was observed in some treatments, suggesting that there are considerable differential effects of these factors in DE efficacy. The increase of insect exposure from 1 to 21 days notably increased insect mortality, suggesting that exposure is a critical factor that may alleviate possible differential effects of certain abiotic conditions. The results of the present work provide data that illustrate the viability of the utilization of DE in stored product protection, as alternatives to chemical control methods. [ABSTRACT FROM AUTHOR]

The insecticidal effect of Trichoderma harzianum (TH), diatomaceous earth (DE), kaolin (KA) and their combinations against Callosobruchus maculatus (F.) and Callosobruchus chinensis L. (Coleoptera: Chrysomelidae: Bruchinae) was evaluated. The fungus T. harzianum was applied at 1 × 105, 1 × 106 and 1 × 107 spores/kg of cowpea seeds individually and mixed with 100, 500 and 1000 mg/kg of DE or KA. The effect of individual and binary treatments on adult mortality after 3 and 7 days of exposure was determined. The progeny production of both insects and weight loss in cowpea seeds were assessed after 45 days of exposure. Complete adult mortality of both insect species was achieved by using the highest application rate of DE/TH mixture (1000 mg/kg of DE+1.0 × 107 spores/kg of TH) after 7 days. A mixture of KA/TH (1000 mg/kg of KA+1.0 × 107 spores/kg of TH) caused 100.0 and 97.9% mortality of C. maculatus and C. chinensis , respectively, after 7 days of exposure. Progeny production of both insect species was significantly decreased for all individual and combination treatments compared to the control. No progeny of C. chinensis was detected in cowpea seeds treated with the mixture 1000 mg/kg of KA+‏ 1.0 × 107 spores/kg of TH after 45 days. Also, the combination treatments protected cowpea seeds from damage caused by C. maculatus and C. chinensis for 45 days. These results indicate that the combinations of TH fungus with DE or KA could be successfully used for the management of C. maculatus and C. chinensis in stored cowpea seeds. • The use of natural products is acceptable approach worldwide to overcome problems associated with synthetic insecticides. • Combination of T. harzianum with DE or KA gave satisfactory management of C. maculatus and C. chinensis on stored cowpea. • Complete adult mortality and progeny suppression were achieved by using high application rates of fungus with inert dusts. • The combinations of inert dusts and fungus were more toxic to C. chinensis than C. maculatus. [ABSTRACT FROM AUTHOR]