scholarly journals Effects of neem leaf extracts on Lepidopteran pest species attacking Solanum macrocarpon L. (Solanaceae) in southern Togo

2019 ◽  
Vol 11 (4) ◽  
pp. 50-57
Author(s):  
Déla Mondédji Abla ◽  
Wolali Nyamador Seth
Keyword(s):  
Pest Species ◽  
Leaf Extracts ◽  
Lepidopteran Pest

Baseline Plant-to-Plant Larval Movement of Spodoptera eridania in Bt and Non-Bt Soybean and Its Possible Impacts on IRM

2020 ◽  
Vol 113 (4) ◽  
pp. 1741-1752
Author(s):  
Thiago L M Fanela ◽  
Edson L L Baldin ◽  
Thomas E Hunt ◽  
Rodrigo D Faria
Keyword(s):  
Larval Mortality ◽  
Pest Species ◽  
Spodoptera Eridania ◽  
Refuge Strategy ◽  
Bt Toxins ◽  
Incomplete Resistance ◽  
Insect Populations ◽  
Transgenic Technologies ◽  
Lepidopteran Pest ◽  
Larval Movement

Abstract The widespread use of transgenic technologies has led to the emergence of insect populations resistant to Bt toxins. Some lepidopteran pest species also appear to naturally have some level of tolerance to certain proteins, such as some species of Spodoptera to Cry1Ac. One of the main strategies to manage resistance is the use of refuge areas, the success of which is in part dependent on larval movement of the target pest. Thus, in order to assess the viability of a refuge strategy addressing Spodoptera eridania Stoll (Lepidoptera: Noctuidae) in Bt soybean, it was evaluated the larval movement across plants in Bt and non-Bt soybean, as well as the larval development and mortality on Bt and non-Bt soybean cultivars. We concluded that apparent S. eridania incomplete resistance resulting from high larval mortality and low adaptability on Bt plants, high larval dispersal, nondirectional larval movement, and random larval spatial dispersion suggest that structured refuge is more suitable than mixed refuge for managing resistance in S. eridania populations.

scholarly journals Ichneumonids (Hymenoptera) and Tachinid Flies (Diptera) Associated to Leptidopterans in Soybean Crops

2018 ◽  
Vol 10 (7) ◽  
pp. 167 ◽  
Author(s):  
Angélica Massarolli ◽  
Ana Regina Lucena Hoffmann ◽  
Bruna Magda Favetti ◽  
Alessandra Regina Butnariu
Keyword(s):  
Biological Control ◽  
New Species ◽  
Natural Enemies ◽  
Management Strategies ◽  
Neotropical Region ◽  
The State ◽  
Pest Species ◽  
Mato Grosso ◽  
Control Programs ◽  
Lepidopteran Pest

Studies on natural enemies are important to find new species and to develop management strategies to preserve them to help control pests in biological control programs. For the state of Mato Grosso, Brazil, which comprises the Amazon, Cerrado, and Pantanal biomes, few studies have been conducted on the diversity of these parasitoids, possible endemic and/or new species, as well as their potential as natural enemies. Thus, the present study was aimed at describing the diversity of parasitoids of the families Ichneumonidae (Hymenoptera) and Tachinidae (Diptera) associated with pest lepidopterans in soybean crops. Weekly sampling of pest lepidopterans was carried out during four soybean seasons (2009/2010, 2010/2011, 2011/2012 and 2012/2013). Parasitoid larvae were observed in the main lepidopteran pest species of soybean during the four soybean seasons. Three genera of the Ichneumonidae family, belonging to the genera Microcharops Roman, Ophionellus Westwood, and Podogaster Brullé. Six genera of the Tachinidae family occur in the state of Mato Grosso in soybean fields. The following genera were recorded: Archytas spp. Jaennicke, Phorocera spp. Robineau-Desvoidy, Gymnocarcelia spp. Townsend, Lespesia spp. Robineau-Desvoidy, Eucelatoria spp. Townsend, Chetogena spp. Rondani. These parasitoids were found parasitizing caterpillars of the Noctuidae (Lepidoptera), in species that had not yet been reported as hosts for the Neotropical region. Further studies are needed on the beneficial entomofauna and their preservation in agricultural environments.

scholarly journals Geographic Monitoring of Insecticide Resistance Mutations in Native and Invasive Populations of the Fall Armyworm

Insects ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 468
Author(s):  
Sudeeptha Yainna ◽  
Nicolas Nègre ◽  
Pierre J. Silvie ◽  
Thierry Brévault ◽  
Wee Tek Tay ◽  
...  
Keyword(s):  
Insecticide Resistance ◽  
Fall Armyworm ◽  
Sub Saharan Africa ◽  
Pest Species ◽  
Resistance Mutations ◽  
Chinese Populations ◽  
Bt Resistance ◽  
Native Populations ◽  
Sub Saharan ◽  
Lepidopteran Pest

Field evolved resistance to insecticides is one of the main challenges in pest control. The fall armyworm (FAW) is a lepidopteran pest species causing severe crop losses, especially corn. While native to the Americas, the presence of FAW was confirmed in West Africa in 2016. Since then, the FAW has been detected in over 70 countries covering sub-Saharan Africa, the Middle East, North Africa, South Asia, Southeast Asia, and Oceania. In this study, we tested whether this invasion was accompanied by the spread of resistance mutations from native to invasive areas. We observed that mutations causing Bt resistance at ABCC2 genes were observed only in native populations where the mutations were initially reported. Invasive populations were found to have higher gene numbers of cytochrome P450 genes than native populations and a higher proportion of multiple resistance mutations at acetylcholinesterase genes, supporting strong selective pressure for resistance against synthetic insecticides. This result explains the susceptibility to Bt insecticides and resistance to various synthetic insecticides in Chinese populations. These results highlight the necessity of regular and standardized monitoring of insecticide resistance in invasive populations using both genomic approaches and bioassay experiments.

Toxicity Studies of Microbial Insecticide Bacillus thuringiensis var. kenyae in Rats, Rabbits, and Fish

2002 ◽  
Vol 21 (2) ◽  
pp. 99-105 ◽  
Author(s):  
S. M. Meher ◽  
S. L. Bodhankar ◽  
Arun Kumar ◽  
J. N. Dhuley ◽  
D. J. Khodape ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Skin Irritation ◽  
Fresh Water Fish ◽  
Pest Species ◽  
Oral Toxicity ◽  
Ocular Irritation ◽  
Powder Formulation ◽  
Microbial Insecticide ◽  
Wettable Powder ◽  
Lepidopteran Pest

Bacillus thuringiensis var. kenyae (B.t.k.) is a microbial insecticide effective against lepidopteran pest species. Acute oral toxicity in rats and acute dermal toxicity, ocular irritation, skin irritation in rabbits were studied for the wettable powder formulation of B.t.k. In addition, toxicity of the wettable powder formulation was also studied in fresh water fish ( Gambussia affinis). The results of these studies indicate that this wettable powder formulation of B.t.k. is nontoxic and nonirritant to rats, rabbits, and fish.

Susceptibility of Cotton Boll Weevil (Coleoptera: Curculionidae) to Spinosyns

2019 ◽  
Vol 112 (4) ◽  
pp. 1688-1694 ◽  
Author(s):  
Guilherme G Rolim ◽  
Lucas S Arruda ◽  
Jorge B Torres ◽  
Eduardo M Barros ◽  
Marcos G Fernandes
Keyword(s):  
Boll Weevil ◽  
Adult Mortality ◽  
Anthonomus Grandis ◽  
Pest Species ◽  
Plant Canopy ◽  
Control Efficacy ◽  
Insecticide Efficacy ◽  
Evaluation Time ◽  
Cotton Plants ◽  
Lepidopteran Pest

AbstractThe control of boll weevil, Anthonomus grandis grandis Boh., relies primarily on synthetic insecticides. Although insecticides are registered to spray cotton fields against boll weevils, only a few offer satisfactory control and most have broad-spectrum action. Alternatively, spinosyns have been recommended against lepidopteran pest species in cotton and are considered comparatively of reduced risk to nontargets. The susceptibility of nine populations of boll weevil to spinosad and spinetoram was determined through dried residue on squares and cotton leaves. Furthermore, control efficacy of spinosad and spinetoram compared with the standard organophosphate malathion was determined for caged adults at two different positions within the plant canopy or treated cotton leaves after different spray intervals. Boll weevil susceptibility varied across the nine populations and tested spinosyns. The lethal concentrations (LC50s and LC90s) varied from 8.62 to 32.25 and 49.86 to 281.70 mg a.i./l for spinosad and from 2.17 to 15.36 and 8.58 to 69.36 mg a.i./l for spinetoram. The location of boll weevil within the plant canopy affected the insecticide efficacy with higher mortality when caged on upper parts rather than on lower parts of cotton plants (>85% vs <45% of control) across all three insecticides. In addition, dried residues of spinosyns resulted in adult mortality >80% until the end of the evaluation period (8 d), while the standard malathion caused only 10% at this last evaluation time. Thus, we can conclude that both spinosyns promoted prolonged adult mortality using recommended field rates compared with the standard malathion.

scholarly journals Large-scale assessment of lepidopteran soybean pests and efficacy of Cry1Ac soybean in Brazil

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Renato J. Horikoshi ◽  
Patrick M. Dourado ◽  
Geraldo U. Berger ◽  
Davi de S. Fernandes ◽  
Celso Omoto ◽  
...  
Keyword(s):  
Large Scale ◽  
Anticarsia Gemmatalis ◽  
Pest Species ◽  
Large Scale Assessment ◽  
Resistance Evolution ◽  
Lepidopteran Pests ◽  
High Level ◽  
Lepidopteran Pest ◽  
Insecticide Sprays ◽  
Chrysodeixis Includens

AbstractThe soybean technology MON 87701 × MON 89788, expressing Cry1Ac and conferring tolerance to glyphosate, has been widely adopted in Brazil since 2013. However, pest shifts or resistance evolution could reduce the benefits of this technology. To assess Cry1Ac soybean performance and understand the composition of lepidopteran pest species attacking soybeans, we implemented large-scale sampling of larvae on commercial soybean fields during the 2019 and 2020 crop seasons to compare with data collected prior to the introduction of Cry1Ac soybeans. Chrysodeixis includens was the main lepidopteran pest in non-Bt fields. More than 98% of larvae found in Cry1Ac soybean were Spodoptera spp., although the numbers of Spodoptera were similar between Cry1Ac soybean and non-Bt fields. Cry1Ac soybean provided a high level of protection against Anticarsia gemmatalis, C. includens, Chloridea virescens and Helicoverpa spp. Significant reductions in insecticide sprays for lepidopteran control in soybean were observed from 2012 to 2019. Our study showed that C. includens and A. gemmatalis continue to be primary lepidopteran pests of soybean in Brazil and that Cry1Ac soybean continues to effectively manage the target lepidopteran pests. However, there was an increase in the relative abundance of non-target Spodoptera spp. larvae in both non-Bt and Cry1Ac soybeans.

scholarly journals Main lepidopteran pest species from an eucalyptus plantation in Minas Gerais, Brazil

2014 ◽  
Vol 54 (2) ◽  
pp. 553 ◽  
Author(s):  
Teresinha V. Zanuncio ◽  
José C. Zanuncio ◽  
Fernando A. De Freitas ◽  
Dirceu Pratissoli ◽  
Camilla A. Z. Sediyama ◽  
...  
Keyword(s):  
Minas Gerais ◽  
Pest Species ◽  
Eucalyptus Plantation ◽  
Lepidopteran Pest

scholarly journals Acetylcholinesterase and α-Amylase inhibitors from Mouriri elliptica Martius leaf extract

2020 ◽  
Vol 36 (2) ◽  
Author(s):  
Letícia Siqueira da Silva ◽  
Cinthia Alves Porfiro ◽  
Fabiano Guimarães Silva ◽  
Agna Rita dos Santos Rodrigues ◽  
Paulo Sérgio Pereira
Keyword(s):  
Pest Control ◽  
Acetylcholinesterase Inhibitors ◽  
Natural Resistance ◽  
Pest Species ◽  
Leaf Extracts ◽  
Ache Inhibitors ◽  
Resistance To Insects ◽  
Cholinergic Synapses ◽  
High Concentrations ◽  
Amylase Inhibitors

Population growth has raised food production, and new sources are needed to increase quantity and quality of agricultural products. Carbamates and organophosphates are insecticide classes used worldwide as acetylcholinesterase (AChE) inhibitors. Plants have a natural resistance to insects, which can be employed in pest control as a new alternative to reduce the use of chemicals. An alternative may be the use of α-amylase inhibitors, which are digestive enzymes that impair pest species growth and development. Another would be acetylcholinesterase inhibitors since they damage the normal functioning of the central and peripheral nervous system, by releasing high concentrations of acetylcholine in cholinergic synapses. This substance accumulation increases stimulations that lead to behavioral changes, asphyxia, hyperactivity, and death. Botanical agrochemicals are believed to have advantages over synthetic ones, as they are rapidly degraded in the environment. In this scenario, plants have played an important role in pest control as sources of interest for the synthesis of new molecules for agricultural use. The present study evaluated acetylcholinesterase and α-amylase inhibition by microplate method, from leaf extracts of Mouriri elliptica Martius with different polarities.

Development of specific ITS markers for plant DNA identification within herbivorous insects

2010 ◽  
Vol 101 (3) ◽  
pp. 271-276 ◽  
Author(s):  
L. Pumariño ◽  
O. Alomar ◽  
N. Agustí
Keyword(s):  
Trophic Relationships ◽  
Food Sources ◽  
Pest Species ◽  
Specific Primers ◽  
Plant Dna ◽  
Control Programs ◽  
Marking Technique ◽  
Dna Fragment ◽  
Lepidopteran Pest ◽  
Dietary Mixing

AbstractDNA-based techniques have proved to be very useful methods to study trophic relationships between pests and their natural enemies. However, most predators are best defined as omnivores, and the identification of plant-specific DNA should also allow the identification of the plant species the predators have been feeding on. In this study, a PCR approach based on the development of specific primers was developed as a self-marking technique to detect plant DNA within the gut of one heteropteran omnivorous predator (Macrolophus pygmaeus) and two lepidopteran pest species (Helicoverpa armigera and Tuta absoluta). Specific tomato primers were designed from the ITS 1–2 region, which allowed the amplification of a tomato DNA fragment of 332 bp within the three insect species tested in all cases (100% of detection at t=0) and did not detect DNA of other plants nor of the starved insects. Plant DNA half-lives at 25°C ranged from 5.8 h, to 27.7 h and 28.7 h within M. pygmaeus, H. armigera and T. absoluta, respectively. Tomato DNA detection within field-collected M. pygmaeus suggests dietary mixing in this omnivorous predator and showed a higher detection of tomato DNA in females and nymphs than males. This study provides a useful tool to detect and to identify plant food sources of arthropods and to evaluate crop colonization from surrounding vegetation in conservation biological control programs.

Gut microbiota metabolic potential correlates with body size between mulberry‐feeding lepidopteran pest species

2019 ◽  
Vol 76 (4) ◽  
pp. 1313-1323 ◽  
Author(s):  
Bosheng Chen ◽  
Sen Xie ◽  
Xiancui Zhang ◽  
Nan Zhang ◽  
Huihui Feng ◽  
...  
Keyword(s):  
Body Size ◽  
Gut Microbiota ◽  
Pest Species ◽  
Metabolic Potential ◽  
Lepidopteran Pest
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