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1.
Braz J Biol ; 84: e253218, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35019097

RESUMEN

Indices are used to help on decision-making. This study aims to develop and test an index, which can determine the loss (e.g., herbivorous insects) and solution (e.g., natural enemies) sources. They will be classified according to their importance regarding the ability to damage or to reduce the source of damage to the system when the final production is unknown. Acacia auriculiformis (Fabales: Fabaceae), a non-native pioneer species in Brazil with fast growth and rusticity, is used in restoration programs, and it is adequate to evaluate a new index. The formula was: Percentage of the Importance Indice-Production Unknown (% I.I.-PU) = [(ks1 x c1 x ds1)/Σ (ks1 x c1 x ds1) + (ks2 x c2 x ds2) + (ksn x cn x dsn)] x 100. The loss sources Aethalion reticulatum L., 1767 (Hemiptera: Aethalionidae), Aleyrodidae (Hemiptera), Stereoma anchoralis Lacordaire, 1848 (Coleoptera: Chrysomelidae), and Tettigoniidae, and solution sources Uspachus sp. (Araneae: Salticidae), Salticidae (Araneae), and Pseudomyrmex termitarius (Smith, 1877) (Hymenoptera: Formicidae) showed the highest % I.I.-PU on leaves of A. auriculiformis saplings. The number of Diabrotica speciosa Germar, 1824 (Coleoptera: Chrysomelidae) was reduced per number of Salticidae; that of A. reticulatum that of Uspachus sp.; and that of Cephalocoema sp. (Orthoptera: Proscopiidae) that of P. termitarius on A. auriculiformis saplings. However, the number of Aleyrodidae was increased per number of Cephalotes sp. (Hymenoptera: Formicidae) and that of A. reticulatum that of Brachymyrmex sp. (Hymenoptera: Formicidae) on A. auriculiformis saplings. The A. reticulatum damage was reduced per number of Uspachus sp., but the Aleyrodidae damage was increased per number of Cephalotes sp., totaling 23.81% of increase by insect damages on A. auriculiformis saplings. Here I show and test the % I.I.-PU. It is an new index that can detect the loss or solution sources on a system when production is unknown. It can be applied in some knowledge areas.


Asunto(s)
Acacia , Hormigas , Escarabajos , Hemípteros , Animales , Insectos
2.
Braz J Biol ; 84: e254095, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35019103

RESUMEN

In northern central Chile, ephemeral pools constitute shallow isolated water bodies with a favourable habitat for fauna adapted to seasonal changes. Based on the limited knowledge about the fauna-particularly insects-associated to these ecosystems, the objective of this study was to characterize the richness, composition, structure and similarity of the insect communities associated with ephemeral pools in Huentelauquén (29º S, Coquimbo Region, Chile). By using pitfall traps, 10,762 individuals were captured, represented by 7 orders, 27 families, and 51 species. Coleoptera and Hymenoptera were the best represented orders, with Neuroptera, Orthoptera and Plecoptera being poorly represented groups. The non-parametric estimators evaluated showed wealth values above those observed for all the studied pools, and their accumulation curves suggest the existence of an incomplete species inventory in the studied community. Additionally, the hierarchical and ordering analysis showed groupings of pools located in the northwest and southeast of Huentelauquén. Preliminarily we found a negative correlation between the area of the pools and the richness (species) and abundance of insects. Additional studies (on other arthropod groups and other seasons of the year) could provide a better understanding of the local processes of extinction and colonization of the species inhabiting these fragile coastal environments.


Asunto(s)
Escarabajos , Ecosistema , Animales , Biodiversidad , Chile , Humanos , Insectos , Estaciones del Año
3.
Methods Mol Biol ; 2360: 49-58, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-34495506

RESUMEN

Various approaches based on RNA interference (RNAi) have garnered significant attention in the field of insect pest management in recent years. For example, the use of double-stranded RNA (dsRNA) has notably been investigated to target transcripts of interest with relevance to insecticide resistance in multiple pests and has emerged as a potential tool to be deployed in agricultural fields in the near future. A careful characterization of a given dsRNA in a laboratory setting, including the assessment of dsRNA-mediated molecular and phenotypical changes observed in the targeted pest upon dsRNA exposure, is nevertheless essential prior to its use in field-based study. The current chapter thus describes the process via which a dsRNA, aimed at a molecular target underlying insecticide response in the Colorado potato beetle Leptinotarsa decemlineata, is conceived, synthesized and injected. Assessment of knockdown efficiency in injected insects is further presented.


Asunto(s)
Escarabajos , Solanum tuberosum , Animales , Escarabajos/genética , Resistencia a los Insecticidas/genética , Insecticidas/farmacología , Interferencia de ARN , ARN Bicatenario/genética
4.
Methods Mol Biol ; 2360: 59-74, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-34495507

RESUMEN

In situ hybridization (ISH) is a methodology by which nucleic acids are detected within fixed tissue samples. Recent advances in detection technology and target recovery have greatly enhanced the technique's ability to detect single mRNA molecules. Here we detail the fixation, paraffin embedding, sectioning, target recovery, and chromogenic detection of an mRNA (DvSSJ1), encoding for a membrane protein associated with the smooth septate junction (SSJ) in Western corn rootworm [Diabrotica virgifera (Dv)]. Further, we demonstrate, the expression of dsRNA of DvSSJ1 in maize root tissues using signal amplification and background suppression technology.


Asunto(s)
Zea mays , Animales , Escarabajos/genética , Hibridación in Situ , Larva , Plantas Modificadas Genéticamente , Interferencia de ARN , ARN Bicatenario , ARN Mensajero/genética , Zea mays/genética
5.
Methods Mol Biol ; 2360: 91-103, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-34495510

RESUMEN

Identification of active target genes in bioassay screening is the first important step for application of RNA interference (RNAi) for pest control. Here, we describe the methodology for performing high-throughput RNAi target screening against important agriculture pest, Western corn rootworm in 96-well microplate. Two approaches are presented to identify active targets from random-cDNA library or testing a certain group of specific targets via in silico sequence analysis. Methods of PCR primer design, DNA template preparation, and dsRNA production described here can be applied for other pests.


Asunto(s)
Escarabajos , Zea mays , Animales , Escarabajos/genética , Larva , Interferencia de ARN , ARN Bicatenario , Zea mays/genética
6.
Colloids Surf B Biointerfaces ; 210: 112252, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-34902712

RESUMEN

Ice accretion on surfaces can cause serious damages and economic losses in industries and civilian facilities. Antifreeze proteins (AFPs) as evolutionary adaptation products of organisms to cold climates, provide solutions for alleviating icing problems. In this work, a chimeric protein Mfp-AFP was rationally designed combining mussel-inspired adhesive domain with Tenebrio molitor-derived antifreeze protein domain. Expectedly, the multifunctional Mfp-AFP can lower the freezing point of water and inhibit ice recrystallization. The chimeric protein could also readily modify diverse solid surfaces due to the adhesive domain containing Dopa, and resist frosting and delay ice formation due to the beetle-derived antifreeze fragment. Moreover, Mfp-AFP coatings display excellent biocompatibility proved by cytocompatibility and hemolysis assays. Here, the designed multifunctional protein coatings provide an alternative strategy for fabricating anti-icing surfaces.


Asunto(s)
Escarabajos , Tenebrio , Animales , Proteínas Anticongelantes/genética , Congelación , Proteínas Recombinantes de Fusión , Agua
7.
Pestic Biochem Physiol ; 180: 104982, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34955175

RESUMEN

The pulse beetle Callosobruchus maculatus causes potential damage to legume crops by infesting the seeds, leading to a reduction of total protein content. Arcelin found in the wild accessions of the common bean, is an insecticidal protein that has the potency to hamper the metabolism of the bruchid beetle. The arcelin gene from the wild accession of Phaseolus lunatus was isolated and the ORF encoding 158 amino acids was cloned in pET-45b (+) vector. The recombinant clones were transformed in BL21 STAR (DE3) pLysS cells, and the expressed arcelin was purified using Ni-NTA column. The recombinant protein was used in preparing an artificial diet, and the insecticidal activity was elucidated against the bruchid pest C. maculatus. Adult emergence and seed damage were drastically reduced in the treated groups. The response towards ingested diet by digestive enzymes involved in metabolism was elucidated through quantitative gene expression. The highest expression was observed in the aminopeptidase, followed by upregulation of alpha-amylase, glycoside hydrolase family 31 and cathepsin D-like aspartic protease, and downregulation of cathepsin L-like cysteine protease. The recombinant arcelin demonstrates effective insecticidal activity against the bruchid beetle. The changes in digestive enzymes to counteract the anti-nutritional nature of the protein were the strategies of the insect defense mechanism.


Asunto(s)
Escarabajos , Phaseolus , Animales , Clonación Molecular , Escarabajos/genética , Phaseolus/genética , Proteínas de Plantas/genética , Semillas
8.
Pest Manag Sci ; 78(1): 369-378, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34538023

RESUMEN

BACKGROUND: Wireworms, the soil-dwelling larvae of click beetles, are a major threat to global agricultural production. This is largely due to their generalist polyphagous feeding capabilities, extended and cryptic life cycles, and limited management options available. Although wireworms are well-documented as economically important pests in the Canadian Prairies, including Manitoba, there are gaps in knowledge on species distributions, subterranean behaviour and life cycles, feeding ecology and damage capacity, and economic thresholds for crop yield loss. RESULTS: We carried out 3 years (2018-2020) of intensive surveillance of larval populations across Manitoba. A total of 31 fields (24 in ≥ 2 consecutive years) were surveyed in early spring using standardized bait trapping approaches. Wireworms were present in 94% of surveyed sites, but the catch within fields varied year to year. While Hypnoidus bicolor predominated (94% of larvae), several other pest species were identified. We then explored the relationships between wireworm trap numbers and agro-environmental factors. The larval catch tended to decrease under conditions of low soil temperatures and increased clay content, coupled with high soil moisture and precipitation during the trapping period. Treatment and cultural methods appeared less influential; however, wheat production in either of the previous two growing seasons was associated with increased wireworm catch. Our models failed to predict a relationship between wireworm catch and crop yields, although infestations were rare in our region. CONCLUSION: Our findings better infer the risks posed by wireworms to crop production in the Canadian Prairies, and the agro-environmental factors that represent the greatest contributors to these risks. This information should be incorporated into future integrated pest management (IPM) strategies for wireworms. © 2021 Her Majesty the Queen in Right of Canada Pest Management Science © 2021 Society of Chemical Industry Reproduced with the permission of the Minister of Agriculture and Agri-Food Canada.


Asunto(s)
Escarabajos , Control de Plagas , Animales , Larva , Manitoba
9.
Methods Mol Biol ; 2360: 155-174, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-34495514

RESUMEN

Reverse transcription quantitative polymerase chain reaction (RT-qPCR) assays are a highly accurate and precise method for measuring transcript expression levels. A major drawback of RT-qPCR is the extensive optimization and validation necessary to produce high-quality assays, as described in the guidelines "Minimum Information for Publication of Quantitative Real-Time PCR Experiments." This chapter describes use of designed and optimized RT-qPCR assays that accurately detect expression of eight genes predicted to be centrally involved in the RNA interference (RNAi) pathways of western corn rootworm (WCR), and appropriate accompanying parameters. Assay gene targets include drosha, dicer-1, dicer-2, pasha, loquacious, r2d2, argonaute 1, and argonaute 2, and detection has been validated at nine different points in the WCR life cycle. These assays can be used with this procedure to assess expression of any one of these core RNAi pathway genes in up to 96 samples per 384-well qPCR plate.


Asunto(s)
Escarabajos , Zea mays , Animales , Escarabajos/genética , Larva , Interferencia de ARN , Reacción en Cadena en Tiempo Real de la Polimerasa , Zea mays/genética
10.
Environ Res ; 204(Pt A): 111996, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-34480944

RESUMEN

Behavior of insects, such as pollination and grazing, is usually determined by biogenic volatile organic compounds (BVOCs). However, particularly in O3-polluted urban forests, the BVOCs-based plant-insect communication can be disrupted by the reaction of O3 with leaf-emitted BVOCs, such as between Japanese white birch (Betula platyphylla var. japonica) and a leaf beetle (Agelastica coerulea). To understand plant-insect communication in O3-polluted environments, it is necessary to identify chemical species of BVOCs that contribute to attractiveness toward insects but are diminished by elevated O3. In this study, we conducted olfactory response tests and gas chromatography mass spectrometry (GC-MS) analyses to clarify whether there is a similarity of BVOC components among Betulaceae host trees that can explain the attraction of the stenophagous insect A. coerulea. The olfactory response tests indicated that Betulaceae host trees attract A. coerulea via leaf-emitted BVOCs, while there was no preference of the leaf beetles to non-host trees (Sorbus commixta and Morus bombycis). However, GC-MS analyses indicated that the composition of BVOC blends considerably differed among Betulaceae host trees, although alders (Alnus hirsuta and A. japonica) had a similar composition of BVOC blend in each season (June and September) during which the adult leaf beetle is active. A distinct characteristic of the emission from B. platyphylla was that 2-carene and limonene, which are O3-reactive species, were emitted with a high monoterpene ratio irrespective of the season. Thus, these volatiles and the blend could be expected to lead the disrupted communication found between B. platyphylla and A. coerulea under elevated O3 in previous field studies. In addition, our results indicated that A. coerulea is attracted to more than one blend within Betulaceae host trees, suggesting that grazing damages can be affected by different host preferences and O3 reactivity with specific BVOCs in the field. BVOCs-based plant-insect interactions should be further studied in multi-species communities to better understand plant-insect communication in O3-polluted environments.


Asunto(s)
Alnus , Escarabajos , Compuestos Orgánicos Volátiles , Animales , Betula , Comunicación , Bosques , Árboles
11.
Sci Total Environ ; 806(Pt 2): 150644, 2022 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-34597572

RESUMEN

Silver nanoparticles (AgNPs) are currently the most frequently used engineered nanoparticles. The penetration of AgNPs into ecosystems is undeniable, and their adverse effects on organism reproduction are of fundamental importance for ecosystem stability. In this study, the survival time of the Egyptian beetle Blaps polychresta Forskal, 1775 (Coleoptera: Tenebrionidae), after a single application of 7 different doses, was calculated for 30 days. Then, for the group for which the effect on mortality was calculated as LOAEL - the Lowest Observed Adverse Effect Level, namely, 0.03 mg AgNPs/g body weight (b.w.t.), the following were assessed: structure and ultrastructure of gonads by TEM and SEM, cell viability by cytometry, DNA damage by the comet assay, and a variety of stress markers by spectrophotometric methods. A dose-dependent reduction in the survival time of the insects was revealed. Detailed analysis of the testes of beetles treated with 0.03 mg AgNPs/g b.w.t. revealed numerous adverse effects of nanoparticles in structure and ultrastructure, accompanied by increased apoptosis (but not necrosis), increased DNA damage, increased lipid peroxidation, and decreased levels of antioxidant enzymes. Most likely, the observed results are connected with the gradual release of Ag+ from the surface of the nanoparticles, which, once applied, are internalized in cells and become a long-lasting, stable source of Ag+ ions. Thus, a single exposure to AgNPs may have the effects of chronic exposure and lead to structural damage and dysfunction of the gonads of B. polychresta.


Asunto(s)
Escarabajos , Nanopartículas del Metal , Animales , Ecosistema , Masculino , Nanopartículas del Metal/toxicidad , Plata/toxicidad , Testículo
12.
Sci Total Environ ; 807(Pt 1): 150575, 2022 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-34634717

RESUMEN

Increases in the frequency and magnitude of suboptimal temperatures as a result of climate change are subjecting insects to unprecedented stresses. This may negatively affect their fitness and the efficiency of their ecosystem service provision. Dung beetles are ecosystem service providers: through feeding on and burying dung, they facilitate nutrient recycling, secondary seed dispersal, parasite control, soil bioturbation and dung decomposition. As such, prediction of how dung beetles respond to multiple anthropogenic environmental changes is critical for the conservation of ecosystem services. Here, we quantified ecosystem services via dung utilisation and dung ball production in three telecoprid species: Allogymnopleurus indigaceous, Scarabaeus zambezianus and Khepher prodigiosus. We examined ecosystem service efficiency factorially under different beetle densities towards different dung masses and under three temperature treatments (21 °C, 28 °C and 35 °C). Khepher prodigiosus, exhibited greatest dung utilisation efficiency overall across dung masses, compared to both S. zambezianus and A. indigaceous. Dung removal was exhibited under all the tested temperatures by all tested species, and therefore the sub-optimal temperatures employed here did not fully inhibit ecosystem service delivery. However, emergent effects among temperatures, beetle species and beetle density further affected removal efficiency: S. zambezianus and A. indigaceous utilisation increased with both warming and beetle density, whereas K. prodigiosus performance was less temperature- and density-dependent. Beetles also tended to exhibit positive density-dependence as dung supply increased. The numbers of dung balls produced differed across species, and increased with temperature and densities, with S. zambezianus producing significantly most balls overall. Our study provides novel evidence for differential density-dependent ecosystem service delivery among species across stressful temperature regimes and emergent effects for dung mass utilisation. This information is essential for biodiversity-ecosystem-function and is critical for the conservation of functionally efficacious species, with implications for natural capital conservation policy in rapidly changing environments.


Asunto(s)
Escarabajos , Dispersión de Semillas , Animales , Biodiversidad , Ecosistema , Heces , Temperatura
13.
Pest Manag Sci ; 78(1): 126-133, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34453875

RESUMEN

BACKGROUND: The potential of Beauveria bassiana and Metarhizium anisopliae isolates obtained from naturally infected oil palm pests was evaluated to control Demotispa neivai as an alternative for organophosphate insecticide use in oil palm crops in Latin America. Two B. bassiana (Bb-0018 and Bb-0025) and two M. anisopliae (Ma-0002 and Ma-0003) isolates were tested against D. neivai adults for hydrophobicity, virulence, survival, adhesion to host cuticle, and mortality in semi-field conditions. RESULTS: Concentration-mortality bioassays demonstrate that isolates had lethal effect on D. neivai adults with Bb-0025 [median lethal concentration (LC50 ) = 3.45 × 107 conidia mL-1 ] and Bb-0018 (LC50  = 3.75 × 107 conidia mL-1 ) being the most effective followed by Ma-0003 (LC50  = 3.38 × 108 conidia mL-1 ) and Ma-0002 (5.33 × 108 conidia mL-1 ). Adult survival was 99% without exposure to fungal isolates, decreasing to 21.65% in insects exposed to Ma-0002, 19.41% with Ma-0003, 20.13% with Bb-0018, and 0.17% with Bb-0025. Mortality of D. neivai adults caused by the entomopathogenic fungal isolates was similar in both laboratory and semi-field conditions. Also, vegetative growth of the entomopathogenic fungal isolates was found in infected D. neivai adults in the field. CONCLUSION: Our data suggest that the tested entomopathogenic fungal isolates are effective against D. neivai with potential to be used as biological control agents contributing to the decrease of the use of chemical insecticides to control this oil palm pest. © 2021 Society of Chemical Industry.


Asunto(s)
Beauveria , Escarabajos , Metarhizium , Animales , Control Biológico de Vectores , Esporas Fúngicas
14.
Pest Manag Sci ; 78(1): 193-204, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34469049

RESUMEN

BACKGROUND: The Asian lady beetle Harmonia axyridis is an important predator of several agricultural pests, including aphids and whiteflies, and thus can contribute to pest management. Commercial viability as a pest control method requires that the beetle can be mass-reared, and that workable conditions for extended shelf-life can be guaranteed. One of the features of Harmonia's life cycle is that it enters diapause in the adult stage when the length of the photophase starts shortening in late summer. Reduction of juvenile hormone (JH) titer has been demonstrated to be the common endocrine mechanism inducing reproductive diapause in insects. However, whether H. axyridis enters diapause dependent on JH shutdown and how the JH level is regulated before diapause remains unknown. RESULTS: Like in other insects, the absence of JH triggers the induction and maintenance of reproductive diapause in H. axyridis, indicated by JH measurements and the knockdown of an intracellular JH receptor methoprene-tolerant (Met). Methoprene, a JH analog, significantly reversed diapause into reproduction via Met. Combined with RNA-sequencing and RNA interference, we also demonstrated that JH biosynthesis rather than the JH degradation pathway determines the reduction of JH titer in diapausing females. CONCLUSION: Our results reveal the vital role of JH in regulating reproductive diapause in female H. axyridis. Harmonia axyridis diapause could thus be manipulated by targeting JH production and JH signaling. © 2021 Society of Chemical Industry.


Asunto(s)
Escarabajos , Diapausa de Insecto , Diapausa , Animales , Femenino , Humanos , Hormonas Juveniles , Metopreno , Reproducción
15.
Pest Manag Sci ; 78(1): 217-229, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34472706

RESUMEN

BACKGROUND: Pistachio (Pistacia vera L.) is a commercially important tree in the Mediterranean basin, where there is a considerable increase in cultivation, especially in Spain. Because of its recent introduction as a crop in the country (1980s), studies on the pests of pistachio in Spain are still rare. Here, we studied the leaf beetle Labidostomis lusitanica (Coleoptera: Chrysomelidae), which was observed on pistachio and might become a serious pest under the expanding Spanish pistachio fields. Because early detection of pests is extremely important to properly plan control strategies, we (i) updated the information on the distribution of the species through samplings and surveys, and (ii) modelled its potential distribution. RESULTS: Currently, L. lusitanica occurs across the whole Iberian Peninsula, especially in its southern and eastern parts, with adults on flight roughly from late April to early June. Analysis of climatic niches showed that L. lusitanica prefers dry and hot areas, which are conditions found especially in the central-southern parts of the Iberian Peninsula. Such highly suitable areas for this pest overlap considerably with the suitable areas for pistachio cultivation. Surveys of pistachio growers weakly suggested a higher pest attack probability, but, unexpectedly, a lower perceived impact in very suitable areas for L. lusitanica, suggesting that other factors may shape its pest potential in a complex way. CONCLUSION: In line with what has been observed for other Labidostomis species on pistachio in other Mediterranean countries, L. lusitanica has a good potential to harm pistachio production in Spain, claiming for further investigations and prevention strategies. © 2021 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.


Asunto(s)
Escarabajos , Mariposas Nocturnas , Pistacia , Animales , España
16.
Ying Yong Sheng Tai Xue Bao ; 32(11): 4139-4146, 2021 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-34898130

RESUMEN

Poplar, as the main tree species of the protection forest in the "Three-North" area of China, has been seriously damaged by Anoplophora glabripennis since 1970s. Populus deltoides cl. Beikang (PDB) shows strong resistance to A. glabripennis, but the biochemical mechanism of resistance is unclear. In this study, the quantities of secondary metabolites and the activity of defense enzymes in bark and xylem from undamaged, mechanically damaged, and A. glabripennis infected PDB were detected by kit and HPLC techniques. The results showed different responses of PDB to mechanical damage and A. glabripennis infection. Secondary metabolites, the quantities of D-(-)-salicin and aspen significantly increased after mechanical injury compared with the undamaged materials, but the quantities of quercitrin decreased. The quantities of D-(-)-salicin and quercitrin significantly increased after insect infection, but without difference for aspen. There was no significant difference for the total quantities of phenolics between insect infected and uninjured xylem, but both were significantly lower than that in the mechanical damaged xylem. The quantities of aspen and flax lignans in the insect infected xylem was higher than those in the mechanical damaged xylem and uninjured xylem, while the quantities of total phenolic glycosides in the mechanical damaged xylem and the insect infected xylem were both significantly higher than that in the uninjured xylem. PAL activity was not different between mechanical damage and insect infection, whereas both were significantly higher than that of uninjured bark. SOD activity in mechanical damaged bark was significantly higher than that in insect infected bark, which were both higher than that of uninjured bark. POD activity had no significant difference between mechanical damage and insect infected xylem, but were higher than that of uninjured xylem. Compared with the uninjured PDB tree, the secondary metabolites and defense enzymes in the mechanical damaged and A. glabripennis infected PDB increased in varied degrees, which would be related with the resistance of PDB to external injury.


Asunto(s)
Escarabajos , Populus , Animales , Bosques , Árboles , Xilema
17.
PLoS One ; 16(12): e0257861, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34928953

RESUMEN

Coffee berry borer (CBB, Hypothenemus hampei Ferrari) is the most serious insect pest of coffee worldwide, yet little is known about the effect that weather variables have on CBB flight activity. We sampled flying female CBB adults bi-weekly over a three-year period using red funnel traps baited with an alcohol lure at 14 commercial coffee farms on Hawaii Island to characterize seasonal phenology and the relationship between flight activity and five weather variables. We captured almost 5 million scolytid beetles during the sampling period, with 81-93% of the trap catch comprised of CBB. Of the captured non-target beetles, the majority were tropical nut borer, black twig borer and a species of Cryphalus. Two major flight events were consistent across all three years: an initial emergence from January-April that coincided with early fruit development and a second flight during the harvest season from September-December. A generalized additive mixed model (GAMM) revealed that mean daily air temperature had a highly significant positive correlation with CBB flight; most flight events occurred between 20-26°C. Mean daily solar radiation also had a significant positive relationship with flight. Flight was positively correlated with maximum daily relative humidity at values below ~94%, and cumulative rainfall up to 100 mm; flight was also positively correlated with maximum daily wind speeds up to ~2.5 m/s, after which activity declined. Our findings provide important insight into CBB flight patterns across a highly variable landscape and can serve as a starting point for the development of flight prediction models.


Asunto(s)
Escarabajos/fisiología , Vuelo Animal/fisiología , Modelos Biológicos , Estaciones del Año , Animales , Femenino , Hawaii , Masculino
18.
GM Crops Food ; 12(1): 459-478, 2021 Jan 02.
Artículo en Inglés | MEDLINE | ID: mdl-34904520

RESUMEN

Event DP-Ø23211-2 (hereafter referred to as DP23211) maize expresses the DvSSJ1 double-stranded RNA (DvSSJ1 dsRNA) and the IPD072Aa protein, encoded by the ipd072Aa gene. DvSSJ1 dsRNA and the IPD072Aa protein each provide control of corn rootworms (Diabrotica spp.) when expressed in plants. As part of the environmental risk assessment (ERA), the potential hazard to non-target organisms (NTOs) exposed to the DvSSJ1 dsRNA and the IPD072Aa protein expressed in DP23211 maize was assessed. Worst-case estimated environmental concentrations (EECs) for different NTO functional groups (pollinators and pollen feeders, soil dwelling detritivores, predators and parasitoids, aquatic detritivores, insectivorous birds, and wild mammals) were calculated using worst-case assumptions. Several factors that reduce exposure to NTOs under more realistic environmental conditions were applied, when needed to provide more environmentally relevant EECs. Laboratory bioassays were conducted to assess the activity of DvSSJ1 dsRNA or the IPD072Aa protein against selected surrogate species, and margins of exposure (MOEs) were calculated by comparing the Tier I hazard study results to worst-case or refined EECs. Based on specificity and MOE values, DvSSJ1 dsRNA and the IPD072Aa protein expressed in DP23211 maize are not expected to be harmful to NTO populations at environmentally relevant concentrations.


Asunto(s)
Escarabajos , ARN Bicatenario , Animales , Escarabajos/genética , Plantas Modificadas Genéticamente/genética , ARN Bicatenario/genética , Medición de Riesgo , Zea mays/genética
19.
J Insect Sci ; 21(6)2021 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-34905604

RESUMEN

The mitochondrial genome sequences of Denierella emmerichi, Epicauta curvispina, and Meloe poggii were determined. Their mitochondrial genomes were found to contain 37 genes (13 protein-coding genes [PCGs], 22 tRNA genes, and 2 rRNAs), of which 4 PCGs, 8 tRNA genes, and 2 rRNAs are encoded by the N-strand, and the remaining genes are encoded by the J-strand. The mitochondrial genomes of D. emmerichi, E. curvispina, and M. poggii are 15,702 bp, 15,813 bp, and 15,626 bp in length, respectively, and their guanine-cytosine contents are 28%, 33%, and 36%, respectively. The 13 PCGs of D. emmerichi, E. curvispina, and M. poggii use ATN as the standard start codon and TAA, TAG, and T as the stop codons. The Bayesian inference and maximum likelihood phylogenetic analysis results based on the 13 PCGs and 13 PCGs + 2rRNAs datasets of the mitochondrial genomes of the Meloidae support Epicauta (Coleoptera: Meloidae) ([D. emmerichi, E. curvispina, E. ruficeps, E. aptera] + [E. chinensis, E. impressicornis, E. gorhami, E. tibialis]). We believe that this research enriches the literature on the mitochondrial genomics of Meloidae and serves as a foundation for the further study of the phylogenetic relationships and characterization of Meloidae and Coleoptera.


Asunto(s)
Escarabajos , Genoma de los Insectos , Genoma Mitocondrial , Filogenia , Animales , Teorema de Bayes , Escarabajos/genética , ARN de Transferencia/genética
20.
PLoS One ; 16(12): e0260532, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34928980

RESUMEN

The western corn rootworm (WCR), Diabrotica virgifera virgifera LeConte, is a major maize pest in the United States causing significant economic loss. The emergence of field-evolved resistant WCR to Bacillus thuringiensis (Bt) traits has prompted the need to discover and deploy new insecticidal proteins in transgenic maize. In the current study we determined the crystal structure and mode of action (MOA) of the Vpb4Da2 protein (formerly known as Vip4Da2) from Bt, the first identified insecticidal Vpb4 protein with commercial level control against WCR. The Vpb4Da2 structure exhibits a six-domain architecture mainly comprised of antiparallel ß-sheets organized into ß-sandwich layers. The amino-terminal domains 1-3 of the protein share structural homology with the protective antigen (PA) PA14 domain and encompass a long ß-pore forming loop as in the clostridial binary-toxB module. Domains 5 and 6 at the carboxyl-terminal half of Vpb4Da2 are unique as this extension is not observed in PA or any other structurally-related protein other than Vpb4 homologs. These unique Vpb4 domains adopt the topologies of carbohydrate-binding modules known to participate in receptor-recognition. Functional assessment of Vpb4Da2 suggests that domains 4-6 comprise the WCR receptor binding region and are key in conferring the observed insecticidal activity against WCR. The current structural analysis was complemented by in vitro and in vivo characterizations, including immuno-histochemistry, demonstrating that Vpb4Da2 follows a MOA that is consistent with well-characterized 3-domain Bt insecticidal proteins despite significant structural differences.


Asunto(s)
Bacillus thuringiensis/metabolismo , Proteínas Bacterianas/química , Insecticidas/farmacología , Secuencia de Aminoácidos , Animales , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Escarabajos/efectos de los fármacos , Escarabajos/crecimiento & desarrollo , Cristalografía por Rayos X , Insecticidas/química , Intestinos/metabolismo , Larva/efectos de los fármacos , Larva/metabolismo , Mutagénesis Sitio-Dirigida , Multimerización de Proteína , Estructura Terciaria de Proteína , Proteínas Recombinantes/biosíntesis , Proteínas Recombinantes/aislamiento & purificación , Proteínas Recombinantes/farmacología , Zea mays/metabolismo , Zea mays/parasitología
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