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1.
Chemosphere ; 360: 142429, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38797206

RESUMO

Heavy metal pollution threatens human and ecological health. Heavy metals can exist in the soil for a long time and migrate to organisms along the food chain. However, only a few studies have investigated the effects of a single stress on broad beans. Here, we aimed to characterize Cd and Pb bioaccumulation, at varying concentrations, in the broad bean, Vicia faba L. We also determined how the bioaccumulated metals are impacted by aphids that consume the plant. No significant difference was noted in the germination rates of broad beans at the early stage of planting (after 8 days), but eventually, the germination rates of broad beans at all time points first decreased and then increased, and the highest inhibition efficiency was observed in the T3 group (12.5 mg/L Cd2+ + 50 mg/L Pb2+). Fourteen days after planting, there was no significant difference in seedling height between the T5 (50 mg/L Cd2+ + 200 mg/L Pb2+) and control groups; however, that in the other groups decreased significantly and there was no dependence between stress concentration and inhibition efficiency. In addition, both Cd and Pb in the soil could be transferred to broad beans, and the concentration of Pb in the roots of broad beans was greater than that of Cd, whereas the opposite was observed in the stems and leaves. Notably, under mixed stress, aphids could significantly reduce the content of Cd in broad beans; similarly, the Pb content in the roots and stems of broad beans decreased significantly after being infested with aphids but increased significantly in the leaves. Further, the aphid infestation decreased the Pb content in the soil and the soil Cd content in the highest concentration group (T5 group) (50 mg/L Cd2+ + 200 mg/L Pb2+). These results highlight the necessity of focusing on the effect of insects on heavy metal remediation in plants and provide a new perspective for reducing plant Cd toxicity.


Assuntos
Afídeos , Bioacumulação , Cádmio , Chumbo , Metais Pesados , Poluentes do Solo , Vicia faba , Vicia faba/metabolismo , Animais , Poluentes do Solo/metabolismo , Poluentes do Solo/análise , Afídeos/fisiologia , Cádmio/metabolismo , Chumbo/metabolismo , Metais Pesados/metabolismo , Solo/química , Germinação/efeitos dos fármacos
2.
Insect Mol Biol ; 2024 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-38450915

RESUMO

Frankliniella occidentalis (Pergande) is a typical omnivorous insect that feeds on host plants, pollens and mite eggs, and poses a threat to crops worldwide. The insulin signalling pathway (ISP) is a typical nutrient-sensitive pathway that participates in the regulation of various functions in insects. Serine/threonine kinases (AKTs) and phosphoinositide-dependent kinases (PDKs) are key components of the ISP. In this study, the FoAKT and FoPDK genes in F. occidentalis were cloned, and the effects of three foods on their expression were determined. The expression of FoAKT and FoPDK in the thrips fed on kidney bean leaves supplemented with pine pollen or mite eggs was higher than in those primarily fed on leaves alone. Meanwhile, the fecundity of thrips fed on leaves supplemented with pine pollen was highest. In addition, RNA interference-mediated knockdown of FoAKT and FoPDK decreased vitellogenin (Vg) content and Vg expression in females, shortened ovariole length, delayed egg development and reduced fecundity and offspring hatching rates. Furthermore, the synthesis of juvenile hormone (JH) was reduced, and the contents of glucose, trehalose, glycogen and trehalase were affected. These results suggest that FoAKT and FoPDK regulate the reproduction of F. occidentalis by regulating Vg and JH production as well as carbohydrate metabolism.

3.
J Econ Entomol ; 117(1): 311-322, 2024 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-38181509

RESUMO

Frankliniella occidentalis Pergande (Thysanoptera: Thripidae) is an agricultural pest threatening various horticultural crops worldwide. Inducing plant resistance is an ecologically beneficial and potentially effective method for controlling F. occidentalis. As an essential nutrient element, exogenous calcium enhances plant-induced resistance. This study investigated the effects of CaCl2 on the secondary metabolites of kidney bean plants and detoxifying and digestive enzymes in F. occidentalis. We found that treatment of plants and treatment time and also the interactions of the 2 factors significantly affected secondary metabolites contents (tannin, flavonoids, total phenol, alkaloid, and lignin) of kidney bean leaves, which indicated that that the effect of treatment of plants on secondary metabolites varied with treatment time. Moreover, when thrips fed on CaCl2-treated plants, the activities of detoxifying enzymes, enzymes glutathione S-transferase and cytochrome P450 substantially increased compared to those in which thrips fed on control plants. However, the activity of carboxylesterase significantly decreased. The detoxifying enzyme genes CL992.contig6, CYP4PN1, and CYP4PJ2 were significantly upregulated at 24 and 48 h. The activities of digestive enzymes (α-amylase, chymotrypsin, and lipase) increased substantially in F. occidentalis. The digestive enzyme gene, FoAMY-1, was significantly upregulated at 24 and 48 h after treatment. The pupation rate and pupal weight of F. occidentalis were significantly reduced. The results indicated that exogenous CaCl2-induced metabolic changes in kidney bean plants and altered the enzymatic activity and development of F. occidentalis that fed upon them.


Assuntos
Phaseolus , Tisanópteros , Animais , Tisanópteros/fisiologia , Cálcio/farmacologia , Cloreto de Cálcio/farmacologia , Produtos Agrícolas
4.
Pestic Biochem Physiol ; 197: 105679, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38072536

RESUMO

Frankliniella occidentalis (Thysanoptera: Thripidae) is a pest that feeds on various crops worldwide. A prior study identified Lecanicillium attenuatum and L. cauligalbarum as pathogens of F. occidentalis. Unfortunately, the potential of these two entomopathogenic fungi for the biocontrol of F. occidentalis has not been effectively evaluated. The internal microbes (endosymbionts and the gut microbiota) of insects, especially gut bacteria, are crucial in regulating the interactions between the host and intestinal pathogens. The role of thrips internal microbes in the infection of these two entomopathogenic fungi is also unknown. Therefore, biological control of thrips is immediately needed, and to accomplish that, an improved understanding of the internal microbes of thrips against Lecanicillium infection is essential. The virulence of the two pathogenic fungi against F. occidentalis increased with the conidia concentration. Overall, the LC50 of L. cauligalbarum was lower than that of L. attenuatum, and the pathogenicity degree was adult > pupa > nymphs. The activities of protective enzymes include superoxide dismutase (SOD), catalase (CAT), peroxidase (POD); detoxification enzymes include polyphenol oxidase (PPO), glutathione s-transferase (GSTs), and carboxylesterase (CarE); hormones include ecdysone and juvenile hormone; and the composition and proportion of microorganisms (fungi and bacteria) in F. occidentalis infected by L. cauligalbarum and L. attenuatum have changed significantly. According to the network correlation results, there was a considerable correlation among the internal microbes (including bacteria and fungi), enzyme activities, and hormones, which indicates that in addition to bacteria, internal fungi of F. occidentalis are also involved in the L. cauligalbarum and L. attenuatum infection process. In addition, the development time of the surviving F. occidentalis exposed to L. cauligalbarum or L. attenuatum was significantly shorter than that of the control group. Furthermore, the intrinsic rate of increase (rm), finite rate of increase (λ), net reproductive rate (R0), mean generation time (T), and gross reproductive rate (GRR) were significantly lower in the treatment groups than in the control group. L. attenuatum and L. cauligalbarum have biocontrol potential against F. occidentalis. In addition to bacteria, internal fungi of F. occidentalis are also involved in the infection process of insect pathogenic fungi. Disruption of the internal microbial balance results in discernible sublethal effects. Such prevention and control potential should not be ignored. These findings provide an improved understanding of physiological responses in thrips with altered immunity against entomopathogenic fungal infections, which can guide us toward the development of novel biocontrol strategies against thrips.


Assuntos
Tisanópteros , Animais , Insetos , Reprodução , Pupa , Hormônios
5.
Insects ; 14(1)2023 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-36662015

RESUMO

Frankliniella occidentalis (Pergande) is an important horticultural pest that causes serious damage to rose plants, which is one of its preferred foods. In this study, rose petals, rose flowers, and 10% honey solution + kidney bean pods were chosen as foods to assess their influence on the growth, development and fecundity of F. occidentalis. The results showed that developmental time of immature F. occidentalis with the following trend: rose flowers <10% honey solution + kidney bean pods < rose petals < kidney bean pods. The longevities of both female and male adults were lowest when feeding on the rose petals and were highest when feeding on rose flowers. The fecundity was in the following order: rose flowers >10% honey solution + kidney bean pods > rose petals > kidney bean pods. The net reproductive rate (R0), intrinsic rate of increase (r), and finite rate of increase (λ) of F. occidentalis feeding on rose petals and kidney bean pods were lower than those feeding on rose flowers and 10% honey solution + kidney bean pods. The development, longevity, fecundity, and parameters have significantly changed since F1 generation after feeding with the three food types. The results indicated that different parts of rose flowers had a significant effect on the development of thrips, and nectar and pollen had a positive effect on thrips population increase and reproduction.

6.
Insects ; 13(12)2022 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-36555037

RESUMO

Frankliniella occidentalis is a destructive pest of horticultural plants, while Orius similis is a natural enemy of thrips. It has been demonstrated that exogenous calcium could induce plant defenses against herbivore attack. We examined whether CaCl2 supplementation altered the volatile emissions of kidney bean plants, which influence the oviposition preference of F. occidentalis. We also assessed the influence of volatile cues on O. similis. Using Y-tube olfactometer tests, we found that exogenous CaCl2 treatment inhibited the selectivity of F. occidentalis but attracted O. similis. In addition, CaCl2 treatment reduced the oviposition preference of F. occidentalis. Gas chromatography-mass spectrometry analyses revealed that CaCl2 treatment altered the number and relative abundance of the volatile compounds in kidney bean plants and that (E)-2-hexen-1-ol, 1-octen-3-ol, ß-lonone, and (E,E)-2,4-hexadienal might be potential olfactory cues. Furthermore, the results of the six-arm olfactometer test indicated that 1-octen-3-ol (10-2 µL/µL), ß-lonone (10-2 µL/µL), and (E,E)-2,4-hexadienal (10-3 µL/µL) repelled F. occidentalis but attracted O. similis. Overall, our results suggested that exogenous CaCl2 treatment induced defense responses in kidney bean plants, suggesting that CaCl2 supplementation may be a promising strategy to enhance the biological control of F. occidentalis.

7.
Insects ; 13(11)2022 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-36421976

RESUMO

Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) is a serious invasive pest in China. In this study, we determined whether exogenous jasmonic acid (JA) and ethylene (ET) treatments could induce resistance against F. occidentalis in faba bean plants. First, we investigated the effects of different concentrations of JA or ET alone on F. occidentalis and then assessed the effects of optimal concentrations of JA and ET combined. Our results showed that the optimal concertation of JA was 2 mmol/L and ET was 0.5 mmol/L. JA + ET mixture showed the greatest inhibitory effect in terms of oviposition and feeding. JA with ET was found to induce changes in the activities of lipoxygenase (LOX), allene oxide synthase (AOS), polyphenol oxidase (PPO), 1-aminocyclopropane 1-carboxylic acid synthase (ACS), and trypsin inhibitor (TI). This treatment also activated or inhibited the relative expression levels of LOX1, ACO2, ACS2, and AP2/ERF. Treatment of faba bean plants with JA and ET significantly prolonged F. occidentalis development and adult preoviposition period, significantly reduced per-female oviposition, and altered male longevity and offspring demographic parameters. These results indicate that JA with ET can induce defenses against the growth and development of F. occidentalis in faba bean plants.

8.
Insects ; 13(10)2022 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-36292877

RESUMO

The development and reproduction of the fall armyworm (FAW), Spodoptera frugiperda, which were reared on artificial diets containing nano-graphene oxide (GO), were determined based on age-stage, two-sex life table analysis. The results showed that GO had adverse effects on FAWs. Compared with the control, the duration of the egg stage and first, second, and sixth instar larval stages increased with increasing GO concentrations; however, the lifespan of male and female adults decreased with increasing GO concentrations. Weights of FAW pupae that were supplied with GO-amended diets increased by 0.17-15.20% compared to the control. Intrinsic growth, limited growth, and net reproductive rates of FAWs feeding on GO supplemented diets were significantly lower than the control, while mean generational periods (0.5 mg/g: 38.47; 1 mg/g: 40.38; 2 mg/g: 38.42) were significantly longer than the control. The expression of genes encoding vitellogenin (Vg) and vitellogenin receptor (VgR) expression was abnormal in female FAW adults feeding on GO-amended diets; the number of eggs laid decreased relative to the control, but Vg expression increased. In conclusion, GO prolonged the developmental period of FAWs, decreased fecundity, and led to a decline in the population size. The study provides a basis for the rational use of GO as a pesticide synergist for FAW control.

9.
Insects ; 13(9)2022 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-36135483

RESUMO

Western flower thrips (Frankliniella occidentalis) pose a serious threat to the global vegetable and flower crop production. The regulatory mechanism for superoxide dismutase (SOD) in the feeding adaptation of F. occidentalis after host shifting remains unclear. In this study, the copper chaperone for SOD (CCS) and manganese SOD (MnSOD) genes in F. occidentalis were cloned, and their expression levels at different developmental stages was determined. The mRNA expression of FoCCS1 and FoMnSOD2 in F. occidentalis second-instar larvae and adult females of F1, F2, and F3 generations was analyzed after shifting the thrips to kidney bean and broad bean plants, respectively. The F2 and F3 second-instar larvae and F2 adult females showed significantly upregulated FoCCS1 mRNA expression after shifting to kidney bean plants. The F1 second-instar larvae and F2 adult females showed significantly upregulated FoCCS1 mRNA expression after shifting to broad bean plants. The RNA interference significantly downregulated the FoCCS1 mRNA expression levels and adult females showed significantly inhibited SOD activity after shifting to kidney bean and broad bean plants. F. occidentalis adult females subjected to RNA interference and released on kidney bean and broad bean leaves for rearing, respectively, significantly reduced the survival rate and fecundity. These findings suggest that FoCCS1 plays an active role in regulating the feeding adaptation ability of F. occidentalis after host shifting.

10.
Int J Mol Sci ; 23(18)2022 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-36142802

RESUMO

The western flower thrips, Frankliniella occidentalis Pergande, is an invasive pest that damages agricultural and horticultural crops. The induction of plant defenses and RNA interference (RNAi) technology are potent pest control strategies. This study investigated whether the anti-adaptive ability of F. occidentalis to jasmonic acid (JA)- and methyl jasmonate (MeJA)-induced defenses in kidney bean plants was attenuated after glutathione S-transferase (GST) gene knockdown. The expression of four GSTs in thrips fed JA- and MeJA-induced leaves was analyzed, and FoGSTd1 and FoGSTs1 were upregulated. Exogenous JA- and MeJA-induced defenses led to increases in defensive secondary metabolites (tannins, alkaloids, total phenols, flavonoids, and lignin) in leaves. Metabolome analysis indicated that the JA-induced treatment of leaves led to significant upregulation of defensive metabolites. The activity of GSTs increased in second-instar thrips larvae fed JA- and MeJA-induced leaves. Co-silencing with RNAi simultaneously knocked down FoGSTd1 and FoGSTs1 transcripts and GST activity, and the area damaged by second-instar larvae feeding on JA- and MeJA-induced leaves decreased by 62.22% and 55.24%, respectively. The pupation rate of second-instar larvae also decreased by 39.68% and 39.89%, respectively. Thus, RNAi downregulation of FoGSTd1 and FoGSTs1 reduced the anti-adaptive ability of F. occidentalis to JA- or MeJA-induced defenses in kidney bean plants.


Assuntos
Phaseolus , Tisanópteros , Acetatos , Animais , Ciclopentanos/metabolismo , Ciclopentanos/farmacologia , Flavonoides/metabolismo , Flores/metabolismo , Glutationa Transferase/genética , Glutationa Transferase/metabolismo , Lignina/metabolismo , Oxilipinas/metabolismo , Oxilipinas/farmacologia , Phaseolus/metabolismo , Fenóis/metabolismo , Interferência de RNA , Taninos/metabolismo , Tisanópteros/genética , Tisanópteros/metabolismo
11.
Environ Entomol ; 51(4): 780-789, 2022 08 19.
Artigo em Inglês | MEDLINE | ID: mdl-35834261

RESUMO

The western flower thrip (WFT) Frankliniella occidentalis (Pergande) is a serious agricultural pest with a wide host range which has developed resistance to several groups of insecticides. In this study, the effect of insecticide resistance on WFT host adaptability was explored by examining changes in detoxification enzyme activities and thrip development, and reproduction on preferred and less preferred host plants, eggplant Solanum melongena L. and broad bean Vicia faba L., respectively. Thrips were screened with spinetoram on kidney bean for six generations. Activities of glutathione S-transferase (GST), mixed function oxidases (MFOs), and cytochrome P450 enzyme (P450) in a resistant strain (RS) reared on broad bean were significantly higher than those in a sensitive strain (SS), and only carboxylesterase (CarE) increased in the RS when reared on eggplant, compared with the SS. Activities of the four detoxification enzymes in the RS reared on broad bean were significantly higher than in those reared-on eggplant. On broad bean, RS adult longevity was lower and developmental duration of offspring was shorter than those of the SS, but fecundity increased. On eggplant, RS fecundity was lower and developmental duration of offspring was shorter than those of the SS. In addition, fecundity was higher and developmental duration was longer in the RS reared on broad bean than in those reared-on eggplant. The results indicated that spinetoram resistance could change WFT host preference and that those changes might be associated with detoxification enzyme activities. Thus, it was hypothesized that adaptability of the RS to the less preferred host broad bean increased, whereas adaptability to the preferred host eggplant decreased.


Assuntos
Inseticidas , Tisanópteros , Animais , Resistência a Inseticidas , Inseticidas/farmacologia , Tábuas de Vida , Macrolídeos
12.
Front Microbiol ; 13: 859886, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35602068

RESUMO

Background: The genus Lecanicillium W.Gams & Zare is a recognized insect pathogen but members of the genus have been found parasitizing various hosts including arthropods, nematodes, plants, and fungi. The new classification system for fungi proposed to reject Lecanicillium and transfer some of the species to the genus Akanthomyces. However, the attribution problem of most species in the original genus Lecanicillium remains unsolved. The current study aimed to improve understanding of the pivotal internal phylogeny in Lecanicillium by estimating the divergence times of Lecanicillium to provide additional insights into the status of this genus within the family Cordycipitaceae. Results: Dating analyses support the supposition that the ancestor of Lecanicillium was in the Cretaceous period (84.36 Mya, 95% HPD: 72.12-94.74 Mya). After originating from a common ancestor, eight clades of Lecanicillium were derived and evolved independently in parallel with other genera of Cordycipitaceae. Based on the clear divergence age estimates, Lecanicillium clade 8 originated earlier as an independent group in the Cretaceous period (75.61 Mya, 95% HPD: 63.31-87.54 Mya), while Lecanicillium clades 1-7 originated later as an independent group in the boundary of the Cretaceous and Paleogene periods (64.66 Mya, 95% HPD: 52.75-76.74 Mya). Lecanicillium huhutii formed an independent branch in a polytomy together with a clade containing Lecanicillium tenuipes (BI posterior probabilities 1, ML bootstrap 100%). Conclusion: The pivotal internal phylogeny, origin, and evolutionary history of Lecanicillium in the family Cordycipitaceae were investigated. Phylogenetic and morphological analyses indicated that there are eight representative clades (four representative branches of evolutionary history), including clade 1 (members have a relatively uniform sporulation structure comprising globose heads with a higher number of conidia), clade 8 (including all members of Gamszarea), clades 2-5 (the differences of the divergence time estimations were smaller compared with other clades), and clade 6-7 (members are close to Gibellula, Hevansia, and Ascopolyporus). Based on the above findings, a novel spider-pathogenic fungus, Lecanicillium huhutii, is described. All other species in Lecanicillium clade 1 (Lecanicillium araneogemum, L. nodulosum, L. pissodis, and L. uredinophilum) should be transferred to the genus Akanthomyces. Furthermore, the monotypic genus Parengyodontium should be merged with the genus Gamszarea. More novel species need to be discovered to thoroughly resolve the attribution problem of Lecanicillium. Finally, no major lineages of Lecanicillium were correlated with the nearby Cretaceous-Tertiary extinction event, indicating that the diversity of Lecanicillium is more likely to be caused by long-term environmental adaptation and coevolution with insects rather than by dramatic extinction events.

13.
Insects ; 12(9)2021 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-34564278

RESUMO

Exogenous calcium (Ca) has been used to induce host plant resistance in response to abiotic and biotic stresses, including from thrips attack. The aim of this study was to determine whether exogenously applied Ca affects the performance of Frankliniella occidentalis. We assessed the development time, total longevity, reproduction, and population parameters of F. occidentalis, and its preference choice on Ca-treated or untreated control kidney bean plants under laboratory conditions. The results showed that F. occidentalis fed on Ca-treated leaves had a longer developmental time but lower longevity (female and male) and fecundity than F. occidentalis fed on control leaves. Population parameters, including the intrinsic rate of increase (r), finite rate of increase (λ), and net reproductive rate (R0), were all found higher in control leaves than in Ca-treated leaves, and the mean generation time (T) was shorter. In preference choices, the number of thrips on control plants was higher than the number of thrips on Ca-treated kidney bean plants. Overall, our results indicated that exogenous Ca pretreatment on kidney bean plants affected the life history and preference choice of F. occidentalis, suggesting Ca might be used as a promising elicitor of inducible plant defense against thrips.

14.
Insects ; 12(5)2021 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-33946774

RESUMO

The stick tea thrip Dendrothrips minowai (Priesner) (Thysanoptera: Thripidae) is a destructive pest in tea plantations in south and southwest China. To control this pest, a non-crop banker plant system was developed using a polyphagous predator Orius strigicollis (Poppius) (Heteroptera: Anthocoridae) with the black bean aphid Aphis fabae (Scopoli) (Hemiptera: Aphididae) as an alternative prey and the faba bean Vicia faba as the banker plant to support the predator in targeting the pest. The fitness of A. fabae on tea plants and faba bean was evaluated to determine its host specificity. Moreover, the control efficacy of the banker plant system on D. minowai on tea plants was tested in the laboratory and compared with that of direct release of O. strigicollis. The experiments showed that faba bean was an excellent non-crop host for A. fabae because, while the aphid population increased quickly on faba bean, it could only survive for up to 9 days on tea plants. Compared with direct release of O. strigicollis, lower densities of pest were observed when introducing the banker plant system. Our results indicate that this banker plant system has the potential to be implemented in the field to improve the control of the pest thrips.

15.
J Econ Entomol ; 114(2): 582-589, 2021 04 13.
Artigo em Inglês | MEDLINE | ID: mdl-33576425

RESUMO

The bug Orius similis Zheng is a native generalist predator of insect pests in southern China. The fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith), is a notorious defoliator that is now an economically important insect pest throughout China. To investigate the ability of O. similis to control FAW, we evaluated the predatory capacity, behavior, and functional response of O. similis with respect to FAW and their olfactory response. Both females and males successfully preyed on FAW eggs and first-instar larvae but not on second-instar or older larvae. Adult O. similis only attacked and killed one egg or one larva at a time before sucking the prey, and similar predatory behavior was also observed with regard to FAW egg masses. Both female and male O. similis exhibited type II functional response when preying on FAW eggs and first-instar larvae. Maximum estimated prey consumed per day was 23.7 eggs and 26.2 larvae for adult females and 22.5 eggs and 19.6 larvae for adult males. Moreover, in a Y-tube olfactometer experiment, both female and male O. similis exhibited a significant preference for maize (Zea mays L.) seedlings damaged by FAW over clean air, healthy seedlings, FAW feces, and FAW, suggesting that seedlings damaged by FAW may releases specific volatiles attracting the predator. Collectively, the results of the study suggest that O. similis is a promising candidate for the biological control of FAW eggs and first-instar larvae, particularly given its attraction to FAW-damaged leaves, which may enable it to locate the target prey rapidly.


Assuntos
Mariposas , Animais , China , Feminino , Larva , Masculino , Spodoptera , Zea mays
16.
Front Microbiol ; 11: 561381, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33193147

RESUMO

BACKGROUND: Frankliniella occidentalis (Thysanoptera: Thripidae) is a highly rasping-sucking pest of numerous crops. The entomogenous fungi of Lecanicillium spp. are important pathogens of insect pests, and some species have been developed as commercial biopesticides. To explore Lecanicillium spp. resources in the development of more effective F. occidentalis controls, efficient barcode combinations for strain identification were screened from internal transcribed spacers (ITS), SSU, LSU, TEF, RPB1, and RPB2 genes. RESULTS: Six genes were used to reconstruct Lecanicillium genus phylogeny. The results showed that ITS, TEF, RPB1, and RPB2 could be used to identify the strains. All phylogenetic trees reconstructed by free combination of these four genes exhibited almost the same topology. Bioassay studies of a purified conidial suspension further confirmed the infection of second-instar nymphs and adult female F. occidentalis by seven Lecanicillium strains. L. attenuatum strain GZUIFR-lun1405 was the most virulent, killing approximately 91.67% F. occidentalis adults and 76.67% nymphs after a 7-day exposure. L. attenuatum strain GZUIFR-lun1405 and L. cauligalbarum strain GZUIFR-ZHJ01 were selected to compare the fungal effects on the number of eggs laid by F. occidentalis. The number of F. occidentalis nymphs significantly decreased when F. occidentalis adults were treated with L. cauligalbarum strain GZUIFR-ZHJ01. CONCLUSIONS: The combination of ITS and RPB1 could be used for fast recognition of Lecanicillium spp. This is the first report of the pathogenicity of L. attenuatum, L. cauligalbarum, L araneogenum, and L. aphanocladii against F. occidentalis. Additionally, L. cauligalbarum strain GZUIFR-ZHJ01 caused high F. occidentalis mortality and inhibited the fecundity of the pest.

17.
PLoS One ; 15(8): e0236249, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32804964

RESUMO

BACKGROUND: The insect predator Coccinella septempunctata can effectively control many types of pests, such as aphids, whiteflies, and small lepidopteran larvae. We previously found that C. septempunctata fed an artificial diet showed diminished biological properties(e.g. fecundity, egg hatching rate, survival rate, etc.) compared with those fed natural prey (Aphis craccivora), likely due to different nutritional characteristics of the diet. In this study, we used transcriptome sequencing analysis to identify nutrition- and metabolism-related genes of C. septempunctata that were differentially expressed depending on diet. METHODOLOGY/PRINCIPAL FINDINGS: The Illumina HiSeq2000 was used to sequence 691,942,058 total clean reads from artificial diet-fed and A. craccivora-fed C. septempunctata libraries, and the clean reads were assembled using Trinity de novo software (Tabel 2). Comparison of transcriptome sequences revealed that expression of 38,315 genes was affected by the artificial diet, and 1,182 of these genes showed a significant change in expression levels (FDR ≤ 0.05,|log2FC|≥1, "FC" stands for "fold change"). These differentially expressed genes (DEGs) were likely associated with the decreased egg laying capacity, hatching rate, longevity, and increased sex ratio (♀:♂) of adult C. septempunctata observed in the group fed the artificial diet. Furthermore, in the most DEGs metabolic pathways for C. septempunctata feeding on the artificial diet accumulated amino acid metabolic pathways, lipid metabolic pathways, and starch and glucose metabolism were down-regulated. CONCLUSIONS/SIGNIFICANCE: We found some differentially expressed genes and metabolic pathways are related to nutrition, from which a more informative feedback for diet formulation was obtained and the artificial diet could be more efficiently optimized.


Assuntos
Fenômenos Fisiológicos da Nutrição Animal/genética , Afídeos , Besouros/fisiologia , Genes de Insetos , Comportamento Predatório/fisiologia , Aminoácidos/metabolismo , Animais , Regulação para Baixo , Fertilidade/fisiologia , Perfilação da Expressão Gênica , Glucose/metabolismo , Metabolismo dos Lipídeos/genética , Longevidade/fisiologia , Redes e Vias Metabólicas/genética , Controle Biológico de Vetores/métodos , Razão de Masculinidade , Amido/metabolismo , Sequenciamento do Exoma
18.
Environ Entomol ; 49(5): 1191-1197, 2020 10 17.
Artigo em Inglês | MEDLINE | ID: mdl-32794573

RESUMO

The western flower thrips, Frankliniella occidentalis, is a major invasive pest of commercially important crops worldwide. We compared the activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) and the expressions of two putative SOD and two putative POD sequences in second instar larvae and adults after three generations of adaptation to kidney bean and broad bean plants. The results showed that the SOD, POD, and CAT activities in adults were significantly higher than those in the second instar larvae. The SOD activities were significantly higher in both the second instar larvae and the adults fed on kidney bean (Phaseolus vulgaris) plants versus broad bean (Vicia faba) plants, whereas the POD and CAT activities showed the opposite trend. The gene expression data showed that the FoPOD-2 expression levels were lower in the second instar larvae after three generations of feeding on broad bean plants versus kidney bean plants. The expression levels of FoSOD-1 and FoSOD-2, and FoPOD-1 under broad bean plant treatment were higher than those under kidney bean plant treatment. Additionally, gene expression fluctuated among the different generations. Our results indicated that western flower thrips demonstrated plasticity in gene expression and activity of protective enzymes, which is related to their adaptability to the host plants. Western flower thrips can change the expression of protective enzyme genes and enzyme activity in vivo to better adapt to kidney bean and broad bean plants.


Assuntos
Phaseolus , Tisanópteros , Animais , Produtos Agrícolas , Flores , Larva , Phaseolus/genética
19.
MycoKeys ; (43): 59-74, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30568536

RESUMO

A new species of entomopathogenic fungi, Lecanicilliumcauligalbarum, was discovered from a survey of invertebrate-associated fungi in the Yao Ren National Forest Mountain Park in China. The synnemata of this species emerged from the corpse of a stemborer (Lepidoptera), which was hidden amongst pieces of wood on the forest floor. It differs from morphologically similar Lecanicillium species mainly in its short conidiogenous cells and ellipsoid to ovoid and aseptate conidia. Phylogenetic analysis of a combined data set comprising ITS, SSU, LSU, TEF, RPB1 and RPB2 sequence data supported the inclusion of L.cauligalbarum in the Lecanicillium genus and its recognition as a distinct species.

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