Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 3.975
Filtrar
1.
BMC Plant Biol ; 21(1): 230, 2021 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-34022807

RESUMO

BACKGROUND: Nitraria tangutorum is an important desert shrub that shows resistance to drought, salt and wind erosion stresses. It is a central ecological species in its area. Here, we have studied how N. tangutorum has adapted to achieve a successful reproduction strategy. RESULTS: We found that N. tangutorum is mainly pollinated by insects of the Hymenoptera, Diptera and Coleoptera orders. Nitraria tangutorum has very small flowers, with the nectary composed of secretive epidermal cells from which nectar is secreted, located within the inner petals. In addition, analyzing the transcriptome of four successive flower developmental stages revealed that mainly differentially expressed genes associated with flower and nectary development, nectar biosynthesis and secretion, flavonoid biosynthesis, plant hormone signal transduction and plant-pathogen interaction show dynamic expression. From the nectar, we could identify seven important proteins, of which the L-ascorbate oxidase protein was first found in plant nectar. Based on the physiological functions of these proteins, we predict that floral nectar proteins of N. tangutorum play an important role in defending against microbial infestation and scavenging active oxygen. CONCLUSIONS: This study revealed that N. tangutorum is an insect-pollinated plant and its nectary is composed of secretive epidermal cells that specialized into secretive trichomes. We identified a large number of differentially expressed genes controlling flower and nectary development, nectar biosynthesis and secretion, flavonoid biosynthesis, plant hormone signal transduction and plant-pathogen interaction. We suggest that proteins present in N. tangutorum nectar may have both an antibacterial and oxygen scavenging effect. These results provide a scientific basis for exploring how the reproductive system of N. tangutorum and other arid-desert plants functions.


Assuntos
Magnoliopsida/fisiologia , Néctar de Plantas/fisiologia , Proteínas de Plantas/metabolismo , Polinização , Proteoma/metabolismo , Transcriptoma , Animais , Besouros/fisiologia , Dípteros/fisiologia , Himenópteros/fisiologia , Magnoliopsida/genética
2.
Nat Commun ; 12(1): 2658, 2021 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-33976202

RESUMO

Many herbivorous insects selectively accumulate plant toxins for defense against predators; however, little is known about the transport processes that enable insects to absorb and store defense compounds in the body. Here, we investigate how a specialist herbivore, the horseradish flea beetle, accumulates glucosinolate defense compounds from Brassicaceae in the hemolymph. Using phylogenetic analyses of coleopteran major facilitator superfamily transporters, we identify a clade of glucosinolate-specific transporters (PaGTRs) belonging to the sugar porter family. PaGTRs are predominantly expressed in the excretory system, the Malpighian tubules. Silencing of PaGTRs leads to elevated glucosinolate excretion, significantly reducing the levels of sequestered glucosinolates in beetles. This suggests that PaGTRs reabsorb glucosinolates from the Malpighian tubule lumen to prevent their loss by excretion. Ramsay assays corroborated the selective retention of glucosinolates by Malpighian tubules of P. armoraciae in situ. Thus, the selective accumulation of plant defense compounds in herbivorous insects can depend on the ability to prevent excretion.


Assuntos
Brassicaceae/metabolismo , Besouros/metabolismo , Proteínas Facilitadoras de Transporte de Glucose/metabolismo , Glucosinolatos/metabolismo , Hemolinfa/metabolismo , Túbulos de Malpighi/metabolismo , Animais , Transporte Biológico , Brassicaceae/parasitologia , Besouros/fisiologia , Herbivoria/fisiologia , Modelos Biológicos , Folhas de Planta/metabolismo , Folhas de Planta/parasitologia , Açúcares/metabolismo
3.
Nat Plants ; 7(4): 445-451, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33846595

RESUMO

Despite the crucial importance of flower-visiting insects in modern ecosystems, there is little fossil evidence on the origins of angiosperm pollination. Most reports of pollination in the Mesozoic fossil record have been based on the co-occurrence of the purported pollinators with pollen grains and assumed morphological adaptations for vectoring pollen. Here, we describe an exceptionally preserved short-winged flower beetle (Cucujoidea: Kateretidae) from mid-Cretaceous amber, Pelretes vivificus gen. et sp. nov., associated with pollen aggregations and coprolites consisting mainly of pollen, providing direct evidence of pollen-feeding in a Cretaceous beetle and confirming that diverse beetle lineages visited early angiosperms in the Cretaceous. The exquisite preservation of our fossil permits the identification of the pollen grains as Tricolpopollenites (Asteridae or Rosidae), representing a record of flower beetle pollination of a group of derived angiosperms in the Mesozoic and suggesting that potentially diverse beetle lineages visited early angiosperms by the mid-Cretaceous.


Assuntos
Besouros/fisiologia , Cadeia Alimentar , Fósseis , Magnoliopsida , Pólen , Animais , Dieta , Comportamento Alimentar
4.
Zoolog Sci ; 38(2): 122-139, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33812352

RESUMO

We focused on Meloe beetles that have lost all flight ability, and conducted molecular phylogeographic analyses based on their mitochondrial DNA COI and nuclear DNA EF1- α regions. Meloe beetles infiltrate bumblebee nests by attaching to bumblebees as they pollinate flowers and thereafter have a unique and specific life history as they complete their life-cycle within the host nest; flight-based dispersal is achieved by piggybacking on bumblebees. In fact, Meloe beetles, which cannot fly, even inhabit remote islands (i.e., "Oceanic Islands"). Regarding four species, i.e., Meloe coarctatus, Meloe proscarabaeus, Meloe violaceus and Meloe corvinus, the conventional morphological classification system based on morphological characteristics was strongly supported by the molecular markers. On the other hand, for two species, Meloe menoko and Meloe auriculatus, it was found that M. menoko may be evaluated as having a paraphyletic relationship with M. auriculatus. Furthermore, two other cryptic, undescribed species were also discovered in this study. One was collected in the Nikko Highland, and inhabited the area sympatrically with M. coarctatus. The other was collected from Hachijo-jima Island. These cryptic species were highly differentiated, independent lineages in terms of mitochondrial and nuclear gene regions. That is to say, a new level of species diversity was revealed among the Meloe beetle species, known for their unique and strange ecological and ethological characteristics.


Assuntos
Distribuição Animal , Abelhas/parasitologia , Besouros/fisiologia , Voo Animal , Fluxo Gênico , Animais , Besouros/genética , DNA Mitocondrial , Interações Hospedeiro-Parasita , Filogenia , Especificidade da Espécie
5.
BMC Plant Biol ; 21(1): 170, 2021 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-33836664

RESUMO

BACKGROUND: Protease inhibitors are defense proteins widely distributed in the plant kingdom. By reducing the activity of digestive enzymes in insect guts, they reduce the availability of nutrients and thus impair the growth and development of the attacking herbivore. One well-characterized class of protease inhibitors are Kunitz-type trypsin inhibitors (KTIs), which have been described in various plant species, including Populus spp. Long-lived woody perennials like poplar trees encounter a huge diversity of herbivores, but the specificity of tree defenses towards different herbivore species is hardly studied. We therefore aimed to investigate the induction of KTIs in black poplar (P. nigra) leaves upon herbivory by three different chewing herbivores, Lymantria dispar and Amata mogadorensis caterpillars, and Phratora vulgatissima beetles. RESULTS: We identified and generated full-length cDNA sequences of 17 KTIs that are upregulated upon herbivory in black poplar leaves, and analyzed the expression patterns of the eight most up-regulated KTIs via qRT-PCR. We found that beetles elicited higher transcriptional induction of KTIs than caterpillars, and that both caterpillar species induced similar KTI expression levels. Furthermore, KTI expression strongly correlated with the trypsin-inhibiting activity in the herbivore-damaged leaves, but was not dependent on damage severity, i.e. leaf area loss, for most of the genes. CONCLUSIONS: We conclude that the induction of KTIs in black poplar is controlled at the transcriptional level in a threshold-based manner and is strongly influenced by the species identity of the herbivore. However, the underlying molecular mechanisms and ecological consequences of these patterns remain to be investigated.


Assuntos
Cadeia Alimentar , Expressão Gênica , Herbivoria , Proteínas de Plantas/genética , Populus/genética , Inibidores de Proteases , Animais , Besouros/fisiologia , Mariposas/fisiologia , Filogenia , Proteínas de Plantas/metabolismo , Populus/metabolismo , Inibidores de Proteases/metabolismo , Análise de Sequência de DNA
6.
Zootaxa ; 4950(1): zootaxa.4950.1.9, 2021 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-33903325

RESUMO

Helochares (Hydrobaticus) MacLeay, 1871 is the largest subgenus of Helochares Mulsant, 1844. The Chinese fauna of Helochares (Hydrobaticus) is still poorly known. Five species are recognized, including three herein described as new: Helochares (Hydrobaticus) hainanensis sp. n. (Hainan); H. wuzhifengensis sp. n. (Jiangxi); H. tengchongensis sp. n. (Yunnan). Helochares minor d'Orchymont, 1925 and H. nipponicus Hebauer, 1995 are recorded from China for the first time. Descriptions, diagnoses, and illustrations of the new species are given. Habitus and aedeagus photos of the new record species are provided.


Assuntos
Besouros , Distribuição Animal , Animais , China , Besouros/classificação , Besouros/fisiologia
7.
Zootaxa ; 4950(1): zootaxa.4950.1.12, 2021 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-33903328

RESUMO

The ceratocanthine genus Pterorthochaetes Gestro, 1898 (Coleoptera: Scarabaeoidea: Hybosoridae) includes about 26 valid species and occurs from the eastern Himalaya (Nepal and India) and southern China to northern Australia (Queensland) and Vanuatu Islands (Paulian 1978, 1987; Ballerio 1999, 2006, 2013, 2014).


Assuntos
Besouros , Animais , Besouros/classificação , Besouros/fisiologia , Masculino
8.
Zootaxa ; 4949(3): zootaxa.4949.3.2, 2021 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-33903330

RESUMO

A new species, Oiceoptoma tangi Sommer, Ruzicka, Nishikawa Schneider, new species, from Zhejiang Province, China, is described and illustrated. The new species is closely related to O. subrufum (Lewis, 1888), distributed in Central and North-eastern China, the Korean Peninsula, Far East of Russia and Japan, and to O. nigropunctatum (Lewis, 1888), endemic to Japan. All three species are keyed, and distribution maps of all three species are presented.


Assuntos
Besouros , Distribuição Animal , Animais , China , Besouros/classificação , Besouros/fisiologia
9.
Zootaxa ; 4949(3): zootaxa.4949.3.3, 2021 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-33903331

RESUMO

This study revises the taxonomy of the genus Eccoptolonthus Bernhauer, 1912 and reports 14 species in the Chinese fauna. A catalogue of the remaining 15 Eccoptolonthus species from the Oriental and Afrotropical regions is also provided. Four new species are described from China: Eccoptolonthus conaensis Fei Zhou, sp. nov. from Tibet, Eccoptolonthus fuyuensis Fei Zhou, sp. nov. from Zhejiang, Eccoptolonthus dafoensis Fei Zhou, sp. nov. from Guizhou, and Eccoptolonthus xiaolongmenensis Fei Zhou, sp. nov. from Beijing. Eccoptolonthus (Eumorimotous) laevigatus laevigatus (Fauvel, 1895) is reported for the first time from Yunnan in China and Vietnam. A preliminary key to the Chinese species of Eccoptolonthus is also included in the paper. Color images and line drawings are provided to show diagnostic characters.


Assuntos
Besouros , Distribuição Animal , Estruturas Animais , Animais , China , Besouros/classificação , Besouros/fisiologia
10.
Zootaxa ; 4949(2): zootaxa.4949.2.6, 2021 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-33903346

RESUMO

Sphaeraphodius gaohani Kakizoe, Jiang Wang, a new genus and new species of the tribe Aphodiini, is described based on two female specimens from Guangxi, China. This new genus differs considerably from any previously known genera of Aphodiini by dorsally swollen body covered by considerably long setae, and lack of transverse setiferous carinae on outer surfaces of meso- and metatibiae. This new taxon is found sympatrically with the termite Macrotermes sp. in the field. Therefore, this species is perhaps termitophilous, but we cannot conclude it at this time due to the insufficient information available in the field.


Assuntos
Besouros/química , Animais , China , Besouros/fisiologia , Feminino , Isópteros
11.
Zootaxa ; 4952(2): zootaxa.4952.2.8, 2021 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-33903372

RESUMO

Most species of Scydmaenus Latreille described by Herbert Franz are impossible to identify without re-examination of the type material. The Chinese fauna is no exception and it is easy to find specimens whose aedeagi resemble those illustrated by Franz, but the only way to identify them is to directly compare new material with types. On the other hand, the aedeagi of type specimens often look slightly or even strongly different from those illustrated in original descriptions, which increases the confusion. Six species of Scydmaenus described by Franz and occurring in continental China are here redescribed, and the aedeagi of holotypes are illustrated in detail: S. chinensis, S. fukiensis, S. kunmingensis, S. sinensis, S. szechuanensis, and S. kiautunensis. The first five species are confirmed to belong in the nominotypical subgenus; S. kiautunensis is transferred from Scydmaenus (s. str.) to the subgenus Nepaloscydmaenus Franz. As previous checklists of Palaearctic or Eastern Asian Scydmaeninae contain incomplete data, an updated and annotated checklist of Scydmaenus species so far recorded from the People's Republic of China, Taiwan and Hong Kong is given, with comments on possible misidentifications, possible synonymies and distributional issues.


Assuntos
Besouros , Distribuição Animal , Estruturas Animais , Animais , Tamanho Corporal , China , Besouros/classificação , Besouros/fisiologia , Tamanho do Órgão
12.
Zootaxa ; 4950(2): zootaxa.4950.2.2, 2021 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-33903437

RESUMO

A checklist of rove beetles recorded from the Republic of Dagestan (221 species) is given, with 47 new records from this region. The genus Oedichirus Erichson, 1839 (Oedichirus rubronotatus Pic, 1903) and species Stenus turk Puthz, 1972 are new additions to the fauna of Russia. Two new synonyms are established: Xantholinus dagestanicus Bordoni, 2011 syn. nov. and X. circassicus Bordoni, 2011 syn. nov. (both =Xantholinus variabilis Hochhuth, 1851).


Assuntos
Besouros , Distribuição Animal , Animais , Besouros/classificação , Besouros/fisiologia , Daguestão
13.
Zootaxa ; 4964(3): zootaxa.4964.3.2, 2021 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-33903504

RESUMO

The type specimens of the New World Stigmoderini deposited in the Natural History Museum in London are catalogued and illustrated. Twenty-eight lectotypes are designated, one of which is a new lectotype, since the previous one is considered invalid under the article 74.2. (ICZN 1999). Holotype and in some cases, paratypes, are recognized for the following taxa: Conognatha nanula Hoscheck, 1934, Conognatha blairi Hoscheck, 1934, Hiperantha decorata var. insignata Hoscheck, 1928 and Hiperantha saundersi Théry, 1928. In addition, Lasionota oberthuri (Kerremans, 1897) rev. stat. is reinstated as a valid species, having been considered to be a junior synonym of Lasionota tetrazonus (Chevrolat, 1838) since 1997. The comparison of the reinstated species, with the recently described species Lasionota inca Moore Diéguez, 2019 showed that both are conspecific and hence L. inca syn. nov. is proposed as a junior synonym of L. oberthuri.


Assuntos
Besouros/química , Museus , Distribuição Animal , Animais , Besouros/fisiologia , Londres , Museus/estatística & dados numéricos
14.
Arch Insect Biochem Physiol ; 107(1): e21782, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33724519

RESUMO

In Leptinotarsa decemlineata, a final-instar wandering larva typically undergoes an ontogenetic niche shift (ONS), from potato plant during the foraging stage to its pupation site below ground. Using high-throughput sequencing of the bacterial 16S ribosomal RNA gene, we determined the hypothesis that the L. decemlineata pupae harbor stage-specific bacteria to meet the physiological requirements for underground habitat. We identified 34 bacterial phyla, comprising 73 classes, 208 orders, 375 families, and 766 genera in the collected specimens. Microbes across phyla Proteobacteria, Firmicutes, Actinobacteria, and Bacteroidetes were enriched in the pupae, while those in the phylum Proteobacteria, Tenericutes, Firmicutes, and Bacteroidetes dominated in the larvae and adults. A total of 18 genera, including Blastococcus, Corynebacterium_1, Gordonia, Microbacterium, Nocardia, Nocardioides, Rhodococcus, Solirubrobacter, Tsukamurella, Enterococcus, Acinetobacter, Escherichia_Shigella, Lysobacter, Pseudomonas, and Stenotrophomonas, were specifically distributed in pupae. Moreover, soil sterilizing removed a major portion of bacteria in pupae. Specifically, both Enterococcus and Pseudomonas were eliminated in the soil sterilizing and antibiotic-fed beetle groups. Furthermore, the pupation rate and fresh pupal weight were similar, whereas the emergence rate and adult weight were decreased in the antibiotic-fed beetles, compared with controls. The results demonstrate that a switch of bacterial communities occurs in the pupae; the pupal-specific bacteria genera are mainly originated from soil; this bacterial biodiversity improves pupa performance in soil. Our results provide new insight into the evolutionary fitness of L. decemlineata to different environmental niches.


Assuntos
Besouros/microbiologia , Microbiota , Pupa/microbiologia , Animais , Bactérias/classificação , Besouros/fisiologia , Ecossistema , Genes Bacterianos , Larva/microbiologia , Larva/fisiologia , Metagenômica/métodos , Metamorfose Biológica , Microbiota/genética , Pupa/fisiologia , RNA Ribossômico 16S/genética
15.
J Chem Ecol ; 47(2): 123-133, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33606109

RESUMO

Wireworms, the larvae of click beetles (Coleoptera: Elateridae), are soil-dwelling insect pests inflicting major economic damage on many types of agricultural crops worldwide. The objective of this work was to identify the female-produced sex pheromones of the Pacific Coast wireworm, Limonius canus LeConte, and the sugarbeet wireworm, L. californicus (Mannerheim) (Coleoptera: Elateridae). Headspace volatiles from separate groups of female L. canus and L. californicus were collected on Porapak Q and analyzed by gas chromatography with electroantennographic detection (GC-EAD) and GC-mass spectrometry. GC-EAD recordings revealed strong responses from male L. canus and male L. californicus antennae to the same compound, which appeared below GC detection threshold. The structure of this candidate pheromone component was deduced from the results of micro-analytical treatments of extracts, retention index calculations on four GC columns, and by syntheses of more than 25 model compounds which were assessed for their GC retention characteristics and electrophysiological activity. The EAD-active compound was identified as (E)-4-ethyloct-4-enoic acid, which we name limoniic acid. In field experiments in British Columbia and Alberta, Canada, traps baited with synthetic limoniic acid captured large numbers of male Limonius click beetles, whereas unbaited control traps captured few. Compared to traps baited with the analogue, (E)-5-ethyloct-4-enoic acid, traps baited with limoniic acid captured 9-times more male L. californicus, and 6.5-times more male western field wireworms, L. infuscatus Motschulsky, but 2.3-times fewer male L. canus. Limoniic acid can now be developed for detection, monitoring and possibly control of L. californicus, L. infuscatus and L. canus populations.


Assuntos
Besouros/química , Atrativos Sexuais/química , Animais , Besouros/fisiologia , Feminino , Masculino , Atrativos Sexuais/fisiologia
16.
J Insect Sci ; 21(1)2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33560362

RESUMO

Laricobius nigrinus (Coleoptera: Derodontidae) Fender and Laricobius osakensis (Coleoptera: Derodontidae) Montgomery and Shiyake have been mass produced by Virginia Tech as biological control agents for the hemlock woolly adelgid (HWA), Adelges tsugae (Hemiptera: Adelgidae) Annand, for the past 15 and 9 yr, respectively. Herein, we describe modifications of our rearing procedures, trends and analyses in the overall production of these agents, and the redistribution of these agents for release to local and federal land managers. Based on these data, we have highlighted three major challenges to the rearing program: 1) high mortality during the subterranean portion of its life cycle (averaging 37% annually) reducing beetle production, 2) asynchrony in estivation emergence relative to the availability of their host HWA minimizing food availability, and 3) unintended field collections of Laricobius spp. larvae on HWA provided to lab-reared larvae complicating rearing procedures. We further highlight corresponding avenues of research aimed at addressing each of these challenges to further improve Laricobius spp. production.


Assuntos
Besouros/fisiologia , Hemípteros/fisiologia , Controle Biológico de Vetores/métodos , Animais , Agentes de Controle Biológico , Besouros/crescimento & desenvolvimento , Hemípteros/crescimento & desenvolvimento , Cicutas (Apiáceas)/crescimento & desenvolvimento , Larva/crescimento & desenvolvimento , Larva/fisiologia , Ninfa/crescimento & desenvolvimento , Ninfa/fisiologia , Virginia
17.
J Insect Sci ; 21(1)2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33560361

RESUMO

Pest management of emerging pests can be challenging because very little fundamental knowledge is available to inform management strategies. One such pest, the red-headed flea beetle Systena frontalis (Fabricius) (Coleoptera: Chrysomelidae), is increasingly being identified as a pest of concern in cranberries Vaccinium macrocarpon Aiton (Ericales: Ericaceae). To improve our understanding of this pest and to develop more targeted management programs, we conducted field and laboratory studies to characterize the development, seasonal emergence patterns, and density-dependent plant injury. We found that significantly more flea beetle eggs hatched when exposed to sustained cold treatment between 0 and 5°C for 15 wk than at warmer temperatures, and for shorter and longer cold-period durations. The adults emerged sporadically over the summer, were patchily distributed, fed on both fruit and foliage, and preferentially fed on new plant growth. Using soil cores, we found eggs and larvae located relatively deep (>30 cm) in the soil. These patterns indicate that S. frontalis likely overwinters as eggs, and that targeting the larval stage may be the most effective management approach. Despite the cryptic nature of the larvae, continuing to improve our understanding of this life stage will be critical to optimizing control strategies.


Assuntos
Besouros/fisiologia , Herbivoria , Controle de Insetos , Traços de História de Vida , Vaccinium macrocarpon , Animais , Besouros/crescimento & desenvolvimento , Larva/crescimento & desenvolvimento , Óvulo/crescimento & desenvolvimento , Densidade Demográfica , Vaccinium macrocarpon/crescimento & desenvolvimento , Wisconsin
18.
J Plant Physiol ; 258-259: 153376, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33571892

RESUMO

Bruchids (Callosobruchus spp.) are destructive storage pests of mung beans (Vigna radiata). Bruchids infest mature seeds during storage and in the field causing heavy losses. Bruchid resistance in mung bean has been characterized as a dominant trait controlled by a single gene. Several independent mapping studies showed that the Br locus on chromosome 5 was a key quantitative trait loci (QTL) involved in bruchid resistance. Two polygalacturonase-inhibitor protein (PGIP) family genes, VrPGIP1 and VrPGIP2, located in the Br locus may be the primary genes responsible for bruchid resistance in mung bean but no experimental proof is available. We isolated the VrPGIP1 and VrPGIP2 genes from bruchid resistant mung bean cultivar V2802 and purified the proteins by prokaryotic expression. Both VrPGIP1 and VrPGIP2 had polygalacturonase inhibitor activity and both of the PGIP proteins conferred resistance to bruchids in an artificial seed test system. VrPGIPs can inhibit the enzyme activity of polygalacturonase present in males, females and fourth instar larvae of C. maculatus. These results demonstrated that VrPGIP1 and VrPGIP2 play a critical role in bruchid resistance probably through inhibiting polygalacturonase activity.


Assuntos
Antibiose/genética , Besouros/fisiologia , Proteínas de Plantas/genética , Poligalacturonase/antagonistas & inibidores , Vigna/genética , Animais , Besouros/crescimento & desenvolvimento , Feminino , Larva/crescimento & desenvolvimento , Larva/fisiologia , Masculino , Filogenia , Proteínas de Plantas/metabolismo , Vigna/metabolismo
19.
Proc Natl Acad Sci U S A ; 118(5)2021 02 02.
Artigo em Inglês | MEDLINE | ID: mdl-33468629

RESUMO

Many small animals use springs and latches to overcome the mechanical power output limitations of their muscles. Click beetles use springs and latches to bend their bodies at the thoracic hinge and then unbend extremely quickly, resulting in a clicking motion. When unconstrained, this quick clicking motion results in a jump. While the jumping motion has been studied in depth, the physical mechanisms enabling fast unbending have not. Here, we first identify and quantify the phases of the clicking motion: latching, loading, and energy release. We detail the motion kinematics and investigate the governing dynamics (forces) of the energy release. We use high-speed synchrotron X-ray imaging to observe and analyze the motion of the hinge's internal structures of four Elater abruptus specimens. We show evidence that soft cuticle in the hinge contributes to the spring mechanism through rapid recoil. Using spectral analysis and nonlinear system identification, we determine the equation of motion and model the beetle as a nonlinear single-degree-of-freedom oscillator. Quadratic damping and snap-through buckling are identified to be the dominant damping and elastic forces, respectively, driving the angular position during the energy release phase. The methods used in this study provide experimental and analytical guidelines for the analysis of extreme motion, starting from motion observation to identifying the forces causing the movement. The tools demonstrated here can be applied to other organisms to enhance our understanding of the energy storage and release strategies small animals use to achieve extreme accelerations repeatedly.


Assuntos
Besouros/fisiologia , Elasticidade , Dinâmica não Linear , Animais , Fenômenos Biomecânicos , Besouros/anatomia & histologia , Metabolismo Energético/fisiologia , Tegumento Comum/fisiologia , Movimento (Física) , Raios X
20.
Ecotoxicol Environ Saf ; 208: 111597, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33396118

RESUMO

Tribolium castaneum (Herbst) is an important pest of stored grain, and benzoquinones secreted by this pest are harmful to humans. T. castaneum has developed strong resistance to fumigants, and an ecofriendly alternative for managing T. castaneum is urgently needed. 1-Octen-3-ol is a major volatile compound present in many mushrooms and fungi. In the current study, the direct toxicity and sublethal and transgenerational effects of 1-octen-3-ol on T. castaneum were investigated. Our results showed that 1-octen-3-ol had strong insecticidal activity against all developmental stages of T. castaneum and repelled T. castaneum adults. 1-Octen-3-ol showed negative effects on the development and reproduction of parental T. castaneum and the subsequent generation: LC30 and LC50 treatments significantly decreased the pupa and adult weights, pupation and emergence rates and fecundity of the parental generation. In addition, LC50 treatment shortened the larval and pupal periods. In the unexposed progeny (F1) of 1-octen-3-ol-exposed parents, decreased survival and pupation rates as well as reduced pupa and adult weights were observed under LC30 and LC50 treatments. In addition, a model food-system experiment showed that 1-octen-3-ol at 98 µL/L exhibited an efficacy of 100% after 7 days of fumigation and completely eliminated T. castaneum offspring. Although a higher concentration of 1-octen-3-ol was needed to achieve an efficacy equal to that of the positive control, dichlorvos (DDVP), 1-octen-3-ol promoted the seedling growth of wheat seeds, suggesting that the concentration used was not only acceptable but also beneficial for wheat seeds. Overall, 1-octen-3-ol seems to be a promising candidate for use as a fumigant and repellent against T. castaneum as well as a seed protectant.


Assuntos
Besouros/fisiologia , Repelentes de Insetos/toxicidade , Inseticidas/toxicidade , Octanóis/toxicidade , Tribolium/efeitos dos fármacos , Animais , Besouros/efeitos dos fármacos , Grão Comestível/efeitos dos fármacos , Fungos/efeitos dos fármacos , Humanos , Larva/efeitos dos fármacos , Pupa/efeitos dos fármacos , Triticum/efeitos dos fármacos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...