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1.
舞毒蛾是世界范围内的重要森林食叶害虫,取食多种阔叶和针叶树木。为了解舞毒蛾在我国危害较轻的原因,作者在林间设立样方,调查下树将要化蛹的舞毒蛾老熟幼虫的死亡率及致死因素,蛹的死亡率及致死因子。发现病毒是导致老熟幼虫死亡的主要因子,死亡率高达96.6%。蛹的致死因子较多,其中一种皮蠹取食导致的致死率较高,达到58%,舞毒蛾黑瘤姬蜂的致死率也较高。研究表明,舞毒蛾化蛹阶段致死因子及死亡率较高,可能是舞毒蛾发生危害较轻的原因之一。  相似文献   

2.
Bactrocera minax is a major citrus pest in China, Bhutan, and India. It is univoltine and exhibits pupal diapause during winter. To better understand pupal diapause in this pest, we investigated pupal survival and pupal developmental duration under field and laboratory conditions. Specifically, we tested if pupal chilling was required for diapause development and termination. Nearly all mature larvae collected at the end of the citrus season entered pupal diapause. For pupae exposed in the field, natural chilling for less than 3 months resulted in more than 70 % mortality. However, exposure to winter conditions for 3 months or more both decreased pupal mortality and developmental duration when pupae were returned to the laboratory and held under constant temperature (25 °C). When pupae were gathered from the field in November and exposed to different chilling regimes in the laboratory, the chilling duration (30 vs 60 days) had significantly more impact on pupal survival than the specific chilling temperature (6, 8, 10, or 12 °C constant). However, both chilling duration and chilling temperature impacted on the pupal developmental duration, with longer chilling duration and higher temperatures decreasing pupal developmental duration. In conclusion, we demonstrated that pupal diapause development and termination in B. minax is strongly influenced by chilling conditions. Increasing cold exposure led to significantly and consistently faster adult eclosion and improved synchronization of adult emergence. This knowledge will help with the laboratory rearing of B. minax, an essential step in the long-term management of this pest.  相似文献   

3.
A series of experiments were conducted in which adults, pupae, and 4-week-old larvae of Tribolium castaneum (Herbst), the red flour beetle, were exposed separately on concrete arenas partially treated (14.4% of the total area) with the insecticide chlorfenapyr (Phantom®) at 1.1 g of active ingredient/m2. A flour food source (patch) was also provided in the untreated portions of the arenas. In the first trial, adult mortality averaged 60.0 ± 10.6%, but progeny production occurred in the provided food patches. Pupal mortality was only 8.3 ± 3.1%, indicating that when adult emergence occurred, those adults were able to escape exposure, and there was no difference in progeny production from that in untreated controls (P = 0.27). In the second trial, few larvae exposed in choice and no-choice arenas were able to emerge as normal adults. In a final trial, residual efficacy declined during a 3-week period, with larvae being more susceptible than adults. Results show mobility of life stage may be a determining factor when assessing susceptibility of T. castaneum to contact insecticides.  相似文献   

4.
Tribolium castaneum is a pest of stored foods that causes serious economic losses. Understanding insect nutritional requirements and the effects of different diets on insect development can provide tools for developing strategies to control insect and integrated pest management systems. In this work we studied the performance of the T. castaneum on different plant diets composed of Vigna unguiculata, Phaseolus vulgaris and wheat flours. The diets interfered differentially with development and insect survival. Larvae size was reduced about 60 % in larvae fed with V. unguiculata flour. A delay in pupae formation was also observed. The larval mortality of 100 % was observed in the P. vulgaris diet. Carbohydrate and triglyceride showed variations during development and with different diets. Larvae fed with wheat diets showed a high concentration of carbohydrates 21 days after hatching (DAH) and triglyceride at 15 and 21 DAH. Larvae fed with wheat diets showed α-amylase activity during development. At 15 DAH the activity of larvae fed with V. unguiculata increased about 50 %. Cysteine protease activity in larvae fed with wheat remained high throughout development. Serine protease activity also varied according to diets. These results show that the nutritional state of developing larvae varies greatly with respect to triglycerides, carbohydrate and digestive enzymes depending on the diet and larval stage. Altogether, these results show that changes in dietary nutrients can interfere with insect physiology. Therefore changes in diet composition that may deprive insects of essential nutrients or include toxic compounds might be a good control strategy for stored product pests.  相似文献   

5.
Ten Egyptian and imported entomopathogenic nematodes were evaluated for their pathogenicity to R. ferrugineus in both the laboratory and the field. In the laboratory, most nematodes were pathogenic to the pest larvae, pupae and adults. Larvae and adults were more susceptible to nematode infection (mostly 100?% mortality) than pupae enclosed in their cocoons. In the field however, the highest insect larval mortality was 66.67?% and most of nematodes failed in controlling the pest. Such failure could be due to hot weather, the tunnelling behaviour of the pest larvae and the too much sap in the infested sites in the trunks of palm trees.  相似文献   

6.
Accumulated grain dust and flour residues in flour mills can potentially decrease the efficacy of contact surface treatments and aerosol insecticides used for control of adult and immature stages of stored product insects. A study was conducted to evaluate the effects of flour residues on the efficacy of piperonyl butoxide-synergized pyrethrin aerosol against different life stages of the confused flour beetle, Tribolium confusum Jacquelin du Val. Twenty individual adults, pupae, or larvae of T. confusum, confined in Petri dishes containing 0, 0.1, 1, 5, or 10 g of wheat flour, were exposed separately inside an empty shed to the label rate of the aerosol. The formulation contained 1 % active ingredient pyrethrin and the label application rate was 1.04 ml/m3. After 2 h of exposure, all dishes were removed from the shed and placed in an incubator set at 27 °C and 60 % RH. Mortality of T. confusum adults decreased with increasing amount of flour. Recovery of moribund adults 15 days after exposure was greater in the 5 and 10 g flour dishes (15 and 46 %) compared to the 0.1 or 1 g flour dishes (0.7 and 5 %). As the flour amounts increased, more larvae and pupae were able to emerge as adults. Results show accumulated flour residues during aerosol application can compromise aerosol efficacy, and also suggest the flour impaired penetration ability of the aerosol. These results also emphasize the importance of sanitation and cleaning to remove spillage and extraneous material prior to an aerosol application.  相似文献   

7.
Cowpea [Vigna unguiculata (L.) Walp] seeds are an important source of nutrients for human and animal. However, part of the seed production is lost due to insect attacks, mainly by the weevil Callosobruchus maculatus (F.) (Coleoptera: Chrysomelidae), a major pest of stored cowpeas. An efficient method for controlling seed infestation is the use of insect-resistant cultivars. In this work, we studied the resistance of different cowpea Brazilian cultivars (BRS) to infestation and damage by C. maculatus. Our results showed that some cultivars interfered in female oviposition. The time necessary for the larvae to perforate the seed coat of some cultivars increased up to 40 %. No relationship between seed coat thickness, textures, or pigmentation and the larval ability of crossing seed coats was observed. Larval survival was also affected by cowpea cultivars. In BRS Xiquexique, only 30 % of the larvae survived at 20 days after oviposition. The weight of larvae developed into BRS Pajeu, and BRS Xiquexique cultivars decreased about 50 %. Cysteine protease, α-glucosidase, and α-amylase activities decreased in larvae developed in some cultivars, mainly in Pajeu, Guariba, Tucumaque, and Xiquexique. Adult emergence also decreased in Xiquexique, Pajeu, Tucumaque, and Paraguaçu BRS cultivars. A direct relationship between higher infestation and lower seed germination and seedling growth potential was observed. From these data, we would recommend the use of Pajeu, Guariba, Tucumaque, and Xiquexique BRS cultivars as a way to reduce cowpea infestation, and suggest that their resistance mechanism is related to the diminishment of larval digestive abilities.  相似文献   

8.
Nontimber forest products are a source of income for women in rural African communities. However, these products are frequently damaged by insect pests. The present study investigates the diversity and damage rates of insect pests that attack Carapa procera seeds and Lophira lanceolata fruits. The experiment was set up in western Burkina Faso and, for C. carapa, consisted of pests collected from seeds that had fallen to the ground and from stockpiled seeds. For L. lanceolata, pests were collected from fruits on the trees, and on the ground. The collected samples were sent to the laboratory to estimate the proportion of damaged seeds/fruits and rear the insects. The results showed that Ephestia spp., Tribolium castaneum, Oryzeaphilus spp., and Tenebroides mauritanicus were the pests of Carapa procera seeds and Lophira lanceolata fruits. Ephestia spp. was recorded as the main pest of both C. procera and L. lanceolata, whereas T. castaneum was only detected from seeds of L. lanceolata. For C. procera, the stocks were the most infested (29 %) by Ephestia spp. The infestation rate of fruits of L. lanceolata by Ephestia spp. on trees (31.42 ± 3.75 %) was less than the rate of fruits by T. castaneum on the ground (44.00 ± 3.5 %). The different body sizes of Ephestia spp. may indicate the occurrence of two putative species, one from C. procera and another one from L. lanceolata. This work provides important information that could contribute to the setting up of a local-scale sustainable management framework for oil tree pests in Burkina Faso and surrounding countries.  相似文献   

9.
The life history and feeding biology of the bamboo powderpost beetle Dinoderus minutus remain poorly understood because the beetles’ oviposition, development, and feeding take place inside bamboo culms. In this study, X-ray computed tomography (CT) was employed to nondestructively quantify the progression of larval body size and tunnel size from the first instar to pupation. Eggs of D. minutus laid between laminates of nutrient-containing filter paper were easily collected. The newly hatched larvae were inoculated singly into pieces of internodes of madake (Phyllostachys bambusoides). The pieces were scanned using a microfocus X-ray CT system every 3–5 days to visualize the beetles’ bodies and tunnels with resolutions of 18–60 μm/voxel. CT scans were continued after adult eclosion to analyze pre-mating adult feeding. The collected eggs were 0.84 ± 0.06 mm (mean ± SD) in length and the egg duration lasted 5.0 ± 0.8 days. Based on CT images, the larvae grew to 3.53 ± 0.23 mm in body length and turned into pupae of 3.42 ± 0.09 mm. The larvae bored tunnels with a length of 80.2 ± 4.8 mm and a volume of 68.0 ± 7.0 mm3 over the larval period of 61 ± 11 days. Newly emerged adults remained in the bamboo pieces to feed before making exit holes in 8 ± 1 days after adult eclosion. During this period, they bored tunnels at rates of 2.64 ± 0.58 mm/day in length and 4.87 ± 1.10 mm3/day in volume.  相似文献   

10.
Spotted wing Drosophila, Drosophila suzukii (Matsumura) (Diptera: Drosophilidae), has caused significant economic losses to small fruit and berry growers throughout the USA and Europe since its invasion. This pest can lay many eggs over its lifetime within ripening and ripe berries, causing yield loss and the risk of fruit contamination. Zero tolerance for this pest has led to increased use of broad-spectrum insecticides to control it, which are costly and pose many other sustainability and pest management concerns. There is an urgent need to evaluate management strategies that can decrease reliance on chemical controls and mitigate economic losses. Over two growing seasons, we compared harvest schedules for their effect on infestation by D. suzukii, revealing that fruit harvested every 1 or 2 days had significantly fewer D. suzukii larvae than a 3-day harvest schedule. Furthermore, we found that yield per unit effort was highest on a 2-day schedule. Sanitation of the crop is another important component of a successful integrated pest management program, and we found that bagging infested waste berries killed 99% of larvae after 32 h, with higher fruit temperatures in clear bags than white or black bags. In combination, these methods can reduce the effects of this invasive pest on raspberry production. This study will provide guidance to growers on culturally based IPM tactics to decrease reliance on chemical management.  相似文献   

11.
The red flour beetle, Tribolium castaneum (Herbst), is one of the most serious secondary pests that feeds on a wide range of durable stored products including cereals, cereal products and other high value produce such as cocoa beans and dried fruits. Toxicity and protectant potential of Calneem® oil derived from the seeds of the neem tree Azadirachta indica A. Juss. towards T. castaneum were evaluated in stored wheat in the laboratory using contact toxicity, grain treatment, persistency, progeny emergence and repellency assays. Calneem® contains about 0.3% azadirachtin as its major active ingredient. The Calneem® was applied at six dosages (0.1, 0.2, 0.5, 1.0, 2.0 and 3.0% v/v). The oil was emulsified with water using 0.07% soap. All dosages of Calneem® oil were toxic and highly repellent to T. castaneum with an overall repellency in the range of 52–88%. The highest dosage of 3.0% of Calneem® oil tested killed at least 90% of the beetles within 72 h on grain, and 88% mortality was obtained on filter paper. T. castaneum mortality was dose dependent. The development of eggs to adults on cracked wheat was significantly (P < 0.05) inhibited by Calneem® oil treatments. The effectiveness of Calneem® oil was significantly reduced by the length of storage after application. The results obtained suggest good potential for the practical use of Calneem® oil as grain protectant for stored product pest control. The use of plant materials such as neem oil may be a safe, cost-effective method of grain preservation against pest infestation amongst low-resource poor farmers who store small amounts of grains.  相似文献   

12.
The pulse beetle, Callosobruchus maculatus F. is a key pest to stored Kersting’s groundnut, Macrotyloma geocarpum Harms. There are many reports evaluating various diatomaceous earths (DEs) against stored product pests, but there is limited information on the efficacy of these materials against C. maculatus and none on Kerstings groundnut. Laboratory experiments were conducted to evaluate the efficacy of the DEs, Diatomenerde, Probe-A, Fossil shield, and Damol-D1 against C. maculatus in seeds of M. geocarpum. Each DE was applied at 0.50, 1.00, 1.50, and 2.00 g kg?1, and each treatment infested with newly emerged C. maculatus in petri dishes. The set up was maintained at 50 and 80 % RH regimes at ambient temperature. Data were collected on adult mortality (at 24 h, 48 h, 7 days, and 14 days), oviposition, and progeny emergence of the beetles, and their effects on weight loss and viability of seeds. Probe-A proved the most effective against the beetle, followed by Damol-D1 and Fossil shield. Adult mortality increased progressively with the increasing dosage of DE and exposure time. Seeds treated at 2.00 or 1.50 g kg?1 recorded significantly lower number of eggs and F1 emergence compared with the lower dosages in all DEs. Increased DE concentration consistently decreased seed weight loss due to low beetle infestation, but there was no significant effect on seed viability. DEs were more effective at 50 % RH than at 80 % RH. Probe-A or Damol-D1 applied at 1.50 or 2.00 g kg?1 at 50 % RH is a viable alternative for preventing C. maculatus infestation in stored Kersting’s groundnut.  相似文献   

13.
Reproductive phenology of multiple use native plant Calo- phyllum inophyllum L. was studied in Yeppoon (23°7’60″ S, 150°43’60″ E), northern Australia (southern hemisphere) and in Meegoda (6o18′51″N, 80o31′3″E), Sri Lanka (northern hemisphere). C. inophyllum trees in Yeppoon, Australia had relatively shorter flowering periods, shorter floral life spans, longer fruit life spans, smaller flowers and larger fruits compared to those in Meegoda, Sri Lanka. Although the number of flower buds/ inflorescence was comparatively higher in Meegoda, C. inophyllum trees in both locations had similar mean number of mature fruits/ cluster due to the higher floral abscission in C. inophyllum trees at Meegoda. Despite having a comparatively lower fruit yield (664 000 fruts·ha 1·a 1), C. inophyllum trees in Yeppoon had higher kernel weights (2 988.0±853.2 kg·ha -1 ·a -1 ) and oil yields (1 332.6±380.5 kg·ha - 1 ·a -1 ) compared to those in Meegoda.  相似文献   

14.
Vitellaria paradoxa, known as Shea tree or karité, is one of the dominant trees of agroforestry parklands in Sahelian region with an immense commercial value. In this study, we examined infestation of fruit-bearing shoots and fruits on two sites in western Burkina Faso across different reproductive phenophases, crown heights and aspects. The number of infested and healthy shoots and fruits were counted on 60 reproductively active trees randomly selected from on-year shea trees in each site, using a metal frame (0.5 × 0.5 m) to mark a fixed area of the canopy for sampling. The shoot and fruit borer was identified as Salebria sp. (Lepidoptera:Pyralidae), which was not reported earlier. The proportion of infested trees and shoots varied significantly between sites and among reproductive phenophases (P < 0.0001). The site close to the natural forest had the highest infestation rate than distantly located site. Among reproductive phenophases, the proportions of infested trees and shoots were the highest during flowering and fruit set, respectively. Fruit infestation also varied significantly between sites, crown heights and aspects (P < 0.001). The site close to the natural forest and the crown with north-east aspect were heavily infested while the bottom part of the crown had the lowest infestation. As a whole, 49–80% of trees, 24–31% of shoots and 4–15% of fruits were found infested, depending on the site. These infestation levels combined with precocious flower and fruit abscissions would pose serious economic losses that justify a call for immediate pest control initiatives.  相似文献   

15.
Agriculture relies on ecosystem services, such as biological control of pests, for economic success and sustainability. Commercially managed lowbush blueberries are an important crop in eastern North America, but pest control by natural enemies has not been well studied. In this paper we address questions about consumption of two blueberry pests by ground beetles (Carabidae) that are common in blueberry fields. In the first experiment, a Poecilus l. lucublandus, Carabus nemoralis, or Pterostichus mutus beetle was placed with two blueberry spanworm larvae, Itame argillacearia, in a simple (cup only or cup + soil) or more complex (cup + soil + blueberry sprigs) treatment arena. In most cases, probability of spanworm consumption reached 100 % in simple arenas by the end of the experiment (48 h) but was 25–50 % lower in more complex arenas. In a second experiment, a male or female Pterostichus melanarius or Harpalus rufipes beetle was placed in a plastic container with saturated or dry soil into which mature blueberry maggots, Rhagoletis mendax, dropped from blueberries to pupate. Approximately 40–80 and 35 % fewer pupae were recovered when a P. melanarius and H. rufipes beetle was present, respectively, but soil moisture and beetle sex were not significant factors. Our results demonstrate that ground beetles can prey upon important blueberry pests, but suggest that consumption may be influenced by microhabitat structure.  相似文献   

16.
The larval stages of Frankliniella occidentalis Pergande (Thysanoptera: Thripidae) cause more direct feeding damage to plants than the adults. We, therefore, investigated the behaviour-modifying effects on second instar larvae of two jasmonic acid derivatives. The artificial application of methyl jasmonate and cis-jasmone, both at 1 % concentration, deterred the larvae from settling in a dual choice bean leaf disc assay. We observed a dose-dependent feeding deterrence of both jasmonates and calculated the concentration required to reduce the feeding damage by 50 % relative to the control treatment (FDC50) for each jasmonate. The feeding damage was reduced by the application of cis-jasmone at 1 % concentration, but not by the jasmonates at the respective FDC50 in no-choice leaf disc bioassays. However, significantly more larvae left jasmonate-treated whole potted bean plants by migrating to the soil compared with control plants. Our results may be exploited extending behavioural manipulation by using plant compounds in thrips control programmes to the full lifecycle of the pest. Plant compounds could be used in integrated and biological pest management strategies against F. occidentalis in combination with the application of various above and below ground control measures.  相似文献   

17.
The larvae of the invasive maize pest Diabrotica virgifera virgifera (Coleoptera; Chrysomelidae, western corn rootworm) hatch in the soil in spring and search for maize roots following CO2 gradients. CO2 is one cue that might be used as an attractant towards soil insecticides, a mechanism already shown in laboratory experiments. This study compared the efficacy of several combinations of in or between-row applications of different rates of CO2-emitting capsules and/or soil insecticides (here tefluthrin) aimed at preventing root damage by the pest larvae under field conditions. CO2 emission of the capsules in the soil lasted up to 28 days with a peak after 21 days coinciding with the first larval hatch. The pest density in the soil was not high enough to cause root damage above the economic threshold. Furthermore all tefluthrin applications, regardless of whether at full, half or quarter rates effectively prevented root damage; thus CO2 did not significantly further increase this efficacy. In-row applications of tefluthrin with or without CO2-emitting capsules prevented root damage to a much larger extent (59–77 % on the node injury scale) than the between-row applications of tefluthrin with or without capsules (17–31 %). In conclusion, further research on belowground orientation and movement of D. v. virgifera larvae, as well as tests with combinations of CO2-emitting capsules and lower rates of soil insecticide are needed to potentially develop attract and kill strategies as a management option against this maize pest.  相似文献   

18.
Chive gnat, Bradysia odoriphaga Yang & Zhang (Diptera: Sciaridae), is the most serious pest of Chinese chive, Allium tuberosum. The present study aimed at determining the biocontrol potential of different indigenous entomopathogenic nematode (EPN) isolates for the management of chive gnat in China. The virulence of 145 EPN isolates belonging to 13 species against B. odoriphaga was evaluated in the laboratory, and then the most promising isolates (Steinernema ceratophorum HQA-87; S. hebeiense JY-82; S. feltiae JY-90, JY-17; S. litorale HXY-68; Heterorhabditis indica ZZ-68; H. bacteriophora NY-63, HQ-94; and H. megidis LFS-10) were selected for further experiments. The mortality of fourth instar B. odoriphaga was significantly affected by nematode isolates and concentrations of infective juveniles (IJ). Third and fourth instars of B. odoriphaga were generally more susceptible to the nematodes than first and second instars and pupae. Pot experiments showed no differences in B. odoriphaga population reduction at 50 and 75 IJ/cm2 of different isolates; the tested isolates caused a 78–94 % reduction of the chive gnat population at an application rate of 75 IJ/cm2. In a field experiment, S. feltiae JY-90 generated the strongest pest suppression 14 days after EPN application, whereas after 28 days pest densities in the plots treated with S. feltiae JY-17 and S. hebeiense JY-82 were similar to those in plots treated with phoxim and yielded significant reductions of the B. odoriphaga populations. Our findings indicate that EPN may have good potential for use in the integrated management of B. odoriphaga populations in Chinese chive.  相似文献   

19.
The pathogenicity of local isolates of the entomopathogenic fungi (EPF) Beauveria bassiana (Balsamo) Vuillemin, Isaria fumosorosea (Wize) (formerly Paecilomyces fumosoroseus (Wise) Brown & Smith) and Metarhizium anisopliae (Metschnikoff) Sorokin (Ascomycota: Hypocreales) were evaluated under laboratory conditions against pupae and adults of Mediterranean fruit fly Ceratitis capitata (Wiedemann) (Diptera: Tephritidae) via different routes of exposure. Average mortality of pupae after immersing them into spore suspensions was in general low and ranged from 18.7 to 23.9 % depending on fungal species and dose applied. However, adults obtained from treated pupae appeared to have higher mortality rates compared to control with all fungi and doses tested. Adults’ average mortalities ranged from 41.9 to 88.0 % after exposing them to EPF either by feeding on a mixture of conidial suspension and artificial food or by bodily contact with conidia, depending on fungal species, dose and method of exposure. The proportion of cadavers, pupae or adults, that produced visible signs of mycosis ranged from 40.4 to 73.3 % with the exception of those that were exposed to M. anisopliae. In that case, none of the insects that died after exposure to conidia of M. anisopliae developed visible mycelium on their surface. Moreover, confining treated with untreated adults indicated horizontal conidial transmission in some cases. Our results indicate that EPF might be a promising biological control agent for the Mediterranean fruit fly and could be utilised with different modes of application: soil application against pupae and cover or bait sprays against adults.  相似文献   

20.
The Chinese citrus fly, Bactrocera minax, is a major tephritid fruit fly pest that infests Citrus spp. fruits. The pest was removed from the national quarantine pest list in China in 2009 owing to its wide spread across the country, and it is currently considered a major threat to citrus industry in Asia. The frequent high infestation levels of B. minax in China emphasize the need for a more comprehensive understanding of its biology and ecology so that more efficient control measures can be developed and applied. In the framework of developing a sterile insect technique program against B. minax, we studied the feeding and mating activities of B. minax in situ (Citrus orchards and surrounding habitats) through open field surveys and video recordings. In the pre-oviposition period, sexually immature adults largely foraged for food (e.g. honeydew from aphids, nectar and sooty mould) on non-host plants. Then, sexually mature adult flies shifted to lick sooty moulds, bird faeces and, to a lesser extent, an unknown substance on the Citrus leaves and fruits during the mating and oviposition periods. Finally, during the post-oviposition period, the flies were observed feeding on ooze from grapes. The mating behaviour patterns of B. minax in the field were described as follows: first, the male established its territory close to the potential oviposition substrate (Citrus fruit), second, the female landed on the fruit and began inspection and ovipositor boring behaviour on the fruit surface (no male courtship observed e.g. wing vibration), and third, the male mounted and copulated with the female. The present study shed light on the feeding ecology and mating behaviour of B. minax in the field; this knowledge will facilitate development of better management strategies against this tephritid fly.  相似文献   

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