首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 31 毫秒
1.
Two-spotted spider mite (TSSM) and onion thrips are serious pests of potatoes in the Ardabil region (Iran). In the present study, anthocorid species were identified in potato fields of this region during 2006 and 2007. The results of the abundance study indicate that Orius niger (Wolff) and O. minutus (Linnaeus) are major predators of these pests in potato fields. The life table parameters of these predators were compared when they were fed 2nd instar larvae of onion thrips or female TSSM on potato leaves. In these experiments, O. niger had a lower nymphal mortality, longer oviposition period, higher net reproductive rate (R 0), and higher intrinsic rate of natural increase (r m ) when fed thrips instead of mites. O. minutus feeding on mites compare to thrips had a lower nymphal mortality, longer oviposition period, higher net reproductive rate, and higher intrinsic rate of natural increase. Based on these results, it can be concluded that these predators could be useful as biological agents in potato fields.  相似文献   

2.
A dramatic decline in forest cover in eastern Africa along with a growing population means that timber and poles for building and fuelwood are in short supply. To overcome this shortage, the region is increasingly turning to eucalyptus. But eucalyptus raises environmental concerns of its own. Fears that it will deplete water supply, affect wildlife and reduce associated crop yields have caused many countries in the region to discourage farmers from planting this exotic. This paper is part of a series of investigations on the growth and water use efficiency of faster growing eucalyptus hybrids, which was introduced from South Africa to Kenya. The hypothesis is that the new hybrids are more efficient in using water and more suitable for the semi-arid tropics than existing eucalyptus and two popular agroforestry species. Gas exchange characteristics of juvenile Eucalyptus grandis (W. Hill ex Maiden), two eucalyptus hybrids (E. grandis × Eucalyptus camaldulensis Dehnh.), Grevillea robusta (A. Cunn) and Cordia africana (Lam) was studied under field and pot conditions using an infrared gas analyzer was used to measure photosynthetic active radiation (PAR), net photosynthetic rate (A), stomatal conductance (g s) and transpiration rate (E) at CO2 concentrations of 360 μmol mol−1 and ambient humidity and temperature. A, E and g s varied between species, being highest in eucalyptus hybrid GC 15 (24.6 μmol m−2 s−1) compared to eucalyptus hybrid GC 584 (21.0 μmol m−2 s−1), E. grandis (19.2 μmol m−2 s−1), C. africana (17.7 μmol m−2 s−1) and G. robusta (11.1 μmol m−2 s−1). C. africana exhibited high E values (7.0 mmol m−2 s−1) at optimal soil moisture contents than G. robusta (3.9 mmol m−2 s−1) and eucalyptus (5.3 mmol m−2 s−1) in field experiment and G. robusta (3.2 mmol m−2 s−1) and eucalyptus (4.2 mmol m−2 s−1) in pot-grown trees. At very low soil moisture content, extremely small g s values were recorded in GC 15 and E. grandis (8 mmol m−2 s−1) and G. robusta (14 mmol m−2 s−1) compared to GC 584 (46.9 mmol m−2 s−1) and C. africana (90.0 mmol m−2 s−1) indicating strong stomatal control by the species. Instantaneous water use efficiency ranged between 3 and 5 μmol mmol−1 and generally decreased with decline in soil moisture in pot-grown trees but increased with declining soil moisture in field-grown trees.  相似文献   

3.
The insecticidal activity of an entomopathogenic fungus, Isaria farinosa on pine bark-weevil (Pissodes punctatus) at different life stages underwent laboratory testing. Larvae, pupae and adults of Pissodes punctatus were exposed to a range of concentrations of fungal conidia in suspension for 5 s; mean mortality and LC50 values were calculated. The results showed I. farinosa can effectively infect larvae, pupae and adult pine bark-weevils, and the highest mean mortalities at each life stage can exceed 88%. The mean mortalities increased with higher concentrations of I. farinosa. Larvae were most susceptible with LC50 1.2 × 106 conidia ml−1 (15 days), pupae (30 days) exhibited the second largest effects, and adults (15 days) with LC50 1.72 × 106 and 1.99 × 106 conidia ml−1, respectively, at end of the experiments. This suggests that I. farinosa could be a potential bio-control agent against the pine bark-weevil.  相似文献   

4.
Numerous occurrence of Echinothrips americanus Morgan, 1913, a relatively newly established pest in European greenhouses, on a wide spectrum of cultivated plants throughout Slovakia has encouraged us to present current data on its food ecology. Analysing 1,650 plant species, the poinsettia thrips was found on 106 species (48 families) including 19 showing sporadic, 75 moderate and 17 high infestation. Larvae were detected on 25 plant taxa from 13 families, most of them being new hosts. Mature clusters of Acalypha hispida, showing moderate to high infestation level and carrying both larvae and adults, were selected for more detailed statistical evaluation. Preference of adults for upper and lower leaf surface tends to be without statistical significance, the larvae on the contrary were strongly related to the lower side (Pearson’s χ2 = 13.3552, P = 0.0013). Concerning the age, increased occurrence was apparent on younger leaves for both larvae and adults. For larvae the nonparametric test gives the statistical difference between three age categories of leaves with the following values: Kruskal–Wallis χ2 = 6.6384, P = 0.03618. The statistical significance of age seems to be more crucial for younger shoots, as proved by the statistics for both larvae (Kruskal–Wallis χ2 = 8.4852, P = 0.0144) and adults (Kruskal–Wallis χ2 = 7.1049, P = 0.0287). Different food preferences of larvae and adults may result in specific approach when applying an effective biological or chemical control. Narrower tolerance of larvae could make them more manageable target in plant protection instead of efforts to control the whole thrips population.  相似文献   

5.
India is the largest grower of Eucalyptus with an area of 3.943 million hectares under plantations and E. tereticornis is the predominant species in the plains of southern India with an average productivity of 12–25 m3 ha−1 year−1. With the aim to establish seedling seed orchards of the species, seed lots of fifteen provenances were imported from Australia and a trial was laid. In the present study the genetic diversity existing in the seed orchard was estimated using ISSR–PCR. Seven ISSR primers amplified 663 amplicons in the size ranging from 255 to 2,711 bp. The total number of polymorphic bands varied from 59 to 123 with 100% polymorphic banding profiles. The average gene diversity (Hj) of all the provenances ranged from 0.0589 to 0.1109 and the total gene diversity estimated was low (H T = 0.130) when compared to the earlier reports from other eucalypts species. Analysis of Molecular Variance partitioned the ISSR variation into inter and intra population components. The inter population component accounted for 55.2% of the variation and the intra population component accounted for 46.3% (P < 0.001). A neighbour-joining analysis was done using the dissimilarity matrix to determine the aggregation of the individuals into clusters. Existence of population structure among the populations was revealed in STRUCTURE analysis but geographical region based clustering was not observed. The assessment of intra and inter genetic variation documented in the present study suggests that, along with the phenotypic traits, knowledge about genetic diversity measured at the DNA level in individuals of seed orchards provide an objective guide for selective culling of trees for maintaining optimal diversity for enhanced genetic gains.  相似文献   

6.
The potential of the entomopathogenic nematode Steinernema feltiae (Filipjev) (Rhabditida: Steinernematidae) Rioja strain was assessed under laboratory conditions. Last instar larvae of Leptinotarsa decemlineata Say (Coleptera: Chrysomelidae), Spodoptera littoralis Boisdouval (Lepidoptera: Noctuidae) and Trichoplusia ni Hübner (Lepidoptera: Noctuidae) were exposed to infective juveniles (IJs) under laboratory conditions. Larval mortality, days to larval death, infection cycle length, and reproductive potential were recorded. Efficacy was assessed performing dose–response experiments. The results indicate that control of L. decemlineata with S. feltiae Rioja strain is not economically profitable (LC50 = 99.61 IJs/cm2), whereas results obtained for T. ni (LC50 = 0.27 IJs/cm2) are promising. Due to the life cycle of this insect, the efficacy needs to be investigated in foliar application studies. The effects on S. littoralis (LC50 = 0.69 IJs/cm2) was considered the most suitable for development of the Rioja strain as a biocontrol agent for soil application.  相似文献   

7.
The function of an Arabidopsis thaliana gene, At5g54160 annotated as a caffeic acid O-methyltransferase CAOMT gene was characterized. The recombinant enzyme of this gene (AtOMT1) catalyzed the O-methylation of phenylpropanoid and flavonoid substrates. The specificity constants (k cat/K m) for 5-hydroxyconiferaldehyde (5-HCAld) and quercetin were both 0.11 μM−1·min−1. On the other hand, lignins of At5g54160-knockout Arabidopsis mutants lacked syringyl units. In addition, we showed that the gene silencing also resulted in significant accumulation of caffeyl alcohol (CaAlc). These results strongly suggested that At5g54160 gene is involved in syringyl lignin synthesis for the methylation of both 5-hydroxyconiferaldehyde and 3,4-dihydroxyphenyl compound(s). Part of this work was presented at the Annual Meeting of Japan Society for Bioscience, Biotechnology, and Agrochemistry, March 24–27, 2007  相似文献   

8.
A micropropagation method for Jaal (Salvadora persica)—a tree of arid horticulture and forestry has been developed. Nodal segments of fresh shoot sprouts originated from axillary buds obtained from a plant around 35–40 years old lopped plant were used as explants for establishment of in vitro cultures. Surface-sterilized explants produced optimum number of shoots through activation of axillary buds on Murashige and Skoog’s (MS) medium containing 8.88 μM BA (6-benzyladenine) + additives (25 mgl−1 each of adenine sulphate, arginine, citric acid, 50 mgl−1 ascorbic acid). The shoot multiplication was influenced by the successive transfer of the mother explants for 4–5 passages. The maximum number (23.1 ± 0.73 shoots per explant) of shoots were regenerated on MS supplemented with 1.11 μM BA + 1.16 μM Kn (Kinetin) + 0.54 μM NAA (α-naphthalene acetic acid). About 90% shoots pulse-treated with a combination of 2460.27 μM Indole-3-butyric acid (IBA) + 494.56 μM NOA (2-naphthoxy acetic acid) were rooted ex vitro on soilrite within 15–18 days. Over 80% cloned plantlets were hardened successfully in a green house and transferred to polybag/pots.  相似文献   

9.
The ethanol extracts obtained from both leaf and seed in the Thorn apple (Datura stramonium L.) (Solanaceae) were investigated for acaricidal, repellent and oviposition deterrent properties against adult two-spotted spider mites (Tetranychus urticae Koch) (Acari: Tetranychidae) under laboratory conditions. Leaf and seed extracts, which were applied in 167,250 and 145,750 mg/l concentrations, respectively (using a Petri leaf disc-spray tower method), caused 98 and 25% mortality among spider mite adults after 48 h. The simple logistic regression analysis showed that the independent variable, an increase in the dose of leaf extract was associated with a significant increase in the death rate of T. urticae females, but an increase in the dosage of seed extracts did not have a significant effect. Using probit analysis and estimating the parameters with a confidence limit of 95%, we determined the LC50 values of leaf extract to be 70,593 mg/l. According to Pearson’s χ2 test, mites showed the strongest run off to bean leaf surfaces sprayed with both leaf and seed extracts (in sub-lethal doses: <7,500 mg/l and <25,000 mg/l, respectively) and moved towards surfaces that had not been sprayed with extracts. Furthermore, repeated measures ANOVA indicated a significant difference between the number of eggs laid on unsprayed bean leaves compared to bean leaves that were sprayed with leaf and seed extracts at sub-lethal doses, 2,500 and 25,000 mg/l concentrations, respectively. These results suggest that D. stramonium extracts could be used to manage the two-spotted spider mite.  相似文献   

10.
Agroforestry systems based on poplar (Populus deltoides) are becoming popular in eastern and northern parts of India. Therefore studies on the structure and function of the systems are important. The investigations included allometric equations for above- and belowground tree components, crop and plantation floor biomass and litter fall estimation at Pusa, Bihar, India. Biomass, floor litter mass, litter fall and net primary productivity (NPP) of plantations increased with an increase in age of trees whereas, crop biomass for any specific crop interplanted with poplar decreased with the age of the plantation. The total plantation biomass increased from 12.08 to 90.59 Mg ha−1 and NPP varied from 5.69 to 27.9 Mg ha−1 year−1. The biomass accumulation ratio ranged from 2.1 to 3.2. Total annual litter fall was in between 1.95 and 10.00 Mg ha−1 year−1, of which 92–94% was contributed by leaf litter. Compartmental models were developed for dry matter distribution in agroforestry systems involving young (3-year-old) and mature (9-year-old) poplar trees interplanted with various crops, the crops being grown in two rotations maize (Zea mays) – wheat (Triticum aestivum) – turmeric (Curcuma domestica) and pigeonpea (Cajanus cajan) – turmeric. This study substantiates the potential of Populus deltoides G3 under agroforestry combinations.  相似文献   

11.
The integrated relationship in a simple mechanistic model between the critical environmental factors controlling leaf photosynthesis of understory species would be a useful tool to optimize the management of the silvopastoral systems. Individual effect of leaf temperature, water stress and light environment over net maximum photosynthetic rate (Pmax) was evaluated on Festuca pallescens leaves grown in a silvopastoral system of two Pinus ponderosa canopy covers (350 and 500 trees ha−1) and natural grassland. The aim was to integrate individual functions for Pmax against these environmental factors into a multiplicative model. We measured pre-dawn water potential (ψ pd), leaf temperature and net photosynthetic rate (Pn), stomatal conductance (gs) and intercellular CO2 concentration (Ci) as a function of photosynthetic photon flux density (PPFD). The highest Pmax under non-limiting conditions was 20.4 μmol CO2 m−2 s−1 and was defined as standardized dimensionless Pmax s  = 1 for comparison of environmental factors. The leaf temperature function showed an optimum range between 20.2 and 21.8°C where Pmax s  = 1. Then, Pmax s declined by an average 1 μmol CO2 m−2 s−1 C−1 from the optimum to 4.7 and 38.5°C. Pmax s decreased at a rate of 9.49 μmol CO2 m−2 s−1 MPa−1 as water potential reaches −1.9 MPa and showed a lower slope as water potential decreased down to −4.3 MPa. The light environment was estimated from hemispherical photograph analysis. Pmax s was 20% higher in leaves of open control plants than under the maximum tree canopy cover. The simple multiplicative model accounted for 0.82 of the variation in Pmax. Such a simple mechanistic model is the first step towards a more effective decision support tool.  相似文献   

12.
Acorn production patterns and the annual evolution of water relations parameters of Quercus ilex ssp. ballota (Desf.) Samp. in a dehesa (an open woodland forest) subject to various soil treatments (ploughing, ploughing + sowing, control) were studied in southwest Spain from June 2006 to December 2008. The effects of soil water holding capacity and effective soil depth on soil and plant water status and acorn production were also investigated. Water parameters showed significant differences between the ploughing treatment and the control, and there were also significant temporal differences. Xylem water potential ranged from −3.4 ± 0.1 to −0.7 ± 0.2 MPa, and cuticular transpiration was 62.4–192.9 mmol H2O kg−1 s−1. Acorn production did not differ significantly according to soil treatment, and showed large intra-specific variability. Individual values ranged from 0 to 1,220 g m−2 (fresh weight). Positive relationships were found between xylem water potential, cuticular transpiration and relative water content measured at midsummer, and acorn production during the three studied years. These results suggest that climatic conditions and soil water availability have a strong influence on plant water status, and therefore on acorn development during summer. The results also reflect the ability of this species to adapt to the Mediterranean climate by preserving water during dry periods, which to a large extent can be attributed to stomatal closure at high relative water content levels, and low cuticular transpiration during these periods.  相似文献   

13.
Bracatinga (Mimosa scabrella) is a legume tree species common in the early stages of succession in Araucaria angustifolia forests in southern Brazil. Bracatinga can form high-density monospecific stands called bracatingais. Its traditional management for charcoal production involves maintenance of the seed bank. Our objective was to analyze the genetic diversity and structure of bracatingais to understand the mechanisms by which intraspecific diversity of M. scabrella is created and maintained in landscapes managed by family farmers in their agroforestry mosaics. We analyzed 14 bracatingais using 8 allozyme loci. We compared parental and progeny generation indices (7 loci) and described the mating system (9 loci) of two progenies. Overall diversity was high: A = 2.69, H o = 0.257, H e = 0.382 and similar between populations. Overall fixation (F = 0.364) was similar to the fixation index (f = 0.329). The genetic divergence among populations was low (Θp = 0.052) but significant. The progenies’ genetic diversity values were similar to those of the previous generation (H e pop11 = 0.342 vs. 0.420/H e pop10 = 0.432 vs. 0.400). Progenies were compatible with half-sib and full-sib crossing expectations (θ xy  = 0.204 and 0.194). Our data showed that there is a tendency for genetic structuring caused not only by the reproductive system but also by genetic drift. It is very likely that the high genetic diversity is amplified by internal migration within each bracatingal. This study showed that current landscape management can contribute to maintaining high levels of bracatinga genetic diversity, which contributes to its regional conservation.  相似文献   

14.
Red flour beetle Tribolium castaneum (Herbst) and rice weevil Sitophilus oryzae (L.) are considered to be the major insect pests in storage. Essential oils from aromatic plants are recognized as proper alternatives to fumigants. Thymus persicus (Ronniger ex Rech. f.) is one of these plants that have medicinal properties and is indigenous to Iran. The essential oil was obtained from aerial parts of the plant and analyzed by GC and GC–MS. Carvacrol (44.69%) and thymol (11.05%) were the major constituents of the oil extracted. In this experiment, fumigant toxicity of the essential oil was studied against T. castaneum, S. oryzae at 27 ± 1°C and 60 ± 5% RH in dark condition. The adult insects were exposed to the concentrations of 51.9, 111.1, 207.4 and 370.4 μl/l air to estimate median lethal time (LT50) values. The fumigant toxicity was increased in response to increased essential oil concentrations. The LT50 values at the lowest and the highest concentrations tested were ranged from 28.09 to 13.47 h for T. castaneum, and 3.86 to 2.30 h for S. oryzae. It was found that S. oryzae adults were much more susceptible to the oil than T. castaneum. After 24 h of exposure, the LC50 values (95% fiducial limit) for T. castaneum and S. oryzae were estimated to be 236.9 (186.27–292.81) and 3.34 (2.62–4.28) μl/l air, respectively. These results suggest that T. persicus essential oil merits further study as potential fumigant for the management of these stored-product insects.  相似文献   

15.
For improving seed germination of Prosopis koelziana and Prosopis juliflora, different treatments of seeds were conducted, including scarification with sulfuric acid 98% for 10 and 15 min, sandy paper, hot water for 5 and 10 min, potasium nitrate 0.1%, gibberellic acid at 250 mg·L−1 and 500 mg·L−1 and combinational treatment of scarification with gibberellic acid of 250 mg·L−1 and 500 mg·L−1. The results show that scarifications with sandy paper and sulfuric acids 98% were the most effective treatments on breaking seed dormancy and seed germination induction. Scarification with sulfuric acid 98% for 15 min was the best treatment. According to the positive effect of scarification and lack of reaction of seeds against KNO3 and gibberellic acid, the kind of seed dormancy was determined as exogenous.  相似文献   

16.
The browse potential of black locust (Robinia pseudoacacia L.) and thornless honey locust [Gleditsia triacanthos f. inermis (L.) Zabel] has not been adequately tested. Our objective was to determine effects of fertilization and pollarding on biomass and foliar nutritive value in separate studies of black locust and thornless honey locust in Arkansas, USA. Shoots were sampled monthly for two consecutive growing seasons in 2002 and 2003 to determine foliar, shoot, and total aboveground biomass, shoot basal diameter, and foliar nutritive value (crude protein and in vitro digestibility). Black locust yielded more foliar biomass when pollarded at 50 or 100 cm and fertilized with 600 kg P ha−1, than at 5 cm with or without P, averaging 3.5 Mg dry matter ha−1. Black locust foliar crude protein and in vitro dry matter digestibility ( ≤ 170 and 534 g kg−1, respectively) decreased as leaves aged, but still met maintenance needs for beef cattle (Bos taurus L.). Thornless honey locust had little agronomic potential because of slow establishment, low foliar yield (330 kg ha−1), and a 2% reversion to undesirable thorny phenotype. Black locust should be considered for livestock browse when drought induces semi-dormancy of herbaceous forages.  相似文献   

17.
The responses of fine root mass, length, production and turnover to the increase in soil N availability are not well understood in forest ecosystems. In this study, sequential soil core and ingrowth core methods were employed to examine the responses of fine root (≤1 mm) standing biomass, root length density (RLD), specific root length (SRL), biomass production and turnover rate to soil N fertilization (10 g N m−2 year−1) in Larix gmelinii (larch) and Fraxinus mandshurica (ash) plantations. N fertilization significantly reduced fine root standing biomass from 130.7 to 103.4 g m−2 in ash, but had no significant influence in larch (81.5 g m−2 in the control and 81.9 g m−2 in the fertilized plots). Similarly, N fertilization reduced mean RLD from 6,857 to 5,822 m m−2 in ash, but did not influence RLD in larch (1,875 m m−2 in the control and 1,858 m m−2 in the fertilized plots). In both species, N fertilization did not alter SRL. Additionally, N fertilization did not significantly alter root production and turnover rate estimated from sequential soil cores, but did reduce root production and turnover rate estimated from the ingrowth core method. These results suggested that N fertilization had a substantial influence on fine root standing biomass, RLD, biomass production and turnover rate, but the direction and magnitude of the influence depended on species and methods.  相似文献   

18.
In a laboratory screening of 12 isolates of entomopathogenic fungi against nymphs of the mulberry whitefly (Pealius mori Takahashi), Beauveria bassiana (Balsamo-Crivelli) Vuillemin CKB-048 was the most virulent, causing 87 ± 3% mortality at 1 × 106 conidia/ml. Infection was confirmed by growth of the fungus from cadavers and by scanning electron microscopy of treated nymphs. Beauveria bassiana CKB-048 was formulated as a wettable powder (1 × 109 conidia/g) and tested in two mulberry (Morus alba Linn) plantations in central and northeastern Thailand. In both locations, two spray applications of B. bassiana CKB-048 at 3.75 × 1012 to 6.25 × 1012 conidia/ha and at 14 day intervals provided good control of whitefly nymphs; control with B. bassiana CKB-048 was comparable to that with the pesticide buprofezin at 250 g of active ingredient/ha. In addition, no mortality of silkworm larvae occurred when the larvae were fed with mulberry leaves sprayed with B. bassiana CKB-048 7, 14, or 21 days earlier.  相似文献   

19.
Bambusa nutans Wall., is an evergreen, perennial, and multipurpose bamboo having strong culms, which are largely used for construction, scaffolding, craft purposes, pulp, and paper industry. Multiple shoots from nodal segments (3–4 cm) of young branches of mature culms were established in Murashige and Skoog (1962) (MS) medium supplemented with various concentrations of 6-benzylaminopurine (BAP) (1.0–6.0 mg l−1) or in combination with α-naphthaleneacetic acid (NAA) (0.5–1.0 mg l−1) or kinetin (Kn) (1.0–2.0 mg l−1). February–March and December were found to be the best seasons for culture establishments. Maximum shoots were achieved on MS medium fortified with BAP (2.0 mg l−1). Embryogenic callus (slightly greenish compact, globular, and slow growing) was initiated from the base of severed sprouted buds in 2–3 subsequent subcultures on MS medium supplemented with 2,4-dichlorophenoxy acetic acid (2,4-D) (5.0 mg l−1) under dark incubations. Maturation and germination of well-organized somatic embryos was achieved on MS medium containing BAP and 2,4-D (1.0 mg l−1 each) with 20.0 mg l−1 ascorbic acid. Full-strength MS medium supplemented with 2% glucose favored further development of proliferated somatic embryos into plantlets. Genetic variations of field-established B. nutans plants regenerated through tissue cultures were assessed by amplified fragment length polymorphism (AFLP) analysis using 6 primer combinations. Four hundred and seven scorable fragments were amplified, of which 402 (98.8%) have recorded conservation at various morphogenetic stages leading to plantlets regeneration, therefore, revealed a high level of genetic stability.  相似文献   

20.
Citrus mealybug Planococcus citri (Risso) (Hemiptera: Pseudococcidae) is one of the main pests on citrus trees. Biological control of the pest is based on the release of hymenopterous parasitoids and coccinellid predators at present. The effectiveness of entomopathogen fungus Isaria farinosa (Holmsk.) Fries ([Sordariomycetes: Hypocreales] (Syn: Paecilomyces farinosus), as an alternative biological control agent on citrus mealybug, was investigated using four different inoculum densities and different relative humidities (RH). The entomopathogen caused 89.39% mortality in ovisacs, 84.07% mortality in second larval stage, 84.53% mortality in adult females, and 78.71% mortality in first larval stage at 95% RH and at 1 × 108 conidia ml−1 inoculum concentration. Percent mortalities were between 50 and 60 in ovisac, first and second larval stage at 95% RH and at 1 × 107 conidia ml−1. Percent mortality was decreased parallel to the decrease in humidity level and inoculum densities; however, the fungus caused significant infection in 70% and 80% RH. These results demonstrated that the effectiveness of the entomopathogen is promising for biocontrol of citrus mealybug.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号