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1.
The pomegranate butterfly Deudorix (=Virachola) livia Klug 1834 (Lepidoptera: Lycaenidae) was encountered for the first time infesting dates (Phoenix dactylifera, variety Deglet Nour) in the oasis of Gafsa, Southern Tunisia in September 2011. Larvae of D. livia only caused damage on date fruits at the phenological stages kimiri (green fruits) and khalal (yellow fruits). The average infestation rate of dates was 10%. In addition, 7.1% of the infested fruits dropped to the ground. Damage caused by this insect on dates is described, the current situation in Tunisia is provided and possible control methods in Tunisia are briefly discussed. Although this pest has previously been reported in Tunisia on pomegranate this is the first report of D. livia on dates in the country.  相似文献   

2.
The pomegranate fruit moth, Apomyelois ceratoniae (Zeller), is the most important pest of pomegranate orchards in Iran, where infestations lead to 20%–80% fruit loss. A. ceratoniae overwinters as larvae in several instars. The success in overwintering determines the fruit loss in the following season, thus overwintering physiology of A. ceratoniae could provide insights into population prediction. To this end, overwintering strategy and some seasonal physiological and biochemical changes were investigated in the field-collected larvae of A. ceratoniae. The lowest supercooling point was recorded in November (?14.6 ± 0.9 °C) and the highest in both October and March (?10.2 ± 0.9 °C). The median lethal temperature (LT50) of larvae was higher than supercooling point, suggesting that A. ceratoniae is chill-susceptible. Overwintering larvae had slightly higher concentrations of glycerol and sorbitol compared to summer larvae. There were no significant seasonal changes in body water content or hemolymph osmolality. Current winter temperatures in Iranian orchards are higher than the cold tolerance thresholds of A. ceratoniae, suggesting that overwintering mortality is not a key factor in determining A. ceratoniae populations.  相似文献   

3.
In October 2019, unusual damage was observed on Carissa macrocarpa (Apocynaceae) fruit at the ornamental nursery of the Higher Agronomic Institute (ISA CM), Chott Mariem (Sousse, Tunisia). Samples of fruit were collected and brought to the laboratory for observation and rearing. After a few days, adult flies emerged from infested fruit. Zaprionus indianus Gupta, Z. tuberculatus Malloch (Diptera Drosophilidae) and Ceratitis capitata Wiedemann (Diptera, Tephritidae) were identified morphologically. Information on the morphology, distribution and ecology of the two Zaprionus species are provided. This is the first record of Z. indianus and Z. tuberculatus in Tunisia.  相似文献   

4.
为了解山东省樱桃主产区果蝇的发生情况,本研究选择了山东省主要樱桃产区的7个地点进行调查,并通过形态学特征和分子鉴定法对果蝇的种类进行鉴定。结果发现,山东省樱桃主产区有4种果蝇,通过形态特征与分子鉴定法最终确定4种果蝇,分别为斑翅果蝇Drosophila suzukii、黑腹果蝇D.melanogaster、海德果蝇D.hydei和伊米果蝇D.immigrans。这4种果蝇对樱桃的为害程度与种植地区、果实腐烂程度和樱桃的品种均有关系;莱芜和泰安地区果蝇分别有4种和3种;烟台和威海地区则只有斑翅果蝇和黑腹果蝇2种。烟台地区果蝇为害率最高,且数量最多,其中烟台丁家夼村樱桃为害率高达45.16%,在第2次采集中烟台薛家村每100粒樱桃中斑翅果蝇和黑腹果蝇的数量最多。美早和先锋2个品种樱桃对果蝇的吸引力较强;采摘后期腐烂的果实可吸引大量的果蝇产卵。因此,应对烟台地区进行重点预防、早期防治,并减少美早和先锋品种樱桃在山东省的种植。  相似文献   

5.
The pumpkin fly Dacus frontalis is reported in this paper for the first time in Tunisia, where it was found in several locations. It is a pest of cucurbits of economic importance and is common especially in the eastern and southern parts of Africa. D. frontalis was collected from infested cucumber fruits in the region of El‐Jebil (Kairouan) and female bait traps for the Mediterranean fruit fly Ceratitis capitata and the olive fly Bactrocera oleae. Preliminary data from Tunisia suggest that D. frontalis is already established in four regions in which cucurbits are important crops. Brief notes on the diagnostic features for the species, its ecology and geographic distribution are given. Symptoms on cucumber from Tunisia are presented.  相似文献   

6.
Citrus leaf and fruit spot disease caused by Phaeoramularia angolensis is a serious production constraint in tropical Africa. In previous studies, essential oils extracted from fruit peels of two tolerant varieties exhibited a strong antifungal activity in vitro against P. angolensis as compared to oils from susceptible ones. In order to investigate if the susceptibility of citrus varieties is associated with the antifungal activity of their essential oils, some 22 varieties of different susceptibility levels (tolerant, susceptible and highly susceptible) and belonging to different botanical groups were studied. Oils extracted from fruit peels were evaluated for their activity against radial growth and sporulation using the poisoned food technique. The optimal doses for growth inhibition and conidial reduction were 2500 and 1000 ppm, respectively. At these doses, radial growth and sporulation exceeded the untreated control respectively for four and nine varieties suggesting that oils from these varieties promote fungal development. In general, oils from the tolerant group were most effective in reducing radial growth irrespective of dose. The highly susceptible group ranked first in reducing sporulation at dose 1000 ppm (45.93%) while at higher doses of about 2000–2500 ppm, oils from the tolerant varieties could reduce sporulation up to 100%. The marked dose effect in reducing sporulation suggests that there may be different compounds acting with changing dose. Botanically, oils from pummelo (Citrus maxima, tolerant group), were best in reducing radial growth (>87% inhibition) while those from grapefruits (C. paradisi, highly susceptible group) were most effective in reducing sporulation (>64% reduction).  相似文献   

7.
The pomegranate aphid, Aphis punicae (Passerini) (Homoptera: Aphididae) is one of the most important pests in Egypt on pomegranate trees. The study presented in this paper was conducted from 2012 to 2013 to compare the efficiency and selectivity of neonicotinoids (acetamiprid, imidacloprid, thiamethoxam and dinotefuran), organophosphate (malathion) and carbamate (pirimicarb) insecticides against pomegranate aphid and the associated predators, Coccinella undecimpunctata Linnaeus, Chrysoperla carnea (Stephens) and Syrphus corolla Fabricius. These insecticides significantly reduced the pomegranate aphid population by an average of between 70.6 and 90.7%. The effects persisted for up to 15 days after the end of treatment. The greatest control of A. punicae was achieved by thiamethoxam > acetamiprid > imidacloprid > pirimicarb > dinotefuran > malathion. Acetamiprid, imidacloprid, thiamethoxam, malathion and pirimicarb were harmful to predators and the observed reduction ranged from 75.4 to 100% and dinotefuran was moderately harmful to lacewings with an average reduction about 64.4%. These results suggested that the neonicotinoid insecticides can be considered as promising candidates for controlling the pomegranate aphid as, although they do have harmful to moderately harmful effects on predators, they are significantly less toxic to these beneficial organisms than malathion and pirimicarb.  相似文献   

8.
Yellow-pigmented bacteria isolated from blight-affected pomegranate leaves and fruit across seven Indian states in epidemics during the years 2008–2016 were characterized and identified using phenotypic and genotypic tools. All bacterial isolates shared phenotypic traits such as colony morphology, NaCl and pH sensitivity and fuscan production, and caused typical lesions on pomegranate plants upon artificial inoculation. Analysis of 16S ribosomal DNA and 16S–23S rDNA intergenic spacer sequences confirmed their identity as Xanthomonas axonopodis pv. punicae. The new isolates collected after 2000 were compared with an old isolate from the 1950s using polyphasic taxonomic approaches including multilocus sequence analysis (MLSA). Nucleotide polymorphism in 24 isolates for nine genomic loci (dnaK, fyuA, gyrB (Young), gyrB (Almeida), rpoD, fusA, gapA, gltA and lepA) showed minor variations in loci fyuA and gyrB. Isolates were grouped into four nearly identical sequence types, ST1, ST2, ST3 and ST4, based on their allelic profiles, ST3 being widespread in Indian states. Molecular phylogenetic analysis of concatenated 5690 bp with other Xanthomonas pathovars revealed its close genetic similarity with the X. citri group. The blight outbreak in diverse geographical locations is attributed to a re-emerged clonal population of X. axonopodis pv. punicae on a genetically homogenous pomegranate cultivar. The latently infected vegetative planting material of elite pomegranate cultivars contributed to the dissemination of the bacterial inoculum. This study highlights and forewarns of the role played by the clonally propagated elite pomegranate cultivars in disseminating and sustaining clonal populations of this bacterial plant pathogen in many Indian states.  相似文献   

9.
The aim of this study was to evaluate the effect of hot water (HW), antagonists and sodium bicarbonate (SBC) treatments applied separately or in combination to control Monilinia spp. during the postharvest storage of stone fruit. Firstly, we investigated the effect of HW temperatures (55–70°C) and exposure times (20–60 s), seven antagonists at two concentrations (107 or 108 cfu ml−1) and four SBC concentrations (1–4%). The selected treatments for brown rot control without affecting fruit quality were HW at 60°C for 40 s, SBC at 2% for 40 s and the antagonist CPA-8 (Bacillus subtilis species complex) at 107 cfu ml−1. The combinations of these treatments were evaluated in three varieties of peaches and nectarines artificially inoculated with M. laxa. When fruit were incubated for 5 d at 20°C, a significant additional effect to control M. laxa was detected with the combination of HW followed by antagonist CPA-8. Only 8% of the fruit treated with this combination were infected, compared to 84%, 52% or 24% among the control, CPA-8, and HW treatments, respectively. However, the other combinations tested did not show a significant improvement in effectiveness to control brown rot in comparison with applying the treatments separately. When fruit were incubated for 21 d at 0°C plus 5 d at 20°C, the significant differences between separated or combined treatments were reduced and generally the incidence of brown rot was higher than when fruit were incubated for 5 d at 20°C. Similar results were observed testing fruit with natural inoculum.  相似文献   

10.
A non-radioactive digoxigenin-labelled RNA probe specific for hop stunt viroid (HSVd) diagnosis has been developed. The high sensitivity and specificity of this RNA probe in dot blot hybridizations to nucleic acids from field samples, allowed the confirmation of the presence of HSVd in apricot (Prunus armeniaca L.) and its detection in two fruit tree species not previously described as hosts of this pathogen, almond (Prunus dulcis Miller) and pomegranate (Punica granatum L.). This result supports and extends the notion of the world wide distribution of HSVd, infecting cultivated fruit trees. HSVd was also found to accumulate to much higher levels in mature apricot fruits than in leaves. Additionally, a sample processing procedure which does not involve the use of organic solvents was demonstrated to render faithful results when used for viroid detection. The combined reliability and facility of use of both this extraction procedure and the non-radioactive probe will benefit agronomic investigations addressing the detection and eradication of HSVd. Other applications of the work described here, as the study of possible causal relations between specific disorders and HSVd infection, are also discussed.  相似文献   

11.
Candidatus Phytoplasma prunorum was detected for the first time in almond (Prunus dulcis Mill.) cv. ‘Abiod’ in Tunisia. Infected trees showed emergence of new growth during dormancy and leafed out before flowers opened in addition to early defoliation in summer. Phytoplasma was detected by nested polymerase chain reaction (PCR) using universal phytoplasma primer pairs P1/P7 and F2n/R2. A band with expected size was observed in samples collected from five symptomatic, but not symptomless almond trees. PCR products (1.2 kbp) were used for restriction fragment length polymorphism (RFLP) analysis after digestion with endonucleases RsaI and SspI. RFLP patterns obtained were similar to those reported previously for the European stone fruit yellows (ESFY, 16SrX-B). Identification has been further confirmed by PCR using ESFY specific primer pairs (ECA1/ECA2). This is the first report of Ca. Phytoplasma prunorum infecting almonds in Tunisia.  相似文献   

12.
为了探讨籽瓜叶片光合能力对源库调节的响应,以种子大小显著不同的3个籽瓜品种为材料,于开花坐果期通过整枝、摘叶、疏果将叶果比分别调整为10、20、30、40、50,并分别于幼果期、果实膨大期、果实成熟期测定叶片叶绿素含量及气体交换速率,收获后测定果实产量。结果表明,籽瓜功能叶叶绿素含量（SPAD值）、净光合速率（Pn）、气孔导度（Gs）和蒸腾速率（Tr）随果实生育期演进逐渐降低,胞间CO22浓度（Ci）逐渐增大。3个供试品种间SPAD、Pn、Gs、Tr和Ci差异显著,大种子品种H26的气体交换参数（Pn、Gs、Ci、Ti）显著低于中等种子品种H14,H14显著低于小种子品种H3,但SPAD和Ci变化规律相反。叶片SPAD、Pn、Gs、Tr均值及其果实生育期降幅均随叶果比增大而显著降低（叶果比50除外）,但叶片SPAD值和气体交换参数变化幅度无显著的品种间差异,说明一定范围内降低叶果比能提高叶片光合能力,但摘叶处理或叶果比过高均会加速叶绿素降解,诱发叶片衰老。3个品种单株果实产量随叶果比增大而提高,50（1.18 kg）>40（1.17 kg）和30（1.17 kg）>20（1.16 kg）>10（0.87 kg）,H3单株果实产量（0.88 kg）显著低于H26（1.20 kg）和H14（1.25 kg）。以上结果表明,适宜范围的源库比能够提高籽瓜叶片光合能力,延缓叶片衰老,有利于籽瓜果实高产。  相似文献   

13.
Surveys of Impatiens and Verbena species in local nurseries in Fredericton, Canada and Verbena species in New Delhi, India showed widespread infection of Citrus exocortis viroid (CEVd) in vegetatively-propagated and seed-grown plants. To determine viroid seed transmission, samples of eight varieties of Impatiens and 11 varieties of Verbena were obtained from four commercial sources. All 19 samples collected contained viroid infection irrespective of variety. The presence of viroid in non-germinated seed was 21%, while the transmission rate in seedlings was 66% in Impatiens walleriana in 2006. Following 2 years of seed storage, the respective figures were 6% and 26%. Similarly, in Verbena x hybrida the presence of viroid in seed was 13% in 2006 with a seed-transmission rate in seedlings of 28%, while the respective figures after 2 years of storage were 5% and 45%.  相似文献   

14.
In August 2013, Phenacoccus madeirensis Green, 1923 (Hemiptera: Pseudococcidae) was identified for the first time in Tunisia, in the region of Akouda (Sousse, coastal area of Tunisia) on Cestrum nocturnum (Solanaceae) during a survey. The infestation was observed on leaves, shoots and also on the collar. This is the first record of P. madeirensis in Tunisia and the first record of this pest in North Africa. Two other mealybugs Peliococcus cycliger and Planococcus citri were also recorded during this survey. They have previously been reported in Tunisia.  相似文献   

15.
Abstract

A programme for the biological control of the citrus leafminer Phyllocnistis citrella Stainton (Lepidoptera, Gracillariidae) was carried out in Tunisia between 1996 and 1998. Two exotic parasitoids, Ageniaspis citricola (Logvinovskaya) (Hymenoptera, Encyrtidae) and Semielacher petiolatus Girault (Hymenoptera, Eulophidae), were introduced from Australia, mass-reared in a greenhouse on Citrus aurantium L. seedlings infested with P. citrella, and released in different orchards located in the major citrus-growing area of Tunisia. In 1996, A. citricola was recovered in 39.13% of release sites, reaching a maximum percentage of parasitism of 28%. In 1997, the parasitoid was recovered in a third of all release points, with an average percentage of parasitism of 5%. However, the wasp was unable to survive the winter 1998, and has become extinct. The non-establishment of A. citricola may have been due to the more arid climatic conditions present during the rainless summer and most of the autumn in Tunisia. By contrast, the establishment, dispersal, and reduction in citrus leafminer population observed with S. petiolatus between 1997 and 1998 shows this species to be well-adapted to the Tunisian climate. The average percentage parasitism of P. citrella by S. petiolatus increased from 6.6% in 1997 to 15% in 1998. Moreover, S. petiolatus was established in 76% of release points in 1997 and in 82% in 1998. It spread as much as 30 km from some release points, with no apparent decline in parasitism levels with distance. Semielacher petiolatus is considered to be an effective biological control of the leafminer in Tunisia. Its biological control action would supplement the action of the native parasitoids Pnigalio sp. and Cirrospilus pictus Nees (Hymenoptera, Eulophidae).  相似文献   

16.
Whole wheat grain bait, treated with sodium fluoroacetate, is used to control field rodents in Israel. However, this bait constitutes a potential primary non-target hazard to seed-eating birds. In the present study black-, red-, green- and yellow-dyed whole wheat and sorghum grains, as well as undyed ones, were offered to feral pigeons,Columba livia, and to chukar partridges,Alectoris chukar, in the laboratory during 4 days. Grains were offered either piled on trays, or scattered. Consumption levels varied significantly (P<0.05) among varieties. The pigeons preferred undyed grain; black and yellow grains were consumed the least. The partridges preferred the undyed and black grains to all the other colored grains. When no undyed alternative was offered, the pigeons preferred red and green, and the partridges — black wheat. The pigeons preferred wheat whole grain, and the partridges — sorghum whole grain. When the pigeons received sorghum, a disliked grain, no significant difference (P>0.05) was observed in the consumption of the differently dyed grains.  相似文献   

17.
Host plant resistance is an important component for management of the melon fruit fly, Bactrocera cucurbitae (Coquillett), owing to difficulties associated with its chemical and biological control. Various biochemical traits including total sugar, reducing sugar, non-reducing sugar, tannins, phenols, alkaloids, flavinoid and pH contents of fruit were studied on 11varieties/ genotypes of muskmelon, Cucumis melo L., in relation to resistance against B. cucurbitae under field conditions. Significant differences were found in tested varieties/ genotypes for fruit infestation and larval density per fruit. AHMM/BR-1, RM-50 and AHMM/BR-8 were the most resistant; MHY-5, Durgapura Madhu and Pusa Sarabati were moderately resistant; AHMM/BR-13, Pusa Madhuras and Arka Jeet were susceptible; whereas Arka Rajhans and GMM-3 were the highly susceptible varieties/ genotypes to fruit fly in both seasons, 2011 and 2012. The larval density per fruit increased with an increase in percent fruit infestation and there was a significant positive correlation (r = 0.97) between percent fruit infestation and larval density per fruit. Total sugar, reducing sugar, non-reducing sugar and pH were lowest in resistant and highest in susceptible varieties/ genotypes, whereas tannins, phenols, alkaloids and flavinoid contents were highest in resistant and lowest in susceptible varieties/ genotypes. Total alkaloid and pH contents explained 97.96% of the total variation in fruit fly infestation and 92.83% of the total variation in larval density per fruit due to alkaloids and total sugar contents.  相似文献   

18.
李果实细菌性穿孔病发生规律及防治   总被引：4，自引：0，他引：4  
在辽宁省多数李树品种的果实上发生细菌性穿孔病,病斑近圆形、暗紫色、边缘具水渍状晕环,使果实去失商品价值。研究结果发现果实自落花后１５ｄ至采收前都可被侵染;雨日多、雨量大、品种感病、树势旺盛为病害流行的因素;防治该病有效措施是栽植抗病品种,消灭初侵染源,加强栽培管理,生长期用药控制病害发生。  相似文献   

19.
桃小食心虫对苹果的为害及其防治指标的制订   总被引：8，自引：0，他引：8  
  相似文献   

20.
棉花品种资源花铃期抗旱性鉴定与评价   总被引：2，自引：0，他引：2  
以272份国内外棉花品种资源为试验材料，设置干旱胁迫与正常灌水2个处理，于花铃期测定不同处理各品种资源的株高、果枝数、有效结铃数等15个农艺性状及叶绿素含量（Chl）、丙二醛含量（MDA）、脯氨酸含量（PRO）等4个生理指标，以抗旱指数（DI）为基本评价指标，利用综合抗旱指数（CDI）、抗旱综合度量值（D）、加权抗旱指数（WDI）3种评价方法，结合灰色关联度及聚类分析，对272份品种资源进行抗旱性综合评价。根据D值聚类分析结果，将272份品种资源划分为5级：强抗旱级别包含关农1号、渝棉1号、辽棉9号、辽棉16号共4份品种资源；抗旱级别包含银棉2、岱字棉16、新陆中10等24份品种资源；耐旱级别包括18N3、司6524、新陆中82等134份品种资源；较敏旱级别包括鄂抗棉8、新陆中65、新陆中22等100份品种资源；敏旱级别包括150030、鄂抗棉10、晋棉12等10份品种资源。CDI值、D值、WDI值存在极显著正相关（相关系数0.958以上），评价结果基本一致，以D值为主，结合CDI、WDI值可有效、准确评价棉花花铃期抗旱特性。筛选的关农1号、渝棉1号、辽棉9号等抗旱品种资源可为棉花抗旱遗传改良提供特异资源。整齐度、比强度、叶绿素含量、果节数、结铃数、单铃重可以作为花铃期抗旱性鉴定的主要指标。  相似文献   

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