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1.
The absence of effective pest monitoring has resulted in an increase in populations of the obscure mealybug Pseudococcus viburni (Signoret) (Hemiptera: Pseudococcidae) in pome fruit orchards in the Western Cape Province of South Africa recently. The sex pheromone for P. viburni was recently identified and synthesized. Flight activity of adult male P. viburni was monitored by placing and servicing three, evenly spaced pheromone-baited traps per orchard in three pome fruit growing regions used for the study. Fortnightly fruit sampling was done by randomly picking three fruits per tree for the duration of each fruit season, dissecting and noting mealybug infestation. The biweekly male P. viburni trap catch information and fruit infestation data collected over two seasons were correlated. There was a positive and significant relationship between the fruit infestation and number of P. viburni adult males caught in pheromone-baited traps (r2 = 0.454, P < 0.001). The action threshold level was estimated to be 2.5 male P. viburni caught per trap per fortnight at an economic threshold of 2% fruit infestation. This monitoring method was less labor intensive, more accurate and quicker than the current visual sampling and monitoring techniques. 相似文献
2.
Adriano E Pereira Pablo C Gontijo Andreza K Fantine Ricardo S Tinoco Mark R Ellersieck Geraldo A Carvalho Jos C Zanuncio Evaldo F Vilela 《Journal of insect science (Online)》2021,21(2)
The coffee berry borer (CBB), Hypothenemus hampei Ferrari (Coleoptera: Curculionidae), is the most important coffee pest in most of the coffee growing countries. CBB females leave old dry berries after harvest and search for dry noninfested berries on the plant or on the ground to lay eggs or to use as refuge until new berries are available on the coffee trees in the following season. The CBB infestation level and emergence from berries on the ground or on the plants were evaluated in two fields post-harvest in the Spring in Brazil over two seasons. Twenty infested or noninfested berries in separate cages (250 ml plastic cups) were placed on the plants or on the ground under the tree canopy, in each field. The number of infested berries and CBB females that emerged from the infested berries were recorded weekly. CBB emergence was higher from berries on the ground than those on the coffee trees in both seasons, whereas CBB infestation was higher on coffee berries on the plants than those on the ground in season I. Insolation (hours of sunlight) and temperature were the main covariates that affected emergence and infestation by this insect. The results are discussed for monitoring CBB during the time of dispersal with implications on integrated management of this pest. 相似文献
3.
Bactrocera invadens, the Asian fruit fly, was first reported in
Kenya in 2003, and it spread fast to most tropical countries in Africa. To our
knowledge, there is no detailed data on the fruit damage and status of fruit
flies in Arba Minch and elsewhere in Ethiopia. Hence, information on the species
composition and pest status of the fruit fly species is urgent to plan
management strategies in the area. Fruit flies were captured using male
parapheromone-baited traps. Matured mango (Mangifera indica)
fruits were collected from randomly selected mango trees and incubated
individually in cages (15 by 15 by 15 cm) with sandy soil. B.
invadens was the predominant (96%; 952 of 992) captured
species and the only fruit fly species emerging from mango fruits incubated in
the laboratory. The mean number of adult B. invadens emerging
per mango fruit was 35.25, indicating that the species is the most devastating
mango fruit fly in the area. The loss due to this species would be serious if no
management strategies are implemented. 相似文献
4.
Bactrocera latifrons is a newly invasive pest species in eastern Africa. Surveys to determine the spatial and temporal abundance of this fruit fly in the Morogoro Region, Eastern Central Tanzania, were conducted from April 2007 to March 2008. The surveys involved trapping of adult flies and collection of host fruits to determine the emergence of adults. The results indicated that the population of B. latifrons was generally low but that adult flies were present throughout the survey period. The population of B. latifrons based on infestation rates and incidence in host fruits, seems to be relatively high during the wet seasons, probably because of availability of many hosts. However, the population of the pest as determined by trapping, indicated a low population but without a specific pattern. The pest shows minimal response to the used attractants. The surveys further indicate that B. latifrons is more abundant in low to medium altitude areas compared to high altitude areas. The results indicate that, because of its low population, B. latifrons might be a minor pest. Results further suggest the possibility of establishing B. latifrons free areas where export valued solanaceous crops can be grown, but further research over longer periods would be needed to establish this. 相似文献
5.
Avocado is an economically important fruit that is severely affected by anthracnose disease due to the infection with Colletotrichum spp. In this study, avocado fruits with anthracnose symptoms were collected in Morelos, Mexico. Two phytopathogenic fungi were isolated from these fruits and identified as Colletotrichum gloeosporioides and Colletotrichum acutatum using ITS sequences. Further, eleven yeasts from avocado (three from fruits, four from leaves and four from rhizospheric soil) were isolated; of which three showed in vitro antagonistic activity against C. gloeosporioides and C. acutatum. ITS sequence analysis of the isolated yeasts revealed that the strains obtained from fruits belonged to Candida intermedia while those isolated from leaves belonged to Wickerhamomyces anomalus. C. intermedia reduced disease incidence caused only by C. gloeosporioides, whereas, W. anomalus caused a significant reduction in the incidence and severity of disease caused by both C. gloeosporioides and C. acutatum. To the best of our knowledge, this is the first report on the antagonistic activity of W. anomalus or C. intermedia against Colletotrichum acutatum. Thus, W. anomalus is a potential natural alternative for controlling anthracnose infection and associated loss in avocado crops. 相似文献
6.
7.
Mark S Hoddle Christina D Hoddle Ivan Milosavljevi&#x; Edith G Estrada-Venegas Armando Equihua-Martínez 《Journal of insect science (Online)》2022,22(2)
Heilipus lauri Boheman (Coleoptera: Curculionidae) is a specialist pest of avocado fruit and is considered an incursion risk for U.S. avocado producers. At the time work reported here was undertaken the flight capabilities of H. lauri were unknown. Consequently, proactive studies were undertaken to quantify aspects of this pest’s flight capabilities to inform potential future control efforts. Flight mill studies were conducted in a quarantine laboratory to measure the dispersal capacity of H. lauri with respect to gender, mating status, and size on the single and repeat flight capabilities of weevils. Gender, mating status, and size did not significantly affect measured flight parameters. Average total distances flown and flight velocity, and mean maximum flight bout distances and durations significantly declined as weevil age increased and when weevils engaged in repeat flights. Survivorship rates were significantly reduced as the number of successive flights undertaken increased. The distribution of total average flight distances flown and total cumulative flight distances flown was platykurtic. The implications of these findings are discussed in terms of developing incursion management plans. 相似文献
8.
9.
The timing of trunk injections of the organophosphate, acephate, and two systemic neonicotinoids, imidacloprid and dinotefuran, was evaluated in field trials for the management of avocado thrips. Following treatments, leaves were sampled over a 6-month period to determine the period of efficacy for each insecticide. The efficacy of acephate was determined using bioassays. Imidacloprid and dinotefuran residues in leaves were quantified by ELISA to determine the window of efficacy for these treatments based on previously determined biological dose response data. In addition, residues in fruit were quantified to determine whether trunk injection of insecticides might present a greater risk for contaminating fruit than traditional application methods. The timing of trunk injection treatments significantly impacted the uptake of imidacloprid and dinotefuran, with mid- and late-leaf flush periods proving more effective in terms of rate of uptake and degree of persistence at threshold levels. Acephate was mobilized very rapidly and gave good control of thrips in bioassays; however, residues of acephate, and its insecticidal metabolite methamidophos, were detected in the fruit for up to 4 weeks after injection. Imidacloprid was most effective when injected during the mid-flush period, which allowed levels to establish within the trees over a period of time when thrips would be actively feeding on young leaf tissue. The establishment of dinotefuran in trees was very rapid following trunk injection. However, its use was compromised by the inability of the chemical to reach effective concentrations for thrips control. Residues of dinotefuran were detected in fruit sampled from one tree, but the levels were below typical MRLs for other crops treated with this insecticide. Imidacloprid was not detected in any fruit sampled from trees in which imidacloprid had established in leaf tissue at concentrations that were toxic to avocado thrips. Overall, trunk injection of imidacloprid could be a viable option for avocado thrips control. However, residues of acephate in fruit may preclude its use because of the requirement for increased pre-harvest intervals. Dinotefuran injections may also be useful due to the rapid uptake and establishment within the canopy; however, it will be necessary to determine whether higher doses of dinotefuran can deliver the required levels of insecticide necessary for thrips control, without contaminating the fruit with residues. 相似文献
10.
Loyapin Bondé Oumarou Ouédraogo Issaka Ouédraogo Adjima Thiombiano Joseph I. Boussim 《Plant Production Science》2013,16(2):143-158
ABSTRACT Shea tree (Vitellaria paradoxa) is one of the main native oil plants with high economic value in Africa. Its fruits are used for food, medicinal, cultural and exportation purposes. However, the lack of efficient tools to assess annual fruit production of the species limits the sustainable management of its resources. Therefore, production statistics are useful to organize the activities of the shea sector. This study aimed to (i) assess the interannual variation in fruit production along a climatic gradient in Burkina Faso, (ii) examine fruit production patterns according to climatic zones and tree size, (iii) assess the contribution of high-yielding trees in the annual potential production and (iv) develop allometric equations for estimating fruit yields of the species. The yield of 212 trees distributed across three climatic zones was monitored over four successive years. Within each climatic zone, fruit production was significantly different among years. Fruit production was positively and significantly correlated with tree size. The interannual variation in fruit production at tree individual level was higher in drier climatic conditions. The mean interindividual synchrony was less than 50% in each zone, suggesting a large range in fruit production patterns of the species. Annually, more than 55% of the total fruit production was supported by high-yielding trees. The best regression models for estimating fruit yields had R 2 values of 69–73% with prediction errors ranging from ?7% to 4%. Our findings are useful tools for the planning of rational exploitation of shea tree’s resources and its sustainable management. 相似文献
11.
The chilli thrips Scirtothrips dorsalis (Hood) (Thysanoptera: Thripidae), a new invasive pest in the USA, is an economically important pest of certain vegetable, ornamental and fruit crops in southern and eastern Asia, Oceania and parts of Africa. These crops cannot be protected from the pest without resorting to the use of chemical insecticides. In order to forestall or delay the development of insecticide resistance in S. dorsalis, we continued our focus on the discovery of insecticides with different modes of action for rotational use. In this study we evaluated candidate insecticides to control S. dorsalis on ‘Jalapeno’ pepper, Capsicum annuum L.; these materials belong to different IRAC mode of action classes as follows: (i) 4A – neonicotinoids, i.e., imidacloprid, thiamethoxam and dinotefuran, (ii) 5 – spinosyns, i.e., spinosad and spinetoram, (iii) 3A – pyrethroids, i.e., β-cyfluthrin, esfenvalerate, ζ-cypermethrin and λ-cyhalothrin and (iv) 8D – borax mixed together with orange oil and detergents in the TriCon® formulation. In addition we evaluated the entomopathogenic fungus, Beauveria bassiana (Botanigard®) alone and in combination with the borax formulation at ½ of their usual rates of application. Each of the 3 neonicotinoid insecticides when applied either as a single foliar spray or as a soil drench significantly suppressed both adults and larvae for at least 10 days; indeed imidacloprid did so for 15 days. Dinotefuran was more effective as a foliar spray than as a soil drench. Spinosyns applied as a single foliar spray, significantly suppressed both adults and larvae through 15 days after treatment (DAT). None of the 4 pyrethroids provided significant suppression of either adults or larvae. The borax formulation suppressed adults and larvae through 10 DAT. B. bassiana significantly suppressed only the larvae at 5 DAT and not at 10 DAT. This study brings the number of insecticides known to be effective against S. dorsalis to 10 and these belong to 7 different modes of action classes. The use of such insecticides in rotation belonging to different classes will help delay the development of insecticide resistance in S. dorsalis. 相似文献
12.
The response of vegetative soybean (Glycine max) to Helicoverpa armigera feeding was studied in irrigated field cages over three years in eastern Australia to determine the relationship between larval density and yield loss, and to develop economic injury levels. Rather than using artificial defoliation techniques, plants were infested with either eggs or larvae of H. armigera, and larvae allowed to feed until death or pupation. Larvae were counted and sized regularly and infestation intensity was calculated in Helicoverpa injury equivalent (HIE) units, where 1 HIE was the consumption of one larva from the start of the infestation period to pupation. In the two experiments where yield loss occurred, the upper threshold for zero yield loss was 7.51 ± 0.21 HIEs and 6.43 ± 1.08 HIEs respectively. In the third experiment, infestation intensity was lower and no loss of seed yield was detected up to 7.0 HIEs. The rate of yield loss/HIE beyond the zero yield loss threshold varied between Experiments 1 and 2 (−9.44 ± 0.80 g and −23.17 ± 3.18 g, respectively). H. armigera infestation also affected plant height and various yield components (including pod and seed numbers and seeds/pod) but did not affect seed size in any experiment. Leaf area loss of plants averaged 841 and 1025 cm2/larva in the two experiments compared to 214 and 302 cm2/larva for cohort larvae feeding on detached leaves at the same time, making clear that artificial defoliation techniques are unsuitable for determining H. armigera economic injury levels on vegetative soybean. Analysis of canopy leaf area and pod profiles indicated that leaf and pod loss occurred from the top of the plant downwards. However, there was an increase in pod numbers closer to the ground at higher pest densities as the plant attempted to compensate for damage. Defoliation at the damage threshold was 18.6 and 28.0% in Experiments 1 and 2, indicating that yield loss from H. armigera feeding occurred at much lower levels of defoliation than previously indicated by artificial defoliation studies. Based on these results, the economic injury level for H. armigera on vegetative soybean is approximately 7.3 HIEs/row-metre in 91 cm rows or 8.0 HIEs/m2. 相似文献
13.
Corrales-García Joel E. del Rosario García-Mateos María Martínez-López Eslí Barrientos-Priego Alejandro F. Ybarra-Moncada María Carmen Ibarra-Estrada Emmanuel Méndez-Zúñiga Sergio M. Becerra-Morales Diana 《Plant foods for human nutrition (Dordrecht, Netherlands)》2019,74(2):210-215
Mexican landrace avocados are naturally distributed mainly in high areas of central Mexico, where they have been produced and consumed since pre-Hispanic times. However, trees of these species are being replaced by improved varieties with greater global demand, and many species have been lost due to the destruction of their natural habitats. Many people in Mexico like to consume the pulp and peel of these fruits and have done so since pre-Hispanic times. This is because the peel of Mexican landrace avocados, unlike the peel of Hass avocados, is very thin and flavorful. The peel color may be bluish-purple or dark reddish due to the presence of anthocyanins, which are compounds with antioxidant activity. The objective of this study was to assess the oil and anthocyanin contents and to evaluate the antioxidant activity in fruits of 11 accessions collected from producing-regions of Mexico. The oil content was 16.2 to 32.3 g 100 g?1 in pulp, and the main unsaturated fatty acids were oleic, linoleic and palmitoleic acids, depending on the accession. The anthocyanin contents in peels ranged from 0.64 to 47 mg g?1 fresh weight. The highest antioxidant activity was found in the peel (53.3–307.3 mmol g?1 fresh weight). The results confirm that the pulp and peel of dark-peel Mexican landrace avocados could be important nutraceuticals for humans.
相似文献14.
Spotted wing drosophila, Drosophila suzukii, is an invasive insect pest that has spread into many fruit production regions of the world. Strategies to protect fruit from infestation by this insect are currently dominated by insecticide applications, so producers need information on relative efficacy and residual activity of insecticides to be able to select effective treatments. Semi-field bioassays in which highbush blueberry shoots with berries were treated then exposed to adult flies at different times after application revealed that fresh residues of organophosphate, pyrethroid, and spinosyn insecticides have strong initial activity on flies, with varying levels of residual protection against fruit infestation. An organic pyrethrum insecticide was not effective, whereas the neonicotinoid insecticide acetamiprid was found to have activity for up to five days. Rainfall after application greatly reduced the level of control achieved by some insecticides. Field-scale evaluation of conventional and organic spray programs initiated in response to capture of D. suzukii flies in monitoring traps indicated that both types of management provide significant fruit protection compared to untreated fields, with less larval detection in the conventionally-produced berries. 相似文献
15.
Mr. R. A. de Fossard Dr. F. H. Lenz 《Plant foods for human nutrition (Dordrecht, Netherlands)》1967,14(4):289-304
Summary The effects of N on quality and storage life of oranges were investigated in a factorial field experiment at Griffith N.S.W.,
Australia. The trees that did not receive any ammonium sulphate (N0) produced fruit with the best quality of juice. However, such trees had only one quarter of the total yield (by weight) of
trees receiving 2 kg ammonium sulphate (N1) per annum. Higher levels of ammonium sulphate (4 and 8 kg; N2 and N4 respectively) did not increase in yield or quality as judged by the total soluble solids (T.S.S.) to titratable acid ratio
of the juice. N1 — trees had produced more juice and total soluble solids than other treatments.
Organoleptic tests favoured juice with the highest T.S.S./acid ratio and the lowest percentage titratable acid.
Although fruit stored at 0°C had the least fungal wastage, that stored at 15°C had less rind breakdown and total wastage (fungal
+ rind breakdown). Low temperature rind breakdown was particularly evident at 7.5°C and most oranges were affected irrespective
of nitrogen treatment. At 20°C and 25°C, a high temperature rind breakdown was found with N4 — fruit on short storage, and
in other fruit after longer storage. Associated with the rind breakdown and preceding its appearance was a higher rate of
respiration. Some typicalSeptoria spot (with pycnidia) was found at 20°C and the high temperature rind breakdown is possibly related to this disease or its
due to another pathogen; it was not possible to decide definitely its origin, whether pathogenic or physiological. In general
N0 — and N1 —fruits stored better at most temperatures than N2 — and N4 — fruits.
Respiration rate at 20°C was similar irrespective of treatment; a climacteric rise in evolution of carbon dioxide was not
found.
Yield, internal quality and storage life of fruit, considered collectively, indicated that trees receiving 2 kg sulphate of
ammonia per tree per annum were, superior to all other treatments in this experiment. 相似文献
16.
The use of plastic rain shields is a very effective method to control fruit cracking in cherry trees. In this study, the effect of plastic rain shields on fruit cracking and fruit decay was investigated in different sweet cherry cultivars. The results showed that the percentage of fruit cracking and fruit decay was significant higher in uncovered than covered cherry trees. Fungi of the genus Monilinia were the main pathogens causing fruit decay in cherry fruits. In fruit with symptoms of cracking, fungi of the genus Alternaria predominated. Finally, the effect of plastic rain shield on the development of the disease Shot Hole (Wilsonomyces carpophilus) was examined. In most of cases, the percentage of the Shot Hole disease was higher in covered than uncovered cherry trees. Differences were found among cultivars.Generally, the use of plastic rain shields is a very effective method to control fruit cracking and fruit decay on cherry trees, but they should be removed during dry periods to reduce the risk of developing of Shot Hole. 相似文献
17.
In sub-Saharan areas of Africa, cotton growers no longer cut the shoot tips from plants (topping), although manual topping was promoted at the start of the 20th century to improve yield and, surprisingly, to reduce pest incidence. In these areas, the bollworms Helicoverpa armigera Hübner, Earias spp., and Diparopsis watersi Rothschild are responsible for the majority of cotton yield losses, and the use of pyrethroids has resulted in resistance in field populations of H. armigera. In the face of these problems and given the scarcity of literature on the effects of topping on pest control, we assessed bollworm infestation levels in 12 trials comparing manual topping and non-topping cotton plots in Mali over a six-year period (2002, 2003, and 2005 to 2008). Topping was performed at the emergence of the 15th sympodial branch or at 10 days after the first flower opening. Our results showed no significant difference in seed cotton yields between topped and non-topped cotton. Bollworm infestations (all species) were always lower on topped cotton and 7 out of 12 trials showed significantly lower infestations on topped cotton. In plots of topped cotton, we recorded an average of 56% fewer H. armigera larvae, 68% fewer Earias spp. larvae, and 71% fewer D. watersi larvae with respectively 5, 4, and 3 out of 12 trials with significant differences in favor of topping and no significant difference in favor of non-topping. To our knowledge, our study is the first to report decreases in D. watersi larval infestation with cotton topping. Further studies are required to understand the mechanisms involved in these effects and to ensure that topping is economically attractive for farmers. 相似文献
18.
The Indian gypsy moth (Lymantria obfuscata) is a pest of national significance, which attacks a wide range of forest and fruit crops in India. The outbreaks of this pest over the past few years spurred interest towards sustainable biointensive approaches for quality fruit production of apple and walnut for agricultural export in Jammu & Kashmir (J & K). The exploratory survey's were conducted for the isolation of native strains of L. obfuscata multiple nucleopolyhedrovirus (LyobMNPV) and field evaluation was conducted to determine the most promising strain as a potential biological control agent of this pest. The virus was recovered from different locations of J&K with its natural incidence varying from 0.77 to 7.43 percent. This is the first report from the Indian sub-continent and worldwide of the occurrence of NPVs in natural larval populations of L. obfuscata. The in vivo mass production was optimised by inoculating per os late 3rd instar L. obfuscata larvae with an inoculum dose of 1.44 × 105 OBs/larva and followed by a 10 day incubation period. To prevent the disintegration of larval cuticle and microbial contamination, moribund larvae were harvested with an average yield of 1.42 × 108 OBs/larva. The field application of LyobMNPV against the host populations on apple and willow with the pre-standardised dosage of 2.5 × 1012 OBs/ha reduced the larval population density by 25–63%. In the year following application, the larval population density in the treated blocks was 19–28% lower as compared to controls on both apple and willow. This suggests that the virus has considerable potential as a biocontrol agent and the timely application with LyobMNPV on non-fruit trees such as willow which are the preferred hosts for egg laying may help to initiate viral epizootics to keep population outbreaks under check. 相似文献
19.
Fruit flies (Diptera: Tephritidae) are a major problem for Australia's $6.9 billion horticultural industry. Bactrocera tryoni (Froggatt) is the most significant fruit fly pest in the eastern states of Australia. Catches of male B. tryoni from cuelure-baited Lynfield surveillance traps in towns bordering the Fruit Fly Exclusion Zone in New South Wales, Australia, from November to May in 2001/2002–2007/2008 were analysed with respect to year, town, property type (urban/rural), and tree species/crop varieties in which the trap was placed (tree type). Average catches of all traps were highest in 2007/2008 and lowest in 2003/2004, and showed an overall positive correlation with rainfall (P < 0.05). More B. tryoni males were caught in Wagga Wagga and Lockhart than in other towns. There were no significant differences in catches of B. tryoni between urban and rurally located traps. With respect to tree type, traps placed in pomefruit trees caught significantly more flies than those in citrus, stonefruit, or nonfruit trees, with no significant differences among the latter three tree groups. Within the pomefruit group, traps in apples (Malus domestica Borkh.) and pears (Pyrus spp.) caught significantly more flies than those in cotoneasters (Cotoneaster spp). Within the citrus group, traps in orange trees (Citrus × sinensis (L.) Osbeck) caught significantly more flies than those in mandarin trees (Citrus reticulata Blanco). No significant differences were detected in catches between any members of the stonefruit group. Within the nonfruit group, traps placed in kurrajongs (Brachychiton populneum (Schott & Endl.) R. Br.) caught significantly more flies than those placed on other tree species in the group. This study demonstrates that although surveillance programs conducted to establish and/or maintain area freedom from specific pests may not provide balanced datasets, careful analysis of the results of such programs can provide valuable insights into the behaviour of the species in question. 相似文献
20.
Control of Cameraria ohridella Deschka and Dimic (Lepidoptera: Gracillariidae), a pest on the horse chestnut tree (Aesculus hippocastanum L.) was tested using systemic injection in the 4-year period (2002–2005). Imidacloprid and abamectin were used with a single systemic tree injection treatment during May, immediately after blossom. A total of 77,760 leaves were sampled in the field to assess the effect on the number of mines caused by the horse chestnut leaf mining moth by comparing population levels in treated vs untreated trees. The mean number of mines per leaf ranged from 0 to 106.54.Both insecticides contained the pest, and their persistence was indicated by the level of effectives during the second year after treatment. The number of mines on the treated plants decreased significantly, and during the last year not more than three mines per leaf were observed, as against 64 mines on the control plants. Generally the infestation was reduced by up to 82%.Most of the holes in the bark of the treated plants were healed within 6–7 months from the treatment. Only in few trees extravasation of mucilaginous exudates or cracks on the trunk occurred. 相似文献