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1.
The cotton whitefly, Bemisia tabaci (Genn.) (Hom., Aleyrodidae) is increasingly a very important pest on many vegetables, field crops and ornamental plants. Therefore,
controlling of this pest is still needed especially under glasshouse conditions. The specialist whiteflies’ predator, Serangium parcesetosum Sicard (Col., Coccinellidae) appears to have a great potential for the cotton whitefly control. In this study, the dynamic
changes in B. tabaci populations in glasshouse cabins in response to S. parcesetosum were monitored. B. tabaci were introduced to cotton plants in three cabins in average of 50 adults per plant. One and two weeks later, adult females
and males of S. parcesetosum were introduced at a rate of one female and one male per plant in the first and second cabins, respectively. The third cabin
was considered as a control. The results showed that the mean number of whiteflies in the control cabin was found significantly
higher than that of either when S. parcesetosum was introduced 1 or 2 weeks after the infestation with the whitefly. Also, the mean number of B. tabaci was significantly higher when the predator was introduced 2 weeks rather than 1 week after B. tabaci infestation. The maximum mean weekly number of whiteflies/plant was 192.3 in the second week, whereas it was 294.6 in the
third week and 1136.4 in the fifth week, in first, second and control cabins, respectively. In the last experimental week,
the mean weekly numbers were 74.7, 122.9 and 684.7 whiteflies/plant in the three cabins, respectively. S. parcesetosum has been successfully fed, reproduced and established its population on B. tabaci on cotton plants. The mean weekly number of the predatory individuals increased gradually with the progress of the experimental
time. The results demonstrated that the maximum reduction percentage in B. tabaci population was 90.7 and 86.5% in the fifth week after B. tabaci infestation, when the predator was introduced 1 and 2 weeks after the infestation with the whiteflies, respectively. Nevertheless,
it is speculated that an earlier release of S. parcesetosum would be more effective in the biological control of B. tabaci. 相似文献
2.
Serangium parcesetosum Sicard (Col., Coccinellidae) is considered one of the important predators of whiteflies. However, knowledge about its preferences for different prey stages, species and parasitized prey is still lacking in the literature. The present work investigated the preferences of S. parcesetosum for different stages of B. tabaci, different prey species and B. tabaci parasitized by Encarsia formosa Gahan (Hym., Aphelinidae) by prey consumption at different temperatures in the laboratory. Results showed that L2 and L4 predatory instars of S. parcesetosum preferred puparia to nymphs and eggs of Bemisia tabaci (Genn.) (Hom., Aleyrodidae). The mean daily prey consumption was 5.1–9.0, 4.5–6.2 and 3.6–4.3 by L2 and 6.4–9.7, 5.5–8.5 and 2.5–7.5 by L4 for puparia, nymphs and eggs, respectively. Adult females, however, indicated a significantly greater preference for both puparia and nymphs, consuming a daily mean of 6.4–7.5 puparia and 5.1–6.7 nymphs, but only 3.0–4.7 eggs. At 18 and 30 °C, all S. parcesetosum stages tested significantly preferred B. tabaci and Trialeurodes vaporariorum Westwood (Hom., Aleyrodidae) over the other three prey species offered. At both temperatures, all predatory stages preferred B. tabaci to T. vaporariorum, the L2 instar at 18 °C, showing significantly more preference for B. tabaci than T. vaporariorum. In contrast, very few individuals were consumed from Aphis gossypii Glover (Hom., Aphididae), Frankliniella occidentalis (Pergande) (Thys., Thripidae) and Tetranychus urticae Koch (Acari, Tetranychidae). At 18 °C, a daily mean of 7.5–8.0, 6.6–9.0 and 6.7–8.1 B. tabaci as well as 5.3–6.4, 5.4–7.8 and 5.6–6.3 T. vaporariorum was consumed by L2, L4 and adult females, respectively, while at 30 °C, L2, L4 and adult females consumed a mean of 9.3, 8.8–9.7 and 8.3–9.7 B. tabaci/day as well as 8.3–9.0, 7.8–9.1 and 5.5–8.4 T. vaporariorum/day, respectively. S. parcesetosum L2 and L4 instars as well as adult females and males at both studied temperatures showed a significant tendency to avoid B. tabaci puparia after 5 days of parasitism by E. formosa and preferred to feed on unparasitized whiteflies. At 18 °C, the mean daily consumption was 8.7 and 0.2 (L2), 11.1 and 0.6 (L4), 12.1 and 1.0 () as well as 10.5 and 0.2 (), while at 30 °C the means were 15.9 and 0.5 (L2), 19.8 and 1.0 (L4), 18.9 and 1.2 () as well as 17.4 and 0.6 () from unparasitized and parasitized B. tabaci puparia, respectively.This paper is gratefully dedicated to Prof. Dr. W Schwenke on his 83rd birthday, 22 March 2004 相似文献
3.
Sarwan Kumar 《Journal of pest science》2017,90(1):129-137
The large white butterfly, Pieris brassicae (L.), is an important pest of Indian mustard, Brassica juncea (L.) Czern., and inflicts heavy damage to all the above ground plant parts with strong yield reducing impacts. Farmers have few practical options other than to spray insecticides to protect their crop. In this study, an attempt was made during 2012–2013 and 2013–2014 crop seasons at Ludhiana, India, to evaluate Ethiopian mustard, Brassica carinata A. Braun as a trap crop to manage this pest as an alternate pest management strategy. B. carinata borders surrounding B. juncea were compared to chemically protected B. juncea and control (without B. carinata borders) plots for their effects on P. brassicae infestation and grain yield. Oviposition preference of adult butterflies was studied in a two-choice test in field cages, while the effect of two host plants on larval performance was studied under laboratory conditions under no choice conditions. B. juncea plots bordered with B. carinata harbored significantly lower larval population compared to control B. juncea plots during both the seasons. The grain yield in the bordered plots was also significantly higher than that from control plots and was statistically non-significant from that obtained in chemically protected plots. Female butterflies showed distinct oviposition preference for B. carinata over B. juncea and the larvae reared on B. carinata completed development in shorter period and grew bigger and heavier than those reared on B. juncea. Results indicated that B. carinata has potential to be used as trap crop to manage P. brassicae. 相似文献
4.
Maman?Turjaman Yutaka?Tamai Hendrik?Segah Suwido Hester?Limin Joo Young?Cha Mitsuru?Osaki Keitaro?Tawaraya
Trees of the family Dipterocarpaceae are the dominant trees in Southeast Asian tropical forests where they play an important ecological role and are also important commercially. An experiment was conducted to determine the effect of ectomycorrhizal fungi on the growth of dipterocarp species in peat soils. Seedlings of Shorea pinanga were inoculated with spores of two ectomycorrhizal fungi, Pisolithus arhizus and Scleroderma sp. were grown in pots containing sterilized peat soil for 7 months. The percentage of ectomycorrhizal colonization on S. pinanga exceeded 86%. Colonization of S. pinanga roots by ectomycorrhizal fungi resulted in increased shoot height, stem diameter, number of leaves, and shoot fresh and dry weight. Survival rates of S. pinanga were greater for inoculated seedlings than control seedlings. These results suggest that inoculation of ectomycorrhizal fungi can improve the early growth of S. pinanga grown in tropical forests and that this technique will accelerate the rehabilitation of degraded dipterocarp forests. 相似文献
5.
Elisabeth Tabone Céline Bardon Nicolas Desneux Eric Wajnberg 《Journal of pest science》2010,83(3):251-256
The diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), is the most important pest of cultivated Brassica worldwide, including those grown in greenhouses
like cauliflower. In this article, we evaluate the potential of various species (and various strains of some species) of Trichogrammatidae
(Hymenoptera: Chalcidoidea) to control this pest on cauliflower in greenhouse in France. We assessed the parasitism levels
on P. xylostella of 17 Trichogrammatidae strains, belonging to 12 different species (2 indigenous strains from France), under greenhouse conditions.
Parasitism levels for each of the Trichogrammatidae species and strains were determined on cauliflower leaves (Brassica oleracea
botrytis L., Brassicaceae) infested with P. xylostella eggs. Nine strains parasitized 60% (or more) of the P. xylostella eggs. Compared to previous results in laboratory conditions, climatic conditions of the greenhouse did not influence parasitism
levels. The presence of the cauliflower plants may have a positive effect on eight strains, a negative effect on four strains
and no effect on five strains. Our study points out the importance of including the host plant of P. xylostella when conducting studies aiming to select the most efficient parasitoid against this pest. 相似文献
6.
Kamil Karut 《Journal of pest science》2007,80(2):93-97
Efficient use of parasitoids in pest control depend on the knowledge of the biological relationships between host and parasitoid.
Eretmocerus mundus Mercet (Hymenoptera: Aphelinidae) is one the most important natural enemies of Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae) that is found in fields and greenhouses in Adana, Turkey. Although more studies have
been done to determine the relationships between E. mundus and B. tabaci, the differences among strains of E. mundus could have important biological concequences. In this study, biological characteristics of native population of E. mundus parasitization of B. tabaci (Q biotype) were determined using bean plants Phaseolus vulgaris (L.) at a constant temperature of 25 ± 1°C, relative humidity 70 ± 10% and 16:8 (L:D) photoperiod regimen. All B. tabaci nymphal instars were parasitized by E. mundus, but the mean number of daily-parasitized nymphs was highest in the second instars (15.3). In addition, second instar females
had the shortest mean development time (15.2 days). Mean development times of parasitoids obtained from first, second, third
and fourth B. tabaci instars varied from 15.2 to 16.2 days and 15.2 to 15.9 days for female and male, respectively. Proportion of female (♀/♂+♀)
varied from first (0.53) to second (0.34) host instars. Impact of results on potential biological control of B. tabaci was discussed through conservation native natural enemies. 相似文献
7.
Tuta absoluta is a pest native to South America that produces significant damage to tomato crops and was first detected in Europe in late
2006. Data obtained during 2008 from commercial tomato crops in which IPM was applied suggested that good pest control was
possible through the combined action of the predatory mirid bugs Macrolophus pygmaeus and Nesidiocoris tenuis and the use of selective insecticides. The aim of our study was to evaluate the lethal and sublethal side effects of three
of the insecticides most widely used to control T. absoluta on these predators: azadirachtin, spinosad and indoxacarb. Seven days after applying the treatment at the maximum recommended
field rates, the mortality produced by indoxacarb ranged from 28% for nymphs of M. pygmaeus to 77% for females of N. tenuis and were significantly higher than those produced by azadirachtin, spinosad and the control (<13%). However, indoxacarb did
not affect the number of descendants of females exposed to residues during the last days of their preimaginal development.
In contrast, spinosad significantly reduced the offspring of M. pygmaeus and azadirachtin significantly reduced the offspring of N. tenuis females. The sublethal effects of azadirachtin and spinosad on predator reproduction should therefore not be ignored. This
information could be useful when selecting the most appropriate insecticide to control T. absoluta in greenhouses and field crops in which M. pygmaeus and N. tenuis are used as biological control agents. 相似文献
8.
The black vine weevil Otiorhynchus sulcatus (Coleoptera: Curculionidae) is a well-known insect pest causing damages and economic losses on various horticultural plants.
In recent times, numerous other weevils like O. rugosostriatus, O. raucus, O. ovatus or O. salicicola are becoming increasingly important in horticulture. We applied mark-release-recapture studies to estimate population size,
survival rates, aggregation patterns and dispersal capabilities of adult O. raucus and O. rugosostriatus in a commercial plantation of perennial ornamental plants. Knowledge of these characteristics is important for the correct
timing and design of efficient control strategies. Of 191 individually coded O. raucus and 340 O. rugosostriatus, 30 and 24%, respectively, were recaptured at least once over a period of 96 days. The majority of weevils were recaptured
within 2–3 m away from their release point and thus both species can be regarded as being quite sedentary. In accordance,
patchiness of weevil distribution was clearly evident in the study area. Population sizes reached maximum values after the
peak of adult emergence from pupae in spring (for O. raucus) and late summer (for O. rugosostriatus), with high survival rates being evident in particular for O. raucus. This study provides for the first time data on population ecology of two weevil species, whose abundance and importance
as putative insect pests in horticulture has increased over the last years. 相似文献
9.
I. Alper Susurluk N. Alper Kumral Uğur Bilgili Esvet Açıkgöz 《Journal of pest science》2011,84(3):321-326
The use of biological control in turf has increased to avoid possible negative effects on humans. Entomopathogenic nematodes
(EPNs) belonging to the families Steinernematidae and Heterorhabditidae have control potential against many economically important
insect pests. In the present study, the efficacy of Heterorhabditis bacteriophora against a new pest on turf, Dorcadion pseudopreissi, was examined in the field. Cages (1 × 1 × 1 m) with female and male D. pseudopreissi were placed on two kinds of turf: Lolium perenne and Festuca arundinacea. After beetles had deposited eggs into the moist soil surface, the cages were removed and H. bacteriophora was applied at 0.5 million infective juveniles/m2 to half the plots. Application of H. bacteriophora caused a statistically significant reduction in numbers of beetle larvae in L. perenne plots and a non-significant reduction in F. arundinacea plots. The area damaged by D. pseudopreissi was significantly reduced by nematode application in both turf species. The number of nematodes declined after application,
but small numbers could still be detected after 6 months. 相似文献
10.
Christian Ulrichs Inga Mewis Sujit Adhikary Atanu Bhattacharyya Arunava Goswami 《Journal of pest science》2008,81(2):79-84
Antifeeding and toxic effects of chemical extracts from Porteresia coarctata Takeoka on the insect pest Spodoptera litura (F.) were investigated in the laboratory. Hexane extracts of P. coarctata leaves were re-dissolved in dimethyl sulfoxide and applied in water to leaves of Ricinus communis L. (castor). A concentration of 1,000 and 2,000 ppm extract exhibited significant antifeeding and toxic effects to third
instar larvae when compared to the same concentration of dimethyl sulfoxide in water as control. One day after feeding on
extract-treated castor leaves, the mortality of S. litura larvae was 50%. Mortality increased to 95% after 11 days at a dosage of 2,000 ppm. Compared to the control, third instar
larvae fed on castor leaves treated with P. coarctata leaf extract at different concentrations showed significant reduction in protein and DNA content in the fat body and midgut
tissues. Results demonstrate the insecticidal and antifeedant properties of P. coarctata leaf extract against the generalist pest S. litura leading to biochemical changes in the insect body. Thus, P. coarctata contains phytochemicals, and the extract, in crude and pure form, has potential as a botanical insecticide in alternative
control strategies against Lepidoptera pests. 相似文献
11.
Gabriella Tait Alberto Grassi Ferdinand Pfab Cristina M. Crava Daniel T. Dalton Roger Magarey Lino Ometto Silvia Vezzulli M. Valerio Rossi-Stacconi Angela Gottardello Andrea Pugliese Giuseppe Firrao Vaughn M. Walton Gianfranco Anfora 《Journal of pest science》2018,91(4):1213-1224
Drosophila suzukii (Diptera: Drosophilidae) is an invasive alien species devastating soft fruit crops in newly invaded territories. Little is known about the importance and potential of long-distance dispersal at a regional scale. The goal of this work is to investigate D. suzukii dispersal ability during different times of the season, and along an elevational gradient in a mountain valley in Trentino Province, Italy. We employed a mark–release–recapture strategy using protein markers. Flies were recaptured using fruit-baited traps. The protein-marked flies were positively identified using ELISA procedure. Additional microsatellite analyses were performed on D. suzukii collected during autumn at different elevations to characterize the population structure. Results suggest that a portion of the local D. suzukii population moves from low to high elevations during spring and summer and travels back to low elevations in autumn. Genetic analysis further revealed that samples collected during autumn at different elevations belong to the same population. These results show that D. suzukii are able to fly up to about 9000 m away from the marking point and that seasonal breezes likely facilitate long-distance movement. We suggest that these migrations have multiple functions for D. suzukii, including conferring the ability to exploit gradual changes of temperature, food, and ovipositional resources in spring and autumn, as well as to assist in the search for suitable overwintering sites in late autumn. Our findings help to unveil the complex ecology of D. suzukii in Italian mountainous regions and provide important clues for improving the efficacy of integrated pest management control techniques to combat this pest. 相似文献
12.
The efficacy of NeemAzal powder, two local neem (Azadirachta indica
) products [neem seed powder (NSP) and neem seed oil (NSO)], as well as a local Lamiaceae, Plectranthus glandulosus leaf powder, applied at four different rates for the control of Sitophilus zeamais was determined. Mortality was recorded 1, 3, 7 and 14 days after S. zeamais infestation, followed by the determination of F1 progeny production. Grain damage, population increase and grain germination were assessed for treated grains that were stored
for 4 months. Grains treated with P. glandulosus powder and NSP had relatively low mortality (5.0–22.5%) after 3 days whereas NeemAzal and NSO had higher mortality (55.0–98.8%).
Maximum mortality of 99, 100, 96 and 74% were achieved for NeemAzal (12 g/kg after 14 days), NSO (4 ml/kg after 7 days), NSP
(40 g/kg after 14 days) and P. glandulosus powder (40 g/kg, after 14 days), respectively. In the same order, 7-day LC50 values were 0.02 g/kg, 1.46 ml/kg, 12.44 g/kg and 28.9 g/kg. The three neem products greatly reduced progeny emergence, while
P. glandulosus powder was less effective. NeemAzal protected the grains against S. zeamais damage better than the local neem products, which in turn provided far better grain protection against the weevil damage
than P. glandulosus powder. NeemAzal was superior to the local neem products in grain protection against germination loss, with P. glandulosus being the least effective. NeemAzal and NSO had sufficient efficacy to be a component of an integrated management package
for S. zeamais. 相似文献
13.
The aphidophagous ladybird beetle, Hippodamia variegata (Goeze), is an important predator in many agricultural ecosystems. However, information on the influence of the prey’s host
plant species on its life history characteristics is still absent in the literature. Therefore, five host plant species of
Aphis gossypii Glover, viz. Cucumis sativus L., Cucurbita pepo var. medullosa L., Cucurbita moschata var. melonaeformis Poiret, Cucumis melo var. cantalupensis L. and Lagenaria siceraria var. gourda Standl., were selected to study the influence of the prey’s host plant species on the development, survival, reproduction
and life table parameters of H. variegata in the laboratory at 25°C. The results showed that all of A. gossypii from five host plant species used were acceptable for the growth, development and reproduction of H. variegata. However, the suitability of aphids from various host plants was different for this ladybird beetle. The complete pre-imaginal
development was longest (14.51 ± 0.17 days) when reared with aphids on C. melo var. cantalupensis and shortest (12.60 ± 0.11 days) on L. siceraria var. gourda. Total immature survival from egg to adult was highest (58.97%) on L. siceraria var. gourda and lowest (44.06%) on C. melo var. cantalupensis. Based on the intrinsic rate of increase as an index of suitability of prey host plant species on the population increase
of H. variegata, the suitability in decreasing order was: L. siceraria var. gourda > C. moschata var. melonaeformis > C. pepo var. medullosa > C. melo var. cantalupensis > C. sativus. This study offered opportunities for better understanding the tritrophic interactions of the plant–aphid–predator relationship. 相似文献
14.
Márk Szalai Judit Papp Komáromi Renata Bažok Jasminka Igrc Barčić József Kiss Stefan Toepfer 《Journal of pest science》2011,84(1):133-142
Modelling population dynamics of the maize pest Diabrotica virgifera virgifera LeConte (western corn rootworm; Coleoptera: Chrysomelidae) requires knowledge on the growth rate (=net reproductive rate)
of the species. We investigated the generational (=annual) growth rate of D. v. virgifera in isolated maize fields in southern Hungary and eastern Croatia over several years. The population densities of D. v. virgifera were assessed by absolute counts of emerging adults in 90 gauze cages per study field. Emergence ranged from 1.3 to 30.7
adults per m2 in continuous maize field sections, and from 0.3 to 5.1 adults per m2 in adjacent first-year maize sections. The annual growth rates of D. v. virgifera ranged from 0.5 to 13, and averaged in close to 4. These experimentally assessed growth rates could complement growth estimates
in population dynamic models, particularly those for forecasting the population growth to economic thresholds or for estimating
population build-ups after new introductions of this alien species in Europe. As an example, the determined growth rate was
used to estimate that the first documented successful introduction of this species into Europe occurred between 1979 and 1984,
which is 8–13 years before the detection of this species and its larval damage in maize fields near Belgrade, Serbia, in 1992. 相似文献
15.
Akram Taghizadeh Saroukolai Saeid Moharramipour Mohammad Hadi Meshkatalsadat 《Journal of pest science》2010,83(1):3-8
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
16.
Toxicity of ivermectin (Ivecop-12), a derivative of avermectin B, produced by a soil actinomycete, Streptomyces avermitilis, was evaluated in laboratory against the larvae of Spirama retorta Cramer (Lepidoptera: Noctuidae), a major stenophagous insect defoliator of Albizia spp. (family Leguminosae) in nurseries and young plantations. The study was conducted with eight treatment concentrations
of lethal and sub-lethal doses. Results revealed that ivermectin is highly toxic and induce larval mortality when applied
separately on host plant leaves and larvae, and on leaves and larvae of the insect pest together. The nature of treatment
affects the larval mortality. Treatment of host plant leaves alone as well as leaves together with larvae showed 100% mortality
by the treatment of 0.075% concentration whereas only 95% larval mortality was recorded due to larval treatment by the concentration
of 1.2%. The LC50 value of the tested product was worked out to be 0.014, 0.170 and 0.012% for leaf and larval treatments separately and leaf
and larval treatments together, respectively, against the insect pest. This clearly shows that ivermectin is more effective
in larval killing when ingested through food. Further, the adults developed from treatments of sub-lethal concentrations and
subsequently, when mated laid significantly (P < 0.05–0.01) less number of eggs and also showed significant (P < 0.05–0.01) reduction in hatching percentage compared to control. These observations suggest that the tested bioproduct,
ivermectin, interfere physiological programming of larvae thereby causing alteration in fecundity and fertility of the target
insect pest. 相似文献
17.
José Alfonso Domínguez Núñez Rosa Planelles González José Antonio Rodríguez Barreal José Antonio Saiz de Omeñaca González 《Agroforestry Systems》2009,75(3):251-259
Mycorrhizal and non-mycorrhizal holm oak (Quercus ilex L.) seedlings inoculated with black truffle (Tuber melanosporum) were grown under nursery conditions and subjected to drought hardening for 4 months in autumn and winter followed by irrigation
for 10 days. Leaf water potential and stomatal conductance were monitored during the 4 months of drought. When the test was
completed (March), measurements were made for each treatment (inoculated or non-inoculated), and watering regime (watered
and water-stressed). Pressure–volume curves, osmotic potential at full turgor, osmotic potential at zero turgor and the tissue
modulus of elasticity near full turgor were calculated. Mycorrhizal colonization and growth, and the content of the main mineral
nutrients N, P, K, Ca and Mg were measured. Water stress affected plant growth, caused an elastic adjustment of the plant
tissues, and decreased the P and K content, and inoculation improved the nitrogen content. Drought acclimation apparently
achieved the goal of improving the drought tolerance of holm oak seedlings, without depressing ectomycorrhizal root colonization
by T. melanosporum.
José Antonio Rodríguez Barreal—Deceased 相似文献
18.
The nature of damage of sweetpotato whitefly, Bemisia tabaci (Gennadius) B biotype was investigated at the vegetative stage on eggplant (Solanum melongena L., family Solanasae, variety Baiyu) under laboratory conditions (temperature 25 ± 1°C, RH 70 ± 10% and photoperiod 12 h
L:12 h D). The investigations were carried out after completing one generation of whitefly on the basis of morphology, physiology
and anatomy of eggplant leaf. Significant differences were observed on three morphological parameters—leaf area, leaf fresh
weight, and leaf dry weight. The reduction percentages of these three parameters were 26.6, 21.8 and 19.27%, respectively.
Significant differences were also observed on two physiological parameters—chlorophyll content and rate of photosynthesis.
The reduction percentages of these two parameters were 9.7 and 65.9%, respectively. There were no damaged tissue observed
in the epidermis and mesophyll, but there were some damage tissue observed in the vascular bundle of infested leaf. There
were no damaged vascular bundles observed in the control leaves. The non-damaged vascular bundles contained both xylem and
phloem; while some damaged vascular bundles contained either xylem or phloem. Associated with the non-damaged vascular bundles
on whitefly infested leaves were two settled whitefly nymphs apparently deriving nutrition from phloem sap. After one generation
of whitefly infestation, the number of damaged and non-damaged vascular bundles of eggplant leaf was significantly different. 相似文献
19.
Bao-Li Qiu Fang Dang Shao-Jian Li Muhammad Z. Ahmed Feng-Liang Jin Shun-Xiang Ren Andrew G. S. Cuthbertson 《Journal of pest science》2011,84(4):419-427
The sweetpotato whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is a widely distributed and destructive agricultural pest on various host plants. The
biology of two biotypes of B. tabaci: the invasive B and a new defined Cv biotype, on a range of host plants (hibiscus, laurel, poinsettia, collard, cucumber
and tomato) were studied in the laboratory. Results revealed that the developmental periods of the B biotype immatures were
not significantly different on the tested host plants except those between laurel and collard. The Cv biotype immatures developed
significantly slower on cucumber and tomato than on the other plants. B. tabaci B biotype had the highest survivorship on collard (68.55%), and the lowest on laurel (33.24%), while the Cv biotype had the
highest and lowest survivorships on laurel (61.63%) and tomato (36.74%). Host plants did not significantly affect the pre-ovipostion
period regardless of biotype. The longest averaged longevity and highest fecundity of B biotype were both recorded on collard:
25.15 days and 143.0 eggs. The highest fecundity of Cv biotype was 196.49 eggs on laurel and its longest longevity was on
hibiscus (19.62 days). The intrinsic rate of natural increase (r
m) of B biotype on the three vegetables were all higher than those on the three ornamentals whereas the r
m of Cv biotype on the three ornamentals were all higher that those on the three vegetables. Our research indicates that B. tabaci B and Cv biotypes have different host plant suitabilities. The three tested vegetables were more suitable for B biotype while
the three tested ornamental plants were more suitable for Cv biotype. The potential mechanism for the different suitability
of B and Cv biotypes on various host plants is also discussed. 相似文献
20.
Sugar beet, Beta vulgaris L. is a strategic crop of sugar industry in Egypt. It is threatened by several insect pests among most important of them
is the beet beetle Cassida vittata. This work deals with the biological control of this insect using four Egyptian and imported entomopathogenic nematodes (EPNs).
The nematodes included Steinernema carpocapsae S2, Heterorhabditis bacteriophora S1, S. feltiae and H. bacteriophora (1-3). Daily mortality of larvae, pupae and adults of C. vittata were recorded after treatment with serial concentrations (from 500 to 4,000 infective juveniles/ml) of each of four studied
EPNs. Development of nematodes in insect bodies was followed up. S. carpocapsae S2 was chosen for the application against different stages of the pest in a sugar beet field. In the field, single application
of S. carpocapsae S2 killed 65% of the larvae, 92% of the pupae and 57.3% of the adults of C. vittata within a week. This work is the first report on using the EPNs to control sugar beet beetle. 相似文献