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1.
In a laboratory study, we determined the potential of three Trichogramma (Hymenoptera: Trichogrammatidae) species, T. brassicae Bezdenko, T. minutum Riley and T. nr. sibiricum Sorokina, for biological control against six species of forest lepidopteran pests, black army cutworm, hemlock looper, eastern
spruce budworm, western spruce budworm, white-marked tussock moth, and gypsy moth. Females of each parasitoid species were
offered eggs from each of the six host species. Parasitization and the effect of the host species on the emerging progeny
were examined and recorded. Trichogramma minutum had the broadest host range and successfully parasitized four host species out of the six offered. Trichogramma nr. sibiricum had the narrowest host range and parasitized only two species of hosts. Of the six host species, black army cutworm was the
most preferred by all three Trichogramma species; white-marked tussock moth and gypsy moth were not parasitized by any parasitoids. There was a positive correlation
between the size of female offspring and their corresponding egg complement in all three parasitoid species. The developmental
time of parasitoids from egg to adult was influenced by both the parasitoid and host species. Our results suggest that T. minutum has the greatest potential for biological control against various forest lepidopteran pests and that the black army cutworm
may be the best target candidate for further study. 相似文献
2.
The acceptance of 40 different strains of 24 Trichogramma (Hymenoptera: Trichogrammatidae) species for oak-silkworm host eggs, Antheraea pernyi Guerin-Meneville (Lepidoptera: Anthelidae) was tested in laboratory experiments. The oak-silkworm, which is commercially used in China to mass produce Trichogramma dendrolimi Matsumura on a large scale, was accepted for egg laying by 10 out of the 24 species tested but only 3 species (four strains of T. dendrolimi, three strains of T. chilonis Ishii and one strain of T. cacoeciae Marchal) successfully completed development to adult emergence. The number of adults emerged per host egg averaged 83.2, 37.0, 42.3, 53.0 for four different strains of T. dendrolimi; 42.5, 10.0 for two strains of T. chilonis; 24.5 and 0 for two strains of T. cacoeciae. Seven other Trichogramma species develoedp in A. pernyi eggs, but no adult emergence occurred and no emergence holes on the chorion were found. The number of Trichogramma larvae, pupae, and adults together per host egg averaged 81.7 and 67.4 for two strains of T. embryophagum Hartig; 39.0 for T. japonicum Ashmead; 35.0, 16.7, 19.0, 0 for four strains of T. evanescens Westwood; 18.7, 0, 0, 0 for four strains of T. brassicae Bezdenko; 11.5 for T. piceum Dyurich; 76.4 and 23.0 for two unidentified strains collected in apple and vine orchards in Germany, respectively. The following 14 Trichogramma species did not parasitize any A. pernyi eggs: T. atopovirilia Oatman & Platner, T. bourarachae Pintureau & Babault, T. buesi Voegél, T. funiculatum Carver, T. ivelae Pang & Chen, T. meyeri Sorokina, T. minutum Riley, T. nerudai Pintureau, T. nubilale Ertle & Davis, T. ostriniae Pang & Chen, T. principium Sugonjaev & Sorokina, T. pretiosum Riley and two further unidentified strains that originated from France and Switzerland. The results confirmed that A. pernyi is a suitable host for rearing T. dendrolimi and T. chilonis and that the two species T. cacoeciae and T. embryophagum, under optimal conditions, might be possible candidates for rearing. 相似文献
3.
Summary A cell line (IPLB-TpE1) was established from embryos of the hymenopteran parasitoid, Trichogramma pretiosum Riley. Cultures contain a mixture of attached, elongate spindle-shaped cells and large aggregates of suspended cells. Chromosomes
of the cells were typical of Trichogramma species and isozyme characterization showed patterns similar to T. pretiosum adults, but distinctly different from Heliothis zea, the lepidopteran host from which parasite eggs were obtained. The cells are capable of growth over a wide range of osmotic
pressures with equal growth between 350 and 600 mO sm/kg. Optimal growth was obtained with a pH of 6.5. Doubling time at the 40th passage was 72 h and cultures are currently subcultured
at weekly intervals.
The mention of a commercial product does not constitute an endorsement by the U. S. Department of Agriculture. 相似文献
4.
Inundative releases of Trichogramma minutum Riley were made in a commercialblueberry field in British Columbia, Canada, todetermine the extent of dispersal of adult wasps, andto determine whether complete parasitism of eggswithin egg masses of the target host [oblique-bandedleafroller (OBLR), Choristoneura rosaceana(Harris)] occurred. Three weekly releases of waspswere made from a single release point in the center ofeach field during the flight of first generation OBLRadults. Sticky trap, sentinel egg mass andtarget-host egg mass data all indicated only a limitedrange of dispersal of T. minutum within thefield. In addition, only partial parasitism of eggmasses of the target host occurred even in closeproximity to the release point. We discuss theimportance of determining the response of Trichogramma females to previously-parasitized eggswhen using Trichogramma wasps for biologicalcontrol of lepidopterous species that oviposit largeegg masses. 相似文献
5.
The responses of 3 phytoseiid mite species Phytoseiulus persimilis Athias-Henriot, Phytoseius finitimus Ribaga and Amblyseius gossipi Elbadry to allelochemics emitted by prey mite species Tetranychus urticae Koch, Brevipalpus pulcher (Canestrini & Fanzago) and Eriophyes dioscoridis Soliman & Abou-Awad were studied using a test of two-choice assays. The repellent effect elicited by the tenuipalpid mite, B. pulcher and the eriophyid mite, E. dioscoridis against P. persimilis could be an evidence for the existence of allomones produced by these 2 prey species. The negative response of P. persimilis to the different stadia of B. pulcher and the attraction of P. finitimus toward the same prey suggest that the volatile semiochemicals produced by this prey act as kairomones for P. finitimus and as allomones for P. persimilis. The strong attraction of P. finitimus and A. gossipi to the different stadia of T. urticae and the considerable attraction of either predator to B. pulcher compared to the neutral response to E. dioscoridis reveal that both predators show a hierarchy of preference for the kairomones of the 3 prey species studied.
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6.
The effectiveness of Trichogramma dendrolimi, Trichogramma embryophagum, Trichogramma sp. strain 45 and Trichogramma sp. strain 48 to control the codling moth Cydia pomonella L. and the summer fruit tortrix moth Adoxophyes orana F.R. was tested in 4 field trials (1984–1986). Four to six Trichogramma treatments (depending on the temperature) each at 400 (pillar trees) to 9,000 (round tops) parasites per tree were carried
out between June and August to insure the continuous presence of Trichogramma in the plots. The monitoring was done by examining 3,000 to 10,000 apple fruits per plot.
T. dendrolimi reduced the damage of C. pomonella by 61.35%, of A. orana by 72.85%. T. embryophagum reduced the damage of C. pomonella by 50.06%, of A. orana by 50.8%. Trichogramma strain 45 reduced the damage of C. pomonella by 41.6% and of A. orana by 87.9%, Trichogramma strain 48 by 57.2% and 51.2% respectively.
The reduction of 67.1% in the number of apple fruits damaged by C. pomonella and A. orana obtained by the inundative releases of T. dendrolimi in these experiments is considered economically and the use of this species in practice is recommended.
相似文献
7.
Simple laboratory methods to select candidate Trichogramma strains for use in biological control were tried. 17 strains were screened for their suitability against the codling moth Cydia pomonella L. as well as the 2 summer fruit tortrix moths Adoxophyes orana F.R. and Pandemis heparana Schiff. In one set of experiments, the capacity of Trichogramma to parasitize each of these target pests was examined, in another set, the preference of Trichogramma to contact and parasitize the target pests compared to the standard mass rearing host Sitotroga cerealella was assessed in choice experiments.
A strain of Trichogramma dendrolimi from the People's Republic of China was found to have the highest fecundity with all the 4 hosts tested. In choice experiments,
however, this strain was shown to have a near equal preference between the target tortrix pests C. pomonella, A. orana and the replacement host S. cerealella. 11 local Trichogramma strains collected from fruit orchards and vineyards in different locations in the Federal Republic of Germany were reared
separately. Four of these local strains, one identified as T. embryophagum, showed clear preference to the tortrix pests C. pomonella and A. orana compared to S. cerealella. The preference of one of these strains was particularly strong and amounted to a near total rejection of S. cerealella eggs in the presence of any of the 2 tortrix pests.
The remaining 12 strains had weaker parasitization capacity and/or less preference to the target pests. Four of the strains
tested in these experiments, including T. dendrolimi and T. embryophagum, were mass reared and released in apple orchards between 1984 and 1986. The results of these field experiments are planned
to be published in this journal.
Mit Unterstützung der Deutschen Forschungsgemeinschaft. 相似文献
8.
Trichogramma wasps are generalist egg parasitoids used in biological control efforts. In a multi host situation they may preferentially parasitize a non-target host species to the detriment of the control program. Plutella xylostella Linnaeus (Lepidoptera: Plutellidae) is a very serious pest of cabbage, but is only one in a number of species in the ‘cabbageworm’ complex. We investigated the host preferences of Trichogramma pretiosum Riley (Hymenoptera: Chalcidoidea) when offered the eggs of Plutella xylostella and the eggs of Pseudoplusia includens Hübner (Lepidoptera: Noctuidae), another species in the ‘cabbageworm’ complex. Trichogramma pretiosum reared on the eggs of the factitious host Ephestia kuehniella Zeller (Lepidoptera: Pyralidae) parasitized both Plutella xylostella and Pseudoplusia includens eggs under laboratory conditions. For both choice and no-choice experiments, T. pretiosum parasitized significantly more P. xylostella eggs than P. includens eggs. Prior ovipositional experience with one or other of the two host species had no effect on the subsequent parasitism levels of the two host species. The preference for P. xylostella eggs was also not affected by this prior ovipositional experience. 相似文献
10.
O-caffeoyltyrosine is a host recognition kairomone for Aphytis melinus DeBach (Aphelinidae) found in the covers of its host, California red scale, Aonidiella aurantii (Maskell) (Diaspidae). This study tests the hypothesis that the concentration of O-caffeoyltyrosine and scale cover size are reliable indicators of scale body size, an important component of host quality
for A. melinus, over a range of scale rearing conditions. Both scale cover area and O-caffeoyltyrosine concentrations were only qualitatively related to scale body size during the third instar, the scale life
stage most suitable for A. melinus. Scale cover area and O-caffeoyltyrosine concentrations were reduced, relative to scale body size, when scale were reared on bark and leaves compared
to fruits. Scale cover area and O-caffeoyltyrosine concentration were also relatively reduced when scales were reared in mid-summer compared to spring and
fall, and when reared on orange cultivars compared to lemon cultivars in the field. Finally, scale cover area and O-caffeoyltyrosine concentration were reduced when scale were reared at 52% compared to 100% humidity in the laboratory. Scales
appear to be chemically conspicuous to A. melinus for a short period of the time in which they are physiologically susceptible. Scales that minimize their cover size and maximize
the incorporation rate of O-caffeoyltyrosine into covers may minimize their conspicuousness to A. melinus. Minimizing scale cover size, but not necessarily incorporation rates, may make scales more vulnerable to predators, however. 相似文献
11.
1. Insect parasitoids are expected to evolve behavioural strategies to exploit resources in competitive environments optimally. Indirect competition between parasitoids is particularly common because exploited host patches remain available in the environment for other foraging individuals. 2. The effects of indirect competition on the behaviour of two closely related generalist egg parasitoids were investigated: Trichogramma pintoi Voegelé and Trichogramma minutum Riley (Hymenoptera: Trichogrammatidae). Patch residence time, a patch‐leaving mechanism, and progeny sex allocation of females foraging were analysed: (i) alone, (ii) in patches partially parasitised by conspecifics, and (iii) in patches partially parasitised by heterospecifics. 3. Each species responded differently to indirect competition. Trichogramma pintoi females shortened their patch residence times, but they did not adjust their progeny sex ratios. In contrast, T. minutum females did not modify their patch residence times, but they did increase their progeny sex ratios in response to competition. Both Trichogramma species used host rejection, either by antenna rejection or by ovipositor rejection, as a patch‐leaving mechanism. 4. In agreement with a companion study of direct competition using the same model species, the present results indicate that even amongst closely related species, responses to competition can vary considerably. 相似文献
12.
In a study of the quality of Trichogramma pretiosum Riley (Hymenoptera: Trichogrammidae), we compared female wasps emerging from natural hosts, parasitized in the laboratory or the field with those emerging from factitious hosts used for commercial mass production. Females from the natural hosts were larger, more fecund, and longer lived than those from the factitious hosts. Compared to small females, large female wasps are substantially more fecund when honey (carbohydrate) is available but marginally more fecund when honey is unavailable. The size of a female T. pretiosum depends on two factors: the size of the host egg from which it emerges even when the wasp was gregarious, and the number of conspecifics that emerge with it. The similarities in the size distribution of female wasps emerging from natural hosts, in conjunction with the mechanism by which Trichogramma measure host size and allocate eggs accordingly, suggests the hypothesis that size related components of fitness in female T. pretiosum are under strong selection in the field. 相似文献
13.
The Box tree pyralid, Cydalima perspectalis Walker (Lepidoptera: Crambidae), is an invasive species in Europe, not yet regulated by natural enemies. It is highly destructive to ornamental and native Buxus due to defoliation by larval feeding. The ability of eight Trichogramma species ( T. brassicae Bezdenko, T. bourarachae Pintureau & Babault, T. cacoeciae Marchal, T. cordubensis Vargas & Cabello, T. dendrolimi Matsumura, T. evanescens Westwood, T. nerudai Pintureau & Gerding and T. pintoi Voegele) to parasitise and locate eggs of C. perspectalis was assessed in the laboratory. In direct observation tests, all species started to examine and oviposit into exposed eggs. Resulting egg parasitism was low and ranged between 4% and 20% for most of the parasitoid species after three days of exposure. Only T. dendrolimi parasitised significantly more host eggs with parasitism rates above 40%. On average, two to three progeny emerged from one host egg and the resulting sex ratio was female-biased, indicating suitability of the target host for progeny production. In subsequent cage tests on potted Buxus plants, again T. dendrolimi was the most efficient species in locating host eggs on foliage. We conclude that C. perspectalis eggs are attractive to various Trichogramma species. T. pintoi had the highest number of egg encounters and active females. T. dendrolimi females were most able to locate host eggs and to oviposit and produce successfully on them. Nonetheless, further study is needed to clarify the suspected role of potentially egg defensive mechanisms that may impede higher parasitisation in C. perspectalis. 相似文献
14.
The fresh waters of the Mekong basin are inhabited by five species of the pufferfish genus Tetraodon Linnaeus, 1758 (sensu lato): the widely distributed T. leiurus Bleeker, 1851; two previously described species endemic to the Mekong, T. baileyi Sontirat, 1989 and T. suvattii Sontirat & Soonthornsathit, 1985; one new species endemic to the Mekong basins. Tetraodon baileyi has now been collected numerous times but only in or near rapids; T. abei, T. barbatus and T. suvattii are often but not exclusively associated with rapids or at least swift flowing streams; while T. leiurus is found in almost all habitats except rapids. Tetraodon abei and T. barbatus are closely related to T. leiurus, from which they differ most strikingly in coloration. Tetraodon survattii differs from all of the others in having a strongly upturned mouth and light and dark stripes or spots radiating outwards
from the eye. Tetraodon baileyi, the most distinctive Mekong pufferfish, has head and body more or less extensively covered with dermal cirri and is entirely
scaleless. 相似文献
15.
The biology and host specificity of the psyllid Heteropsylla spinulosa Muddiman, Hodkinson & Hollis collected from Mimosa invisa Von Martius, was studied in Brazil and in Australia. Oviposition was recorded on 19 of 100 plant species tested but nymphs
died without feeding, except on M. invisa. H. spinulosa was shown to be specific to M. invisa and was subsequently released and established in Australia and Western Samoa.
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16.
The effect of adult learning through an oviposition experience, and pre-adult learning through development inside a host was
investigated in two strains of an Australian egg parasitoid, Trichogramma nr ivelae (Hymenoptera: Trichogrammatidae). Host response was measured in two types of laboratory preference tests. In single host
tests, females reared on three lepidopteran hosts ( Heliothis punctigera (Noctuidae), Papilio aegeus (Papilionidae), and Hypolimnas bolina (Nymphalinae)) were presented host eggs individually, and allowed two ovipositions. Pre-adult experience affected host preference
in only one strain, while acceptance of a host was increased in both strains when they had previously oviposited in this host
species. An oviposition experience had a stronger effect on host preference than pre-adult experience. In choice tests, pairwise
combinations of hosts were arranged in an alternating grid. The ratio of host acceptances to host contacts was computed for
the whole test and up to the first oviposition. These indicated that effects of rearing host were weak or absent, but the
host chosen initially had a strong effect on host preference. Relative size of the hosts had a strong effect on choice of
the first host. The implications of learning in Trichogramma are discussed in relation to host preference testing procedures and the selection of candidate strains for mass rearing and
inundative release. 相似文献
17.
Emergence, preening, and flight initiation were studied in laboratory-reared Trichogramma minutum Riley (Hymenoptera: Trichogrammatidae). Male parasitoids emerged first and flew before females. When both sexes were present in flight cylinders, female parasitoids flew before males. Flight propensity in males was negatively related to the number of emerging females, while flight propensity in females was independent of the number of males present. Ambient temperature significantly affected the propensity and timing of flight; between 70–80% of the parasitoids flew at 25 and 30 °C while less than 4%, mostly males, flew at 20 °C. No flights were observed at 15 °C. The presence of fresh host eggs caused a reduction in the proportion of female parasitoids that flew and a delay in the time to flight for the females that did fly. The presence of food increased the flight propensity of female parasitoids, but did not affect the timing of flight. The relationship between flight behaviour and the efficiency of mass-reared Trichogramma is discussed in terms of its importance for inundative release programmes. 相似文献
18.
The genetic relationships of Aechmea mexicana, A. lueddemanniana, A. macvaughii and A. tuitensis were investigated using starch gel electrophoresis. Eight enzyme systems encoded by ten putative gene loci were resolved in seventeen populations. Nei's (1978) genetic distances were obtained from allelic frequencies and used with UPGMA algorithm. Results indicate that some populations belonging to different species display genetic similarities closer to each other than to some conspecific populations. Our results do not support the proposed genus Ursulaea ( Read & Baensch 1994), since A. tuitensis was closer to A. lueddemanniana and A. mexicana than to A. macvaughii. 相似文献
19.
ME, PGM and PGI electrophoretic banding patterns in 20 laboratory cultures representing 14 species of Trichogramma were studied. Variations in PGM were found in T. exiguum, T. marylandense, and T. pretiosum. PGI also showed variation in T. exiguum, T. marylandense, T. minutum, and T. parkeri. However, ME variations were found only in T. pretiosum. Based on progeny analyses, we concluded that ME is a tetramer in Trichogramma with fast and slow alleles at a single locus, and that both PGM and PGI have a single locus and each has four alleles. PGM
is a monomer, but PGI is a dimer.
Résumé Les bandes électrophorétiques de l'enzyme malique, de la P.G.M. et de la P.G.I. ont été étudiées chez 20 souches de laboratoire
représentant 14 espèces deTrichogramma. Des variations de la P.G.M. ont été trouvées chezT. exiguum, T. marylandense etT. pretiosum. La. P.G.I. montre aussi des variations chezT. exiguum, T. marylandense, T. minutum etT. parkeri. Par contre, des variations de l'enzyme malique ne sont trouvées que chezT. pretiosum. En nous basant, sur l'analyse de progénitures, nous avons conclu que l'enzyme malique est un tétramère chezTrichogramma comprenant un allèle “lent” et un alléle “rapide”, à un seul locus, et que la P.G.M. et la P.G.I. ont chacune un seul locus
à quatre allèles. La P.G.M. est un monomère mais la P.G.I. est un dimère.
相似文献
20.
Trichogramma spp. (Hymenoptera: Trichogrammatidae) parasitoids have been commonly used as biological control agents in insect pest management. Host quality is believed to influence parasitism, host preference, and suitability for parasitoids. To date, limited studies have compared the parasitism of Trichogramma parasitoids on fertilized, unfertilized, and sterilized host eggs. Hence, we studied the performance of three Trichogramma egg parasitoids, Trichogramma japonicum Ashmead, Trichogramma chilonis Ishii, and Trichogramma leucaniae Pang & Chen, on fertilized, unfertilized, and ultraviolet (UV)‐irradiated fertilized (UVF) eggs of rice moth, Corcyra cephalonica (Stainton) (Lepidoptera: Pyralidae). In a no‐choice test, T. japonicum and T. leucaniae parasitized significantly more fertilized or UVF than unfertilized hosts, and T. chilonis parasitized significantly more UVF than either fertilized or unfertilized hosts. In a choice test, all three Trichogramma parasitoids parasitized UVF hosts the most, and unfertilized hosts the least. There were similar percentages of adult emergence and female progeny among fertilized, unfertilized, and UVF hosts for all three Trichogramma parasitoids, except that T. japonicum had significantly lower adult emergence on fertilized hosts. We also found that all three Trichogramma parasitoids developed slower on unfertilized hosts. Regardless of host treatments, T. leucaniae had the longest developmental time and T. chilonis had the shortest. We conclude that Trichogramma parasitoids prefer parasitizing UVF eggs of C. cephalonica without negative effects on their emergence and sex allocation. 相似文献
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