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1.
Drosophila suzukii, commonly known as the spotted-wing Drosophila, is an invasive polyphagous fruit pest, which has emerged as a global threat to agriculture in the Americas and in Europe. Due to the rapid spread, great economic losses and its pest behavior, D. suzukii represents a powerful model for invasion biology and pest management studies. However, its current European distribution, invasion routes and levels of genetic diversity in populations of D. suzukii are poorly understood. We present the first report of D. suzukii from Ukraine, with the invasion likely occurring close to 2014. The pattern of genetic variation at cytochrome oxidase I among D. suzukii populations from Europe, USA and Asia reveals comparatively high genetic diversity in the Ukrainian population of this pest species, suggesting a complex invasion scenario from multiple sources. Further monitoring patterns of genetic variation across space and time, to better understand the invasion routes of this invasive insect pest, will be an essential part for developing successful pest management strategies.  相似文献   

2.
Yeasts play an important role in nutrition physiology and host attraction of many Drosophila species, and associations with various yeast species are documented for several drosophilid flies. The pest Drosophila suzukii (Matsumura) has a predominant association with the yeast Hanseniaspora uvarum. However, research has not been conducted on the nutritional physiology of the yeasts associated with D. suzukii (spotted wing drosophila). Therefore, in this study, we determined whether dietary yeast was nutritionally relevant and whether yeast species closely associated with D. suzukii positively affected life-history traits. Our results confirm a crucial role of dietary yeast in the larval development and survival of D. suzukii. Furthermore, we found specific effects of the closely associated yeast species H. uvarum and Candida sp. on larval survival. Observations of the egg-laying behaviour of D. suzukii on cherry fruits artificially colonised with different yeast species revealed that the number of eggs laid increased on fruits colonised with Candida sp. and Saccharomyces cerevisiae.  相似文献   

3.
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   

4.
In the current study, we have designed two experimental devices to study the potential of Metarhizium brunneum (Petch) and its crude extract (filtered growth medium) for the control of Drosophila suzukii (Matsumura). An experimental autoinoculation device impregnated with conidia of EAMa 01/58-Su strain was designed for a lure-and-infect strategy. D. suzukii adult mortality resulted in a 62.2% with an average survival time of 3.6 days, with no significant differences among attractiveness to adults of red and black colours used in the devices. Nevertheless, a 48.0% mortality of untreated males was obtained after being coupled with inoculated females, whereas only 24.0% of untreated females was killed after being coupled with inoculated males, thereby revealing the horizontal transmission potential of the strain in these inoculation devices. We observed an 84.7% reduction in fecundity in M. brunneum-challenged D. suzukii females. Finally, we designed a lure-and-kill device to dispense a crude extract of the EAMb 09/01-Su strain that had previously shown acute mortality in D. suzukii, with an exposure time of 6.9 h required to achieve 50.0% mortality. Mixing the extract with feeding attractant caused a 61.6% D. suzukii adult mortality rate. These results show the high potential of using M. brunneum in lure-and-infect and lure-and-kill strategies contributing to an integrated pest management program for D. suzukii control.  相似文献   

5.
Drosophila suzukii, commonly known as the spotted wing drosophila (SWD), is an exotic fruit fly from Southeast Asia that was introduced to the temperate regions of North America and Europe in 2008. It attacks a wide variety of fruits and has become a devastating pest of soft-skinned fruit crops. Due to the rapid spread of SWD across the newly invaded continents, fresh fruit markets have a zero-tolerance policy regarding D. suzukii infestation. Specific and efficient D. suzukii detection tools are urgently needed so that farmers can deliver timely management interventions to meet market demands. Since SWD is known to be attracted to damaged and rotting fruits, headspace volatiles from fresh and fermented apple juices were collected and analyzed by gas chromatography–mass spectrometry. Special attention was given to the compounds produced and/or enriched during the fermentation process. After performing a series of laboataory and field tests, we identified a quinary blend, which is more efficient and selective for D. suzukii than the currently standard apple cider vinegar and commercially available SWD lure under field conditions. Identification of SWD attractant will help growers accurately detect D. suzukii adult infestations in orchards, thereby allowing for timely pest management interventions while reducing conventional insecticidal usage to protect our crops, environment, and ecosystem.  相似文献   

6.
The Asian spotted wing drosophila, Drosophila suzukii, has recently become a serious pest of soft fruits in Europe. Classical biological control through the introduction of larval parasitoids from its native range in Asia is presently being considered. However, host specificity of potential biological control agents has to be determined to avoid releasing species that may have unintended non-target impacts. Larvae of six different European non-target fly species and the target D. suzukii were exposed either on diet or blueberries to three Asian larval parasitoids, Asobara japonica, Leptopilina japonica, and Ganaspis cf. brasiliensis, and one European species, Leptopilina heterotoma. Asobara japonica showed the lowest specificity, attacking and developing in all Drosophilidae. Leptopilina japonica successfully parasitized two non-target Drosophilidae, D. melanogaster and D. subobscura, with one singly progeny emerging from D. immigrans. Ganaspis cf. brasiliensis had the highest level of specificity but variations occurred between two geographical populations tested. A Japanese population was strictly specific to D. suzukii, whereas another population from China parasitized D. suzukii, D. melanogaster and sporadically D. subobscura. The European L. heterotoma successfully developed in D. melanogaster, D. subobscura and occasionally in D. immigrans, but nearly all eggs and larvae in D. suzukii were encapsulated. These results show that Ganaspis cf. brasiliensis is the species with the highest potential for biological control, but more studies are needed on its taxonomic status and the existence of biotypes or cryptic species varying in their specificity before field releases can be conducted in Europe.  相似文献   

7.
Drosophila suzukii is widely studied because of its status as a global pest of berries and soft fruits. Environmental conditions and access to food resources impact the physiology and fitness of D. suzukii; these factors could also affect dispersal. Flight mills are a convenient tool for measuring and comparing the flight performance of insects. In this study, two experiments examined the effects of diet and humidity on D. suzukii flight performance using custom-built flight mills, and a third experiment compared the energy reserves of D. suzukii flown or not flown on flight mills. Over all flight assays, the median flight distance and duration were 27.16 m and 2.37 min, respectively, and the mean flight velocity was 0.18 m/s. The maximum flight distance and duration by an individual were 1.75 km and 2.35 h, respectively. Drosophila suzukii provisioned with blossoms, fruits, or standard laboratory diets flew farther distances and longer durations than starved flies. While starvation was associated with reduced flight performance, there were no observed differences between diet types. It remains unclear whether D. suzukii consistently use lipids, glycogen, sugar, or another energy source for flight because tethered individuals may not have flown enough to deplete energy reserves. Humidity did not affect flight performance of D. suzukii within a?~?2 h test period. These data indicate that most D. suzukii are likely to remain within limited area (e.g., within a field) but that some individuals can disperse long distances (field to field spread).  相似文献   

8.
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   

9.
Pea weevil (Bruchus pisorum) is a damaging insect pest affecting pea production worldwide. The aim of this study was to identify sources of resistance to pea weevil in a Pisum spp. germplasm in multi-environment field tests. Seed infestation and larval development were assessed in each environment and subjected to a heritability-adjusted genotype and genotype x environment biplot analysis. Results showed that seed infestation and larval development are independent traits. Accessions P669 (P. sativum ssp. elatius) and P656 (P. fulvum) showed a stable reduction in seed infestation across environments. Meanwhile, accessions P314 (P. sativum ssp. elatius) and P1 (P. abyssinicum) showed a stable reduction in larval development. The most promising accession was P665 (P. sativum ssp. syriacum) which showed resistance at both pod and seed levels. This study demonstrates the importance of environmental conditions for pea weevil infestation. Moreover, by submitting data to a CCA, the influence of climatic parameters over seed infestation and larval development has been elucidated.  相似文献   

10.
Information on population genetic structure and crop genetic diversity is important for genetically improving crop species and conserving threatened species. The PAL gene sequence is part of a multigene family that can be utilized to design DNA marker systems for genetic diversity and population structure investigation. In the current study, genetic diversity and population structure of 100 accessions of wild Pistacia species were investigated with 78 PAL markers. A protocol for using PAL sequences as DNA markers was developed. A total of 313 PAL loci were recognized, showing 100% polymorphism for PAL markers. The PAL markers produced relatively more observed and effective alleles in Pistacia falcata and Pistacia atlantica, with a higher Shannon’s information index and expected heterozygosity in P. atlantica, Pistacia vera and Pistacia mutica. Pairwise assessment of Nei’s genetic distance and genetic identity between populations revealed a close association between geographically isolated populations of Pistacia khinjuk and Pistacia chinensis. The accessions of wild Pistacia species had more genetic relationship among studied groups of species. Analysis of molecular variance indicated 19% among-population variation and 81% within-population variation for the PAL gene based DNA marker. Population structure analysis based on PAL revealed four groups with high genetic admixture among populations. The results establish PAL markers as a functional DNA marker system and provide important genetic information about accessions from wild populations of Pistacia species.  相似文献   

11.
We investigated the effects of two commercial diatomaceous earth based insecticides (DE), Protect-It® and SilicoSec®, the nano-structured silica product AL06, developed by the section for Urban Plant Ecophysiology at Humboldt University Berlin, and the monoterpenoids, eugenol, and cinnamaldehyde on two stored product pests, Callosobruchus maculatus and Sitophilus oryzae. Protect-It® was more effective than SilicoSec® against C. maculatus while the reverse was true for S. oryzae. Generally C. maculatus was more sensitive towards DE and silica treatment than S. oryzae. Mortality rate of both pest species increased when DE’s were applied to food commodities previously treated with a monoterpenoid. In admixture experiments, the toxicity of SilicoSec® + cinnamaldehyde (LD50 = 42.73 ppm), SilicoSec® + eugenol (LD50 = 24.30 ppm), and Protect-It® + eugenol (LD50 = 2.60 ppm) was increased over DE alone against S. oryzae. Both substances showed a synergistic effect considering their co-toxicity coefficient relative to the LD50-value. In contrast, we could not find any synergistic effects in experiments with C. maculatus. Here only Protect-It® + cinnamaldehyde (LD50 = 20.84 ppm) showed an additive effect while all other combinations of monoterpenoid and DE indicated antagonistic effects. In addition to contact insecticidal effects both monoterpenoids showed a strong fumigant action. The presented results indicate that the natural product DE has great potential to replace synthetic pesticides commonly used in stored product pest management. Efficacy of DE can be improved by adding certain monoterpenoids against certain insect pests.  相似文献   

12.
Tobacco beetle, Lasioderma serricorne (F.) (Coleoptera: Anobiidae), is one of the most serious insect pests of stored tobacco, and traps baited with the female-produced sex pheromone, serricornin, are used for monitoring the pest. In two trapping experiments carried out in tobacco warehouses in Greece, two commercially available trap and lure systems for L. serricorne were found to be equally effective in terms of the numbers of beetles trapped. In contrast to previous reports, anhydroserricornin was unattractive and lures containing serricornin and anhydroserricornin were less attractive than lures containing serricornin only. The sex pheromone of the other main insect pest of tobacco, Ephestia elutella (Hübner) (Lepidoptera: Pyralidae), could be added to the lures without affecting the attractiveness of either pheromone to their respective species. Lures remained attractive for at least 4 weeks under field conditions, and, in laboratory tests, release of pheromone could still be detected after 30 days at 27 °C. The stereoisomeric composition of the serricornin in the two commercial lures was similar with high proportions of the attractive (4S,6S,7S)-isomer. The proportion of the (4S,6S,7R)-isomer was low, and this is known to reduce the attractiveness.  相似文献   

13.
Nontimber forest products are a source of income for women in rural African communities. However, these products are frequently damaged by insect pests. The present study investigates the diversity and damage rates of insect pests that attack Carapa procera seeds and Lophira lanceolata fruits. The experiment was set up in western Burkina Faso and, for C. carapa, consisted of pests collected from seeds that had fallen to the ground and from stockpiled seeds. For L. lanceolata, pests were collected from fruits on the trees, and on the ground. The collected samples were sent to the laboratory to estimate the proportion of damaged seeds/fruits and rear the insects. The results showed that Ephestia spp., Tribolium castaneum, Oryzeaphilus spp., and Tenebroides mauritanicus were the pests of Carapa procera seeds and Lophira lanceolata fruits. Ephestia spp. was recorded as the main pest of both C. procera and L. lanceolata, whereas T. castaneum was only detected from seeds of L. lanceolata. For C. procera, the stocks were the most infested (29 %) by Ephestia spp. The infestation rate of fruits of L. lanceolata by Ephestia spp. on trees (31.42 ± 3.75 %) was less than the rate of fruits by T. castaneum on the ground (44.00 ± 3.5 %). The different body sizes of Ephestia spp. may indicate the occurrence of two putative species, one from C. procera and another one from L. lanceolata. This work provides important information that could contribute to the setting up of a local-scale sustainable management framework for oil tree pests in Burkina Faso and surrounding countries.  相似文献   

14.
The cotton bollworm Helicoverpa armigera is a destructive pest that affects a variety of crop plants. Because of its polyphagous feeding habit, mobility as adults, and high fecundity, the expanding infestations of H. armigera in different crops have caused economic losses and difficulties for pest population management. In Brazil, a sequence of different crop systems in the same area and crop rotation during the year can create a spatio-temporal mosaic of crops where H. armigera can persist. However, the consequences of the simultaneous and/or alternating presence of host plants for H. armigera populations through generations are unknown. In this study, we simulated, in the laboratory, hypothetical situations for the availability of soybean and cotton crops in the landscape. We evaluated the effects of: (1) the number of generations during which a population feeds on a host-plant species; (2) the succession of host-plant species on which populations have fed for two generations; and (3) the parental host plant on the fitness of H. armigera populations. Only the current host plant on which larvae fed affected the performance of the H. armigera populations. Decrease of mortality rates during the immature period was slowed when the larvae fed on soybean. The lowest value of reproductive potential (R 0) was found for individuals originating from mating between females and males reared in cotton. Our results indicated that pest-management and biological-control plans for H. armigera should be developed on a regional scale rather than for just a specific crop area.  相似文献   

15.
Delottococcus aberiae De Lotto (Hemiptera: Pseudococcidae) is a new invasive citrus pest in Spain. It causes severe fruit distortions and, as a new invasive mealybug, there is a lack of information about its biology. This research aims to examine the seasonal trend of D. aberiae in citrus, using several sampling methods, as a first step to develop an integrated pest management program. Ten citrus orchards from Eastern Spain were periodically sampled during three years using absolute (plant material) and relative (corrugated cardboard band traps and sticky traps) sampling methods. The three sampling methods showed that D. aberiae completes multiple generations per year, two of them being clearly defined and resulting in high populations. D. aberiae peaked between May and June, damaging the developing fruit. Corrugated cardboard band traps were able to detect prepupa and pupa male instars and gravid females, providing a quantitative measurement of D. aberiae density at its first population peak. The use of corrugated cardboard band traps is recommended to monitor population levels and sticky traps to determine male flight periods, representing simple sampling techniques to monitor D. aberiae. These results will improve the sampling protocols and allow for the development of an integrated pest management program.  相似文献   

16.
Taxus chinensis and T. wallichiana in have been threatened in their distribution areas in recent decades because of their over-exploitation and reduction and destruction of native habitats. Determining the genetic diversity in populations of the two species will provide guidelines for their protection and preservation. Two hundred and fifteen trees from six populations of T. chinensis and 150 sampled trees of T. wallichiana were sampled. Six microsatellite primer pairs selected from 16 primer pairs were used to investigate genetic variation at the population and species levels. Five yielded polymorphic alleles, and among the 13 putative alleles amplified, 11 were polymorphic (accounting for 76.33 %).Shannon’s information index (I) and percentage of polymorphic bands (PPB) (I = 0.202 and PPB = 67.22 % for T. chinensis; I = 0.217 and PPB = 65.03 % for T. wallichiana). Both species had low levels of genetic diversity (mean H o = 0.107, H e = 0.121 for T. chinensis; H o = 0.095, H e = 0.109 for T. wallichiana). Genetic differentiation among populations was higher (F ST = 0.189) for T. chinensis and lower (0.156) for T. wallichiana, indicating limited gene flow (Nm) among populations for T. chinensis (0.68) and T. wallichiana (0.65). Variation among individuals of T. chinensis was 63.59 and 73.12 % for T. wallichiana. Thus, the threatened status of the two conifers is related to a lack of genetic diversity. All populations are isolated in small forest remnants. An ex situ conservation site should be established with a new population for these species that comprises all the genetic groups for the best chance to improve their fitness under environmental stresses.  相似文献   

17.
Halyomorpha halys, originating from East Asia, has become an important agricultural pest in northern temperate regions since its accidental introduction into North America in the mid-1990s and Europe in 2007. Trissolcus japonicus is the predominant egg parasitoid of this pest in its native range. Here, we tested the hypothesis that T. japonicus uses volatiles associated with H. halys adults during host location. The effects of these volatile compounds on H. halys adults were also assessed. Chemical analysis with GC-MS and electrophysiological analysis with GC-EAD revealed the presence of two bioactive volatile compounds from H. halys adults, n-tridecane and (E)-2-decenal. In the Y-tube assays, female T. japonicus were attracted by n-tridecane but strongly repelled by (E)-2-decenal. Furthermore, host searching time of female T. japonicus was significantly reduced when an H. halys egg mass was treated with n-tridecane and prolonged when treated with (E)-2-decenal or a mixture of (E)-2-decenal and n-tridecane. Male H. halys were significantly attracted by n-tridecane, whereas females had no response to this compound in the Y-tube assays. (E)-2-Decenal strongly repelled male and female H. halys in the Y-tube assays. We discuss the multifunctional kairomonal and other possible roles of these semiochemicals at different trophic levels in the context of intra- and inter-specific chemical communication, in the H. halys–T. japonicus system.  相似文献   

18.
The relationship between Xenorhabdus nematophilus and Photorhabdus luminescens, the bacterial symbionts of the entomopathogenic nematodes Steinernema carpocapsae and Heterorhabditis bacteriophora, against the diamondback moth, P. xylostella (L.), pupae showed the pathogenic capability of P. luminescens to be over that of X. nematophilus. They gave 60 and 40?% mortality with LC50 values of 5?×?104 and 5.5?×?105 cells/ml, respectively.The number of bacterial cells influences the rate of killing the pupae of P. xylostella and a direct correlation between mortality of the pupae, percentage of deformed adults and the spraying dose with significant differences were observed. An inverse correlation found between the no. of eggs laid/female, percentage of hatching, adult survival and the spraying dose. These bacterial effects have been attributed to different toxic bacterial enzymes which damage the haemocytes and inhibit activation of the humoral immune system of the insect.  相似文献   

19.
The oriental armyworm Mythimna separata (Walker) is a major cereal crop pest, causing severe economic losses worldwide every year. Yet, few studies documented the biological control of M. separata using natural enemies such as egg parasitoids of the genus Trichogramma. To evaluate the possibility of biological control of M. separata eggs at various ages (0-, 1-, 2-, and 3-day old), we compared under laboratory conditions the parasitism, emergence, development, and female progeny (sex ratio) of five Trichogramma species indigenous in China: Trichogramma dendrolimi Matsumura, T. chilonis Ishii, T. ostriniae Pang & Chen, T. leucaniae Pang & Chen, and T. japonicum Ashmend. All five Trichogramma species parasitized M. separata at all egg ages but showed a preference for younger eggs. T. dendrolimi parasitized 55.1, 36.6, 19.3, and 14.3 hosts in 24 h on 0-, 1-, 2-, and 3-day-old eggs, respectively, and it exhibited the highest parasitism and suitability on all egg ages. T. japonicum showed the lowest parasitism rate and the poorest host acceptance. T. ostriniae, T. leucaniae, and T. chilonis presented similar rates of adult emergence and sex ratio for all M. separata egg ages. T. ostriniae developed significantly slower on 2- and 3-day-old M. separata eggs. With the exception of T. leucaniae, all species showed no difference in adult emergence at all egg ages. T. dendrolimi was identified as the best for biological control of M. separata. The present study provides valuable information for future development of Trichogramma species in biological control programs targeting M. separata as pest.  相似文献   

20.
The pest Halyomorpha halys is a recent example of severe worldwide biological invasion. In Italy, after the first detection in 2012, it has rapidly spread and economic damage has already been reported in commercial fruit orchards, eliciting enormous concern for Italian agricultural production. As a long-term solution, biological control investigations are focusing on the potential of natural antagonists, such as generalist predators, in the invaded areas. Due to their biology, ecology and behavior, ants represent one such generalist predator potentially suitable for inflicting mortality on H. halys. In this research, Crematogaster scutellaris was used as a study model. Specifically, the effect of ant predatory behavior on the survival of all H. halys pre-imaginal stages was tested in the laboratory environment. The results suggest that C. scutellaris has a significant predatory impact on all H. halys pre-imaginal stages except for eggs. The reduction of survivorship is between 95 and 85% for instars 1 and 2 and between 38 and 52% for instars 3, 4 and 5. The different levels of predation success suggest that these ants could act as useful generalist predators when associated with other antagonists and/or other control strategies. Although further field investigations are needed, the potential of ants as biocontrol agents of invasive species in agroecosystems deserves consideration in integrated pest management programs.  相似文献   

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