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1.
The Colorado potato beetle, Leptinotarsa decemlineata Say, is a serious pest of potato, Solanum tuberosum L., worldwide. Leptinotarsa decemlineata has a history of repeated adaptation to insecticides, and exhibits a geographic pattern of decreasing insecticide resistance from east to west in the USA. Imidacloprid is one of the most widely used insecticide in western states. In this study, we measured imidacloprid resistance among larval and adult L. decemlineata from ten locations in the Columbia Basin (southeastern Washington and northeastern Oregon) using topical LD50 bioassays, and compared them to estimates from ten locations in Minnesota and Wisconsin. Larval and adult imidacloprid LD50’s and mean percent mortality were generally lowest in Washington and Oregon, but some sites exhibited reductions in mortality comparable to those observed at some Wisconsin sites. Adult LD50’s suggest L. decemlineata in the Columbia Basin may be evolving in response to selection by neonicotinoid insecticides, but larval data suggest high susceptibility to imidacloprid remains in most populations. Future work should expand resistance monitoring efforts to include more regions in the West and other insecticide modes of action.  相似文献   

2.
Clones selected from the wild diploid species,Solanum berthaultii, have been shown to possess valuable levels of resistance to the Colorado potato beetle (Leptinotarsa decemlineata), as well as to insects such as aphids, flea beetles, leafhoppers and the potato tuber moth. Resistance is associated with the presence of glandular trichomes on the foliage ofS. berthaultii (2). Six generations after producing a hybrid between the diploid species and a tetraploid variety, a clone with good beetle and leafhopper resistance, as well as reasonable agronomic characteristics has been produced.  相似文献   

3.
Resistance of 20 F2 Solarium chacoense Bitter clones to the Colorado potato beetle,Leptinotarsa decemlineata (Say), was measured in a field test. Levels of total glycoalkaloids (TGA) and composición of the glycoalkaloid mixtures in foliage of the clones were also determined. Clones with either commersonine or dehydrocommersonine as the major foliar glycoalkaloid were significantly more resistant (lower damage ratings, fewer larvae and adult insects) than clones with solanine and chaconine. Damage ratings were negatively correlated (r = -0.67, p = 0.01) with foliar TGA levels. The results indicate that the types of glycoalkaloids present in the foliage ofS. chacoense may be as important as the level of TGA in limiting damage and numbers of insects.  相似文献   

4.
Potato glycoalkaloids, a class of steroid glycosides, possess antimicrobial and pesticidal properties. These phytochemicals have been implicated as natural resistance factors inSolanum species against the Colorado potato beetle,Leptinotarsa decemlineata Say, and the potato leafhopper,Empoasca fabae (Harris). Adverse effects of these secondary metabolites on insect behavioral and developmental biology are described, as well as considerations in manipulation of foliar glycoalkaloids in breeding for varietal resistance to insects.  相似文献   

5.
Six insect pests of potato, green peach aphid,Myzus persicae (Sulzer); potato leafhopper,Empoasca fabae (Harris); Colorado potato beetle,Leptinotarsa decemlineata (Say); tarnished plant bug,Lygus lineolaris (Palisot de Beauvois); red-legged grasshopper,Melanoplus femurrubrum (DeGeer); and southern army worm,Prodenia eridania (Cramer), were tested for their ability to transmit potato spindle tuber viroid (PSTV). PSTV infection was determined by a gel electrophoretic assay made 6 weeks after transfer of insects from infected to non-infected plants of the cultivar, ‘Katahdin.’ Plants grown from tubers of the original non-infected hosts were also assayed. PSTV was detected in only 2 of 183 test plants; these 2 plants had been infested with the tarnished plant bug. These results suggest that the insect species studied are relatively insignificant as vectors of PSTV.  相似文献   

6.
Reciprocal grafts were done between potato (Solanum tuberosum) and six wildSolanum species known to be resistant to the Colorado potato beetle (Leptinotarsa decemlineata (Say)). Potato or wildSolanum foliage from each reciprocal graft was fed to first instar beetles or adult potato aphids (Macrosiphum euphorbiae (Thomas)). The proportion of second instar larvae after 48 h and survival and fecundity (number of nymphs per female) of the aphids were used to i estimate the resistance level of the foliage. Survival and fecundity of potato aphid were reduced on wildSolanum foliage (except withS. circaeifolium ssp.capsicibaccatum andS. okadae) used as scion or rootstock, but were not different from the control (potato-potato graft) on potato foliage. Development of Colorado potato beetle onSolanum foliage was reduced. In some cases, potato foliage grafted to wildSolanum became resistant to the beetle. Results suggest that a chemical factor or factors providing resistance to Colorado potato beetle are translocated from foliage of some wildSolanum species to potato foliage. They also indicate that mode of resistance to the two insects differs quantitatively or qualitatively.  相似文献   

7.
Colorado potato beetle (CPB, Leptinotarsa decemlineata Say) (Coleoptera: Chrysomelidae) is one of the most serious insect pest feeding on wild and cultivated Solanaceae plants. This pest poses a significant threat to potato crops. CPB originated from North America but has become widespread and has adapted in new localizations. Currently, it is reported in many countries worldwide. Endosymbiotic bacteria might have an influence on insect adaptation to new conditions. They are known to play a role in invasiveness of insect hosts and to facilitate colonization of new niches; however, information on endosymbionts of the CPB is very limited. In this study, we screened CPB populations collected from 20 evenly distributed locations in Poland for the presence of Arsenophonus, Cardinium, Wolbachia, and Flavobacterium. We found the presence of Flavobacterium in the studied insects. Little is known about CPB–endosymbionts interactions, thus this study may provide a reference for future studies in this subject.  相似文献   

8.
This paper describes a new source of host-plant resistance to the Colorado Potato Beetle (CPB;Leptinotarsa decemlineata (Say)) in a tetraploid potato (Solanum tuberosum L.) selection, ND2858-1. This hybrid was recorded as a cross betweenS. fendleri ssp.fendleri (A. Gray) and NDSU selection ND1215-1. Field defoliation of this and progeny clones from a subsequent cross to an cultivar was reduced by 50% to 90% in open-choice field screening plots. Progeny of ND2858-1 are vigorous, with high yield potential, and some clones have tuber glycoalkaloid content equivalent to commercial cultivars. These clones are male and female fertile and may be useful to other potato breeding programs. Further characterization of this resistance source is in progress.  相似文献   

9.
The potential of teflubenzuron was assessed in a series of laboratory studies in order to achieve consistent, long-term, integrated management of the Colorado potato beetle, Leptinotarsa decemlineata (Say). Teflubenzuron exhibited excellent stomach toxicity to the larvae. Its larvicidal activity was comparable with those of cyhalothrin, chlorantraniliprole and spinosad. Moreover, the teflubenzuron-fed larvae consumed less foliage, grew slower, and needed a longer period to develop, in a dose dependent manner. Most of these larvae died during larval-larval molting, larval-pupal ecdysis or adult emergence. Furthermore, chitin contents in body carcass (without midgut) and integument specimen of the teflubenzuron-fed larvae significantly decreased, whereas the chitin amount in the midgut peritrophic matrix was not affected. In addition, uridine diphosphate-N-acetylglucosamine-pyrophosphorylase gene (LdUAP1), which was mainly responsible for chitin biosynthesis in ectodermally-derived tissues, was suppressed after teflubenzuron ingestion, in contrast to its partner LdUAP2 for chitin formation in the midgut peritrophic matrix. In a word, by inhibition of chitin production in ectodermally-derived tissues, teflubenzuron is an effective benzoylurea insecticide to L. decemlineata larvae. It can be a valuable tool in effective integrated pest management and insecticide resistance management programs against L. decemlineata.  相似文献   

10.
Repeated use of neonicotinoid insecticides has resulted in the first reported cases of Colorado potato beetle (Leptinotarsa decemlineata (Say)) resistance to imidacloprid. In the laboratory we determined susceptibility of the imidacloprid-resistant Colorado potato beetles from a population in Southern Maine to other insecticides currently registered for use on potato. This population was about 30-fold resistant to imidacloprid and could not be effectively controlled by its applications. Control mortality was significantly higher for the imidacloprid-resistant larvae than for the susceptible larvae, suggesting that fitness disadvantages may be associated with the resistance trait. Resistant larvae exhibited significantly less mortality than susceptible larvae when exposed to cyfluthrin, carbaryl, azinphosmethyl, and methamidophos. Their susceptibility to oxamyl was also somewhat reduced, although it did provide nearly 100% mortality at the highest concentration tested. Disulfoton was highly toxic to the resistant larvae. Oxamyl killed about 40% of the adults in greenhouse assays with potted potato plants, altered their feeding behavior (fewer adults up on plants), and reduced defoliation by more than 90%. Disulfoton was not lethal to adults, but significantly suppressed their feeding. In field trials with the resistant population, oxamyl and imidacloprid + spinosad provided the best beetle control. Novaluron had no detectable effect on beetle densities. There was little difference between the plots treated with imidacloprid or thiamethoxam and the untreated control. Our results suggest that insecticide rotation may be a valuable option for managing imidacloprid-resistant Colorado potato beetle populations. We also had a good consistency between the results of the Petri dish, greenhouse, and field experiments, indicating that screening under laboratory confinement may be useful when developing initial recommendations to potato growers in areas affected by resistance to neonicotinoids.  相似文献   

11.
Adult fruit flies (Drosophila melanogaster Meig.) artificially contaminated withErwinia carotovora var.carotovora (Jones) Dye (Ecc) and/orE. carotovora var.atroseptica (van Hall) Dye (Eca) readily transmitted the bacteria to plants in the field that had been injured by crushing the stem. Injured, inoculated plants developed disease symptoms when maintained at high relative humidities.Erwinia was transmitted to ten-hour-old injuries and they became infected as frequently as freshly made wounds. Insect transmission ofEca, Ecc, and mixtures was greatest during the afternoon, which was the warmest part of the day.Ecc was transmitted significantly less frequently during the cold morning than during afternoon or evening hours. A potato cull pile placed in a commercial potato field attracted a natural insect population which increased during the season. BothEcc andEca were isolated from uninoculated rotting tubers in the cull pile and from insects associated with the pile from May through September. These naturally infested insects transmittedEcc and/orEca from the cull pile to artificially injured field plants during July and August at distances as great as 183 m from the cull pile. NoErwinia was isolated from injured plants in a neighboring control field, which lacked a cull pile, further than 6 m upwind from the cull pile. We suggest that insects are important agents in the epidemiology of potato blackleg and soft rot even in areas with low relative humidities.  相似文献   

12.
Pesticide use in US fall crop potato production was surveyed for the years 1990 to 1994. The purpose of the study was to provide information about the relative importance of each pesticide and potential alternatives. The objectives were to: (1) inventory pesticides used on potatoes, (2) rank the target pests and (3) estimate the economic value of the major pesticides. Extension specialists working on potatoes in twelve states provided the main source of survey data. The most commonly used pesticides in four categories were: fungicide —chlorothalonil, insecticide —methamidophos, herbicide —metribuzin, and “other” -diquat. The most frequent target pests were: early blight (Alternaria solani), late blight (Phytophthora infestans), aphids (primarily Myzuspersicae), Colorado potato beetle (Leptinotarsa decemlineata), lambsquarter (Chenopodium album), and pigweed (Amaranthus spp.). The pesticides that provided the most annual value to potato growers were methamidophos ($281 million), diquat ($86 million), metribuzin ($81 million), CIPC ($56 million) and esfenvalerate ($52 million).  相似文献   

13.
In laboratory tests conducted to determine the effectiveness of the exotoxin ofBacillus thuringiensis against the Colorado potato beetle,Leptinotarsa decemlineata (Say), applications sprayed on tomato foliage at dilutions ranging from 10?1 through 10?4 killed 90% of the 1st and 2nd stage beetle larvae. As the dosage decreased, the time to achieve this level of mortality increased from 4 to 9 days. Adult beetles were not killed by these treatments; however they did cease feeding. In field tests, the highest dosages ofB. t. sprayed on either tomato or potato plants provided adequate or nearly complete protection when applied weekly. Young larvae that ingested sub-lethal doses developed into adults with atrophied mouthparts and antennae, transformations of the paired parts of the labial palps into an unpaired part, the appearance of a tarsal-like claw on a palp, and malformation of the cranial sclerities.  相似文献   

14.
Ten genera from 9 families of dipterous insects collected in the field in the San Luis Valley of Colorado were contaminated withErwinia carotovora var.atroseptica (Eca) andErwinia carotovora var.carotovora (Ecc).Erwinia-contaminated insects were collected from settling ponds near potato warehouses, potato cull piles on growers’ farms, municipal dumps, lettuce and potato fields. The percentage of contaminated insects reached 14.5% in early spring but decreased as the season progressed. Insects were more commonly contaminated withEca thanEcc early in the season. Later the proportion of contamination byEcc increased while that ofEca decreased. We suggest that insects may play a potentially important role in the epidemiology of potato blackleg especially in the reintroduction ofErwinia intoErwiniafree potato fields.  相似文献   

15.
TuberousSolanum accessions were screened for resistance to Colorado potato beetle (CPB),Leptinotarsa decemlineata (Say), in terms of CPB-caused defoliation in field trials with natural infestations of CPB. Cluster and multivariate discriminant analyses were used to distinguish among species and accessions. Several highly CPB-resistant and relatively homogeneous accessions were identified.  相似文献   

16.
Controlled environment experiments were used to determine the effect of light intensity on levels of glycoalkaloids and resistance to the Colorado potato beetle (CPB),Leptinotarsa decemlineata Say, inSolanum chacoense Bitter clones that synthesized acetylated glycoalkaloids, the leptines. Plants were grown under two light intensities, 50 or 250 ?mol m-2S-1, and bioassayed for CPB resistance by placing neonate larvae on excised foliage. Larval development stage and mortality were recorded after four days. The leptine-synthesizing clones responded to the increase in light intensity with a 2–4 fold increase in level of foliar leptines. Larval development rate on foliage from plants grown under high light intensity was reduced and larval mortality increased. Results showed a significant (p>0.05) effect of light on glycoalkaloid synthesis and CPB resistance.  相似文献   

17.
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18.
The Association of Potato Inter-genebank Collaborators (APIC) constructed a database of all wild potato holdings of the most important potato genebanks in Europe, the United States, Peru, and Argentina. The Inter-genebank Potato Database (IPD) now contains data of 11,819 wild potato accessions conserved in seven potato genebanks. The collector’s number is the key identifier used to merge all databases into the IPD. A total of 7,112 different wild potato accessions were identified, which comprise 5,306 accessions with known collector’s numbers. The IPD passport database showed that almost 30% of accessions held in APIC genebanks are from Argentina, a country that comprises less species diversity than Peru and Bolivia. These latter countries are represented by 24% and 20% of accessions, respectively. APIC genebanks maintain 188Solarium taxa out of more than 230 recognized by the latest comprehensive treatment of potatoes(Solarium sect.Petota) by Hawkes (1990). About 60% of the accessions comprise only 20 taxa represented by 785 to 92 accessions each. Conversely, 2% of the accessions comprise 72 taxa and are represented by five or fewer accessions each. About 70 taxa are not available in any genebank. The IPD evaluation database comprises 5,603 records with data from more than 33,000 evaluations of wild potato accessions. Fifty-five traits are summarized, including the reactions of the accessions to 12 pathotypes or races or strains of 12 fungi, four bacteria, 12 viruses, one viroid, 13 nematodes, and seven insects; response to heat and cold stress; and content of dry matter, starch, vitamin C, amylase, reducing sugars, and glycoalkaloids. About 30% of the wild potato populations screened showed various levels of resistance to most of the diseases and pests evaluated. The IPD database is available on the Internet at www.potgenebank.org.  相似文献   

19.
Three species of potato-infesting insects were evaluated under laboratory and field conditions for their capability to transmitCorynebacterium sepedonicum (Spieck. & Kotth.) Skapt. & Burkh., the bacterial ring rot (BRR) pathogen of potatoes. Laboratory and field studies confirmed the vector capability of the Colorado potato beetle (CPB),Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae) and the green peach aphid (GPA),Myzus persicae (Sulzer) (Homoptera: Aphididae). Both adults and larvae of the CPB proved to be vectors of the pathogen. Only adult GPA were evaluated. Bacterial transmission was most likely mechanical: analyses of the CPB mouthparts stained by the indirect immunofluorescence antibody staining (IFAS) procedure confirmed the presence of the bacterium after the beetles were exposed to infected plant tissue. Eggs, haemolymph, feces, regurgitations, and macerates of the digestive tract failed to show the presence of the bacterium. The aster leafhopper,Macrosteles fascifrons (St∮al) (Homoptera: Cicadellidae) failed to acquire and transmitCorynebacterium sepedonicum.  相似文献   

20.
The potato genotypes (Solanum tuberosum L.) with russet tuber skin are generally resistant to powdery scab (Spongospora subterranea f.sp. subterranea or Sss). Lipoxygenase (LOX; EC 1.13.11.12) and patatin are two key storage proteins that are known to offer resistance to several diseases and insects. The objective of this study was to find out the relationship of these proteins in stored tubers with potato tuber powdery scab resistance, especially in russet skinned potatoes. An evaluation of potato germplasm with different tuber characteristics in a greenhouse environment over several years (2006–’11) suggests that russet skinned tuber genotypes (Mesa Russet, Centennial Russet and Russet Nugget) with negligible tuber disease severity index (DSI) and 100 % marketability were resistant to powdery scab. Higher physiological levels of LOX protein (on a dry weight basis) were negatively correlated with tuber DSI and positively correlated with tuber russet skin. Tuber total protein and patatin-lipase levels did not have a significant relationship with tuber powdery scab resistance. The proposed role of LOX protein in suberin- and/or non-suberin-mediated mechanisms of powdery scab resistance in russet skinned tubers are discussed here. The physiological levels of LOX protein can be considered as a useful marker for powdery scab resistance in potato breeding programs.  相似文献   

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