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1.
Observations, linear measurements, dissections, and histological preparations were made of parasitized and nonparasitized larvae of the alfalfa weevil,Hypera postica (Gyllenhal), on a daily basis. The observed developmental period lasted from 24 h after oviposition byBathyplectes curculionis (Thomson) orBathyplectes anurus (Thomson) until parasite larvae emerged from their hosts. Adult and larval parasites significantly altered growth and development ofH. postica larvae.B. curculionis andB. anurus caused 24 and 29% greater premature mortality in young host larvae than that observed in the unparasitized controls. Rate of development for parasitized larvae during the 1st 12 days was essentially the same as for nonparasitized larvae. Nonparasitized larvae reached maximum size in 17–18 days, whereas larvae parasitized byB. curculionis andB. anurus required 14–21 and 19–22 days, respectively. Larvae parasitized byB. curculionis are smaller in overall lengths, widths and head capsule widths than nonparasitized larvae and those parasitized byB. anurus.  相似文献   

2.
The l-alanine mediated germination of food isolated Bacillus cereus DSA 1 spores, which lacked an intact exosporium, increased in the presence of d-cycloserine (DCS), which is an alanine racemase (Alr) inhibitor, reflecting the activity of the Alr enzyme, capable of converting l-alanine to the germination inhibitor d-alanine. Proteomic analysis of the alkaline extracts of the spore proteins, which include exosporium and coat proteins, confirmed that Alr was present in the B. cereus DSA 1 spores and matched to that encoded by B. cereus ATCC 14579, whose spore germination was strongly affected by the block of conversion of l- to d-alanine. Unlike ATCC 14579 spores, l-alanine germination of B. cereus DSA 1 spores was not affected by the preincubation with DCS, suggesting a lack of restriction in the reactant accessibility.  相似文献   

3.
Larvae ofEpilachna varivestis Mulsant, parasitized byPediobius foveolatus (Crawford), were collected in soybean fields in Maryland during 1975. AdultP. foveolatus emerging from the larvae were sexed and counted. The ratio of males to females increased as the availability of food within the host decreased. This information is useful in development of exponential models predicting hostparasite interactions.  相似文献   

4.
A world revision of the genusCrossidium Jur. recognizes 11 species, which are described and discussed in the context of important taxonomic characters. An identification key is provided.C. asirense Frey & Kürschner is reduced to synonymy withC. davidai Catcheside, and the geographical range ofC. laevipilum Ther. & Trab. is extended to Europe. Phylogenetic trends are interpreted on the basis of two main evolutionary lines associated with the presence or absence of hyaline hair-points on the leaves. A twelfth species is transferred toMicrocrossidium Guerra & Cano, gen. nov., asM. apiculatum (Magill)Guerra & Cano, comb. nova, because of differences in stem anatomy, peristome configuration, and spore morphology.  相似文献   

5.
The biosynthetic pathway for gallic and ellagic acids in young, mature and autumn leaves ofAcer buergerianum andRhus succedanea was examined by tracer experiments, and also by isotope competition, withd-shikimic acid-14C,l-phenylalanine-U-14C,l-phenyllactic acid-U-14C, gallic acid-G-14C and their unlabeled compounds. In young leaves of both plants, the incorporation rate of labeled shikimic acid into gallic acid was significantly higher than that of labeled phenylalanine, whereas in the mature and autumn leaves the latter was a good precursor rather than the former for the gallic acid biosynthesis. Therefore, two pathways for gallic acid formation, through β-oxidation of phenylpropanoid and through dehydrogenation of shikimic acid, could be operating inAcer andRhus leaves, and the preferential pathway is altered by leaf age. In both plants, the incorporation rate of labeled phenyllactic acid during a 24 hr metabolic period was almost the same as that of labeled phenylalanine. The incorporation ofd-skikimic acid-G-14C,l-phenylalanine-U-14C andl-phenyllactic acid-U-14C into ellagic acid was very similar to the case of the radioactive gallic acid formation. Furthermore, regardless of the presence of unlabeled shikimic acid and/or phenylalanine, incorporation of the radioactivity of labeled gallic acid into ellagic acid occurred at a very high rate, suggesting the reciprocal radical reaction of gallic acid for the ellagic acid formation. The incorporation of labeled compounds into ellagitanins was also examined and their biosynthesis discussed further.  相似文献   

6.
Bifidobacterium longum NRRL B-41409 l-arabinose isomerase (l-AI) was overexpressed in Lactococcus lactis using a phosphate depletion inducible expression system. The resting L. lactis cells harboring the B. longum l-AI were used for production of d-tagatose from d-galactose in the presence of borate buffer. Multivariable analysis suggested that high pH, temperature and borate concentration favoured the conversion of d-galactose to d-tagatose. Almost quantitative conversion (92 %) was achieved at 20 g L?1 substrate and at 37.5 °C after 5 days. The d-tagatose production rate of 185 g L?1 day?1 was obtained at 300 g L?1 galactose, at 1.15 M borate, and at 41 °C during 10 days when the production medium was changed every 24 h. There was no significant loss in productivity during ten sequential 24 h batches. The initial d-tagatose production rate was 290 g L?1 day?1 under these conditions.  相似文献   

7.
A laboratory colony of 50 adults ofAltica carduorum Guérin-Méneville was established at South Dakota State University. Beetles reared in this colony had an average preoviposition period of 7 days when exposed to a regular cycle of 16 hr of light (24°C) and 8 hr of darkness (12.7°C). The laboratory reared females, whose longevity averaged 100 days, laid an average of 259.3±9.7 eggs. High temperatures and/or low RH are limiting factors to beetle survival. In the field eggs were laid throughout June on the underside of leaves along the edges of the veins. Adults fed throughout the summer and then over-wintered in the soil. Some of these beetles emerged the following spring and laid viable eggs. Factors limiting establishment in South Dakota, however, were high temperatures, low humidities, and the predators,Lebia viridis Say andHarpalus pennsylvanicus Degeer.A. carduorum originates from the Swiss Rhône valley where there is a relatively “continental” climate, but is limited to special habitats where comparatively high humidity occurs. South Dakota climate is characterized by cold winters, and hot, dry summers, therefore establishment would be most difficult.  相似文献   

8.
Z. Rüzička 《BioControl》1975,20(4):393-402
The suitability of thirteen aphid species for the polyphagous larvae ofMetasyrphus corollae (Fabr.) was investigated in laboratory tests. The length of larval and pupal development, weight of puparia, mortality during larval and pupal stages were compared. Cannibalism was not observed in the larvae reared in groups on suitable food.Aphis sambuci Linneaus was not a suitable prey for the larvae.Cavariella theobaldi (Gillette Bragg) collected fromPastinaca sativa L. was toxic to larvae ofM. corollae, although it was possible to rear the larvae onAphis fabae Scopoli orAnuraphis subterranea (Walker) from the same host plant.  相似文献   

9.
Four species of the genusBrachysporium Sacc. emend.Mason etHughes are treated in this paper from Czechoslovakia:B. nigrum (Link)Hughes,B. obovatum (Berk.)Sacc. and two new species,B. abietinum Hol.-Jech. andB. brevius Hol.-Jech.  相似文献   

10.
The mode of infection and cycle of development ofTolypocladium cylindrosporum Gams was examined inAedes sierrensis andCulex tarsalis. Larvae were found to be infected through the external cuticle, the pharynx and the midgut. Blastospores and conidia were both infective although for equal numerical concentrations blastospores proved more virulent causing high mortality within the first 48 h after inoculation (80 % for L2 larvae exposed to 5×105 spores/ml), while conidia generally took 7–10 days to produce the same results. Sporulation did not occur on submerged cadavers. Conidia were produced only on floating cadavers in contact with air. Conidial production on floating 4th instar larvae was found to average 1.8×107 conidia/larva. Invasion of the haemocoele and fairly extensive growth of the fungus almost invariably occurred before larvae were killed. This was particularly true forAedes sierrensis larvae. Details are presented of growth within the host and post-mortem penetration of the fungus out of the cadaver. AdultA. sierrensis sprayed with a conidial suspension proved susceptible to infection with 100 % mortality being recorded at 10 days. Infections originated in the thorax, suggesting, the integument or possibly the thoracic spiracles to be the most probable site of infection.  相似文献   

11.
Six species of the genusBactrodesmium M. C. Cooke are described in this paper from Czechoslovakia:B. betulicola M.B. Ellis,B. obovatum (Oudemans) M.B. Ellis,B. spilomeum (Berk. etBr.)Mason etHughes including three new speciesB. globosum Hol.-Jech.,B. pyriforme Hol.-Jech. andB. submoniliforme Hol.-Jech.  相似文献   

12.
Chromosome numbers are reported for 14 species collected in Cuba. The first chromosome records are reported forAlbizzia cubana Britton etWilson (2n=26),Atkinsia cubensis (Britton etWilson)Howard (2n=26),Caesalpinia violacea (Mill.)Standl. (2n=24),Colubrina ferruginosa Brongn. (2n=24). Chromosome numbers of the following species were confirmed:Albizzia lebbeck (L.)Benth. (2n=26),Canavalia maritima (Aubl.)Thouars (2n=22),Casuarina equisetifolia Forst. (2n=18),Cedrela mexicana M.J. Roem. (2n=56),Delonix regia (Bojer)Raf. (2n=28),Guazuma tomentosa H.B.K. (2n=16),Lysiloma bahamense Benth. (2n=26),L. latisiliqua (L.)Benth. (2n=26),Samanea saman (Jacq.)Merrill (2n=26),Thespesia populnea (L.)Soland (2n=26).  相似文献   

13.
Die vorliegende Arbeit befasst sich mit zwei, die Vegetation felsiger vulkanischer Substrate einschliessenden Verbänden:Alysso-Festucion pallentis Moravec 1967 undFestucion valesiacae Klika 1933, in deren Rahmen acht Assoziationen untersucht wurden:Alysso-Festucetum Klika ex?e?ovský 1949,Asperulo-Festucetum Preis inKlika 1939,Allio-Sedetum Klika 1939,Melico-Sempervivetum Preis inKlika 1939,Alysso-Potentilletum Preis 1939,Carici-Festucetum Klika 1951,Erysimo-Festucetum Klika 1933 undFestuco-Stipetum Sillinger 1931. Im ökologischen Abschnitt wurde auf den Vergleich von chemischen eigenschaften der Böden (Azidität und ihr Saisonverlauf, Gehalt an Austauschionen—H+, Al3+, Ca2+, Mg2+ und an C und N) und deren morphologischen Eigenschaften (Tiefe und Stratigraphie der Bodenhorizonte, ihre Beschreibung) Nachdruck gelegt. Ebenso wurde dem Standort und den Beziehungen der Gesellschaft zu den anschliessend benachbarten Gesellschaften an der Lokalität Aufmerksamkeit gewidmet. In der Arbeit werden auch einige selten vorkommende oder noch nicht beschriebene Syntaxa erwähnt, die mit den oben erwähnten Assoziationen in Kontakt stehen:Calluno vulgaris-Cytisetum nigricantis Prsg. 1953 em.Oberd. 1957,Polytricho piliferi-Scleranthetum perennis Moravec 1967,Geranio sanguinei-Dictamnetum albae Wendelberger 1954,Geranio sanguinei-Trifolietum alpestris Th. Müller 1961,Dictamno albae-Sorbetum Knapp 1942; weiter die neubeschriebenen Syntaxa:Alysso saxatilis-Festucetum duriusculae cotoneasteretosum integerrimae, Potentillo opacae-Festucetum sulcatae pulsatilletosum patentis mit Var.Vaccinium myrtillus und Var.Pimpinella saxifraga und Subass.eryngietosum campestris, Pulsatillo pratensis-Avenochloetum pratensis, Koelerio macranthae-Stipetum joannis mit fünf Subassoziationen:verbascetosum lychnitis, stipetosum pulcherrimae, stipetosum smirnovii, stipetosum glabratae undstipetosum tirsae undErysimo crepidifolii-Festucetum valesiacae dictamnetosum albae. Alle Syntaxa sind mit Aufnahmematerial belegt und ihre Sukzessions- und topographischen Beziehungen werden beschrieben.  相似文献   

14.
A recombinant l-fucose isomerase from Caldicellulosiruptor saccharolyticus was purified as a single 68 kDa band with an activity of 76 U mg?1. The molecular mass of the native enzyme was 204 kDa as a trimer. The maximum activity for l-fucose isomerization was at pH 7 and 75°C in the presence of 1 mM Mn2+. Its half-life at 70°C was 6.1 h. For aldose substrates, the enzyme displayed activity in decreasing order for l-fucose, with a k cat of 11,910 min?1 and a K m of 140 mM, d-arabinose, d-altrose, and l-galactose. These aldoses were converted to the ketoses l-fuculose, d-ribulose, d-psicose, and l-tagatose, respectively, with 24, 24, 85, 55% conversion yields after 3 h.  相似文献   

15.
On the basis of allozyme and cultivation data, and of additional herbarium material, a taxonomic and nomenclatural revision ofTaraxacum sect.Piesis A.J. Richards exKirschner et?těpánek is provided. The section is made up of halophilous, sexually reproducing taxa. InT. stenocephalum Boiss. etKotschy,T. pindicum Kirschner et?těpánek, sp. nov., andT. perenne Kirschner et?těpánek, sp. nov., a tetraploid chromosome number has been recorded, representing the only known case of sexuality at the tetraploid level in the genus. The complex ofT. stenocephalum, includes some geographically and morphologically extreme populations treated as subspecies: subsp.gumusanicum (Soest)Kirschner et?těpánek, comb. nov., subsp.magnum Kirschner et?těpánek, subsp. nov., and subsp.daralagesicum (Schischk.)Kirschner et?těpánek, comb. nov. In addition toT. bessarabicum (Hornem.)Hand.-Mazz., a widely distributed Eurasian species,T. stenocephalum, a complex centred in Transcaucasia and Anatolia, andT. pachypodum H. Lindb., a North African endemic, four new species are described:T. salsum Kirschner et?těpánek, sp. nov., a diploid endemic confined to E Crimea,T. perenne Kirschner et?těpánek, sp. nov., a tetraploid sexual species known only from SW Crimea,T. pindicum Kirschner et?těpánek, sp. nov., a remarkable tetraploid endemic to the Pindos Mts., Greece, andT. salsitatis Kirschner, ?těpänek etYirdirimli, sp. nov., an Anatolian diploid species. Furthermore, a hybrid betweenT. salsum andT. bessarabicum from Crimea (documented on the basis of allozyme data elsewhere) is given a binomial,T. xmesohalobium Kirschner et?těpánek, nothosp. nov.  相似文献   

16.
The cell free culture filtrate of Bacillus cereus associated with an entomopathogenic nematode, Rhabditis (Oscheius) sp. exhibited strong antimicrobial activity. The ethyl acetate extract of the bacterial culture filtrate was purified by silica gel column chromatography to obtain four bioactive compounds. The structure and absolute stereochemistry of these compounds were determined based on extensive spectroscopic analyses (FABMS, 1H NMR, 13C NMR, 1H–1H COSY, 1H–13C HMBC) and Marfey’s method. The compounds were identified as cyclic dipeptides (CDPs): cyclo(l-Pro-l-Trp), cyclo(l-Leu-l-Val), cyclo(d-Pro-d-Met), and cyclo(d-Pro-d-Phe), respectively. Compounds recorded significant antibacterial activity against all the test bacteria (Staphylococcus epidermidis, Staphylococcus aureus, Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa and methicillin-resistant S. aureus) except cyclo(l-Leu-l-Val). Cyclo(l-Leu-l-Val) recorded activity only against Gram positive bacteria. Best antibacterial activity was recorded by cyclo(l-Pro-l-Trp) against S. aureus (4 μg/ml). The four compounds were active against all the five fungi tested (Trichophyton rubrum, Aspergillus flavus, Candida albicans, Candida tropicalis and Cryptococcus neoformans) and the activity was compared with amphotericin B, the standard fungicide. The highest activity of 1 μg/ml by cyclo(l-Pro-l-Trp) was recorded against T. rubrum, a human pathogen responsible for causing athlete’s foot, jock itch, and ringworm. The activity of cyclo(l-Pro-l-Trp) against T. rubrum, C. neoformans and C. albicans were better than amphotericin B, the standard antifungal agent. To our knowledge, this is the first report of antifungal activity of CDPs against the human pathogenic fungi T. rubrum and C. neoformans. The four CDPs are nontoxic to healthy human cell line up to 200 μg/ml. We conclude that the bacterium associated with entomopathogenic nematode is promising sources of natural antimicrobial secondary metabolites, which may receive greater benefit as potential sources of new drugs in the pharmaceutical industry.  相似文献   

17.
Two new species ofPhellinus rimosus complex are described, viz.Phellinus coffeatoporus Kotl. etPouz. from Florida (U.S.A.) characterized by globose spores andPhellinus resinaceus Kotl. etPouz. from Papua-New Guinea and Australia which is distinguished by a very thick and faintly yellowish tinted spore wall.  相似文献   

18.
P. J. Joy  K. J. Joseph 《BioControl》1973,18(3):317-319
Nephantis serinopa Meyrick is now known to be parasitised by six species ofBrachymeria, viz.,B. nephantidis Gahan,B. lasus Walk.,B. excarinata Gahan,B. (Neobrachymeria) nosatoi Habu,B. euploeae Westw., andB. hime attevae Joseph Of these,B. (N.) nosatoi is the most effective pupal parasite ofN. serinopa in Kerala. Certain aspects of the biology of this parasite have been studied.  相似文献   

19.
The seasonal histories and phenological relationships of European corn borer,Ostrinia nubilalis (Hübner), and its 2 parasitoids,Macrocentrus grandii (Goidanich) andEriborus terebrans (Gravenhorst) were studied in southcentral Minnesota. Both parasitoids overwintered in mature borer larvae, broke diapause, completed development, and emerged at the same time as did borer adults. Thus the 1st generation parasitoids coincided with the peak abundance of their preferred larval instars of the 1st host generation. Both parasitoids had a 2nd generation, matching the bivoltinism ofO. nubilatis in Minnesota. The activity of 2nd generationE. terebrans was before the peak 2nd generation borer moth flight and was not synchronized with the peak abundance of 2nd generation borer larvae. The peak activity of 2nd generationM. grandii occurred after the peak 2nd generation borer moth flight and was fully synchronized with the peak abundance of 2nd generation borer larvae. Thus,M. grandii has both generations synchronized with the host seasonal history, and was the more effective of the 2 parasitoids.  相似文献   

20.
First and second instars ofChrysopa carnea Stephens andColeomegilla maculata (De Geer) were able to search much faster on cotton than tobacco. Searching speeds of the two predators on tobacco were inversely dependent on density of glandular trichomes.  相似文献   

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