Bioecological characteristics of Bracon intercessor Nees (Hymenoptera: Braconidae) as a parasitoid of the poplar clearwing moth, Paranthrene tabaniformis (Rott.) (Lepidoptera: Sesiidae) in Bulgaria     

G. Georgiev 《Journal of pest science》2005,78(3):161-165

The major bioecological characteristics of Bracon intercessor Nees (Hymenoptera: Braconidae), a parasitoid of the poplar clearwing moth, Paranthrene tabaniformis (Rott.) (Lepidoptera: Sesiidae), were studied from 1987 to 2003. Poplar shoots infested with P. tabaniformis larvae were collected in 11 localities in Bulgaria and examined in the laboratory, and infestations were also studied in the field. B. intercessor was recorded in seven localities and was found to be a gregarious external larval parasitoid of P. tabaniformis. Two generations of the parasitoid developed on the host. The first (summer) generation was associated with early and mid-stage (up to third instar) host larvae, and the second (overwintering) generation with third- to fifth-instar larvae. The average number of parasitoid individuals feeding on a host was 4.5 and 12.4 in summer and overwintering generations, respectively. The maximum number recorded was 25 individuals per host in the overwintering generation. B. intercessor overwintered as a mature larva on the host and completed its development in early spring. The adults from the overwintering generation appeared in April, about 1 month prior to emergence of P. tabaniformis. The life cycle of B. intercessor was not in close synchrony with the development of P. tabaniformis in the spring, but the parasitoid adults which fed on honey-sugar solution lived for up to 31 days (males) and 86 days (females), respectively. This suggests that, in the field, B. intercessor females eclosing in the spring could survive until the host larvae appear if nectar is available. Adults of the summer generation emerge from July to September when sufficient suitable host larvae are available. B. intercessor was responsible for 1.5% of the average mortality of the P. tabaniformis overwintering larvae. The host mortality caused by the summer generation of the parasitoid ranged from 3.2% to 5.8%.  相似文献   

Parasitoids of Saperda populnea (L.) (Coleoptera: Cerambycidae) on aspen (Populus tremula L.) in Bulgaria     

G. Georgiev 《Journal of pest science》2001,74(6):155-158

The parasitoids of Saperda populnea (L.) (Col.: Cerambycidae) were studied in Bulgaria during the period 1997?–?2001. Galls with pest larvae were collected from young aspen trees at eight locations (Sofia, Kokaliane, Plana, Churek, Gorni Lom, Gintzi, Dolno Kamartzi and Klisura) and examined under laboratory conditions. Four species were reared from 1118 galls containing overwintering pest larvae: Iphiaulax impostor (Scop.) (Hym.: Braconidae), Dolichomitus populneus (Ratz.), Schreineria populnea (Gir.) (Hym.: Ichneumonidae) and Billaea irrorata (Meig.) (Dipt.: Tachinidae). All of the parasitoids were solitary. Schreineria populnea was found as a new parasitoid of the host in Bulgaria. B. irrorata emerged mainly from late-stage S. populnea larvae; the remaining species from both early- and mid-stage larvae. In the parasitoid complex of S. populnea, the most numerous were B. irrorata (59.8?%) and D. populneus (29.4?%). The percentage of host larval parasitism varied from 2.4 to 33.3, with an average of 9.7?%. B. irrorata was the most important in reducing the pest number. The average mortality of S. populnea caused by the tachinid was 5.8?%, and the highest mortality observed in individual study was 20.2?%.  相似文献   

Absorption features in the x-ray spectrum of an ordinary radio pulsar     

O Kargaltsev  M Durant  Z Misanovic  GG Pavlov 《Science (New York, N.Y.)》2012,337(6097):946-949

The vast majority of known nonaccreting neutron stars (NSs) are rotation-powered radio and/or γ-ray pulsars. So far, their multiwavelength spectra have all been described satisfactorily by thermal and nonthermal continuum models, with no spectral lines. Spectral features have, however, been found in a handful of exotic NSs and were thought to be a manifestation of their unique traits. Here, we report the detection of absorption features in the x-ray spectrum of an ordinary rotation-powered radio pulsar, J1740+1000. Our findings bridge the gap between the spectra of pulsars and other, more exotic, NSs, suggesting that the features are more common in the NS spectra than they have been thought so far.  相似文献   

Interplay of intra- and intermolecular H-bonding in a progressively solvated macrocyclic peptide     

Nagornova NS  Rizzo TR  Boyarkin OV 《Science (New York, N.Y.)》2012,336(6079):320-323

Studying solvation of a large molecule on an atomic level is challenging because of the transient character and inhomogeneity of hydrogen bonding in liquid water. We studied water clusters of a protonated macrocyclic decapeptide, gramicidin S, which were prepared in the gas phase and then cooled to cryogenic temperatures. The experiment spectroscopically tracked fine structural changes of the clusters upon increasing the number of attached water molecules from 1 to 50 and distinguished vibrational fingerprints of different conformers. The data indicate that only the first two water molecules induce a substantial change of the gramicidin S structure by breaking two intramolecular noncovalent bonds. The peptide structure remains largely intact upon further solvation, reflecting the interplay between the strong intramolecular and weaker intermolecular hydrogen bonds.  相似文献   

The relationship between spotted fever group Rickettsiae and Ixodid ticks     

Cristina Socolovschi  Oleg Mediannikov  Didier Raoult    Philippe Parola 《Veterinary research》2009,40(2)

Spotted fever group Rickettsiae are predominantly transmitted by ticks. Rickettsiae have developed many strategies to adapt to different environmental conditions, including those within their arthropod vectors and vertebrate hosts. The tick-Rickettsiae relationship has been a point of interest for many researchers, with most studies concentrating on the role of ticks as vectors. Unfortunately, less attention has been directed towards the relationship of Rickettsiae with tick cells, tissues, and organs. This review summarizes our current understanding of the mechanisms involved in the relationship between ticks and Rickettsiae and provides an update on the recent methodological improvements that have allowed for comprehensive studies at the molecular level.  相似文献   

New parasitoids of Paraphytomyza populi (Kltb.) (Diptera, Agromyzidae) in Bulgaria     

G.Ts. Georgiev  P. Boyadzhiev 《Anzeiger für Sch?dlingskunde》2002,77(2):69-71

The parasitoid complex of Paraphytomyza populi (Kltb.) (Diptera: Agromyzidae) was studied in Sofia, Bulgaria in 1997. Poplar leaves with P. populi larvae and pupae were collected from poplar stump shoots and examined in a laboratory. As a result, eleven parasitoid species were established: Chorebus albipes (Haliday) (Hymenoptera, Braconidae), Pediobius metallicus (Nees), Danuviella subplana Erdos, Chrysocharis nephereus (Walker), Chrysocharis pubicornis (Zetterstedt), Diglyphus crassinervis Erdos, Diglyphus isaea (Walker), Diglyphus albiscapus Erdos, Cirrospilus diallus Walker, Cirrospilus pictus (Nees) (Hymenoptera, Eulophidae) and Elasmus sp. (Hymenoptera, Elasmidae). Six species (D. crassinervis, D. isaea, D. albiscapus, C. diallus, C. pictus and Elasmus sp.) have been recorded as new parasitoids of P. populi. The genus Danuviella was found for the first time in Bulgaria. Five species (C. albipes, P. metallicus, D. subplana, D. crassinervis and D. albiscapus) are new records for the fauna of the country. The total mortality of P. populi caused by parasitoids was 19.1% and 49.0% for the overwintering and the summer generations, respectively. P. metallicus was the most important in reducing the pest number.  相似文献   

Infectivity, pathogenicity, and genetic characteristics of mammalian gastric Cryptosporidium spp. in domestic ruminants.     

Martin Kvác  Bohumil Sak  Dana Kvetonová  Oleg Ditrich  Lada Hofmannová  David Modry  Jirí Vítovec  Lihua Xiao 《Veterinary parasitology》2008,153(3-4):363-367

Farm ruminants were infected experimentally with four mammalian gastric Cryptosporidium, namely Cryptosporidium andersoni LI03 originated from cattle and three isolates of Cryptosporidium muris from brown rat (isolate RN66), Bactrian camel (isolate CB03) and firstly characterized isolate from East African mole rat (isolate TS03). Sequence characterizations of the small-subunit rRNA gene showed that the LI03 isolate was C. andersoni and the other three isolates belonged to C. muris, although the TS03 isolate showed unique sequence variations (one single nucleotide change and four nucleotide insertions). C. andersoni LI03 was infectious for calves only, whereas lambs and kids were susceptible to C. muris CB03. C. muris TS03 and RN66 were not infectious for any farm ruminants. Infection dynamics including prepatent and patent period and infection intensity of the isolates used differed depending on the host species, but no clinical signs of cryptosporidiosis were observed in any of experimentally infected hosts. Cryptosporidium developmental stages were only detected in infected animals in the abomasum region. Histopathological changes were characterized by dilatation and epithelial metaplasia of infected gastric glands with no significant inflammatory responses in the lamina propria.  相似文献   

Hematology of dairy cows with purulent-necrotic processes in the digital area treated with Subtilin ointment     

Valiyan Gimranov  Evgeny Skovorodin  Ilshat Giniyatullin  Azamat Mirzin  Oleg Dyudbin 《Canadian journal of veterinary research》2022,86(1):48

The objective of this study was to investigate the effect of Subtilin ointment on the hematology of dairy cows when used to treat inflammation and necrotic tissue in the digital area. Holstein-Friesian cows were allocated to 2 groups of 10 animals each. The first group consisted of clinically healthy cows and the second group consisted of cows with a purulent-necrotic lesion in the digital area. To make a comparative analysis, blood samples of healthy and diseased cows were taken and tested before treatment with Subtilin ointment and 10 days after treatment. The blood of the diseased cows had more leukocytes (53.38%), lymphocytes (46.81%), erythrocytes (15.78%), granulocytes (64.56%), and platelets (34.76%), and a higher mean cell volume (of 8.37%) and increased level of monocytes/eosinophils (65.12%) than did the blood of clinically healthy cows. At the same time, there were no evident changes in the level of erythrocytes, hemoglobin, mean cell hemoglobin, mean cell hemoglobin concentration, and percentage of lymphocytes in either clinically healthy or diseased cows. The hematology of diseased cows treated with Subtilin ointment demonstrated positive dynamics in the healing of ulcerative processes.  相似文献   

Behavior of the dwarf pig during various degrees of air humidity and heat load     

S Georgiev  A Schoen 《Berliner und Münchener tier?rztliche Wochenschrift》1973,86(11):208-213

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Effect of different environmental temperatures and atmospheric humidity degrees on some physiological parameters of the Goettinger miniature pig in various growth phases. I. Shoats     

S Georgiev  A Schoen  R Georgieva 《Berliner und Münchener tier?rztliche Wochenschrift》1972,85(9):171-173

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