Search Results

You are looking at 1 - 10 of 15 items for

  • Author or Editor: G. Jenser x
Clear All Modify Search

The occurrence and host range of Tomato spotted wilt virus (TSWV) was investigated in Central and Eastern Europe. The relationships among the TSWV, the vector species and weed plants were surveyed.

Restricted access

The available data referring to the occurrence and geographical distribution of the females and males, the host range, the virus vector capability and the monitoring of Thrips tabaci Lindeman, as well as susceptibility and resistance of cultivars of some cultivated plant species are discussed.

Restricted access

Eight Hymenopteran parasitoids: Itoplectis alternans (Grav.), Itoplectis maculator (F.), Pimpla spuria Grav., Diadegma apostata (Grav.), D. longicaudata Horst., D. tenuipes (Thoms.), D. holopyga (Thoms.) and Dibrachys cavus (Walk.), and one hyperparasitoid Gelis areator (Panz.) have been reared from the larvae and pupae of the grape moth Lobesia botrana (Denis et Schiffermüller), collected between 1996 and 2003 in two wineyards of southern Romania. Nine host-parasitoid relationships have been recorded, from which seven are new for Romania and the other two new to science. The role played by these parasitoids in the regulation of the host populations is 12.3%. Diadegma longicaudata Horst. is the most important member of this parasitoid complex with a parasitizing ratio of 7.75%. The parasitism of hibernating stages is more important than the summer ones, both in percentage (24.2/8.94%), and in species diversity (6/1). The small number of species and the low values of aestival and hibernal parasitizing are the effect of intensive chemical treatments in these vineyards.

Restricted access

The Fabaceae species Lathyrus tuberosus, Vicia species and Coronilla varia, all of which have an extended flowering period, provide the larvae food and shelter long enough for the pea thrips Kakothrips pisivorus to complete its development, and to have two generations yearly. Although flowers of pea cultivars also confer suitable conditions for egg laying, their flowering period is rather short. Therefore, the larvae are forced to move to developing pea pods in damaging numbers, resulting in the development of only one generation yearly on pea. However, specimens of K. pisivorus are able to colonize pea cultivars that have a similar phenology as Lathyrus tuberosus. Here we show that Hungarian pea thrips populations having either one or two generations are genetically identical.

Restricted access

Yellow proved to be the most reliable colour for monitoring of Thrips tabaci. White and blue could be used with weak, but still reasonable effectiveness.

Restricted access

Thysanoptera species were collected from Stellaria media in autumn, winter and spring in different biotopes, in Hungary. The total number of the sampled specimens was 5121. The most frequent species were (in order of frequency): Thrips tabaci, T. atratus, Frankliniella intonsa, Apti­no­­thrips rufus, T. minutissimus, T. nigropilosus and Anaphothrips ob­scu­rus. The number of species as well as the composition of the species occurr­ing on S. media depends on the characteristics of biotopes. The number of species considerably increased in spring from 15 to 43. Among them seven species occurred from autumn through winter till spring. S. media provides a suitable site for winter refuge, and an alternative food source for a few species, which hibernate under bark, fallen leaves and dry grass as well as in the soil, leaving their winter quarters move and accu­mulate temporarily on this plant. Specimens of T. tabaci capable of harbouring tomato spotted wilt virus occurred in every investigated biotopes.

Restricted access

By the sampling on chickweed ( Stellaria media ) carried out from autumn till the end of spring, the occurrence of the larvae of 12 Thysanoptera species has been established under climatic conditions in Hungary. Only the larvae of T. atratus and T. tabaci were present in this period in relatively high number. Since chickweed is frequently infested by Tomato spotted wilt virus (TSWV) the continuous presence of the larvae of T. tabaci in the whole period is a notable circumstance. This relationship is one of the significant ways of the survival of tomato spotted wilt virus which might be a source of new epidemics.

Restricted access

The LIFE 02ENV/RO/000461AIR-AWARE project is partly dedicated to research on the flora and invertebrate fauna of downtown Bucharest (Romania). In this area, products of local industrial pollution, heavy metals, SO 2 and powders in suspension exceed standard levels. The pilot zone is represented by two public parks in downtown Bucharest. Thysanopterological samples were collected from the herbaceous layer, on both weeds and ornamentals, following a transect approach. The preliminary results revealed a biodiversity that decreased from the park centres, which suffered the least air pollution, towards the edges of the parks, which were the most polluted. The dominant species was Frankliniella intonsa , which had high values for structural and functional indices, as well as morphological changes in body size, colour and antennae, all due to the air pollution. F. intonsa could be considered to be a very sensitive bioindicator of environmental pollution. Future analysis, however, may reveal whether Bagnalliella yuccae, F. intonsa or Haplothrips niger are more sensitive bioindicators for air pollution.

Restricted access

Among the blue, green, fluorescent yellow, red, white and yellow coloured sticky traps the fluorescent yellow caught greatest number of both females and males of the vine trips (Drepanothrips reuteri) followed by yellow. Other colours caught negligible numbers. Fluorescent yellow sticky traps proved to be suitable for the monitoring of the flight activity of the vine thrips during the vegetative season. Both females and males immigrated in high number to the vineyards throughout the vegetation period. Based on trends of catches of the males the species develops presumably threes or four overlapping generations in a year under the climatic conditions of Hungary. The fluorescent yellow sticky traps tested in the present study may offer an usable tool for detection and monitoring of this pest.

Restricted access

Although Thrips tabaci is a well-known vector of Tomato spotted wilt virus (TSWV) it does not belong to the spreaders of this dangerous pathogen in North America. The possible explanation of the differences in its vector efficiency in Europe and in North America is rooted in the fact that out of the two subspecies of T. tabaci, i.e. T. tabaci tabaci and T. tabaci communis only the specimens of the latter were introduced from Europe into North America. To support our hypothesis we have used a molecular marker that detects intraspecific ribosomal DNA sequence variations between the two subspecies of T. tabaci.

Restricted access