Brandmieren Solenopsis in Nederland (Hymenoptera: Formicidae)

Tijdens importinspecties worden geregeld brandmieren aangetroffen. Solenopsis invicta, S. geminata en S. richteri zijn notoire invasieve exoten die in grote delen van de wereld voor veel overlast zorgen. Hierdoor besloot het Team Invasieve Exoten van het Ministerie van el&i om een risicoanalyse voor brandmieren uit te laten voeren. Deze moest inzicht geven in het aantal importen in Nederland, of ze zich kunnen vestigen, welke gevolgen vestigingen kunnen hebben voor de mens en de natuur, en op welke wijze brandmieren bestreden kunnen worden. In dit artikel worden de resultaten van die risicoanalyse samengevat

Thysanoptera larvae living on chickweed ( Stellaria media Linnaeus) under continental climatic conditions

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

Meer zicht op trips in aardbeienteelt : elk bedrijf zijn eigen dierentuin; biodiversiteit speelt een duidelijke rol

PRI onderzocht de ecologie van trips in de vollegronds aardbeienteelt en de mogelijkheden voor biologische bestrijding d.m.v. roofwantsen. Op een aantal biologische bedrijven werden tripssoorten geteld en infectiebronnen (waardplanten) geïnventariseerd. De variatie tussen bedrijven blijkt groot te zijn. Gewassen in de omgeving, onkruiden en bloeiende planten kunnen infectiebronnen vorme

The arthropod community of Scots pine (Pinus sylvestris L.) canopies in Norway

We summarise the findings of arthropods collected by fogging the canopy of 24 pine trees in two sites in Eastern and Western Norway. From the samples, taken in 1998 and in 1999, almost 30,000 specimens were determined to 512 species, with Diptera being most species rich (210 species), followed by Coleoptera (76 species) and Araneae (49 species). Of the 96 new species records, nine were new to science (5 Diptera and 4 Oribatida), two were new to the European, three to the Scandinavian and 82 to the Norwegian faunas. The paper demonstrates the need for detailed faunistical inventories of European forests

Mating behavior and species status of host-associated populations of the polyphagous thrips, Frankliniella schultzei

The thrips taxon, Frankliniella schultzei Trybom, could possibly comprise a complex of unrecognised cryptic species. We therefore made a range of reproductive behavioral observations on F. schultzei individuals from different host-associated populations to investigate their species status. We first described the mating behavior of F. schultzei taken from flowers of a primary host species, Malvaviscus arboreus. The pattern of male-female interaction was complex and protracted, with several behavioral steps being performed. These steps were similar for all mating pairs. Most females responded to male presence before physical contact, suggesting that male pheromones may be involved. We then compared mating behaviors, brood sizes and sex ratios of F. schultzei pairs derived from different host plant species. All pairs in crosses regardless of their original host plant species produced female offspring, indicating successful mating. Frequencies of behaviors were similar for all pairs. Only those crosses involving F. schultzei individuals from Erythrina crista-galli flowers differed from the general pattern in pre-copulation and copulation times. The females from E. crista-galli also produced significantly fewer offspring than females from other crosses. Finally we used traps baited with males from two populations, but set among flowers of one host plant species, to test for differential attraction of females. We found no evidence that the different host-associated populations investigated differ from one another functionally in their sex pheromone system. However, these results do not yet discount the possibility of cryptic species within the taxon F. schultzei. Populations of F. schultzei on many other host species need to be investigated from this perspective