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Wolfgang Völkl 《Behavioral ecology and sociobiology》2001,49(2-3):135-144
Pauesia picta, P. pinicollis and P. silvestris (Hymenoptera: Aphidiidae) are common parasitoids of the conifer aphid Cinara pinea, which is regularly attended by red wood ants (Formica spp.). In this study, I tested whether females of these parasitoid species learned during interactions with honeydew-collecting Formica polyctena workers that caution is not necessary if searching behaviour is adapted, and whether parasitoids benefit from being able
to learn. When searching on Scots pines, naive females of P. picta and P. pinicollis generally retreated to a pine needle when making contact with a honeydew-collecting ant, did not approach ants from the side
or from the front and kept a ”safe distance” from ants when sitting on needles. After some non- aggressive ant encounters,
experienced female parasitoids changed their behaviour: they reduced their searching speed, approached ants from the side
and even from the front, retreated less often in response to an approaching ant and reduced the ”safe distance”. These experienced
females had a significantly higher rate of oviposition than naive females or females foraging for an unattended host. Thus,
the ability of the parasitoid to learn during interactions with an antagonist led to a prolonged retention time and a higher
oviposition rate. By contrast, there was no evidence of learning in P. silvestris. Females of this species showed no behavioural change in response to ant encounters, and there was no difference in the foraging
success of naive and experienced female parasitoids.
Received: 7 December 1999 / Revised: 23 September 2000 / Accepted: 10 March 2000 相似文献
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VIRGINIA GALLEGOS PÉRULA RAFAEL M. NAVARRO CERRILLO PILAR FERNÁNDEZ REBOLLOo GEMADEL VALLE MURILLO 《Environmental management》2003,31(1):0086-0099
The objective of this study was to examine postfire regeneration of tree, shrub, and dwarf shrub species, in relation to levels
of damage in four planted pine forests (Pinus pinea, Pinus pinaster) in Andalusia. A prefire vegetation map was used for detailing species composition, vertical structure, and density and another
for detailing the extent and intensity of fire damage. Between 3 and 7 years after the fires, an inventory was made of the
vegetation in each area, using the step-point method. The information thus obtained was used to determine the amount of cover
in the dwarf/shrub and tree layers, the frequency of species in each of the layers, floristic richness, and diversity (Shannon
index). The botanical composition of the dwarf and shrub layer was analyzed using TWINSPAN. Variables were poorly correlated
with level of fire damage, which suggests that the forests in this study followed the autosuccession model. Because of the
artificial origin or seminatural condition, regeneration of the dominant tree species is poor, and it seems unlikely that
forests will recover to their prefire state. Therefore action is recommended to restore these ecosystems. 相似文献
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