Anzeiger für Schädlingskunde, Pflanzenschutz, Umweltschutz (1997) 70, 145-154
B. Gharadjedaghi (1997)
Phytophage Arthropoden an Erlen (Alnus spp.) in bachbegleitenden Gehölzsäumen Oberfrankens. Teil 2: Blattfraß
[Phytophagous arthropod fauna on alders (Alnus spp.) in banks of brooks in Upper Frankonia. Part 2: Leaf consumption]
Anzeiger für Schädlingskunde, Pflanzenschutz, Umweltschutz 70 (8), 145-154
Abstract: 1. The apparent leaf consumption by folivorous arthropods (especially sawfly and lepidopteran larvae and beetles) on Grey and Black Alders was investigated in banks of three brooks near Bayreuth (Upper Frankonia, FRG) during 1990. Additional data about some folivorous guilds were drawn by assessement of twig samples.
2. The gallmites (Eriophyiidae) were the most important gall formers reaching high densities in early summer. Leaf rollers were very rare. Phyllonorycter species (Gracilliriidae) and Coleophora serratella (Coleophoridae) were the most significant leaf miners. Nevertheless the miners reached only comparatively low densities in 1990.
3. The relative apparant leaf consumption on Black Alder (Alnus glutinosa) reached 17% in two of the three investigation areas, at the third site the maximum was 9,7%. The maximal recorded leaf consumption on Grey Alder (A. incana) amounted to 14.8%. Between the different feeding trasks the leaf holes and the 'window' feeding were likewise responsible for the major amount of the leaf consumption. In contrast to this the leaf tissue loss caused by mines of C. serratella and by otherfeeding types was only slight.
4. The assessment of the early leaf abscission (nearly 40%) showed that leaves consumed to a higher extend felt off earlier than others. In consideration of this, the real leaf consumption is roughly estimated to be about 2% higher than the measured appearent leaf consumption. Also the frequency of gall mites was higher in the early summer leaflitter. The results are not definite in case of the leaf miner guild.
5. There were distinct between-site differences in consumption rates and its seasonal development. The consumption rates differed only at few sampling dates between the north and south exposed sides of the banks. Remarkable exposition preferences were found in case of a gall mite (Eriophyes laevis). The measurement of leaf area loss in different layers of trees first points to a higher consumption rate at 5 m shifting to lower branches (3.5 m, 2 m) during summer.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
(original language: German)
Link to article at publishers website
Research topic(s) for pests/diseases/weeds:
surveys/sampling/distribution
damage/losses/economics
