Original paper

Nitrogen and Phosphorus in Molinia caerulea (Gramineae) and its Impact on the Larval Development in the Butterfly-Species Lasiommata megera (Lepidoptera: Satyridae)

Bink, Frits A.; Siepel, Henk

Entomologia Generalis Volume 20 Number 4 (1996), p. 271 - 280

16 references

published: May 6, 1996

DOI: 10.1127/entom.gen/20/1996/271

BibTeX file

ArtNo. ESP146002004005, Price: 11.00 €

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Abstract

As grasses have few secondary plant compounds to protect them from herbivore grazing, fluctuation of leaf nitrogen [N] content may be a good alternative strategy. Grasses, such as Molinia caerulea (Gramineae) growing on various soil types with large differences in nutrient load have site-dependent differences in food quality for grass-feeding larvae. M caerulea has been collected and analyzed from 5 localities in the Netherlands. Plants from one locality have been cultivated in hydroculture [Hc] at 5 levels of nitrogen [N] and 4 levels of phosphate [P]. M caerulea has a predominant seasonal cycle in leaf content of N and P. It appeared that this can only be modified slightly by treatments in Hc. The quality as food for leafchewing insects was tested for larvae [Lv] of Lasiommata megera Linnaeus 1758 (Satyrinae). The growth response of the Lv was measured as pupal weight for both MM and FF. There were no significant differences of pupal weight in the first generation because of overall high N-contents in the leaves. The second generation however, responded significantly; pupal weight decreased with decreasing N-content of the leaves. Moreover, there appears to be a trend that diapause induction depends not only on light period but also on nitrogeleaf N-content. Considering the growth cycle of M caerulea, it is comprehensible that in the field, it is excluded as a hostplant for L megera because of the seasonal lack of sufficient N levels.

Kurzfassung

Bei Lasiommata megera Linnaeus 1758 wurde durch Puppen-Gewichts-Analysen das Wachstum der an in Hydrokultur von Molinia caerulea gezüchteten Larven ermittelt. In der Frühjahrsgeneration liegen keine signifikanten Unterschiede im Puppengewicht vor - parallel zum gleichbleibend hohen Nitrat-Gehalt der Grashalme. Bei der Sommergeneration jedoch nimmt das Puppen-Gewicht signifikant mit sinkendem N-Gehalt der Blätter ab. Außerdem scheint der Diapause-Beginn nicht nur lichtperiodisch ausgelöst zu werden, sondern auch durch den N-Gehalt der Grashalme. Aufgrund des Lebenszyklus von M caerulea ist L megera im Freiland als Wirtspflanze ungeeignet, da der für das Larvenwachstum notwendige hohe N-Gehalt nicht lange genug anhält.

Keywords

Lasiommata megera Linnaeus 1758diapause inductionfood qualitygrowth cyclegrowth reponsehydrocultureplant-insect relationshippupal weigh