Premium
Response of beech ( Fagus sylvatica ) to elevated CO 2 and N: Influence on larval performance of the gypsy moth Lymantria dispar (Lep., Lymantriidae)
Author(s) -
Henn M. W.,
Schopf R.
Publication year - 2001
Publication title -
journal of applied entomology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.795
H-Index - 60
eISSN - 1439-0418
pISSN - 0931-2048
DOI - 10.1046/j.1439-0418.2001.00592.x
Subject(s) - lymantria dispar , beech , biology , zoology , larva , relative growth rate , fagus sylvatica , dispar , botany , gypsy moth , instar , lepidoptera genitalia , horticulture , growth rate , entamoeba histolytica , geometry , mathematics , microbiology and biotechnology
Two‐year‐old beech seedlings were kept from germination to bioassays with Lymantria dispar under the following conditions: ambient CO 2 /low N, elevated CO 2 /low N, ambient CO 2 /elevated N, and elevated CO 2 /elevated N. The effect of these growing conditions of the trees on the performance of the defoliator L. dispar was studied 2 years after initiating the tree cultivation. The developmental success of third‐instar larvae of L. dispar was characterized by the weight gained, percentage of weight gain, relative growth rate (RGR), relative consumption rate (RCR), and efficiency of conversion of ingested food into body substance (ECI). Contrary to our expectations, additional N‐fertilization did not increase and elevated CO 2 did not delay larval growth rate. However, the environmental treatments of the beech seedlings were found to affect the larval performance. Larvae consumed significantly higher amounts of foliage (RCR) on beech trees under controlled conditions (ambient CO 2 and low N) compared to those under elevated CO 2 and enhanced N. The opposite was true for ECI. The lowest efficacy to convert consumed food to body substance was observed under control conditions and the highest when the larvae were kept on beech trees grown under elevated CO 2 and additional N‐fertilization. These opposite effects resulted in the weight gain‐based parameters (absolute growth, percentage of growth, and RGR) of the gypsy moth larvae remaining unaffected. The results indicate that the gypsy moth larvae are able to change their ECI and RCR to obtain a specific growth rate. This is discussed as an adaptation to specific food qualities.