Premium
Interactions between Apion species (Coleoptera: Curculionidae) and Polygonaceae. II. Apion violaceum Kirby and Rumex obtusifolius L.
Author(s) -
HOPKINS M. J. G.,
WHITTAKER J. B.
Publication year - 1980
Publication title -
ecological entomology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.865
H-Index - 81
eISSN - 1365-2311
pISSN - 0307-6946
DOI - 10.1111/j.1365-2311.1980.tb01147.x
Subject(s) - biology , polygonaceae , instar , larva , curculionidae , botany , rumex , pupa
.1 The biology of Apion violaceum is described, particularly with respect to its primary host, Rumex obtusifolius.2 Oviposition in Rumex acetosa is directly into the stem, but in R. obtusifolius it takes place through the sheath enclosing developing flowers, stem leaves and stem. 3 Larvae cannot complete development in the leaf petioles and must migrate downwards to the stem or die before pupation. 4 Mortality of A. violaceum in the stems was highest in eggs and first instar larvae and in third instar larvae. The latter mortality was caused almost entirely by parasitoids. 5 Stems of R. obtusifolius on the study site increased in number up to August and reached the maximum height in late June. 6 Over the 4 year study period there was a parallel decline in stem numbers and mean stem height at two of the sites studied. At these sites there was also a decline in A. violaceum numbers and density per stem. 7 The quality of sites for A. violaceum , as defined by the product of stem numbers and stem height, showed a significant correlation with A. violaceum numbers.