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Suitability of native and ornamental oak species in C alifornia for A grilus auroguttatus
Author(s) -
Haavik L.J.,
Graves A.D.,
Coleman T.W.,
Flint M.L.,
Venette R.C.,
Seybold S.J.
Publication year - 2014
Publication title -
entomologia experimentalis et applicata
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.765
H-Index - 83
eISSN - 1570-7458
pISSN - 0013-8703
DOI - 10.1111/eea.12141
Subject(s) - biology , larva , pest analysis , ornamental plant , instar , phloem , botany , lobata , oak forest , range (aeronautics) , ambrosia beetle , curculionidae , horticulture , ecology , materials science , composite material , medicine , alternative medicine , pathology , pueraria
Abstract G oldspotted oak borer, A grilus auroguttatus S chaeffer ( C oleoptera: B uprestidae), is a new invasive species in southern C alifornia, USA. The extent of the host range of this insect is not known, but this knowledge will have a major impact on assessment of the risks that this pest poses to oaks [ Q uercus spp. ( F agaceae)]. We conducted laboratory tests to determine the potential suitability of native and ornamental oak species for larvae and adults of A . auroguttatus . We infested 179 cut logs (from 163 different trees) with eggs or larvae, measured neonate survival and, after 5 months, counted feeding galleries, and noted the proportion of galleries with late instars. Initial larval survival was generally high when larvae penetrated the phloem (range: 62–98% among oak species), and low by the time larvae began to feed at the phloem/xylem interface (range: 0–25% among oak species). The majority of larvae that established a visible feeding gallery survived to the fourth instar (total of 73% for all oak species). Larval galleries were established with greater frequency in red oaks ( S ection L obatae ) compared with other oaks (19 vs. 7 or 4%). All red oaks tested ( Q . agrifolia N ée, Q . kelloggii N ewberry, and Q . wislizeni A . DC .) were likely suitable hosts for larvae. Larvae were apparently able to feed on some of the other oaks ( Q . chrysolepis L eibmann, Q . suber L ., Q . lobata N ée, and Q . douglasii H ook & A rn), although it remains unclear whether these species would be preferred hosts under natural conditions. Adult longevity and fecundity varied little by species of oak foliage fed to adults. The host range of A . auroguttatus is likely limited by suitability of oak species for the larval rather than the adult life stage. Results support published field observations that red oaks are more suitable hosts than white oaks.