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Summary: PLANT-INSECT INTERACTIONS
Relative Suitability of Virginia Pine and Loblolly Pine as Host Species
for Dendroctonus frontalis (Coleoptera: Scolytidae)
JESSICA S. VEYSEY, MATTHEW P. AYRES, MARI´A J. LOMBARDERO,1
RICHARD W. HOFSTETTER,
AND KIER D. KLEPZIG2
Department of Biological Sciences, Dartmouth College, Hanover, NH 03755
Environ. Entomol. 32(3): 668Ð679 (2003)
ABSTRACT Dendroctonus frontalis Zimmerman is a major disturbance agent in American pine
forests, but attack preferences for various host species, and their relative suitability for reproduction,
are poorly known. We studied patterns of beetle attack and reproduction during an infestation of
stands containing Virginia pine and loblolly pine. Nearly all Virginia pine were attacked and killed,
whereas a third of the loblolly pine escaped attack. Among attacked trees, the density of landings and
attacks on Virginia pine was 56Ð106% higher than on loblolly pine at one site, whereas it was similar
between species at another site. Paradoxically, D. frontalis preferred the host that was least suitable
for reproduction: mean SE 0.89 0.33 versus 4.65 1.40 progeny/attack in Virginia pine versus
loblolly pine. Poor reproduction in Virginia pine was attributable to increased adult mortality,
decreased oviposition, and decreased larval survival. Phloem thickness and nitrogen content were
similar between the two pine species. Loblolly pine was signiÞcantly more suitable for the growth of
Ophiostoma minus, a fungal associate of D. frontalis. Resin ßow was lower in Virginia pine than in
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