1. Editors' Note

   • James L. Nation
   • David A. Jones

   EditorialNotes Pages: 881 - 881

2. Ontogenic development of chemical defense by seedling resin birch: Energy cost of defense production

   • John P. Bryant
   • Riitta Julkunen-Tiitto

   OriginalPaper Pages: 883 - 896

3. Plasticity in allocation of nicotine to reproductive parts inNicotiana attenuata

   • Ian T. Baldwin
   • Michael J. Karb

   OriginalPaper Pages: 897 - 909

4. Tracking variable environments: There is more than one kind of memory

   • Frederick D. Provenza

   OriginalPaper Pages: 911 - 923

5. Turnabout is fair play: Secondary roles for primary compounds

   • May R. Berenbaum

   OriginalPaper Pages: 925 - 940

6. Bioactivity of beaver castoreum constituents using principal components analysis

   • Bruce A. Schulte
   • Dietland Müller-Schwarze
   • Francis X. Webster

   OriginalPaper Pages: 941 - 957

7. Pheromone-mediated mating in the aphid parasitoid,Aphidius nigripes (hymenoptera: Aphididae)

   • Jeremy N. McNeil
   • Jacques Brodeur

   OriginalPaper Pages: 959 - 972

8. Multifunctional communication inRiptortus clavatus (Heteroptera: Alydidae): Conspecific nymphs and egg parasitoidOoencyrtus nezarae use the same adult attractant pheromone as chemical cue

   • Walter Soares Leal
   • Hiroya Higuchi
   • Mikio Ono

   OriginalPaper Pages: 973 - 985

9. Quantitative high-resolution gas chromatographic determination of stereoisomeric composition of chiral volatile compounds in the picogram range by ec-detection

   • Ann-Britt Wassgren
   • Gunnar Bergström

   OriginalPaper Pages: 987 - 994

10. Enantiomeric composition of ipsdienol: A chemotaxonomic character for north American populations ofIps spp. in thepini subgeneric group (coleoptera: Scolytidae)

    • Steven J. Seybold
    • Toshikazu Ohtsuka
    • Isao Kubo

    OriginalPaper Pages: 995 - 1016

11. Why not be a queen? Regioselectivity in mandibular secretions of honeybee castes

    • E. Plettner
    • G. R. J. Sutherland
    • M. L. Winston

    OriginalPaper Pages: 1017 - 1029

12. Testing the “new associations” biological control concept with a tachinid parasitoid (Euclytia flava)

    • J. R. Aldrich

    OriginalPaper Pages: 1031 - 1042

13. Semiochemicals from bark beetles: New results, remarks, and reflections

    • Wittko Francke
    • Jochen Bartels
    • Jean Pierre Vité

    OriginalPaper Pages: 1043 - 1063