1. Editorial

   • J. Billen

   EditorialNotes Pages: 1 - 1

2. Queen condition and alate density affect pleometrosis in the antLasius pallitarsis

   • P. Nonacs

   Research Articles Pages: 3 - 13

3. Genetic differentiation of disjunct populations of the antsFormica aquilonia andFormica lugubris in Europe

   • P. Pamilo
   • D. Chautems
   • D. Cherix

   Research Articles Pages: 15 - 29

4. Extreme queen-worker dimorphism inRopalidia ignobilis, a small-colony wasp (Hymenoptera: Vespidae)

   • J. W. Wenzel

   Research Articles Pages: 31 - 43

5. Development of the embryo nest ofVespa affinis (Hymenoptera: Vespidae) in Southern Japan

   • S. J. Martin

   Research Articles Pages: 45 - 57

6. Trail laying behaviour during food recruitment in the antLasius niger (L.)

   • R. Beckers
   • J. L. Deneubourg
   • S. Goss

   Research Articles Pages: 59 - 72

7. The effects of colony characteristics on life span and foraging behavior of individual wasps (Polybia occidentalis, Hymenoptera: Vespidae)

   • S. O'Donnell
   • R. L. Jeanne

   Research Articles Pages: 73 - 80

8. Relations entre la fourmi parasiteFormicoxenus provancheri et son hôteMyrmica incompleta. Données biologiques et éthologiques (Hym. Formicidae)

   • A. Lenoir
   • C. Errard
   • R. Loiselle

   Research Articles Pages: 81 - 97

9. Colony defence against ants inVespa

   • S. J. Martin

   Research Articles Pages: 99 - 111

10. Young queens of the harvesting antMessor semimfus avoid founding in places visited by conspecific workers

    • T. J. Kawecki

    Short Communication Pages: 113 - 115