Prior host feeding experience influences ovipositional but not feeding preference in a polyphagous insect herbivore David R. Coyle 1 *, Katherine E. Clark 2,3 , Kenneth F. Raffa 1 & Scott N. Johnson 2 1 Department of Entomology, University of Wisconsin, 345 Russell Labs, 1630 Linden Drive, Madison, WI 53706, USA, 2 Scottish Crop Research Institute, Invergowrie, Dundee DD2 5DA, UK, and 3 Department of Biology and Environmental Science, School of Life Sciences, University of Sussex, Falmer, Brighton, BN1 9QG, UK Accepted: 19 November 2010 Key words: aversion learning, black vine weevil, Coleoptera, Curculionidae, induced preferences, nutritional chemistry, Otiorhynchus sulcatus, secondary metabolites Abstract Black vine weevils, Otiorhynchus sulcatus (Fabricius) (Coleoptera: Curculionidae), are globally-dis- tributed polyphagous pests of many horticultural crops. We investigated how adult weevils were affected by host switching and, in particular, how host plant species nutritional and defensive chemis- try affected subsequent host plant species selection and oviposition. Adults were fed one of three host plant species, blackcurrant [Ribes nigrum L. (Grossulariaceae)], raspberry [Rubus idaeus L. (Rosa- ceae)], or strawberry [Fragaria x ananassa Duchesne (Rosaceae)], throughout their pre-reproductive periods and then subjected to behavioral choice assays with these plants. Foliar chemistry differed significantly among the three host plant species. Compared to raspberry and strawberry foliage, blackcurrant foliage was 13% lower in nitrogen, 3% higher in carbon, and 28% higher in phenolic compounds. Initial host plant species had a significant effect on weevil mortality, with more weevils dying when previously fed blackcurrant (12%) than strawberry (3%) or raspberry (0%) regardless of subsequent host. Initial host plant species also affected oviposition, with weevils laying only ca. two eggs per week when previously fed blackcurrant, compared to those on raspberry or strawberry (ca. 11 and 15 eggs per week, respectively). When given a choice, weevils discriminated among host plant species and tended to oviposit on plants on which they had previously fed, even when the plant was nutritionally inferior for egg production and adult survival. In contrast, feeding behavior was only affected by the current host plant species. Feeding and oviposition were related to leaf chemistry only in blackcurrant, as leaf consumption was negatively correlated with foliar carbon and zinc concentra- tions, and positively correlated with foliar phosphorus and potassium concentrations. Introduction Host selection by phytophagous insects is an intricate process, involving a complex set of abiotic and biotic vari- ables, all of which must be interpreted by the insect prior to a decision (West & Cunningham, 2002). Experience- induced changes in host plant preference are often influ- enced by plant nutritional and defensive chemistry, which can shape both herbivore fitness and host selection (Bern- ays & Chapman, 1994). In particular, prior experience with host plants has been linked to associative and non- associative learning (Papaj & Prokopy, 1989; Schoonhoven et al., 2005). Associative learning, in which the herbivore relates a particular stimulus (e.g., odor) with another stim- ulus (e.g., food), can include aversion behavior (Dethier, 1988), advantageous selection of multiple host plant spe- cies (Bernays et al., 1992), or behavior based on oviposi- tion experience (Prokopy et al., 1982; Prokopy & Papaj, 1988). Non-associative learning involves habituation to deterrents (Glendinning et al., 2001; Akhtar & Isman, 2004), sensitization, or induced preferences based on ini- tial host experiences (Jermy et al., 1968). Induced preference learning, whereby insects are more likely to continue feeding on host plant species they have *Correspondence and current address: David Coyle, D.B. Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA 30602, USA. E-mail: drcoyle@uga.edu Ó 2010 The Authors Entomologia Experimentalis et Applicata 138: 137–145, 2011 Entomologia Experimentalis et Applicata Ó 2010 The Netherlands Entomological Society 137 DOI: 10.1111/j.1570-7458.2010.01083.x