Domestication of Chili Pepper Has Altered Fruit Traits Affecting the Oviposition and Feeding Behavior of the Pepper Weevil

Abstract

The pepper weevil, Anthonomus eugenii, Cano (Coleoptera: Curculionidae), is one of the most destructive pests of chili pepper. It causes extensive damage on varieties selected for consumption. However, the occurrence of this pest on wild and ornamental peppers remains unknown. We investigated the consequences of chili domestication on the feeding and oviposition of A. eugenii on fruits and flowers. We used plants of one wild accession, Bird Eye Pepper, five ornamental varieties (Pops Yellow, Black Pearl, Sedona Sun, Chilli Chilli, and Salsa Deep), and two domesticated varieties selected for consumption (Scotch Bonnet and Jalapeño). First, we characterized the plants according to their fruit and flower sizes, pericarp thickness, capsaicin level, fruit position, and flower color. Then, we evaluated the susceptibility of fruits and flowers to A. eugenii. Overall, domestication increased fruit and flower sizes and pericarp thickness, altered capsaicin levels, and altered fruit position and flower color. Weevils laid more eggs and caused more feeding damage on varieties selected for consumption than on wild and ornamental plants. Our results add to the growing literature on the consequences of crop domestication on herbivores. This knowledge could be integrated into breeding programs to select varieties resistant against the pepper weevil.

Keywords: Anthonomus eugenii; chili domestication; feeding behavior; oviposition; plant traits; wild chilies.

Figure 1

Pepper weevil damage on chili fruits (a–c) and flowers (d–f). All images © Y. Chabaane.

Figure 2

Characterization of capsaicin level in wild (Brown), domesticated as ornamental (Blue), and domesticated for consumption (Green) peppers according to the Scoville scale. © Y. Chabaane.

Figure 3

Effect of chili domestication on fruit size (a) and pericarp thickness (b). Sample size: Bird Eye (N = 25); Pops Yellow (N = 20); Black Pearl (N = 25); Sedona Sun (N = 30); Chilli Chilli (N = 20); Salsa Deep (N = 41); Scotch Bonnet (N = 32); Jalapeño (N = 62). The differences among treatments are indicated by different letters (F-test, Tukey’s post-hoc test with Bonferroni correction: p < 0.001).

Figure 4

Infestation by pepper weevil on ornamental and domesticated peppers showing the mean number of feeding holes per fruit (a) and the oviposition marks per fruit (b). No-choice tests using two fruits per Petri dish. The differences among treatments are indicated by different letters (F-test, Tukey’s post-hoc test with Bonferroni correction: p < 0.001, N = 20).

Figure 5

Effect of fruit size on the feeding and oviposition of the pepper weevil on Pepperoncino variety, using choice (a–c) and no-choice tests (d–f). The differences among treatments are indicated by different letters (F-test, Tukey’s post-hoc test with Bonferroni correction: p < 0.01, N = 10). All images © Y. Chabaane.

Figure 6

Pepper weevil attacks on flowers of wild pepper (Bird Eye), ornamental pepper (Black Pearl), pepper domesticated for consumption (Jalapeño), and eggplant. Searching time to find the flower (a), percentage of infested flowers (b), and mean number of eggs per flower (c). The differences among treatments are indicated by different letters for 20 min and stars (*) for 24 h (F-test (a, c) and Chi-test (b) followed by Tukey’s post-hoc test with Bonferroni correction: p < 0.05, N = 5). All images © Y. Chabaane.