Evaluation of pepper cultivars with different heat units on the feeding preference of pepper weevil (Coleoptera: Curculionidae)

Pepper weevil, Anthonomus eugenii Cano, is a devastating pest of pepper that is typically controlled, to varying degrees, with chemical insecticides. Additional tools are needed to manage this pest, including host plant resistance. Field and laboratory studies were conducted over 4 yr to determine pepper weevil preferences for pepper hosts with different Scoville heat units (SHU): bell (0 SHU), jalapeño (2,500 to 8,000 SHU), habanero (100,000 to 350,000 SHU), ghost (855,000 to 1,041,427 SHU), and scorpion (1,200,000 to 2,000,000 SHU) peppers. In field trials, jalapeño had the highest number of weevil-infested fruit, and ghost pepper had the lowest. The number of adult weevils on the foliage was highest in jalapeño (0.94 ± 0.23) and lowest in ghost pepper (0.11 ± 0.05). The density of the weevils inside infested fruit was highest on jalapeño and lowest in scorpion pepper. Laboratory olfactometer tests documented a higher preference of adult weevils for bell and jalapeño followed by habanero, ghost, and scorpion peppers. Differences in plant height and width among hosts were not correlated with weevil infestation level. Pepper weevil host preference appears inversely related to pepper hotness (SHU), as bell and jalapeño peppers, the hosts with the lowest SHUs, were the most susceptible to weevil infestation. The greater weevil susceptibility of jalapeño and bell pepper than other species/cultivars may be related to the fact that jalapeño and bell pepper and the weevil co-evolved in Mexico. This study could help in the selection of resistant pepper species for managing pepper weevil.