<p>The quantity and quality of diet consumed by ladybugs can influence their life cycle and behavior, in both females and males. Diet can influence female’s pre-oviposition period, mate choice and ovary development, and male’s spermatophore composition and foraging for copulation. We tested the reproductive behavior of Cryptoleamus montrouzieri (Coleoptera: Coccinellidae) in four different diet treatments: (1) males and females fed only on honey; (2) males fed on honey and females fed on mealybugs; (3) males fed on mealybugs and females fed on honey; (4) males and females fed only on mealybugs. We also tested if the shift from honey to mealybug restores sexual behaviors on male and females. We found that the alternative diet modifies the sexual behavior of the species. Males fed on honey had significantly fewer engagements and copulations and females became more susceptible to male harassment. A variation in female behavior in both diets indicates that copulation frequency is likely related to the males’ diet. There was a significant increase in the behavioral events when the individuals fed mealybug for seven days. The study suggests that the exclusive consumption of alternative diets, like honey, is an important inhibitory factor in pre-copulatory behavior in C. montrouzieri. These findings suggest that carbohydrate-rich alternative diets may reduce reproductive efficiency in mass-rearing systems and should be carefully managed when maintaining populations of biological control agents.</p>