The influence of feeding twenty cabbage cultivars of Brassica oleraceae var. capitata (L.) to the diamondback moth Plutella xylostella (L.) on the development of the egg parasitoid Trichogramma pretiosum Riley, was evaluated under laboratory conditions. The kale cultivar Couve de Verão, B. oleraceae var. acephala (L.) was included as control. After the 2nd-generation, leaf discs of each cultivar with 1-d-old eggs of diamondback moth were exposed to T. pretiosum for 12 h. The period of egg-adult emergence and the apparent viability of the parasitoids were affected by the cultivars and ranked as follows: `Green Cup' and `Chato de Brunswick' were classified as "favorable"; `Quatro Estações', `Roxo Precoce' and `Chato de Quintal', as "neutral" and `XPH', `Kenzan' and `Liso de Verão' as "unfavorable" in relation to both parameters. The others 12 cabbage cultivars and Kale studied were grouped in different categories according to the presented results. Correlation between egg-adult period and apparent viability of T. pretiosum and larval and pupal duration and viability, pupal weight, sexual ratio, fecundity, Adjusted Reproductive Potential (PRC) of P. xylostella evidenced that when cabbage cultivars took longer pest developmental stages and lower larval viability a shorter egg-adult and higher apparent viability of parasitoid was achieved. Only the correlation between pest pupal viability and apparent viability of parasitoid indicated "unfavorable" for the association P. xylostella - T. pretiosum.
Insecta; biological control; host plant resistance; diamondback moth
