Diamondback moth larvae generally survive better on the Brassica crops, including cabbage and broccoli, than on wild Brassicas, and not at all on yellow rocket (Barbarea vulgaris). It also takes longer to complete their development on the wild Brassicaceae than on the Brassica crops.

D. insulare parasitized the fewest diamondback moths on hoary alyssum, field pepperweed (Lepidium campestre) and wormweed mustard. More diamondback moth larvae were parasitized on wild mustard (B. kaber) than on the other wild Brassicaceae. Also, parasitized larvae fed on wormseed mustard, field pennycress (Thlaspi arvense), and hoary alyssum took significantly longer to develop to D. insulare pupae than when they were fed on the other Brassicaceae plants.

Diamondback moth infestation and percentage of parasitism in the field were higher on broccoli than on the other Brassica crops. The presence of wild Brassicaceae, especially yellow rocket and wild mustard, in the field could reduce diamondback moth populations, increase the impact of D. insulare, provide a reservoir for insecticide-susceptible diamondback moth, and increase the success of diamondback moth management programs.

Source:

Idris, A. B. and E. Grafius. 1996. Effects of wild and cultivated host plants on oviposition, survival, and development of diamondback moth (Lepidoptera: Plutellidae) and its parasitoid Diadegma insulare (Hymenoptera: Ichneumonidae). Environmental Entomology 25: 825-833.