Phyllotreta spp flea beetles and Psylliodes chrysocephala cabbage stem flea beetle

Dry, warm spring weather favours these insects and, where seedlings are under water stress, increases crop losses. Sowing or mulching of Brassica crops diminishes their attractiveness for flea beetles. There is some suggestion that the use of organic as opposed to soluble fertilizers also discourages flea beetles. Unsuccessful attempts at biological control have involved the use of nematodes pathogenic to flea beetles. Some researchers have suggested that brassicas such as Chinese cabbage for which flea beetles show markedly preferential feeding might be used as trap crops for these pests and could be planted mixed with or adjacent to crops such as white head cabbage (Trdan et al., 2005). Regrettably, populations of insects on Chinese cabbage become so high that there is no benefit for the cash crop white cabbage.

Insecticides applied to the seed, at drilling or post-emergence, will reduce pest impact. Overwintered crops are sprayed in early autumn, reducing the populations of egg-laying adults, and again after about 4 weeks to eliminate larval survivors. Crop monitoring aids the effectiveness of chemical control; those materials used for caterpillar control may also be effective against flea beetles.

Beetle Diagram

Fig. 7.8. Line diagram of the flea beetle (Phyllotreta spp.).

+1 0

Post a comment