What's eating my pak choi 'dwarf white stem'?

Pak Choi 'Dwarf White Stem' is targeted by flea beetles, cabbage caterpillars, aphids, and slugs. Cabbage root fly is the single most damaging threat, with larvae tunnelling roots causing wilting and collapse. Floating row covers fitted at sowing are the headline defence for all these pests.

Larvae tunnel into roots; plants wilt suddenly, leaves turn blue-green then yellow, and the plant may collapse even with adequate water. Fit fine mesh or fleece row covers at sowing; use brassica collars at soil level to stop the fly laying eggs near stems.

Tiny round shot-holes peppered across young leaves; seedlings can be skeletonised in warm, dry spells. Row covers exclude adults; delay sowing until plants are vigorous; kaolin clay spray reduces feeding damage.

Irregular holes through leaf blades; frass visible on inner leaves; heavy feeding can strip plants bare. Hand-pick eggs and caterpillars; spray Bacillus thuringiensis (Bt) kurstaki for organic control; row covers prevent egg-laying.

Ragged holes with slime trails, especially overnight; seedlings and soft young leaves most at risk. Use iron phosphate slug pellets, beer traps, or copper tape; remove debris where slugs hide during the day.