Flat, dark grey-brown bugs that gather on squash plants and suck sap from leaves and stems, causing yellow spots, wilting and eventually brown, dead foliage.

Small, dark, water-soaked spots develop on leaves and may merge, causing yellowing and leaf drop. Fruit develops raised, rough, scabby spots that can crack and become corky.

mall round tan or grey spots with reddish-purple borders develop on leaves; heavy infection can cause foliage to yellow, wither and die.

Small white maggots tunnel into onion roots and bulbs, causing seedlings to wilt or die and older bulbs to become soft, damaged and prone to rot.

Tiny, soft-bodied insects clustered on leaves and stems, causing curling, yellowing or distorted growth.

Swollen, distorted roots interfere with water and nutrients, leaving plants stunted, yellow and prone to wilting.

Yellow V-shaped patches spread inward from leaf edges as veins darken, leaving plants wilted, stunted and damaged.

Small white spots spread across onion leaves, causing the foliage to yellow, collapse and die back.

White fluffy growth, soft rot and wilting — often followed by the plant collapsing.

Pale green to yellow, angular patches appear on the upper leaf surface, white, fluffy, downy growth underneath.

Pale green or yellow blotches appear on the upper surface of older leaves. On the underside, directly beneath those spots, an olive-green to brown, velvety mold develops. As the disease progresses, leaves turn yellow, curl, wither and may eventually die and drop from the plant

Early symptom is leaves begin turning yellow and brown at the margins, called "firing"

Tunnels winding through the root. Damage often concentrated toward at the bottom. Small cream-coloured maggots.

Leaves have dark brown to black spots with yellow halos.

Lower leaves turn yellow and droop, often on one side only

Leaves have small brown spots. Distinctive "bullseye" pattern of concentric rings. Can be surrounded by a yellow halo.