• Whitefly

  sap and transmitting harmful viruses. Their feeding weakens plants, causes leaf yellowing and leads to honeydew deposits that reduce crop quality. Effective [...] which growth is retarded. In full sunlight, leaves can wilt and drop. Such leaf damage can in turn influence the development of fruit and lead to a reduction

• Greenhouse whitefly

  which growth is retarded. In full sunlight, leaves can wilt and fall. Such leaf damage can in turn influence the development of fruit and lead to a reduction [...] are mobile, whereas the rest of the larvae stadia remain flattened on the leaf. The fourth larva stadium develops into a white, oval case encircled by a

• Cyclamen mite

  brittle and smaller than usual. In cyclamen, the flowers are damaged and leaf growth is inhibited. In hedera, a mite attack can cause baldness in parts [...] between larva and adult mite during which the mite remains immobile on the leaf surface and does not feed.

• Leek

  times erroneously called a stem or stalk. This part is actually a bundle of leaf sheaths. This bundle is blanched by putting soil around it (so-called ‘t

• Beet armyworm

  mainly on the growing tips. They produce large holes in the leaf, sometimes stripping the leaf down to the mid-rib. Flowers and buds are also attacked. This

• Diamond back moth

  Damage symptoms The caterpillar is a surface feeder. They feed from the lower leaf surface, leaving the wax layer on the upper surface intact, thereby creating [...] remain quite small and active. Except for the first instar, which mines in the leaf tissue, the larvae are voracious surface feeders. The pupae of the diamond

• Fusarium wilt

  symptoms Fusarium fungi cause vascular wilt, root rot, foot and stem rot, leaf lesions, fruit rot, head blight in cereals and post-harvest decay. Fusarium

• Early blight

  then turn into dark brown angular lesions with a yellow halo restricted by leaf veins. Lesions can easily rupture. Other symptoms are brown lesions on stem

• Onion thrips

  can shrivel. Onion thrips (Thrips tabaci) is found mostly along the main leaf veins, with most damage evident where these veins join. Fruit damage, for

• Phytophthora blight

  zoospores produced in the sporangia. For germination on above-ground plant parts, leaf wetness is required. Dispersal is by wind and rain causes the pathogen to