Franco Banfi / Sea star (Hacelia attenuata) on coral covered with mucilage, a symptom of rising sea temperature, Vis Island, Croatia, Adriatic Sea, Mediterranean.

Nigel Cattlin / Tomato (Solanum lycopersicon) with blossom end rot, symptom of calcium deficiency, cultivated in glasshouse. Berkshire, England, UK. July.

Nigel Cattlin / Apple (Malus domestica) tree leaves with interveinal chlorosis, symptom of iron deficiency.

Nigel Cattlin / Apple (Malus domestica) branch with fruits and leaves. Leaves exhibiting interveinal chlorosis, symptom of iron deficiency.

Franco Banfi / Red gorgonian coral (Paramuricea clavata) covered with mucilage, a symptom of rising sea temperature, Ventimiglia, Italy, Ligurian Sea, Mediterranean.

Franco Banfi / Yellow gorgonian (Eunicella cavolini) covered with mucilage, a symptom of rising sea temperature, Punta Campanella Marine Reserve, Massa Lubrense, Italy, Tyrrhenian Sea, Mediterranean.

Franco Banfi / Red gorgonian coral (Paramuricea clavata) covered with mucilage, a symptom of rising sea temperature, Punta Campanella Marine Reserve, Massa Lubrense, Italy, Tyrrhenian Sea, Mediterranean.

Franco Banfi / Sea urchin (Sphaerechinus granularis) on coral covered with mucilage, a symptom of rising sea temperature, Vis Island, Croatia, Adriatic Sea, Mediterranean.

Franco Banfi / Yellow gorgonian (Eunicella cavolini) covered with mucilage, a symptom of rising sea temperature, Vis Island, Croatia, Adriatic Sea, Mediterranean.

Franco Banfi / Red gorgonian coral (Paramuricea clavata) covered in mucilage, a symptom of rising sea temperature, Punta Campanella Marine Reserve, Massa Lubrense, Italy, Tyrrhenian Sea, Mediterranean.

Nigel Cattlin / Early symptoms of False smut (Ustilaginoidea virens) on Rice (Oryza sativa) ears , Philippines.

Paul D Stewart / Woodcut illustration of the 'Monster of Krakow' was reported widely in the mid sixteenth century as a real occurence. It was seen by many protestants as a monstrous symptom of divine displeasure at th...

Nigel Cattlin / Dark, necrotic spots on Barley (Hordeum vulgare) leaves, a symptom of manganese deficiency, England, UK.

Shane Gross / Yelloweye rockfish (Sebastes ruberrimus) showing esophageal eversion, a symptom of barotrauma, Entrance Island, British Columbia, Canada.

Shane Gross / Yelloweye rockfish (Sebastes ruberrimus) showing esophageal eversion, a symptom of barotrauma, Entrance Island, British Columbia, Canada.

Nigel Cattlin / Exterior skin of a potato (Solanum tuberosum) tuber showing spraing, a symptom of Tobacco rattle virus (TRV) and Potato mop-top virus (PMTV).

Nigel Cattlin / Cross section of a potato (Solanum tuberosum) tuber showing spraing, a symptom of Tobacco rattle virus (TRV) and Potato mop-top virus (PMTV).

Nigel Cattlin / Early symptom of Verticillium dry bubble disease (Lecanicillium fungicola) lesions on the fruiting cap of a commercially grown mushroom (Agaricus bisporus).

Nigel Cattlin / Necrosis and chlorosis on potato leaflets, a symptom of magnesium deficiency in a garden crop, Berkshire, UK, July.

Nigel Cattlin / Purple seed stain (Cercospora kikuchii) characteristic staining symptom caused by the disease to soybean seeds

Nigel Cattlin / Mottling and reticulation of an apple leaf caused by apple mosaic virus (AMV)

Nigel Cattlin / Interveinal chlorosis a symptom of manganese deficiency on an apple leaf

Nigel Cattlin / Sugar beet rust (Uromyces beticola) fungal disease pustules on a sugar beet leaf, Champagne Region, France

Nigel Cattlin / Sugar beet rust (Uromyces beticola) fungal disease pustules on a sugar beet leaf, Champagne Region, France

Nigel Cattlin / Powdery mildew (Erysiphe betae) fungal disease on the leaf of sugar beet, Champagne region, France, September

Nigel Cattlin / Apple scab (Venturia inaequalis) infection spots germinated from a spore shower on an apple leaf, New York, USA,

Nigel Cattlin / Early leaf spot (Cercospora arachidicola) fungal disease necrotic lesions on a peanut leaflet, North Carolina, USA

Nigel Cattlin / Rhizomania symptom of hairy secondary root development and necrosis caused by beet necrotic yellow vein virus (BNYVV) to sugar beet, Greece

Nigel Cattlin / Rhizomania symptom of hairy secondary root development caused by beet necrotic yellow vein virus (BNYVV) to sugar beet, Greece

Nigel Cattlin / Needle cast (Rhabdocline pseudotsugae) discolouration and symptoms of infection on douglas fir needles

Nigel Cattlin / Chocolate spot (Botrytis fabae) early symptoms of discreet necrotic loesions on the leaf of a field bean (Vicia faba)

Nigel Cattlin / Black sigatoka (Mycosphaerella fijiensis) lesions and necrosis on the leaves of young bananas, Malaysia, February,

Nigel Cattlin / Yellow sigatoka (Mycosphaerella musicola)lesions and necrosis on the leaves of young bananas, Malaysia, February,

Nigel Cattlin / Yellow sigatoka (Mycosphaerella musicola)lesions and necrosis on the leaves of young bananas, Malaysia, February,

Nigel Cattlin / Focus of infection of BYDV (barley yellow dwarf virus) with chlorosis and leaf tipping symptoms in maturing wheat crop in ear. England, UK.

Nigel Cattlin / Severe symptoms, chlorosis and necrosis, caused by magnesium deficiency on the edge of an oilseed rape leaf

Nigel Cattlin / Focus of infection of barley yellow dwarf virus (BYDV), red leaf damage symptoms on young oats crop, Hampshire, England, UK.

Nigel Cattlin / Focus of infection of barley yellow dwarf virus (BYDV), red leaf damage symptoms on young oat crop, Hampshire, England, UK.

Nigel Cattlin / Symptoms of magnesium deficiency on grapevines in fruit in Gironde, France, August

Nigel Cattlin / Symptoms of magnesium deficiency on grapevines in fruit in Gironde, France, August

Nigel Cattlin / Leaf-rolling sawfly (Blennocampa pusilla) leaf rolling symptom on rose leaves, Devon, England, UK, July

Nigel Cattlin / Leaf-rolling sawfly (Blennocampa phyllocolpa) leaf rolling damage symptom on rose leaves, Devon, England, UK, June

Nigel Cattlin / Twisted flag leaf a symptom of copper deficiency in a wheat crop and a lack of nutrient minerals in the soil

Nigel Cattlin / Blossom end rot, calcium deficiency symptoms on a glasshouse grown tomato fruit var. Roma, Berkshire, England, UK, September

Nigel Cattlin / Blossom end rot, calcium deficiency symptoms on a glasshouse grown tomato fruit var. Roma, Berkshire, England, UK, July

Nigel Cattlin / Blossom end rot, calcium deficiency symptoms on a glasshouse grown tomato fruit var. Roma, Berkshire, England, UK, July

Nigel Cattlin / Yellow leaf striping, chlorosis symptoms of magnesium deficiency in a maize, corn crop in mature cob

Nigel Cattlin / Typical symptom of blank ears or whiteheads caused by root and stem diseases in a wheat crop, premature ripening