Aphid propagation is mainly influenced by temperature. As more hours are close to the optimum temperature (20-32°C) and there is a food source available as higher will be the propagation rate. Whereas eggs and young instars are susceptible against dry air. Low relative humidities can damage aphid populations too (Model below 30% r.h.). Beside of insecticides, aphids are controlled by pretators and parasitic fungi. The prasitic fungi will be depending on moisture. Most of this species like Beauvaria bassiana are favoured by free moisture.
GRAPHS HAVE TO BE ADDED!!! In FieldClimate we display the risk of the propagation of aphids as follows:
Indrease of risk: optimal temperature between 20 and 32°C and relative humidity between 30 and 95% r. h.
Decrease of riks: too wet (leaf wetness, rain, or relative humidity above 95%), too cold (temperatures lower than 20°C) or too hot (temperatures above 32°C), wet nights (leaf wetness in night hours).
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