Coccinellidae November depending on location and weather conditions. Homes or other buildings near fields or woods are particularly prone to infestation. After an abnormally long period of hot, dry weather in the summer of 1976 in the UK, a marked increase in the aphid population was followed by a "plague" of ladybirds, with many reports of people being bitten as the supply of aphids dwindled. The presence of coccinellids in grape harvests can cause ladybird taint in wines produced from the grapes. "Harmonia axyridis" (the harlequin ladybird) is an example of how an animal might be partly welcome and partly harmful.
Weather forecasting essential for preventing and controlling wildfires. Different indices, like the "Forest fire weather index" and the "Haines Index", have been developed to predict the areas more at risk to experience fire from natural or human causes. Conditions for the development of harmful insects can be predicted by forecasting the evolution of weather, too. Electricity and gas companies rely on weather forecasts to anticipate demand, which can be strongly affected by the weather. They use the quantity termed the degree day to determine how strong of a use there will be for heating (heating degree day) or cooling (cooling degree day).