Insects are really highly adaptable organisms, with the highest diversity in the Animal Kingdom.

Till now, around 925,000 species have been described and the real number may be at least 3 times higher. Their adaptability enables them to cope with many environmental changes, including the recent climate's shifts due to global warming.

A new study made at University of Washington suggests that global warming seems to lead in fact to more insects. Warmer climates seem to increase their reproductive rate and population growth, with widespread effects on agriculture, public health and conservation.

An analysis of previous studies has shown that insects readily adapt to the environment's temperature. Those living in deserts easily tolerate high temperatures, but are much less tolerant to cold than mountain insects. Now scientists have found that insects that are adapted to warmer climates have faster population growth rates. "Warmer is better" for insects, said Melanie Frazier, a UW biology doctoral student. "Enhanced population growth rates for butterflies might be a good thing, but enhanced growth rates for mosquito populations is much more dubious," said Frazier. Or for pest insects, termites (photo) and so on…

"The findings suggest that evolutionary adaptation to climate warming will have profound ecological effects because rates of population growth eventually will alter entire ecosystems," Frazier said.

The web relationships inside the ecosystems are very sensitive to the population growth rates of the species that are part of the nutritional chains. Insects adapt to warmer climates using biochemical adaptation or behavioral shifts (they can change seasonal activity patterns), but may also avoid warmer temperatures moving to cooler habitats.

Of course, some insects may not adapt at all and disappear, but those that win will suffer population explosions. "No matter which scenario plays out for a given species, local ecosystems will be profoundly altered," Frazier said.

Already in Alaska and Siberia longer summers produce demographic explosions in defoliating and wood eating insects, that have led to the devastations in thousands of forest hectares, forest fires and damages of millions of dollars.