How insects survive floods


This photo taken by the UK’s Department for International Development (DFID), following an unprecedented monsoon season in Pakistan, reveals the dramatic effect severe flooding can have on local environments. In July 2010 the same amount of rain that would typically fall in a decade fell in a week in southern Pakistan, and the water didn’t recede for months.

The extent of the flood spanned an area the size of the UK and forced the local wildlife – including birds, animals and insects – to seek refuge on higher ground. Four months later something remarkable began to happen: all the trees and other plantlife in the region started to develop ghostly white veils of silk. Millions of spiders, as well as other bugs, were spinning webs in the trees high over the water.

An interesting reported side effect of this unusual natural phenomenon was that, despite the fact the water was receding slowly and leaving massive pools of stagnant water, mosquito numbers remained relatively low. This was unusual because still water conditions are ideal for helping complete the mosquito life cycle. Authorities had therefore expected the mozzie population to soar; instead numbers were down. The mosquitoes were thought to be getting ensnared in these blankets of silk. This positively impacted on public health by reducing the incidences of malaria in the area as a result.