Shifting herbivory pattern due to climate change: A case study of himalayan balsam from Pakistan

Pests,diseases and weeds cause significant impact on crops and natural vegetation each year. climate change is likelyto cause a spread of tropical and sub-tropical species into temperate areas and to increase the numbers of many temperatespecies currently limited by low temperatures at high altitudes. the potential expansion of geographical ranges of pestspecies will be disruptive to quarantine barriers and is likely to result in increased damage to crops and natural vegetation inpreviously pest free areas. elm leaf beetle pyrrhalta luteola (mueller) is been reported to increase due to 0.3°c rise intemperature and 3-4% decrease in rainfall in the moist himalayan forest of pakistan. the insect attacks impatiencegladulifera royle.,a plant of medicinal importance. the plant is not only used in a variety of local medicines but is also oneof the important constituent of undergrowth natural vegetation in these forests. during the last 10 years the leaf damagedcased by the insect is on a hike and has increased up to 85%.