~1~ Journal of Entomology and Zoology Studies 2014; 2 (2): 1-7 ISSN 2320-7078 JEZS 2014; 2 (2): 1-7 © 2014 JEZS Received: 06-02-2014 Accepted: 12-03-2014 A. Khaliq Department of Agricultural Entomology, University of Agriculture, Faisalabad, Pakistan. E-mail: abdulkhaliq1931@gmail.com; Tel: +923444667987 M. Javed Department of Agricultural Entomology, University of Agriculture, Faisalabad, Pakistan. E-mail: mudassar_560@yahoo.com Tel: +923026409218 M. Sagheer Department of Agricultural Entomology, University of Agriculture, Pakistan. E-mail: sagheersharif@yahoo.com Tel: +923338360262 Mubasshir Sohail University College of Agriculture, University of Sargodha, Pakistan. E-mail: mubasshirsohailroy@gmail.com Tel: +923217963946 Correspondence: A. Khaliq Department of Agricultural Entomology, University of Agriculture, Faisalabad, Pakistan. E-mail: abdulkhaliq1931@gmail.com; Tel: +923444667987 Environmental effects on insects and their population dynamics A. Khaliq, M. Javed, M. Sohail, Muhammad Sagheer ABSTRACT Insects are powerful and rapid adaptive organisms with high fecundity rate and short life cycle. Due to human interruption in agro-ecosystem and global climatic variations are disturbing the insect ecosystem. Erosion of natural habitats, urbanization, pollution and use of chemicals in agro- ecosystem manifold the intensity of environmental variations. Both a-biotic (temperature, humidity, light) and biotic (host, vegetative biodiversity, crowding and diets) stresses significantly influence the insects and their population dynamics. In response to these factors insect may prolong their metamorphic stages, survival and rate of multiplication. Insect’s immune responses as melanization, lysozyme level and phenoloxidase (PO) modify the physiology and morphological behavior against different factors like diets, gases and chemicals. Keywords: Gymnopleurus, Karyotype, Chromosomal rearrangements, Scarab beetle. 1. Introduction Global changes are responsible for wide range of anthropogenic and natural environmental variation [27] . These climatic and weather changes not only affect the status of insect pests but also affect their population dynamics, distribution, abundance, intensity and feeding behavior [5] . Intensity of change in climatic ecosystem noted by meteorological science has showed a direct and indirect affect on the prey and host relationship, their immune responses and rate of development, their fecundity and various physiological functions [64, 65, 5] . Studies conducted during 2008-2012 on various factors including anthropogenic, biotic and a-biotic were assume to be the responsible of Asian Longhorn Beetle distribution [52, 10] . A-biotic disturbances particularly upper and lower thermal affects check the insect multiplication, diapauses, emergence, flight and the dispersal rate [64, 65] . Not only high temperature thresh hold is responsible for these variation but cool temperature play an important role in intrinsic properties of insect species [46] . For instance, insects facing to cooled stress will possess dark body color as compare to those living in hot climate. In addition to a-biotic factors, biotic changes are also equally responsible for the physiological, behavioral and morphological adaptations in the insects along with its population fluctuation [44, 31] . Among biotic stresses of agro-ecosystem, terrestrial flora played most vital role in the development of various stages of terrestrial insects, their oviposition and hatching success. On the plants different insects feed like pollinator and other herbivorous. Plants showed various responses against different insect pests. Certain bivore induce plant volatile influence the carnivorous insects to attack on folivorous species [11, 36] . In this study strong effect of florivory and folivory were significantly affected due to emission of HIPVs contrary to the pollinator visitation [36] . 2. A-biotic factors Anthropogenic and natural environmental variations are voraciously affecting the arthropods with the passage of time. Certain factors like thermal affect is changing the status of pest by suppressing or stimulating genetic potential, rate of fecundity and mortality and range of hosts [21, 46] . Variable wavelength of white light specifically for red and far red light when absorbed by photosynthetic system as an unambiguous signal of proximity of hearers causing a good developmental responses like shade avoidance responses [49] . Survival rate of young ones of Cnaphalocrosis medinalis (Rice leaf folder) was affected at 35 °C even adults emerging from these pupae could not laid eggs. In some biological control agents particularly C. lividipennis (egg predator) showed a positive response to predation and decrease the handling time [28] .