CLIMATIC DETERMINATION OF SYNANTHROPIC PEST ARTHROPOD PERFORMANCE: SPECIES RICHNESS, PESTICIDE RESISTANCE, AND CONTROL STRATEGIES

Abstract:
This review concerns aspects of climatic and microclimatic effects on biology and pest status of synanthropic pest species. The number of medical and synanthropic pest species in an area parallels overall species richness and the pest faunas of tropics and subtropics are more abundant than the fauna of temperate regions. The richer is the fauna of pest species the greater is probability of appearance of a “key pest”. The increased species richness is not necessarily correlated with overall pest damage, however, it requires greater complexity of control measures. The length of season favorable for performance of pest species increases as one moves from temperate zone to tropics. As a consequence, generation time of pest species decreases and the importance (pest status) of key species increases. Global increase of temperature may spread the area of high pest importance towards the North/South. Microclimatic changes associated with human activity already influence pest status and distribution of many species and proceeding urbanization spread convenient conditions nearly worldwide. Climatization of buildings may even change the timing of pest activity making winter period more convenient for pest breeding than the summer and set out of phase the dynamics of indoor and outdoor pests. Decreasing efficiency of chemical control increases the importance biological methods and baits. The frequency of insecticide resistant populations of medical and stored product pests is greatest in tropical and subtropical regions. The zone of highest frequency of origin of resistant strains of medical pests is between 20 - 40o latitude. This is the area of maximum conflict between temperature-driven speed of pest population growth and human effort to protect the resources from animal competitors. Climatic change may shift the boundary of this zone northwards.