MOUSE-POPULATIONS AND THEIR CONTROL IN NEW-YORK-CITY

Field studies were conducted to establish correlation between mouse po pulation infestation levels and environmental, sanitary and maintenanc e standards of apartment, commercial buildings and food establishments in the New York City. In general, higher relative mouse infestation l evels were encountered in the apartment buildings in comparison to com mercial and food establishments. The well-maintained structures with e xcellent status of environmental and maintenance conditions had signif icantly (p < 001) lower rate of mouse infestation (trap index 0 . 85-1 . 89) when compared to buildings with poor to fair status (trap index 8 . 48-26 . 75). This correlation was more evident in the case of apa rtment buildings, where relative mouse density was about 10 times lowe r in excellent status buildings when compared to poor status buildings possessing all adverse conditions conducive for mice survival and mul tiplication. The field efficacy of various rodenticides and their form ulations revealed Bromadialone (0 . 005%) meal to be effective in cont rolling mouse populations (94 . 5%) followed by pellet formulation 0 . 005% of Brodifacoum (91 . 25% control success). In dry, non-humid con ditions, the use of zinc phosphide (10%) tracking powder controlled mo use populations at 100% levels. All observations are discussed in rela tion to the ecology, biology and ethology of house mice.