The bionomics of the tufted apple budmoth, Platynota idaeusalis in Michigan.
The tortricid Platynota idaeusalis (Wlk.) has 2 generations a year in south-western Michigan apple orchards. Populations diminish as one proceeds in a north-easterly direction from the south-western corner of the state. Injury to apple fruit and foliage was slight throughout south-western Michigan. The appearance of percentages of the adult male population at predicted day-degree accumulations is reported. Variation among orchard locations occurs, with more day-degrees being accumulated at corresponding population percentages as one moves inland (east) from Lake Michigan. The adult male is active throughout the night, peak flight occurring between midnight and 04.00 h. An insignificant number of larvae was parasitised by a braconid, Microgaster pantographae Mues. Windsor and Schmidt sweet cherries serve as additional hosts.