THE EFFECT OF PEAR VARIETY, NUMBERS OF LACE BUG INSECTS AND SOME OTHER ENVIRONMENTAL FACTORS ON THE DAMAGE AREA AND PERCENTAGE RESULTING FROM INFECTION BY THE LACE BUG INSECT IN MOSUL CITY-IRAQ

Abstract

Findings of the current study have shown that the damage volume and percentage have started with the primary appearance of lace bug adults. The more the insect numbers increased; the more the damage area and percentage were, and have reached 3.10, 3.52, 4.5Cm3 and 67, 16, 91, 17, 20.08% for Zafarnia, Othmani, and Le-Cont varieties respectively when the insects average number was 7, 13.5, 17.5 insectleaf for the varieties at temperature average of 27.96C and relative humidity of 51.5%, whilst damage area and percentage have reached in the 1st of August 7.7, 8, 11.52 for the damage area respectively and 15, 34, 89, 33, 40.67% for damage percentage respectively; at temperature average of 27.16C and relative humidity of 35.5%. A decrease in the insects average number to 2.25, 4, 9.75 insectleaf for the Zafarnia, Othmani, and Le-Cont pear varieties has resulted in a damage area and percentage of 0.39, 0.78, 2.62Cm2 and 2.16, 4.06, 10.83% respectively at temperature average of 10.08C relative humidity of 75.81%. The results also revealed a significant and positive correlation between insect number and temperature and the damage average area and percentage while the correlation with relative humidity was significant and negative for the varieties under discussion.