Population Fluctuations and Infestation Rates of the Peach and Mediterranean Fruit Flies on Fig Fruits in Relation to the Prevailing Weather Factors in Fayoum Governorate

Abstract

The Egyptian fruits are attacked by two of the most harmful tephritid pests, the peach fruit fly, Bactrocera zonata (Saunders), and the Mediterranean fruit fly, Ceratitis capitata (Wiedmann) causing considerable damage. In Fayoum governorate, fig trees are cultivated in condensed plantations to produce their fruits in two overlapped crops per year from July till December. This paper was contributed to saving more information about the occurrence of B. zonata and C. capitata flies in a fig cultivated areas in Fayoum governorate in relation to the effect of various weather factors on their activity and estimating the mentioned fruit flies infestation rates. During the 1st season (2016), the highest peaks of B. zonata and C. capitata population were observed during the 2nd week of October and 1st week of November with respective mean values of captured flies per trap per day (FTD) of 0.48 and 0.74 fly/trap/day. While during the 2nd season (2017), the highest peak of B. zonata and C. capitata males were observed during the 1st week of September and 2nd week of November with a mean FTD values of 1.31 and 0.62 flies/trap/day, respectively. Concerning infestation rates, during the 1st season, the highest mean percentage of fruit infestation was observed during the 1st week of October with a mean of 4.32% occurring by B. zonata females indicating by the emerged flies of B. zonata flies from sampled infested fruits. The fig fruits infestation by B. zonata females continued until the 1st week of November, while, C. capitata females started to attack fig fruits during the 4th week of October and continued until the 3rd week of November. Concerning the 2nd season(2017), the highest mean percentage of fig fruits was recorded during the 1st week of September with a mean of 5.42% occurring by B. zonata females, while, C. capitata infestation on fig fruits was observed firstly during the 2nd week of October and continued until the 2nd week of December coinciding with end of fig fruits harvesting. Throughout the two studied seasons, the trapped males of B. zonata were negatively and insignificantly correlated with both of maximum and minimum temperatures, while, the relative humidity % affected positively insignificantly and positively significantly on B. zonata males activity during 2016 and 2017, respectively. On the other side, C. capitata trapped males were significantly and negatively correlated with maximum and minimum temperatures, while, relative humidity reflected a significant positive correlation with the population of the fruit fly.