B: Seasonal abundance of a Maskel or Oystershell scale Lepidosaphes pallidula (Williams) infesting mango trees at Qaliobiya Governorate
Lepidosaphes pallidula (Williams) (Figure 59) was the second serious diaspidid pest on mango trees, which is distinguished from other related species by the fusion of the antennal setae into a thick one on each antenna, the presence of blunt and sclerotized marginal spur on each side of each of the 2nd & 3rd abdominal segments; and the 3rd & 4th abdominal segments with 3-6 marginal gland spines on either side. so the seasonal fluctuation is studied.
Seasonal fluctuations of a Maskel or Oystershell scale Lepidosaphes pallidula (Williams) stages and total population infesting mango trees at Qaliobiya Governorate during two studied years from 1st January 2005 till mid December 2006 as shown in tables VIII & IX and illustrated in figures from 53 to 58.
Seasonal fluctuation of the pre-adult: As in the previous tables & figure (53), it showed that: there are three peaks and three depressions during each year of the study period; the highest peak was during March, which recorded (55 insect / leaf). Although the lowest & long depression, through the two studied years, was during summer season which reached (9 scale / leaf).
Seasonal fluctuation of the adult: Data in the tables and figure (54) gave also the same results, where the adult females through the two years of investigation have three peaks, the highest one detected on early March, with 31 insect / leaf. Also the adult females have three depressions during the two years that reached 8 insect / leaf during summer season.
Seasonal fluctuation of the gravid females: As for the gravid females in the same tables and figure (55), it was clear that the second year give two connected and raised peaks during late winter and spring ,reached(35-25insect/leaf) respectively and suddenly , continuous increasing during autumn(26 insect/leaf).
Seasonal fluctuation of the total population: The data obtained from the tables and figure (56) insured the presence of the maskel scale all over the year, also it showed that the total population of this scale insect during the two studied years gave the same picture, where the second year of investigation with clearly increasing in the numbers of the scale than the first one. There are also three peaks at the end of winter, spring and autumn seasons, but the summer season shows elongated depression. The highest value usually recorded at March, reached 103insect/leaf, the lowest one was at July with27 insect/scale.
The rate of the half monthly variation (H.M.V.):-
Data in tables VIII&IX and figures (57&58) indicated that rate of the monthly changes in the population of lepidosaphes pallidula (Williams) on mango trees during the two studied years (2005 & 2006). Data of the 1st year clearly showed there was a clearly increasing during autumn season reached 2.58 at November, this...