The combined effect of the tested climatic factors on the pre-adults activity: The combined effect of these climatic factors on the pre-adults population was significant for the first year (2016/2017) and a highly significant through the second year (2017/2018) where the «F» values were 3.77 and 4.61 during the two years, respectively in Table 2. The percentage of variability that could be attributed to the combined effect of these tested factors on the insect population which were 44.25 and 49.27% for the two years, respectively.

Adult females population

Effect of daily mean maximum temperature: Results are represented in Table 1 showed that the simple correlation (r) between the daily mean maximum temperature and the population density of adult females was insignificant positive (+0.28 and +0.13) during the first and second years, respectively. As well as, the calculated regression coefficient (b) for the effect of this factor indicated that every 1 ˚C increase in the daily mean maximum temperature, would increase the population by 0.29 and 0.13 individuals per branch for the both years, respectively (Table 1). The precise effect of this factor on the adult females population (Table 2) showed that it was insignificant effect and positive relation (P. reg. value was +2.80), the value of the partial correlation was (+0.43) and (t) value was (+2.07) for the first year and insignificant negative for the second year (P. reg. was -0.80). Also, the value of partial correlation was (-0.21) and the value of t-test was (-0.95) when the mean daily minimum temperature, mean relative humidity and dew point become around their means. The obtained results revealed that, daily mean temperature within the optimum range of adult females activity for the first year and around the optimum range of adult females population during the second year. This climatic factor was responsible for the certain changes in the population of adult females by 14.13 and 3.28% during the two years, respectively (Table 2).

Effect of daily mean minimum temperature: The results of statistical analysis of simple correlation in Table 1 showed positive relation and insignificant effect between the daily mean minimum temperature and adult females population (r values were +0.26 and +0.20) during the two years of study, respectively. The unit effect regression coefficient (b) indicates that an increase of 1 °C in the daily mean minimum temperature, would increase the population by 0.26 and 0.21 individuals per branch in the two years, respectively (Table 1). Concerning, the partial regression values are represented in Table 2, emphasized an insignificant positive relation (+0.31 and +5.27), the values of partial correlation were (+0.08 and +0.43) and t-test) values were (+0.37 and +2.08) in the two years, respectively, when the mean daily maximum temperature, relative humidity and dew point become around their means. The obtained results revealed that, daily mean minimum temperature within the optimum range of the adult females activity in the both years. This factor was the least effective variable in changes of the adult females population by 0.45% during the first year and was responsible for the certain changes in the population by 15.65% during the second years, respectively (Table 2).

Effect of the mean relative humidity: As shown in Table 1, it was noticed a insignificant negative effect between this climatic factor and the adult females population (r value was -0.05) in the first year and insignificant positive correlation (r value was +0.07) for the second year. In the same time, the simple regression coefficient indicates that an increase of 1% in the mean relative humidity, would decrease the population by 0.03 individuals per branch through the first year and would increase the population by 0.04 individuals per branch, for the second year (Table 1). The real effect of this factor appeared from the partial regression values that, referred to the significant positive effect (P. reg. values were +1.37 and +1.74), the values of the partial correlation were (+0.54 and +0.44) and t-test values were (+2.83 and +2.11) for the 1st and 2nd years, respectively, when the mean daily maximum temperature, minimum temperature and dew point become around their means. Results revealed that, mean relative humidity was under the optimum range of adult females activity and this climatic factor was the most effective climatic variable in population changes of the adult females by 26.46 and 16.13% during the both years, respectively (Table 2).

Effect of mean dew point: Data in Table 1 obtained that, the effect of mean dew point on adult females activity was insignificantly positive (+0.32 and +0.33), the calculated regression coefficient (b) for the effect of this factor indicated that for every 1˚C increase, the population would increase by 0.61 and 0.65 individuals per branch during the first and second years, respectively.

The partial regression coefficient for the effect of mean dew point on the adult females population are represented in Table 2, revealed that it was insignificant negative relation (P. reg. values were -1.97 and -4.63) and the values of the partial correlation were (-0.40 and -0.36), also (t) values were (-1.93 and -1.71) during the both the two years, respectively, when the mean daily maximum temperature, minimum temperature and relative humidity become around their means. The obtained results revealed that, mean dew point was around the optimum range of adult females population and this climatic factor was responsible for the certain changes in the population of adult females by 12.31 and 10.57% during the two years, respectively (Table 2).

The combined effect of the tested climatic factors on the adult females: The results showed that the combined effect of these tested factors on the insect population of adult females was insignificant where the «F» values, were 2.81 and 2.14 during the two year respectively (Table 2). The multiple regression analysis revealed that the tested studied variables together were responsible of the changes in the adult females population. The percentages of explained variance were 37.20 and 31.04% for the two years, respectively.

Gravid females’ population

Effect of daily mean maximum temperature: The results in Table 1, the correlation coefficient (r) between the daily mean maximum temperature and gravid females activity was feeble insignificant effect and positive relation (+0.01) in the first year (2016/2017) and negative relation (-0.07) during the second year (2017/2018). The unit effect regression coefficient (b) indicates that an increase of 1 °C in the daily mean maximum temperature, would increase the population by 0.02 individuals per branch for the first year and would decrease the population by 0.09 individuals per branch for the second year (Table 1).

Concerning, the partial regression values are represented in Table 2, emphasized an insignificant negative relation (-1.77), the partial correlation was (-0.22) and (t-test) value was (-1.00) in the first year (2016/2017) and it was a significant negative (P. reg. value was -2.53), the partial correlation was -0.46) and the value of t-test was (-2.25) during the second year (2017/2018), when the mean daily minimum temperature, relative humidity and dew point become around their means. The obtained results revealed that, daily mean maximum temperature around the optimum range of the gravid females activity in the first year (2016/2017) and above the optimum range of the gravid females population during the second year (2017/2018) and this factor was responsible for the certain changes in the gravid females population by 4.28% during the first and was the most effective variable for the changes in the population by 17.93% during the second years (Table 2).

Effect of daily mean minimum temperature: Data in Table 1 showed the correlation coefficient (r) between daily mean minimum temperature and the gravid females population was insignificant positive and weak (+0.10 and +0.03) for the 1st and 2nd years, respectively. The calculated regression coefficient (b) for the effect of this factor indicated that for every 1 ˚C increase, the population would increase by 0.12 and 0.05 individuals per branch for two years of study, respectively (Table 1).

The precise effect of this factor on gravid females population revealed that, it was insignificant positive from the partial regression (P. reg. value = +2.20), the partial correlation was (+0.42) and t value was (+2.02) in the first year (2016/2017) and was insignificant negative effect (P. reg. value = -1.91), the partial correlation was (-0.57) and the value of t-test was (-0.13) during the second year (2017/2018), when the mean daily maximum temperature, relative humidity and dew point become around their means (Table 2). The obtained results revealed that, mean minimum temperature was within the optimum range of gravid females activity in the first year and around the optimum range in the second year. This climatic factor was the most effective weather variable in changes of the gravid females population by 17.66% during the first year and was least effective variables during the second year by 1.13% (Table 2).

Effect of the mean relative humidity: As shown in Table 1, it was noticed a insignificant effect and feeble positive correlation between this climatic factor and the population density of gravid females (r value was +0.01) for the first year and insignificant negative (r value was -0.11) in the second year. In the same time, the simple regression coefficient indicates that an increase of 1% in the mean relative humidity, would increase the population by 0.01 %, for the first year and would decreased the population by 0.10 % through the second year (Table 1). The exact effect of this factor appeared from the partial regression value that, referred to the insignificant positive effect (P. reg. value was +0.29), the values of the partial correlation was (+0.11) and the value of t-test was (+0.46) during the first year (2016/2017) and insignificant negative effect (P. reg. value was -1.94), the value of the partial correlation was (-0.37) and the value of t-test was (-1.76) during the second year (2017/2018), when the mean daily maximum temperature, minimum temperature and dew point become around their means (Table 2).

Results revealed that, mean relative humidity was within the optimum range of gravid females activity during the first year and around the optimum range during the second year and this climatic factor was the least effective variable for the changes in the population of gravid females by 0.92% for the first year and was responsible for the certain changes in the population by 10.90% during the second year (Table 2).

Effect of mean dew point: Data in Table 1 obtained that, the effect of mean dew point on the population activity of gravid females was insignificantly effect and feeble positive relation (+0.03 and +0.01) during the both years, respectively. The calculated regression coefficient (b) for the effect of this factor indicated that for every 1 ˚C increase, the population of gravid females would increase by 0.06 and 0.02 individuals per branch during the two years, respectively (Table 1). The partial regression coefficient for the effect of mean dew point on the population density of gravid females are represented in Table 2, revealed that it was insignificant negative effect and weak (P. reg. value = -0.07), the partial correlation was (-0.01) and the value of t-test was (-0.05) during the first year (2016/2017) and it was insignificant positive effect (P. reg. value was +4.62), the partial correlation was (+0.28) and t value was (+1.28) in the second year (2017/2018) and when the mean daily maximum temperature, minimum temperature and relative humidity become around their means (Table 2). The obtained results revealed that, mean dew point was around the optimum range of gravid females activity in the first year and within the optimum range in the second year. This climatic factor was the least effective weather variable in changes of the gravid females population by 0.01 and 5.76% during the two years, respectively (Table 2).

The combined effect of the tested climatic factors on the gravid females activity: The combined effect of these climatic factors on the population density of gravid females was insignif icant where the «F» values, were 1.04 and 2.33 during the two years, respectively (Table 2). The percentage of variability that could be attributed to the combined effect of these tested factors on the activity of gravid females which were 18.00 and 32.89% for the two years, respectively (Table 2).

Total population

Effect of daily mean maximum temperature: As reported in Table 1, the correlation coefficient (r) between the mean daily temperature and total population of W. mimosae was insignificant positive (+0.11 and +0.23) in the two years, respectively. The unit effect regression coefficient (b) indicates that an increase of 1 °C in the mean daily maximum temperature, would increase the population by 1.57 and 3.05 individuals per branch during the both years, respectively (Table 1).

The partial regression values emphasized an significant negative, relation was (-39.47), the partial correlation was (-0.48) and the value of ‘’t test ‘’ was (-2.36) for the first year (2016/2017) and it was a significant positive effect (P. reg. value was +25.68), the partial correlation was (+0.53) and the value of t-test was (+2.74) during the second year (2017/2018), when the mean daily minimum temperature, relative humidity and dew point become around their means. The obtained results indicates that, daily mean maximum temperature above the optimum range of total population activity for the first year and under the optimum range of insect population during the second year and this climatic factor was responsible for the certain changes in the total insect population of by 15.97 and 19.10% during the two years, respectively in Table 2.

Effect of daily mean minimum temperature: Data in Table 1 showed the correlation coefficient (r) between daily mean minimum temperature and the total population of pest was insignificant positive and weak (+0.10 and +0.12) for the 1st and 2nd years, respectively. The calculated regression coefficient (b) for the effect of this factor indicated that for every 1 ˚C increase, the population would increase by 1.38 and 1.62 individuals per branch for two years of study, respectively (Table 1). The exact effect of this factor on insect population revealed that, it was insignificant negative from the partial regression (P. reg. value = -7.88), the partial correlation was (-0.17) and t value was (-0.77) in the first year (2016/2017) and it was highly significant negative effect (P. reg. value was -107.80) the partial correlation was (-0.66) and t value was (-3.81) in the second year (2017/2018), when the mean daily maximum temperature, relative humidity and dew point become around their means (Table 2). The obtained results revealed that, mean minimum temperature was around the optimum range of total population activity in the first year and was entirely above the optimum range of insect population activity during the second year. This climatic factor was the least effective variable in changes of the total population by 1.100% during the first year and was the most effective weather variable for the changes in insect population during the second year by 36.99% (Table 2).

Effect of the mean relative humidity: Results in Table 1 revealed that, the effect of this weather factor on total population of W. mimosae. The correlation coefficient (r) was insignificant relation and negative (r values were -0.30 and -0.31) for the two years, respectively. The calculated regression coefficient (b) for the effect of this factor indicated that for every 1% R.H. increase, the population would decrease by 2.47 and 2.79 individuals per branch for the both years, respectively (Table 1). The exactly relationship between this climatic factor and total population of pest was determined by the partial regression values (Table 2), which emphasized an highly significant negative during the two years. An increase of one degree in the mean relative humidity, would decrease the total population of pest by 23.10 and 31.80 individuals per branch provided that other three factors remain constant during the two years, respectively. Also, the values of the partial correlation were (-0.66 and -0.62) and the values of t-test were (-3.87 and -3.45) when the mean daily temperature and dew point become around their constant means during the two years, respectively in Table 2. The obtained results revealed that, the mean relative humidity entirely above the optimum range of total population activity during the both years. This factor was the most effective variable in the insect population by 42.86% during the first year and was responsible for the certain changes in the population by 30.33% during the second year Table 2.

Effect of mean dew point: Data in Table 1 showed that, the effect of mean dew point on total population activity was feeble insignificant effect and positive relation (+0.01) in the first year (2016/2017) and was insignificantly negative relation (-0.03) during the second year (2017/2018). The unit effect regression coefficient (b) indicates that an increase of 1 °C in the mean dew point, would increase the population by 0.25 individuals per branch for the first year and would decrease the population by 0.77 individuals per branch for the second year (Table 1).

The real relationship between this climatic factor and the activity of the insect population was determined by the partial regression values (Table 2), which emphasized highly significant positive relation in the both years. An increase of one degree in the mean dew point, would increase the population by 36.82 and 97.92 individuals per branch provided that other three factors remain constant during the two years, respectively. The values of the partial correlation were (+0.56 and +0.60) and the values of t-test were (+2.93 and +3.23) during the two years, respectively, when the daily mean maximum temperature, minimum temperature and relative humidity become around their constant means. The results revealed that, mean dew point was entirely under the optimum range of insect population activity and this climatic factor was the responsible for the certain changes in the total population density by 24.61 and 26.65 % during the two years, respectively in Table 2.

The combined effect of the tested climatic factors on the total population of L. tapleyi: The results in Table 2 showed that, the combined effect of these tested factors on the total population of W. mimosae was insignificant where the «F» value was 3.99 during the first year and highly significant where the «F» value was 5.06 during the second year, respectively. The amount of variability that could be attributed to the combined effect of the tested factors on the total population of insect were 45.65 and 51.56% for the two years, respectively. The remaining unexplained variances are assumed to be due to the influences of other undetermined and unconsidered factors that were not included in this study in addition to the experimental error.

Prediction of different alive stages of W. mimosae: Furthermore, the most effective climatic factors, that could be used to predict different alive stages of W. mimosae, were daily mean maximum air temperature (x₁), minimum temperature (x₂), relative humidity (x₃) and dew point (x₄). Prediction equation for general, the preadults, adult females, gravid females and total population of W. mimosae were concluded according to the statistical analysis on basis the two cumulative years together and presented as follow:

a. For pre-adults population:

Y = 600.1 + 4.47x₁ − 25.12x₂ ** −11.73x₃ * +15.17x₄E.V. = 23.67%

b. For adult females population:

Y = −40.50 + 0.33x₁ + 1.18x₂ + 0.73x₃ * –0.69x₄ E.V. = 21.98%

c. For gravid females population:

Y = 71.02 * –2.53x₁** + 1.54x₂ – 0.49x₃ + 0.81x₄ E.V. = 18.54%

d. For total population of pest:

Y = 630.63 * +2.27x₁ – 22.40x₂ * –11.49x₃ ** + 15.83x₄ E.V. = 24.38%

Where is, Y= Prediction value. E.V.% = Explained variance

*Significant at P ≤ 0.05 **Highly significant at P ≤ 0.01

The aforementioned results on the effect of tested weather factors on the insect population of W. mimosae during the two successive years emphasize that the effect of these factors varied from year to another. Also, the mean of relative humidity and dew point during the first year (2016/2017) and the daily mean minimum air temperature and mean of relative humidity through the second year (2017/2018) was the most effective variables for the changes in the total insect population.

Effect of the biotic factor (Ants density) on the activity of different stages of W. mimosae population

Impact of ant exclusion versus ant presence on the population density of different stages of W. mimosae on sunt trees

The impact of foraging ants, Messon sp. (Hymenoptera: Formicidae) on the population size of the honeydew-producing wax scale insect, W. mimosae on sunt trees were carried out at Esna district, Luxor Governorate during the two successive years through the period from September 10th, 2016 up to August 25th, 2018 are represented in Table 3 & 4 and graphically illustrated in Figure 2. The trends of fluctuation in the numbers of insect population of W. mimosae between branches of sunt trees with and without ants were almost similar, however, with different values. Accordingly, its better to discuss the seasonal activity on the basis of monthly mean number of insect population counts per branch in trees containing ants and in trees which ants were excluded at the successive sampling dates.

For each stage of pest, means for population density of W. mimosae among the untreated (ant presence) and treated trees (ant exclusion) with the pesticide were compared using paired T-test.

For each stage of pest, means for population density of W. mimosae among the untreated (ant presence) and treated trees (ant exclusion) with the pesticide were compared using paired T-test.

The obtained results are presented in Tables 3 & 4 and graphically illustrated in Figure 2, showed that, the foraging ants were more abundant on the branches of untreated sunt trees and were absent on the branches of treated sunt trees with diazinon 60% EC (3ml/Liter water) during all studied months in the both two years of study. Also, the results indicated that significantly greater differences in the numbers of different stages of W. mimosae were occurred between trees with ants and without ants in all dates of inspection during the both years of study. The mean number of total population per branch through the whole year was 110.18 ± 9.39 and 114.06 ± 9.71 individuals per branch in trees containing ants and 66.84 ± 5.53 and 65.21 ± 5.41 individuals per branch in trees which ants were excluded during the first and second years, respectively.

Over first year (2016/2017), the mean numbers of insect population through the whole year was 50.03 ± 7.41, 28.86 ± 4.19, 16.81 ± 2.82, 95.70 ± 10.21, 6.88 ± 0.71 and 7.60 ± 0.81 individuals per branch in trees with ants and it was 29.72 ± 4.28, 17.21 ± 2.49, 10.84 ± 1.82, 57.77 ± 5.99, 4.58 ± 0.45, 4.49 ± 0.47 and 66.84 ± 5.53 individuals per branch in trees without ants were recorded on the first instar nymphs, second instar nymphs, third instar nymphs, pre-adults total, adult females and gravid females of W. mimosae, respectively are represented in Table 3 and illustrated in Figure 2.

During the second year (2017/2018) the mean numbers of insect population through the whole year was 56.41 ± 8.34, 26.65 ± 3.76, 14.90 ± 2.35, 97.96 ± 10.36, 7.20 ± 0.73 and 8.89 ± 0.98 individuals per branch in trees containing ants and it was 31.91 ± 4.63, 15.10 ± 2.13, 9.19 ± 1.45, 56.20 ± 5.79, 4.55 ± 0.44 and 4.46 ± 0.49 individuals per branch in trees excluded ants were recorded on first instar nymphs, second instar nymphs, third instar nymphs, pre-adults total, adult females and gravid females of W. mimosae, respectively are represented in Table 4 and illustrated in Figure 2. The difference in the mean population density of W. mimosae among the untreated (with ants) and treated trees (without ants ) with the pesticide was highly significant differences (paried T-test) during the two years of study, the values t-test during the first year (2016/2017) were (3.17, 2.98, 2.73 and 3.94) and through the second year (2017/2018) were (3.18, 3.25, 3.05 and 3.96) for the pre-adults total, adult females, gravid females and total population of W. mimosae, respectively at P ≤ 0.05.

The aforementioned results clearly showed that the high abundance of W. mimosae on sunt trees containing foraging ants. As well as, mean numbers of different stages of W. mimosae population on trees included foraging ants was substantially greater about one and half times than that on trees of foraging ants exclusion. This is may be due the ants may increase the survival and reproductive capacity of the coccids [22] and can stimulate its development [23]. Ants can protect hemipteran species from their natural enemies thereby compromising biological control [24]. Also, ants may remove dead scale insects from aggregation, perhaps reducing the spread of parasitoids into the remainder [6]. Removal of honeydew improves the sanitation of coccid aggregation by reducing physical fouling caused by both the sugary excreta and the sooty moulds which grow on it [25].

Generally, it may be concluded that the honeydew-seeking ants can markedly stimulate the development of W. mimosae on sunt trees. These results agree with that obtained by Ahmed [26], in Egypt, however with different insect species, also studied the effect of ant exclusion on sugarcane infestation by Pulvinaria tenuivalvata (Newatead). He reported that the foraging ants were more abundant on the sugarcane plants of untreated plots and were absent on the sugarcane plants of treated plots during the period of the experiment.

Evaluation of the density dependent-relationship between population density of different stagesof w.mimosae and ants density

The density- dependent response was determined for the honeydew-seeking ants, Messon sp. to the different stages of W. mimosae population during the different seasons of year (autumn, winter, spring and summer) and on the over year through the two years of study (2016/2017 and 2017/2018) are represented in Table 5 and graphically illustrated in Figure 3 & 4.

By plotting numbers of the percentages of ants density on sunt trees (dependent factor) against the age structure of different stages of W. mimosae (independent factor), the analysis indicated

that the percentages of ants were relatively more correlated and positive with the percentages of adult females and gravid females of pest in all seasons of the year and on the over year through the both years of study. But, there are negative correlations between the percentages of ants and the percentages of pre-adults population of W. mimosae during the all seasons of the year and on the whole year through the two years are represented in Table 5 and graphically illustrated in Figure 3 & 4.

a = Constant; r = Simple correlation; b = Simple regression; S.E = Standard error; *Significant at P ≤ 0.05; **Highly significant at P ≤ 0.01

The simple regression revealed that, significant increase in the percentages of ants, Messon sp. was shown in the different seasons of the year and on the whole year with increasing the percentages of adult females of insect ranged from (0.03 to 0.31%) for the first year and from (0.03 to 0.24%) during the second year, respectively. A similar trend in the increase of the percentages of ants and the percentages of gravid females was observed. The effect regression coefficient (b) indicates that an increase of 1% in the population of gravid females, would increase the percentages of ants about 0.02- 0.04% for the first year and 0.03-0.04 % during the second year in the different seasons of the year and on the whole year, respectively. Differently, the synchronization between percentages of pre-adults population and the percentages of ants activity are negative. An increase of one% in the population of pre-adults, would decrease the percentages of ants density about 0.02- 0.04% for the first year and 0.02-0.03 % during the second year in the different seasons of the year and on the whole year, respectively are represented in Table 5 and graphically illustrated in Figure 3 & 4.

The density relationship between the percentages of ants density on sunt trees (Y) against the percentages of different stages of W. mimosae population (X) could be represented by the following submodels.

In the first year (2016/2017)

a. Pre-adults population stage:

Y = 2.7971 − 0.0281xIn autumn;Y = 3.0014 − 0.0295xIn winter

Y = 3.5065 − 0.0351xIn spring;Y = 2.0214 − 0.0166xIn summer

Y = 2.8172 − 0.0274xOver the year

b. Adult females population stage:

Y = −0.0323 + 0.1215 x In autumn;Y = 0.5216 + 0.0404x In winter

Y = 0.209 + 0.3124x In spring;Y = 0.2489 + 0.0264x In summer

Y = 0.5173 + 0.036x Over the year

c. Gravid females population stage:

Y = −0.0077 + 0.0365x In autumn;Y = 1.2299 + 0.0275x In winter

Y = −0.024 + 0.0393x In spring;Y = 0.8172 + 0.0217x In summer

Y = 0.4824 + 0.0333x Over the year

In the second year (2017/2018)

a. Pre-adults population stage:

Y = 2.317 − 0.0234x In autumn;Y = 2.3739 − 0.0238x In winter

Y = 2.885 − 0.0291x In spring;Y = 2.537 − 0.0246x In summer

Y = 2.4602 − 0.0244x Over the year

b. Adult females population stage:

Y = −0.0004 + 0.0882 x In autumn;Y = 0.436 + 0.0291x In winter

Y = 0.2073 + 0.2482x In spring;Y = −0.0266 + 0.0369x In summer

Y = 0.3928 + 0.0321x Over the year

c. Gravid females population stage:

Y = −0.0199 + 0.0315x In autumn;Y = 0.7444 + 0.031x In winter

Y = −0.0527 + 0.0327x In spring;Y = 0.705 + 0.0357x In summer

Y = 0.3707 + 0.031x Over the year

Overall, the synchronization between the percentages of adult females and gravid females of pest and percentage of ants density were good and the simple regression analysis were more correlated and its positive in all seasons of the year and on the over year. In contrary, the percentages of pre-adults individuals and the percentages of ants were not good and it exhibited negative response in all seasons of the year and on the whole year. The obtained differentiations may be that the adult females and gravid females of pest produced more honeydew than preadults individuals. These results were coincided with results of Henneberry et al. [27], mentioned that the adult females of Bemisia tabaci produced more honeydew than nymphs and was subject to large degrees of variation. Also, changes in plant physiology may be reflected in B. tabaci feeding biology.

There is little published information comparing the quantity of honeydew produced by adult females and nymphs of insect pests. Henneberry et al. [27], reported that the honeydew drops of females, on average, were larger in size compared with those of nymphs. The implications of the differences in honeydew excreted by nymphs and females are unknown. However, differences in amounts may be partially explained by differences in the sizes of nymphs and females. The carbohydrate aspects of the pest host interaction are complex and may significantly reflect on biological and ecological adaptations of the insect. Blua & Toscano [28], reported that nymphs did not initiate honeydew production for 3 to 5 days following emergence.

From this study, it may be concluded that the population density of honeydew-seeking ants on sunt trees is interfering with biological control, increasing the possibility of out breaks of the honeydew producing insects. Also, the method of excluding ants that is effective and non disruptive to the ecosystem in urgently required to ensure continued stability in sunt trees in Luxor Governorate, southern Egypt.

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