The relationship between some insect predators and aphid insects in Qena Governorate

The sweep net was used for studying the relationship between predators (Hippodamia convergens Guer. and Chrysopa carnea Stephens) and preys (Aphis faba Scopoli, Aphis gossypii Glover and Myzus persicae Sulzer). Regular samples were collected weekly from Alfalfa at the two stations (A & B) in the two trapping years (March 2007February 2009). The seasonal distributions showed that Hippodamia convergens Guer. ,Chrysopa carnea Steph., Aphis faba Scopoli, Aphis gossypii Glover and Myzus persicae Sulzer had three generations per year. The relationship between the activity of predators (H. convergens, C. carnea) and preys (A. faba, A. gossypii, M. persicae) explained that the more increasing in the predators the more decreasing in the population of the preys.


INTRODUCTION
Predation is a kind of intimacy where attacking one a predator to prey for food, and eliminate the predator with the prey a period of time and may exercise the predatory habits in the larval or nymph stages or in the adult insect, but some insects are predators in the adult insect or incomplete phase, such as (Family: Coccinellidae) or predators in the developed larvae only, such as some types of Aphid lion (Family: Chrysopidae).
The aim of the present work initiates to throw abeam light on the seasonal distribution of some species of Coleoptera, Hemiptera and Neuroptera..Moreover, this work is aimed to clarify the association between the predatory behaviors of Coccinellidae, Chrysopidae and aphid species.

MATERIAL AND METHODS
The sweep net was used for studying the relationship between catches of predators (Hippodamia convergens Guer.and Chrysopa carnea Stephens) and preys (Aphis faba Scopoli, Aphis gossypii Glover and Myzus persicae Sulzer) at the two stations (A& B) in the two trapping years (March 2007-February 2009).
The catches of predators (Hippodamia convergens Guer.and Chrysopa carnea Steph.) and preys (Aphis faba Scopoli, Aphis gossypii Clover and Myzus persicae Sulzer) in each station were counted to study the seasonal distribution and the relationship between catches of predators and Mohamed Z. Y. Aly et al. 132 preys.One was added to avoid the zero catches, and then the daily numbers were transformed into logarithms (Williams, 1935&1937).The five running mean was calculated in order to smooth the curve.The smoothed curve was superimposed on the histogram to have an idea about the number of generations.

RESULTS AND DISCUSSION
The seasonal distribution of Hippodamia convergens Guer.: An examination of

The seasonal distribution of Aphis faba Scopoli:
Table (2) shows that the total catch of Aphis faba collected in the two years by sweep net was 4836 individuals.Moreover, in the 2 nd year the catches were higher than that in the 1 st year.In addition to that, the largest numbers were collected in winter at the two stations in the two trapping years.In contrast, the lowest population was recorded in spring.The second generation was captured from mid August till late October but at station (B) of the 2 nd year this period started from mid August till early November.
The third generation appeared from early November to late February.The obtained results disagree with that obtained by Aly (1991), found that Aphis sp. had two generations per year.Disagreement perhaps result from the difference in the methods of the study, where the mentioned author, used the light trap nocturnally, while the present catches were collected diurnally by the sweep net.

The relationship between populations of Hippodamia convergens G. and Aphis faba Scopoli:
An examination of Figure (3) explained that, there is a relationship between the activity of H. convergens Guer.and A. faba Scopoli.This relation explains that the more increasing in the predator (H.convergens Guer.) reverse the more decreasing in the population of the preys (A.faba Scopoli) especially during summer and autumn.In contrast, the more decreasing in the population of predators (H.convergens Guer.) the more increasing in populations of preys (A.faba Scopoli) during winter.
Thus, it might be H. convergens populations had a high quality predation on A. faba.Results obtained by Dixon (1998) and Solomon et al., (2000) were in agreement with those results.They pointed out that most of predatory species especially Coccinellidae become abundant when the aphid density was already high.Some of present result was studied by Papachristos and Milonas (2008) and confirmed it when they worked on lady bird bettle as a predator and Vicia faba as a prey.Moreover the present result was agreed with those of Pinol et al., (2009).The last authors proved high quality of the coccinellids a predator on aphids.The relationship between some insect predators and aphid insects in Qena Governorate

135
The seasonal distribution of Aphis gossyipi Clover: Table (3) shows that the total catch of Aphis gossypii Glover collected in the two years by sweep net was 24960 individuals.However, in the 1 st year the catches were higher than that in the 2 nd year.In addition to that, The highest population of Aphis gossypii was recorded in winter at stations (A) of the 1 st year and (B) of the 2 nd year and in autumn at stations (B) of the 1 st year and (A) of the 2 nd year.Inversely, the lowest populations were collected during spring at the two stations in both years.As shown in (Fig. 4-B of the 1 st year and (A&B) of the 2 nd year) The first generation occurred from early March till late July, the second generation started from late July till early November and the third generation was captured from early November till late February.The second and the third annual periods were extended to be overlapped.

The relationship between catches of Hippodamia convergens Guer. and Aphis gossypii Glover:
An examination of Fig. ( 5), explains that, there is a relationship between the activity of H. convergens and A. gossypii.This relation explains that, the more decreasing in the predator (H.convergens) the more increasing in the population of the preys (A.gossypii) especially during summer and winter.Therefore, it could be a balanced relationship between the two mentioned predators and preys populations during spring.In contrast, disagreement was obtained by Conway et al., (2006), where they reported that the Coccinellids are generally most abundant and is most synchronized with cotton aphid density.Simelane et al., (2008) found that both N. fresenii and coccinellids (including Coccinella septempunctata) simultaneously contribute to declines of A. gossypii Glover densities in cotton fields.This disagreement may be due to the difference in species of the family.The seasonal distribution of Myzus persicae Sulzer: Table (4) shows that the total catch of Myzus persicae collected in the two years were 2240 individuals.Moreover, in the 2 nd year the catches were higher than that in the 1 st year.Regarding to the 1 st year, the seasonal distribution of M. persicae was recorded in winter at the two stations (A & B).However, the highest populations were recorded in spring at the two stations (A & B) during the 2 nd year.Inversely, the lowest population collected during autumn at station (A) of the 1 st year and in summer at stations (B of the 1 st year and A&B of the 2 nd year).Figure ( 6), shows that, M. persicae Sulzer had three generations per year.At station (A) of the 1st year, the first generation started from early March till late July, the second generation was captured from late July till early December and the third generation beginning on late December till late February as shown in (Fig. 6-A).At station (B) of the 1 st year, M. persicae Sulzer had three generations.The first generation started from early March till late July, the second generation occurred from mid September till early December and the third generation started from early December till late February as shown in (Fig. 6-B).Concerning the2 nd year at stations (A& B) three generations were detected.The 1 st generation was captured from early March till late July, the second generation beginning on mid September till early December and the third generation was collected from early December till late February.The relationship between populations of Hippodamia convergens Guer.and Myzus persicae Sulzer: An examination of Fig. ( 7), explains that, a relationship between H. convergens and M. persicae where, the more increasing in the predator (H.convergens) the more decreasing in the population of the prey (M.persicae) especially during autumn.Inversely, the more decreasing in the population of the predator (H.convergens) the more increasing in the population of the prey during winter.In addition, the predator may be able to consume most of preys during late summer and autumn.The relationship between some insect predators and aphid insects in Qena Governorate 139 However, they can be consuming less during spring.These results agree with those obtained by Obrycki et al., (1998), who found that Coccinella septempunctat.(Coleoptera: Coccinellidae reduced peak densities of M. persicae Sulzer (Hemiptera: Aphididae) (green peach aphid) on potatoes.Results obtained by Mack and Smilowitz (1982) are in agreement with results, where they showed that the interactions between coccinellids and aphids pests predict reductions of aphid densities based on predation rates and numbers of Coccinellidae, and these predictions are supported by empirical field studies.The seasonal distribution of Chrysopa carnea Steph.: Table (5) shows that the total catch of Chrysopa carnea collected in the two years were 885 individuals.However, in the 2 nd year the catches were higher than that in the 1 st year.In addition to that, the highest population of C. carnea was recorded in spring at stations (A) of the 1 st year and (A&B) of the 2 nd year and in autumn at station (B) of the 1 st year.Inversely, the lowest populations were recorded during summer at stations (A&B) of the 1 st year and (A) of the 2 nd year and in winter at station (B) of the 2 nd year.(2007)(2008)(2009).
Fig. ( 8), shows that, C. carnea had three generations during the 1 st year and two generations during the 2 nd year.The first generation started from early March till late May.The 2 nd generation was captured from early July till early November and the third generation occurred from early November till early January.Concerning the 2 nd year at station (A) two generations were detected.The relationship between population of Chrysopa carnea Stephens and Aphis faba Scopoli: An examination of Figure ( 9), explains that, there is a relationship between C. carnea and A. faba the more increasing in the predator (Chrysopa carnea) the more decreasing in the populations of the preys (Aphis faba) Spring, Summer .So, there is a relationship between the two mentioned predators and preys populations where C. carnea population has a high quality predation on A. faba especially during summer, autumn.In contrast, the more decreasing in the population of predators (C.carnea) the more increasing in populations of preys (A.faba) during winter.The above results agree with Honek and Kraus (1981), Aly (1991), where found that the size of the catch of C. carnea increase, with the density of aphid populations.

The relationship between catches of Chrysopa carnea Stephens and Aphis gossypii
Glover: An examination of Figure ( 10), explains that, a relationship between C. carnea Steph.and A. gossypii Glover where, the more decreasing in the predator (C.carnea) the more increasing in the populations of the preys (A.gossypii).So, there is a parallel relationship between the two mentioned predators and preys populations.This result disagree with Kabissa et al., (1996) claims that Chrysoperla sp.occurred on cotton when both H. armigera and A. gossypii were present.This dissimilarity may be due to the difference in the methods of the study or the weather factors.

The relationship between population of Chrysopa carnea Stephens and Myzus persicae Sulzer:
An examination of Fig. ( 11), indicated that, a relationship between C. carnea Steph.and M. persicae Sulzer where, the more increasing in the predator (C.carnea Steph.) the more decreasing in the population of the preys (M.persicae Sulzer) especially during autumn.In contrast, the more decreasing in the population of predators (C.carnea Steph) the more increasing in populations of preys (M.persicae Sulzer) during winter.In addition, the predator may be able to consume most of preys during autumn.However, they can be consuming less during spring.

Figure ( 2
Figure (2), shows that A. faba Scopoli had three generations per year.The individuals of the first generation were collected from early March till late April at the two stations in the two trapping years.
Fig 3: The relationship between the catches of Hippodamia convergens and Aphis faba over a period of two years (March 2007-February 2009)

Fig. ( 4
Fig. (4), shows that, A. gossypii Glover had three generations per year.The first generation started from early March till mid August, the second generation was collected from mid August till early December and the third generation was captured from early December till late February.
Fig. 5: The relationship between the catches of Hippodamia convergens and Aphis gossypii over a period of two years (March 2007-February 2009).

Fig. 6 :
Fig. 6: The daily fluctuations of Myzus persicae (superimposed curve on histogram represents the smoothed 5-days running mean).Number of individuals expressed as Log (n+1) Fig 7: The relationship between the catches of Hippodamia convergens and Myzus persicae over a period of two years (March 2007_ February 2009).
Fig. 8: The daily fluctuations of Chrysopa carnea (superimposed curve on histogram represents the smoothed 5-days running mean).
Fig. 9: The relationship between the catches of Chrysopa carnea and Aphis faba over a period of two years (March 2007-February 2009).

Fig. 10 :
Fig. 10: The relationship between the catches of Chrysopa carnea and Aphis gossypii over a period of two years (March 2007_ February 2009).Number of individuals expressed as Log (n+1)

Table 1 :
Table (1), suggests that the largest numbers of H. convergens were collected in autumn 2007, while in spring 2009 at the two stations (A&B).The number of H. convergens captured in two years was 6459 individuals.This result indicated that H. convergens was abundant in the 1 st year than the 2 nd year.On the other hand, the least numbers were trapped in winter of both years.Catches of Hippodamia convergens Guer at two different areas in Qena over a period of two years(2007)(2008)(2009).

Table 3 :
Catches of Aphis gossypii Glover at two different areas in Qena over a period of two years(2007)(2008)(2009).

Table 4 :
Catches of Myzus Persicae Sulzer at two different areas in Qena over a period of two years(2007)(2008)(2009)

Table 5 :
Catches of Chrysopa carnea Steph.at two different areas in Qena over a period of two years The 1 st one started from early March till early June.The 2 nd generation occurred from late August till late November.At station (B) C. carnea had two generations too, the 1 st generation started from early March till late May and the 2 nd period started from late August till early November.