Population dynamics of soil mites, Nesoribatula pacifica Aoki (Oribatulidae), Pediculaster geotrupi Mahunka (Pygmephoridae) and Arctoseius bilinear Nasr (Ascidae) under wheat was carried out in two districts, Diarb-Nigm and Zagazig, Sharkia Governorate, Egypt during two growing seasons 2020/2021-2021/2022. The population of N. pacifica increased forming two peaks; the first peak was recorded on December 20th, reaching to (24&9 individual) in both seasons, while the second peak was recorded on (January 19th & February 3rd ), reaching to (30 &11 individual) in the two seasons in Zagazig, respectively. while, in Diarb-Nigm, (3 & 4 peak) were recorded in both seasons, as follow: during (January 4th, February 3rd & March 20th), reaching to (15,26 & 28 individual) in the 1st season, respectively and during (December 5th, January 19th, February 18th & March 20th), reaching to (12, 7, 15 & 17 individual) in the 2nd season, respectively. The mite, P. geotrupi recorded three peaks during both seasons on (December 5th, January 4th & February 3rd) and (January 4th, February 3rd & March 5th), was reaching to (15, 12 & 20 and 20, 27 & 23 individual) in Zagazig, respectively. While, in Diarb-Nigm, (2 & 3 peak) were recorded in the 1st and 2nd seasons, respectively as follows: in the first season appeared two peaks during (February 3rd & March 20th), were reaching to (15 & 23 individual), respectively; the 2nd season recorded three peaks during (January4th , February 3rd & March 5th), were reaching to (15, 31 & 43 individual), respectively.
In the two districts, A. bilinear was recorded three peaks in both seasons except that the 1st season in Diarb-Nigm (2 peaks). The peaks appeared as follows: three peaks during (December 5th, January 19th &February 18th) and (December 20th, February 18th & March 20th), were reaching to (7, 5 & 4 and 4, 4 & 3individual) in both seasons in Zagazig, respectively; while they were on (December 19th & March 5th), reaching to (9 & 4 individual) in the 1st season, (December 5th, February 19th & March 5th), reaching to (5,9 &18 individual) in the 2nd in Diarb-Nigm, respectively. Interaction between the mites with soil temperature recorded highly significant during 2020/2021-2021/2022 in both districts. The mite, N. pacifica was the most dominant mite species recorded (145 & 127 individual) during the 1st season in both districts, respectively. While, P. geotrupi recorded the highest average (171 & 139 individual) in both districts during the 2nd seasons, respectively. Therefore, A. bilinear recorded the lowest average (17 & 55 individual) in both districts during the two seasons. The correlation between P. geotrupi and soil temperature was significant negative (r= -0.65*) (b= -0.23) in Zagazig during the 2nd season, but it was highly significant negative (r= -0.78**) (b= -0.14) regarding to N. pacifica during the 1st season. On the other hand, the correlation between the mites and soil temperature was non-significant in Diarb-Nigm during both seasons.
Conclusively, population dynamics of the three soil mites, Nesoribatula pacifica (Oribatulidae), Pediculaster geotrupi (Pygmephoridae) and Arctoseius bilinear (Ascidae) under wheat was carried out during two seasons 2020/2021-2021/2022 in two districts, Diarb-Nigm and Zagazig. Interaction between M. pacifica and soil temperature was highly significant in Zagazig, followed by P. geotrupi was significant in Diarb-Nigm; while, A. bilinear was non-significant. N. pacifica was the most dominant species recorded during the 1st season, followed by P. geotrupi during the 2nd season in both districts while A. bilinear was the lowest numbers.