Population fluctuations of American bollworm, Helicoverpa armigera (Hüb.)‎ influenced by some weather factors in pea, Pisum sativum (L.)‎ and cotton, Gossypium barbadens (L.)‎ fields in Sharkia governorate, Egypt

Abstract EN

The present study was conducted in Zagazig Distrcit, Sharkia Governorate, Egypt in pea (Pisum sativum) and cotton (Gossypium barbadens) fields under environmental conditions during ٢٠١٣/٢٠١٤ and ٢٠١٤/٢٠١٥ seasons.

Results indicated that the population of the American bollworm male moths, Helicoverpa armigera (Hübner) had five peaks in the two investigated seasons and it started from the ٢nd week of December until the end week of March in the first season and form the end week of Dec.

until the ٤th week of April in pea fields in the second one.

The highest mean number of moths was recorded during the ٤th and the ٢nd week of March during the aforementioned seasons, respectively.

Which being ٣.٣٣ and ١٠.٠٠ moths/trap/week in both seasons, respectively.

Statistical analysis showed that the relationship between weekly mean numbers of H.

armigera male moths on pea plants, mean temperature and mean RH (%) was positive and negative insignificant in the season of ٢٠١٤; was negative and insignificant with mean temperature, while RH (%) showed positive and significant in the season of ٢٠١٥.

The tested weather factors of mean temperature and mean RH (%) affected the catch male moths of H.

armigera negatively or positively with significant or insignificant differences as explained variance values of ١٧.١٨ and ٢٥.٤٦% were recorded during first and second seasons, respectively.

In cotton fields, the population of H.

armigera male moths was detected in pheromone traps showing ٥ and ٧ peaks during the period from the ٢nd week of May until the end week of August in the first season, while the populations started form the ٤th of April until ١٢th of Sept.

in the ٢nd season.

The highest number of moths was recorded during the ٣rd of July and ٢٩th of May in the ١st and ٢nd seasons, respectively exhibiting ١٨٨.٠٠ and ٦٠.٠٠ moths/trap/week in both seasons, respectively.

Also, results indicated negative and insignificant correlation between the weekly mean numbers of H.

armigera male moths on cotton plants and mean temperature and mean RH (%) in the season of ٢٠١٤, but it was positive and significant as well as negative and insignificant correlation in the season of ٢٠١٥, respectively.

The total effect of the tested factors was ١٥.٩٩ and ٢٤.٨٨% during the seasons of ٢٠١٤ and ٢٠١٥, respectively.