Popis: |
The pomegranate butterfly Virachola livia constitutes a severe pest to the pomegranate in Tunisia, since its record in 2006. However, V. livia was found to breed not only in the pomegranate but also in the pods of Acacia farnesiana which is a very common plant in Gabes region (South-East of Tunisia). This study which was carried out in Metwia (the most infested area in Gabes) from April to July 2013, aims to clarify some biological aspects of V. livia on A. farnesiana such as: fly of adults, egg laying, larva development, pupae and number of generation. Randomized samples of green Acacia pods were collected weekly from different trees of A. farnesiana. In the lab, pods were examined under a binocular to detect eggs, after pods were desiccated to count larva stage and pupae. The monitoring of adults activity and emergence were made by experimental apparatus both in the field and the laboratory. The preliminary results show that A. farnesiana is the main and primary host plant of V. livia in South Tunisia. On A. farnesiana this pest develops three annual generations, each one lasts about four weeks. The first generation starts late in April and finished in the end of May. The second one is from the end of May to about the twenty five of the next month; the third is from the last one to the middle of July. Due to the absence of green pods on the tree from July, the butterfly migrates to its alternative host the pomegranate. |