Population dynamics of cabbage looper [Trichoplusia ni (Hübner, 1803) (Lepidoptera: Noctuidae)] in almond orchards

Abstract

Background: Cabbage looper [Trichoplusia ni (Hübner, 1803) (Lepidoptera: Noctuidae)] is a significant pest of field crops and greenhouses in various parts of the world. Although cabbage is the preferred host for the pest, it harms several other crops. Cabbage looper infests almond orchards in Turkey; however, its population dynamics is unknown. Methods: The current study determined population dynamics of cabbage looper in three almond (Amygdalus communis L.) orchards located in Eyyübiye, Haliliye, and Karaköprü districts of Şanlıurfa province, Turkey. Population dynamics were monitored by sex pheromone traps (5.0 mg E5 Decenyl acetate and 1.0 mg E5 Decenol). Three pheromone traps were set up in each orchard during the last week of March, and emergence time, population density, population peaks, and activity duration of cabbage looper were monitored with the traps. The traps were monitored twice a week until the first adult emerged. Afterward, the traps were monitored weekly, and the numbers of adults captured by the traps were recorded. Results: The peak population development of cabbage looper was recorded in Eyyübiye (45 adults/trap), Karaköprü (43 adults/trap), and Haliliye (40 adults/trap) on 13, 20, and 27 April, respectively. The population declined after these peaks, and the pest could not develop a significant population from the second half of June until September. The pest population was again recorded at the end of September and in the first week of November. The total number of adults caught by pheromone traps was 156, 181, and 117 adults/trap in Eyyübiye, Haliliye, and Karaköprü orchards, respectively. Conclusion: It is concluded that cabbage looper adults remain active for at least seven months from the beginning of April to the beginning of November in almond orchards situated in Şanlırfa province, Turkey. Therefore, management strategies should be developed during the peak development periods. Nevertheless, the damage caused by the pest is still unknown in the country; therefore, economic damages should be determined in future studies. Furthermore, pest risk analysis and modeling of the potential spread of cabbage looper in almond production areas could further provide valuable information on the risks related to the species.

Keywords

• Population development
• Almond orchards
• Non-conventional pest
• Pheromone traps