Cannibalistic behavior of biological control agent Oenopia conglobata (Linnaeus, 1758) (Coleoptera: Coccinellidae) under laboratory conditions

Abstract Background Oenopia conglobata (Linnaeus) (Coleoptera: Coccinellidae) is a generalist predator feeding on several insect pests and utilized as a biological control agent in Türkiye. However, significant cannibalism has been observed among its different life stages under low food/prey availability. This study determined adult-egg, adult-larva, larva-egg, and larva-larva cannibalism of O. conglobata under laboratory conditions. Results Cannibalism among different life stages was observed under no supplemental diet (treatment group) or sufficient (100 Ephestia kuehniella eggs per individual) supplemental diet (control group). Fifty eggs per adult were provided to the 24 h-starved male and female adults for determining adult-egg cannibalism. Similarly, male, and female adults received 30 and 20 1st and 2nd instars, respectively to observe adult-larval cannibalism. Likewise, 10, 20, 30 and 40 eggs to 24-h starved 1st, 2nd, 3rd, and 4th instars, respectively were provided to record larval–egg cannibalism. By the same way, 12-h starved 4th instar was provided 1st instar (20 per individual) to determine larval–larval cannibalism. The experiments for males, females, and instars were conducted separately and cannibalism was assessed by prey consumption in treatment group relevant to the control group. Cannibalism significantly differed among sexes and instars (for larva-egg cannibalism). Overall, males and females consumed higher number of eggs in treatment group compared to their relevant controls. Female and male adults in treatment group exhibited 8.27- and 7.16-fold cannibalism on eggs. Likewise, females exhibited the highest cannibalism (2.84-folds) on 1st instar. The 4th instar consumed the highest number of eggs; however, the highest cannibalism rate was recorded for the 3rd instar. The 3rd instar exhibited 4.63-fold cannibalism on eggs. Nevertheless, the 4th instar exhibited 3.56-folds cannibalism on 1st instar. Conclusions Starved O. conglobata individuals exhibited significant cannibalism among different life stages. Therefore, during mass rearing they shouldn’t be starved. Furthermore, the cannibalistic behavior should be considered during the mass release of O. conglobata

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

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