Co-parasitization effect of Anagyrus pseudococci (Girault) and Coccidoxenoides perminutus Girault (Hymenoptera: Encyrtidae) on the vine mealybug Planococcus ficus (Signoret) (Hemiptera: Pseudococcidae) and their intrinsic interspecific larval competition

Abstract Background The vine mealybug Planococcus ficus (Signoret) (Hemiptera: Pseudococcidae) is a cosmopolitan species that causes economic damage to grapevines, especially in Mediterranean countries, South Africa, North and South America and Europe. In this study, the co-parasitization effect of Anagyrus pseudococci (Girault) and Coccidoxenoides perminutus Girault (Hymenoptera: Encyrtidae) on the vine mealybug Planococcus ficus (Signoret) (Hemiptera: Pseudococcidae) and their intrinsic interspecific larval competition were investigated under laboratory conditions. Results In non-choice experiments, the highest parasitism value (11.75 ± 0.87) was obtained on 2nd instar mealybug nymphs in containers with only C. perminutus, while the highest parasitism value (11.20 ± 0.59) in choice experiments was obtained on female mealybugs in containers with both parasitoids. It was determined that C. perminutus parasitized the 1st, 2nd and 3rd nymph stages, while A. pseudococci parasitized the 2nd, 3rd nymph and female stages of vine mealybug. These mean that mealybug populations can be controlled more effectively by parasitizing all mealybug stages in the environment when parasitoids are together. In intrinsic interspecific larval competition experiments on the mealybugs 2nd and 3rd nymph stages, where both parasitoids can parasitize, it was determined that C. perminutus generally won the competition, even though A. pseudococci had a three-day parasitism priority. The highest A. pseudococci emergence rate in competition trials occurred on 2nd instar mealybug nymphs when A. pseudococci had 72 h parasitism priority (36.09%). In addition, head capsule width and tibia lengths of A. pseudococci and C. perminutus adults obtained from intrinsic interspecific larval competition were measured, and it was determined that the head capsule width and tibia length of adult parasitoids generally increased as the host period progressed. In addition, it has been determined that there may be some differences in the measured characteristics of the adult parasitoids obtained due to intrinsic interspecific competition compared to the control. Conclusions Using these two parasitoids together in the biological control of vine mealybugs will allow parasitizing all mealybug nymph stages and females in the environment and provide more effective pest control.