Potential of Neoseiulus barkeri Hughes (Acari: Phytoseiidae) as a control agent for Tetranychus neocaledonicus André (Acari: Tetranychidae)

The red mite Tetranychus neocaledonicus has gained increasing prominence in agriculture due to its high biotic potential. To date, no registered biological control agents are available for the management of T. neocaledonicus. Therefore, the objective of this study was to evaluate the potential of Neoseiulus barkeri as a biological control agent for T. neocaledonicus. Feeding preference tests with and without choice were conducted, as well as assessments of the consumption and oviposition behavior of N. barkeri on various developmental stages of T. neocaledonicus. Additionally, the predation and oviposition performance of N. barkeri when fed T. neocaledonicus eggs were evaluated, along with the functional and numerical responses of N. barkeri when provided with T. neocaledonicus eggs. All tests were repeated 30 times, using gravid females of the predator (~4 days old) in each trial. Each repetition corresponded to a single trial. The average consumption of N. barkeri differed among the developmental stages of T. neocaledonicus, with the highest mean number of prey consumed being 12.43 phytophagous mite eggs. The younger stages of T. neocaledonicus resulted in a higher oviposition rate of N. barkeri compared with the older stages, with an average of 1.40 eggs laid per female. The consumption of T. neocaledonicus by N. barkeri exhibited a direct proportional relationship to the number of eggs provided, up to a density of 35 eggs, beyond which consumption stabilized. Conversely, the proportion of preys consumed exhibited an inverse relationship with increasing egg density. The predatory mite N. barkeri demonstrated a Type II functional response. The highest average consumption was 15.93 T. neocaledonicus eggs at the maximum density offered. The attack rate (a) and handling time (Th) of N. barkeri females on T. neocaledonicus eggs were 0.04 ± 0.003 h⁻¹ and 0.96 ± 0.05 h⁻¹, respectively. Based on these findings, N. barkeri shows promising potential for controlling T. neocaledonicus.