Neoseiulus longispinosus (Evans, 1952)

K, Prajjval Sharma, Sharma, Prem Lal, Verma, Subhash Chander, Chandel, Rajeshwar Singh & SharmaK, Shubham, 2025, Predatory potential ofNeoseiulus longispinosus (Acari: Phytoseiidae) following exposure to fungicides, Acarologia 65 (1), pp. 116-129 : 117-118

Treatment of Neoseiulus longispinosus with fungicides

To determine the impact of four fungicides on the predatory potential of Neoseiulus longispinosus , the wettable powder (WP) formulations of mancozeb 75% WP (Indofil M-45®; 2500 ppm), copper oxychloride 50% WP (Blitox® 50 W; 3000 ppm), thiophanate methyl 70% WP (Roko®;

1000 ppm), and metalaxyl 4% + mancozeb 64% WP (Ridomil Gold®; 2500 ppm) were used. Tomato leaf discs ( 3 cm × 3 cm) from the ′Solan Lalima′ variety were treated with these fungicides at the recommended doses using a modified leaf dip technique based on the of Helle and Overmeer (1985). Each leaf disc was immersed in the fungicide solution for

15 seconds, while control discs were dipped in distilled water. After air drying for three hours, the treated discs were placed upside down on a damp sponge within experimental trays. Concurrently, tomato plants of the same variety grown in a polyhouse were sprayed with the respective fungicides using the knapsack sprayer for the residual toxicity experiments. For each treatment and control, 600 gravid females of N. longispinosus (5 days old) were individually placed on the treated leaf discs over a water saturated sponge in plastic trays. Each treatment included two experimental setups. In the first setup, 300 gravid females were provided with T. urticae eggs ad libitum as prey, while in the second setup, 300 N. longispinosus females were provided with T. urticae protonymphs ad libitum for a 48-hour exposure period. Six plastic trays, each containing 50 tomato leaf discs, were used for each setup within a treatment. To observe the mortality of N. longispinosus females after the exposure period, the leaves were transferred using forceps onto a wet sponge placed in a Petri plate and examined under a binocular microscope. The predatory mite females that exhibited no appendage movement when touched were considered dead. A cohort of N 100. longispinosus eggs from each experimental setup were collected from the surviving females in each treatment and control group for further experiments.