Effect of different food on adult productivity of Sympherobius pygmaeus (Rambur) (Neuroptera: Hemerobiidae)

Abstract: As in many other beneficial insects, biological studies are carried out on Chrysopidae and Hemerobiidae (Neuroptera) in order to increase the density of their populations in nature. Within a developed variety of methods, two of them are the most popular. One is mass production and release of beneficial insects to nature and the other is applying artificial foods on crop plants to ensure that adults lay more eggs. In this study, adult Sympherobius pygmaeus lifetime and egg numbers were compared according to results obtained by feeding on different foods. Four different artificial and natural food experiments were carried out at 25 °C constant temperature with 60 ± 10% relative humidity in (16:8) long day lighting climate cabinets. In this experiment, water, 10% of honey-water, mealybug and mealybugs + 10% honey-water were given as nutrients to determine adult S. pygmaeus total egg, daily egg production, and the periods of preoviposition, oviposition, postoviposition and total lifetime. When foods given to adult S. pygmaeus were compared, the highest daily egg rate (30.34 eggs/female/day) was observed with the mealybug and the lowest (1.74 eggs/female/day) with water. The maximum preoviposition period (4.00 days) was obtained with water and the lowest (1.40 days) with mealybug + 10% honey-water. When the effects of different foods to the lifetime were examined, the longest lifetime was 22.70 days for mealybug while the shortest was 9.38 days for water. The highest total number of eggs and daily egg number were 349.67 and 30.34, respectively, on mealybug as food; the lowest was 15.87 and 1.74, respectively, on water. Finally, the highest intrinsic rate of increase (rm, females/female/day) was 0.128 in the mealybug nutrient experiment and the lowest was found to be 0.054 for water. The net reproductive rate (Ro, females / female) parameter obtained was 150.7 for mealybug and the lowest 6.8 for water.