Evaluation of Artemia franciscana Cysts to Improve Diets for Mass Rearing Stethorus gilvifrons, a Predator of Tetranychus turkestani

Abstract

Stethorus gilvifrons is an acarophagous coccinellid distributed in the Mediterranean region and could potentially be mass-reared for the augmentative biological control of Tetranychus turkestani and related species on crop plants. The hypothesis that brine shrimp Artemia franciscana cysts can improve diets for rearing of S. gilvifrons was tested in laboratory experiments. The diet treatments included A. franciscana cysts (D1), A. franciscana cysts plus a vitamin B complex (D2), A. franciscana cysts plus date palm pollen (D3), and A. franciscana cysts plus date palm pollen and Ephestia kuehniella eggs (D4). The results indicated that D1 did not support immature development. D2 supported egg–larval development but not pupal–adult development. Both D3 and D4 supported development to the adult stage and reproduction. However, D4 was the most effective diet, determined by observations of S. gilvifrons oviposition behavior and fecundity. A life table analysis corroborated these results; an intrinsic rate of increase, net and gross reproductive rates, and mean generation time were best for S. gilvifrons fed D4 rather than D3. A mixed diet composed of A. franciscana cysts, date palm pollen, and E. kuehniella eggs can be used to mass rear S. gilvifrons.

Comparison of natural prey Tetranychus turkestani, date palm pollen, and bee pollen diets on development, reproduction, and life table parameters of the predator Amblyseius swirskii

“…Even if date palm pollen was not harvested from the field, it could have been purchased at a low price. In a previous study, date palm pollen sheaths were obtained from a rural supplier in Ahvaz at a cost of 3.0-3.5 USD per kg (equivalent to four sheaths); approximately 6 g of pollen grains were within each kg of sheath (Ebrahimifar et al 2021). Commercial bee-collected pollen (of unknown plant origin) was purchased from a rural supplier in Ahvaz city.…”