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

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.

First record of two insects preying on the red tomato spider mite Tetranychus evansi (Acari: Tetranychidae) in Latakia governorate, Syria

The red tomato spider mite Tetranychus evansi is an important invasive pest of solanaceous plants worldwide. It has been recorded in Syria since 2011 in Latakia governorate, a Mediterranean coastal region. During survey conducted in 2019, the ladybird beetle, Stethorus gilvifrons (Mulsant) (Coleoptera: Coccinellidae) and the acarivorous gall midge, Feltiella acarisuga (Vallot) (Diptera: Cecidomyiidae) were identified in association with T. evansi colonies on tomato and black nightshade from 12 sites in Latakia. Larvae of F. acarisuga, and larvae and adults of S. gilvifrons, were observed preying on all developmental stages of T. evansi. This is the first record of T. evansi as a prey of S. gilvifrons. A literature review of Stethorus and Feltiella species previously reported in association with T. evansi on solanaceous plants is also provided.

Effects of Three Artificial Diets on Life History Parameters of the Ladybird Beetle Stethorus gilvifrons, a Predator of Tetranychid Mites

Background: The ladybird beetle Stethorus gilvifrons (Mulsant) is an important natural enemy of tetranychid mites and functions as a biological control of these plant pests. The development, survival and reproduction of S. gilvifrons were studied when fed on three artificial diets. The components of the artificial diet that S. gilvifrons could be reared successfully on for one generation with no use of tetranychid mites were examined. Methods: Artificial diets consisted of sucrose, honey, royal jelly, agar, yeast, date palm pollen supplemented in different diets with hen’s egg yolk (AD1, as basic diet), Ephestia kuehniella Zeller eggs (AD2), or E. kuehniella eggs and 2,4-dihydroxybenzoic acid (AD3). Results: Adults and larvae of Stethorusgilvifrons fed on AD1 had a shorter immature development and preoviposition periods than those fed on AD2 and AD3. The total number of deposited eggs was significantly higher for the females fed on AD3 than on the other diets. The intrinsic rate of increase (r) of S. gilvifrons was highest on AD3, followed by AD2, and AD1. Conclusion: Stethorus gilvifrons performed best on AD3, indicating the potential of this artificial diet for the mass rearing of this important predatory ladybird beetle.

Biological and Ecologiacl Studies of Pradator Stethorus Gilvifrons (Mulsant((Coleopter:Coccinellidae) on Mites Tow Spotes Tetranychus Urticae (Koch) (Acari:Tetranychidae) in Province of Babylon

This study was conducted in the lab to find out effect of different temperature degree and humidity on life and environment of predator Stethorus gilvifrons which feeding on mites (tow spotes) Tetranychus urticae. The study showed that the predator has three ecdison which represent four larva stagest the temperature degree wide effected on the predator life the average life are ( 23.00 , 17.00 , 12.00 and 10.00) day and the average of eggs for female are ( 126.6 , 180.0 , 225.0 and 106.6) egg at 20 , 25 , 30 , 35c° respectively. The results showed that females at 30c° lay out high average at eggs (225.0) while lay out less average at 35c° ( 106.6) the high average of period lay out eggs at 20c° represented 80 day at daily average lay out egg (1.5) day while raged (34.3) day at 35c° at average daily lay at egg reached (3.1) day. The results showed that high average pre period and after lay out reached 8.6, 25 day respectively at 20c° wile reached lay average at 2.3, 5.6 day at 35c° respectively.