A survey for primary and secondary Hymenopteran parasitoids of scale insects (Homoptera: Coccoidea) in fruit orchards (apple, plum, date, olive, fig, citrus), was conducted in Syria during 2009–2012. Thirty three species of parasitoids belonging to the families Aphelinidae, Encyrtidae, Eulophidae and Pteromalidae were recorded as parasitoids on scale insects. Thirty two of these were primary parasitoids and one was a hyperparasitoid. The family with the greatest number of genera and species is Encyrtidae with 8 genera (48% of the total) and 12 species (35% of the total). The genus with the greatest number of Encyrtid species was Metaphycus. Parasitoids of scale insects identified included several species already included on the List of biological control agents widely used in the EPPO region ‘EPPO Positive list' and suggestions for additions to this list were made.

A survey of the common Aphytis spp. Howard (Hymenoptera: Aphelinidae) parasitoids was carried out at four citrus orchards (which were not treated with chemical pesticides) in AL‐Hanade, Stamo, Tarjano and Hmaiem in Lattakia Governorate from September 2010 to September 2011. Six parasitoid species of the genus Aphytis were reared from living armoured scale insects isolated in four states. They were Aphytis lepidosaphes (Compere), Aphytis lingnanesis (Compere), Aphytis chrysomphali (Mercet), Aphytis melinus (DeBach), Aphytis maculicornis (Masi) and Aphytis hispanicus (Mercet).

Morphobiological indicators and selection index are helpful tools to obtain promising genotypes and selecting multiple traits for genetic improvement of the predator, Cryptolaemus montrouzieri (Mulsant) (Coleoptera: Coccinellidae). The present study was carried out at the Biological Control Department, Lattakia, Syria, during 2016. Three quantitative traits (QTs), fecundity, preying potential of the 3 rd larval instar and larval developmental period, were studied through inbreeding program of 12 successive generations. The numerical changes of the (QTs) were studied across the generations and according to the three tested lines in comparison with control in order to determine the effect of each genetic line. Genetic parameters variances (phenotypic, genetic, environmental, phenotypic coefficient, genotypic coefficient, environmental coefficient, and broad-sense heritability) were estimated for each trait, separately and according to their approved lines, as well as the relative economic value of each trait involved in the design of the selection index equation. Obtained results showed that there were significant reductions in all the studied quantitative traits in the control, when (Po) was compared with (F12). Fecundity and reproduction showed the highest depression and response to the inbreeding program (42.28 and 46.93%), respectively. Statistical analyses of the fecundity line showed significant increases in length of the female, fecundity, and reproduction attained (+ 9.53, + 40.96, + 37.78%), respectively, while significant decreases in all other quantitative traits, survival rate, preying potential of female, preying potential of the 3 rd larval instar, and larval developmental period, were recorded (− 2.09, − 27.81, − 15.84, and − 11.10%), respectively. Results of the second line (preying potential of the 3 rd larval instar) showed significant reductions in all the studied quantitative traits except, preying potential of the 3 rd larval instar and preying potential of female recording (+ 22.81 and + 0.83%), respectively. The third genetic improvement line (larval developmental period) significantly increased only in the same trait (+ 23.83%), while there were significant decreases in all others. Obtained results revealed that broader sense heritability of the three quantitative traits attained 47.43, 31.66, and 17.66%, respectively in the control, increased to 63.70, 40.80, and 33.50% in the three genetic lines of each trait, respectively. A selection index (index weights of the quantitative traits) was calculated. The application of this selection index is necessary to apply it in the genetic improvement programs in order to increase the efficacy of the predator breeding.

The temperature is an important factor that affects the efficacy of biological control agents. Effect of the temperature on life table, parameters of Scolothrips sexmaculatus (Pergande) (Thysanoptera: Thripidae), the predator of the two-spotted spider mite Tetranychus urticae Koch (Acari: Tetranychidae) was studied under laboratory conditions at three constant temperatures (20, 25 and 30°C). These experiments were conducted at the General Commission for Scientific Agricultural Research (GCSAR), Damascus countryside, Syria. The durations of development of egg, 1 st and2 nd larval instars, pupa, and adult at the three tested constant temperatures were measured. The total developmental period from egg to adult's emergence was estimated by 23.2, 13.3 and 10.8 days, respectively. The developmental period decreased significantly with increasing the temperature from 20 to 30°C. Survival rate was the highest at temperature (30°C) in comparison with the other temperatures (20 and 25°C). Egg stage of S. sexmaculatus showed highest mortality levels at all temperatures. Generation period, as well as the ovipositional period decreased significantly at the temperatures ranged from 25.1 to 11.54 days, 52.8 to 41.2 days between the two temperature extremes, respectively. The maximum total fecundity (229.3 eggs/ female) and the minimum (94.1 eggs/female) were recorded at 30 and 20°C, respectively. The mean number of fertile eggs, laid per female per day, was highest at 30•C (4.9 eggs) and lowest (2.7 eggs) at 20•C. Thermal requirements for developmental thresholds and thermal constant of S. sexmaculatus were estimated as 10.8°C and 200 degree-days (DD), using the common linear model. 30°C was the optimum temperature for development. The results showed that the population of S. sexmaculatus was able to develop at a broad range of temperatures; therefore it is well adapted to the temperatures of the Mediterranean region.

A survey was performed between 2007 and 2013 to investigate the complex of parasitoids on Cydia pomonella (codling moth) in apple and walnut orchards in Syria. This study showed the presence of 17 species belonging to 7 families from two orders (Hymenoptera and Diptera). The families Ichneumonidae and Braconidae were most common, comprising 8 and 4 species, respectively. Mastrus ridibundus and Neoplectops pomonella were new records for Syria.