Sulaiman1*, Z.S. Khamis1 and M. El-Nabhan2
(1) Department of Plant Protection, Faculty of Agriculture, Homs University, Homs, Syria; (2) General Commission for Scientific Agricultural Research GCSAR, Hama Syria
*Email address of the corresponding author: [email protected]
The predator Orius laevigatus (Fieber) (Anthocoridae: Hemiptera) is one of the most important natural enemies of many insect pests, such as thrips, aphids and whiteflies. The effect of the type of plant material as a substrate for egg laying on bean pods, Phaseolus vulgaris and Geranium tuberosum leaves on some biological parameters of the predator was investigated under laboratory conditions. Results obtained showed that rearing on bean pods gave significantly higher predator offspring than rearing on G. tuberosum leaves. The number of F1 adults reached 157.67, 350.67, 541.40 adults on bean pods, whereas it decreased to 140, 302, 471 adults on G. tuberosum leaves at densities of 10, 20, 30 predator pairs, respectively, under laboratory conditions. The results obtained also showed that rearing on bean pods gave significantly higher predator offspring than rearing on hibiscus leaf, as the number of adults in the first generation (F1) reached 157.67, 350.67 and 541.40 adults on bean pods, whereas it decreased to 140, 302 and 471 adults on the flowering hibiscus leaf (Geranium) at densities of 10, 20, 30 predator-prey pairs, respectively, under laboratory conditions. The sex ratio of offspring produced on the hibiscus leaf was higher in favor of females at all studied rearing densities compared to rearing on bean pods. The average female reproduction on bean pods was higher than that on baker’s paper at all studied rearing densities. The effect of mass rearing on O. laevigatus on alternative host Ephestia kuehniella eggs and bean pods was also studied to determine the optimal predator adult density within rearing units. The number of adults and offspring produced increased when the predator pair density increased within the quantitative rearing units and reached 2213.33, 4704.67 and 2213.33 adults in F1 at different parental densities (125, 250 and 375 adult pairs/breeding unit), respectively. The reproductive rate of female predator at 125 pairs was 17.63 individuals, and at 250 pairs 18.82 individuals, but when the density of predator parents was increased to 375 pairs, the female reproductive rate decreased to its lowest value of 13.80 individuals.
Orius laevigatus, mass rearing, Plant substrate for egg laying, Breeding density.
https://doi.org/10.22268/AJPP-001447