دراسة تأثير مساحة الوحدة التجريبية في فعالية البحث للمفترس Scymnus syriacus عند التربية على حشرة منّ القطن Aphis gossypii مخبرياً

Abstract

The experiment was conducted in 2024 at the Biological Control Laboratory, Faculty of Agricultural Engineering, University of Latakia to study the search efficiency related to the experimental unit area of the adult female predator Scymnus syriacus when reared on cotton aphid Aphis gossypii nymphs, using six different densities         (5, 10, 20, 40, 80 and 160 nymphs/experimental unit), and five different experimental arena sizes (136, 234, 390, 525, and 650 cm²). The female predator exhibited a type II functional response. The results indicated that the search efficiency (a) was highly correlated with the predator's search area (R² = 0.985) and this correlation was negative (R=-0.97), as search efficiency decreased with increasing experimental arena size and was highest at the smallest arena (a = 0.209 hour⁻¹). Across all arenas, the area swept by the predator decreased with increasing prey density and increased with larger arena size at the same density, reaching 108.85, 178.52, 279.5, 304.93, and 334.75 cm² from the smallest to the largest arena, respectively. Thus, both experimental arena size and prey density played a fundamental role in the feeding and searching behavior of the predator S. syriacus.