Starvation Time and Predatory Efficiency of Spider Species on Bemisia tabaci (Homoptera: Aleyrodidae)

Four predatory spider species, Leucauge venusta (Orchard) (Araneae: Tetragnathidae), Lycosa pseudoannulata (Boeset) (Araneae: Lycosidae), Larinioides cornutus (Clerck) (Araneae: Araneidae), and Tetragnatha shikokiana (Yaginuma) (Araneae: Tetragnathidae), were used to control Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) in the laboratory and greenhouse, and their longevity without food was observed. For the laboratory experiment, the spiders' feeding capabilities were checked at 1, 4, 8, and 16 h of exposure in a 10 mL vial containing 50 five-d-old whiteflies. For the greenhouse experiment, the preys' feeding ability was recorded at 24 and 48 h, with 100 five-d-old adult whiteflies in a screened cage. Individual spiders were kept in the lab in 10 ml vials, and their survival time was recorded every 5 h. Of the 4 spider species, L. pseudoannulata was the most active in the lab and consumed an average of 3.00 +/- 0.22, 6.17 +/- 0.27, 9.67 +/- 0.43, and 13.50 +/- 0.49 at 1, 4, 8, and 16 h of the bioassay, followed by L. venusta, L. cornutus, and T. shikokiana. However, in the greenhouse experiment, L. venusta consumed the greatest number of whiteflies, with an average of 24.66 and 51.33 (out of 100) at 24 and 48 h, respectively, followed by L. pseudoannulata, L. cornutus, and T. shikokiana. The maximum longevity was recorded for L. venusta with 26.67 h, followed by T. shikokiana, L. pseudoannulata, and L. cornutus without prey. All spider species killed and consumed adult whiteflies in both experiments, which suggests that they are a controlling tool in the natural ecosystem. The results from our experiment will contribute to the biological control of whitefly.