CHAPTER 2
REVIEW OF RELATED LITERATURE
This chapter presents the available literature and studies conducted that are crucial to the investigation of researchers in Pediculicide activity of Premna odorata leaves against Lipeurus caponis.
The Plant Material
The plant sample, Premna odorata Blanco (“Alagaw” in Filipino) is from the family of Verbenaceae/Lamiaceae genus Premna. It is also known as Alagau (Tagalog), Abgau (Bisaya), Fragrant premna (English), Saliargo (Central Bisaya). Alagaw can be found in the secondary forests in the Philippines and abundant in a low-altitude thicket (Giltendez, 2015).
Plant Description Verbenaceae has 75 genera with 3000 species is grown on a commercial scale for its leaves which yield verbena oil used in perfumery. Several species are cultivated as bedding plants and a number of cultivars with a wide color-range are now available (Hickey & King, 2007).
Plate 1 shows the picture of physical feature of Alagaw (Premna odorata)
Plate 1. Alagaw (Premna odorata) Retrieved from Stuart, 2015…show more content… It is also known by a few other scientific names such as Premna curranii H., Premna oblongata (Quisumbing, 1978). Alagaw is a small hairy tree 3 to 8 meters high, the leaves are ovate to broadly ovate, 10 to 20 centimeters long, with a broad, rounded, or somewhat heart-shaped base, and pointed tips, under the surface of the blade is usually covered with short hairs, aromatic when crushed, flowers are greenish-white or nearly white, 4 to 5 millimeters long and borne on terminal inflorescences (cymes) 8 to 20 centimeters in diameter, the fruit is fleshy, dark purple, rounded, about 5 millimeters in diameter (Stuart, 2016). Found in the secondary forests in the Philippines abundant in a low-altitude thicket (Giltendez,