Study On Ultrastructures Of Wax Glands And Their Waxy Secretions Of Eight Mealybug Species (Hemiptera, Coccoidea, Pseudococcidae)

Mealybugs belong to Hemiptera, Coccoidea, Pseudococcide, with more than 2000 species in 264 genera on the world, they are a group of important pests of agriculture and forestry. On mealybug body, there are a variety of wax glands, which can secrete wax, and compose the protective wax shell. Mealybug pests spend most of their life hidden under the wax shell, it is very difficult to be controlled. So, study on ultrastructures of wax gland and their wax secretion as well as wax secreted mechanism are not only important to correct classification of Pseudococcidae, but also has important theoretical significance and application value to the mealybug study on physiological, biochemical, genetic, system development and growth, cell evolution, scientific prevention and control and so on.Ultrastructural study on morphology had been done by using the techniques of scanning electron microscopy (SEM) for eight mealybug species:Phenacoccus aceris Signoret, Chaetococcus bambusae Maskell, Peliococcus shanxiensis Wu, Heliococcus dorsiporosus Danzig, Rastrococcus invadens Williams, Pseudococcus comstocki Kuwana, Nesticoccus sinensis Tang and Ceroputo pilosellae Sulc. The results are as follows:1. The ultrastructural morphological characteristics of all kinds of wax glands and their secretion in 8 mealybug species are described and photographed.2. Although the trilocular pore is common in mealybug species, but its ultrastructure and wax filament secretion have big difference among species. The trilocular pore of Phenacoccus aceris Signoret has three clockwise sector holes, each hole secretes one silk ribbon wax filament, which made up of the wax shell on surface of the body; each trilocular pore of Chaetococcus bambusae Maskell has three small round opening, each opening secretes a hollow tubular wax secretion; the trilocular pore of Pseudococcus comstocki Kuwana has three holes, each hole with a fleshy protuberance, look like the letter "B", the secretion is ribbon-like with thin in middle part and thick in both sides; the trilocular pore of Ceroputo pilosellae Sulc has three pinched holes, the secretion of silk ribbon wax can curled up into a large lump; the three holes of trilocular pore of Rastrococcus invadens Williams spread in different directions, which makes its silk ribbon wax secretion is divergent.3. The structure of crateriform duct was firstly studied with scanning electron microscopy technology on the body Heliococcus dorsiporosus Danzig.4. Bilocular pores were firstly found on Nesticoccus sinensis Tang.5. Ultrastructure of other morphological features except wax glands were also observed and described for the eight kinds of mealybugs.