Abstract:  【Aim】 To define the biological characters of Planococcus lilacinus and achieve its visual detection. 【Methods】 The morphological characteristics and duration of different developmental stages and female adult fecundity of P. lilacinus were determined in the laboratory. Then based on the 28S rDNA sequence of P. liacinus, the specific primers of loop-mediated isothermal amplification (LAMP) were designed to establish the corresponding visual detection method, and the specificity, sensitivity and stability of LAMP detection were verified. 【Results】 The female and male P. lilacinus have different generational life histories. From the egg when it is laid, the outline of insect body and one pair of dark red ocelli just can be seen. The 1st instar nymph moves fast and it is difficult to identify its female and male. The 2nd instar nymph has thin white wax rods on the body margins with differentiated body morph between female and male. The 3rd instar nymph only belongs to female and has similar shape to female adult. The pupa only belongs to male and includes prepupal and pupal stages. The female adult is covered by thick white wax powders, with 18 pairs of visible wax rods on the body margins. The male adult has one pair of transparent and developed fore wings, and one pair of long white wax filament at the terminal part of the abdomen. The duration of egg and female adult lasted (1.37±0.26) h and (32.67±4.82) d, respectively, while that of each instar nymph, pupa and male adult all lasted no more than (7.65±0.82) d. Meanwhile, the number of eggs laid per female and the egg hatching rate in sexual reproduction were (531.92±69.98) grains and 96.02%±1.35%, respectively, while those in parthenogenetic reproduction were (403.50±71.11) grains and 88.41%±3.03%, respectively. Furthermore, the established LAMP visual detection method could effectively amplify the DNA of P. lilacinus, it had the optimal reaction temperature of 66 ℃, optimal reaction time of 55 min, detection limit of at least 100 fg/μL and detection rate of 91.67%-100.00% with the positive green reaction products. But the LAMP detection could not amplify the DNA of the other seven mealybug species with the negative saffron yellow reaction products. 【Conclusion】 There is sexual dimorphism in P. lilacinus life cycle with fast growth and development and strong fecundity, therefore it is necessary to be detected and monitored. The LAMP visual detection method is rapid, specific, sensitive and reliable, it shows an excellent potential in rapid and accurate identification of this mealybug for non-professional identifier on-site.

Key words: Planococcus lilacinus, morphological characteristics, development and fecundity, LAMP, visual detection