Effect of Temperature on the Life History of the Mealybug <I>Paracoccus marginatus</I> (Hemiptera: Pseudococcidae)

Abstract

Effect of temperature on the life history of the mealybug Paracoccus marginatus Williams & Granara de Willink (Hemiptera: Pseudococcidae) was investigated in the laboratory. P. marginatus was able to develop and complete its life cycle at 18, 20, 25, and 30 +/- 1 degrees C. At 15, 34, and 35 degrees C, the eggs hatched after 27.5, 5.9, and 5.5 d of incubation, respectively, but further development of the first-instar nymphs was arrested. No eggs hatched at 37 degrees C. The developmental time for egg to adult was the longest at 18 degrees C for both males and females. Approximately 80-90% of the eggs survived between 20 and 30 degrees C. The highest fecundity was at 25 degrees C with each female producing an average of 300 eggs. Adult longevity, and preoviposition and oviposition periods increased with decreasing temperature up to 25 degrees C. The proportion of females was approximately 42% at 25 degrees C and was between 70 and 80% at 18, 20, and 30 degrees C. Adult males and females required 303.0 and 294.1 degree-days (DD), respectively, to complete their development. The estimated minimum temperature thresholds for the adult males and females were 14.5 and 13.9 degrees C, respectively. For adult males, the estimated optimum and maximum temperature thresholds were 28.7 and 31.9 degrees C; and for adult females, they were 28.4 and 32.1 degrees C, respectively. The ability of P. marginatus to develop, survive, and reproduce successfully between 18 and 30 degrees C suggests that it has the capability to develop and establish in areas within this temperature range.