Abstract:

Objective: Monellia carylella is one of the critical pests that seriously threatens pecan industry in China. This study aims to provide a vital basis for the prediction and scientific control the pest by investigating its morphological and biological characteristics. Method: In the Hefei area of Anhui Province, a detailed field investigation and indoor feeding observation of M. carylella were carried out to describe its morphological characteristics, biological characteristics, and annual life history. Result: Both the gynoparae and sexual generation of M. carylella are winged. The nymph has four instars all of which are wingless. Under 25°C and 75% humidity, the average duration of nymph was (7.12±0.96) days, the average pre-reproductive period was (1.91±0.54) days, the average lifespan of adults was (22.88±12.87) days, and the average reproductive yield of gynoparae was (73±45.72). In Hefei area, this aphid was able to produce 20–25 generations per year. Overwintering fertilized eggs started to hatch in early April of the following year, and then the gynoparae continued until early October. Male aphids gradually appeared in mid-October. After mating, female aphids always laid their eggs on the surface of the branches for overwintering. Approximately 77% of the fertilized eggs were distributed on the surface of branches, 18% on the leaf scars, and only 5% of the fertilized eggs were laid on the leaf buds. Conclusion: M. carylella is autoecious holocyclic life type with long parthenogenesis period. The gynoparae and sexual generation aphids are all winged. There is no oversummering phenomenon, and the damage lasts long. They overwinter with eggs, and are the key prevention and control target in pecan planting areas of Hefei.

Key words: Monellia caryella, Caray illinoensis, morphology, biology, life history