Abstract:

This study aims to delve into the morphological characteristics and biological traits of Cyamophila willieti, providing a foundational reference for integrated pest management. Using molting as the boundary for nymphal instars, we observed and recorded the developmental periods, reproductive capabilities, and behavioral patterns from egg to adult. Photographic documentation and measurements of morphological changes during each developmental stage were conducted using stereomicroscopy. The eggs of Cyamophila willieti are spindle-shaped, measuring (362.13±3.53) µm in length and (152.06±1.61) µm in width. Initially white, the eggs gradually shift to orange, revealing two red spots through the eggshell; the egg stage lasts (3.81±0.03) days. Nymphs undergo five instars with distinct morphological differences. First-instar nymphs have heads wider than the abdomens and lack wing buds; second-instar nymphs show initial and smaller wing buds, with forewings and hind wings separated; third-instar nymphs exhibit well-defined wing buds, with the anterior and posterior wing buds initially adjacent without overlapping, and later partially overlapping; fourth-instar nymphs have hind wings overlapped by half of the forewings; fifth instar nymphs display substantial overlap of both forewings and hind wings. The number of antennal segments for first to fifth instar nymphs is 3, 4, 6, 8, and 10, respectively, and body lengths are (371.82±4.31) µm, (728.15±36.2) µm, (996.9±34.03) µm, (1271.06±24.65) μm, and (2083.33±22.89) µm, with developmental periods for these instars are (3.81±0.03) days, (3.47±0.06) days, (2.13±0.06) days, (2.03±0.07) days, (2.46±0.06) days, and (4.81±0.06) days, respectively. Adults have ten antennal segments, with females having a tapered posterior end and males having an upturned reproductive plate. The developmental periods for summer-type females and males are (20.88±0.92) days and (28.29±1.67) days, respectively. Over wintering adults are slightly larger than summer counterparts. Summer and winter females measure (4.04±0.12) mm and (3.85±0.24) mm, respectively, while males measure (4.02±0.24) mm and (3.31±0.16) mm. The pre-oviposition period for summer-type females are (5.60±0.24) days, with an individual laying an average of (647.75±52.94) eggs. The peak oviposition period occurs between days 7 and 14 after emergence, constituting 71.2% of the total egg production. Cyamophila willieti nymphs undergo five instars, each characterized by distinct wing bud development, antennal segment count, and body length changes. The adult lifespan and oviposition period are longer, with a significant occurrence of overlapping generations.

Key words: Cyamophila willieti, morphological characteristics, developmental period, biological traits, reproductive capacity, ornamental plant pest