Research of the individual development morphology and life history of Halyomorpha halys (Stål)

To clarify the ontogenetic morphological variations of Halyomorpha halys across all instars, document its complete life history and primary adult behaviors, and explore the correlations between these morphological changes and environmental pressures, thereby providing a basis for pest management and developmental morphology research in related taxa.

Under controlled laboratory conditions (25 ℃, (70 ± 5)% RH, 16 L : 8 D photoperiod), an experimental colony established from field-collected adults was group-reared in specially designed containers. Morphological characteristics of eggs, all nymphal instars, and adults were observed and documented using a stereomicroscope imaging system. Key developmental processes including oviposition, hatching, molting, and growth were monitored in detail.

Morphological characteristics for each developmental stage were described in detail. Egg masses were predominantly irregularly arranged; individual eggs possessed a false operculum, with a triangular egg burster evident prior to hatching. Body lengths and developmental durations were measured for all nymphal instars. Dynamic ontogenetic changes in key morphological traits—including body coloration, protuberances, trichobothria, and dorsal markings—were characterized. Sexual dimorphism in adult body length was confirmed. Specific adult behaviors (feeding, mating, oviposition) were documented, with a common oviposition of approximately 28 eggs per mass. Critical morphological transition nodes were identified, such as the development of the metathoracic scent glands and the closure of the abdominal scent glands.

The stage-specific morphological changes during the ontogeny of H. halys reflect adaptive responses to environmental conditions. This study provides comprehensive data on its life history and instar-specific morphology, offering essential morphological evidence for understanding the species' adaptive mechanisms and evolutionary processes.