Cotton insect resistance and integrated pest management: current research and future directions

Abstract Cotton production has long been challenged by combined damage from chewing and piercing-sucking pests. Bt cotton has provided effective control of the cotton bollworm in many production regions. However, several factors have rendered single-tactic management unsustainable. These include the increasing prominence of piercing-sucking pests, accelerating resistance evolution, and growing concerns over non-target effects. Critically, the lack of standardized, cross-environment protocols for reproducible resistance phenotyping has become the primary bottleneck preventing the translation of laboratory-discovered resistance genes into field-effective cultivars. Over the past three decades, major advances have been made in elucidating resistance mechanisms and developing gene identification technologies. Breeding-to-field transformation efficiency has not improved in parallel. Standardized, cross-environment protocols for reproducible insect-resistance phenotyping are still lacking. Specifically, there is a lack of unified specifications for defining pest pressure levels, selecting sampling time points, determining tissue positions for investigation, and establishing criteria for resistance evaluation. Moreover, agronomic cost assessments that balance resistance with yield have rarely been incorporated into breeding decision pipelines. Consequently, many candidate genes remain at the stage of functional validation rather than deployment. At present, insect-resistance breeding is shifting from simply identifying new resistance genes toward evaluating their effects in combination with yield and performance in field trials. In essence, this transition expands breeding objectives from single resistance indices to a broader assessment of yield stability, multi-pest management, and field ecological function. The overarching objective is to improve yield stability under multi-pest pressure while slowing pest adaptation and preserving field ecological functions. Achieving this objective will require explicitly linking genetic resistance traits with physical, chemical, and biological control measures within a dynamic, threshold-based Integrated pest management (IPM) framework.