Figure 8.

Seasonal average maximal density ( ± SEM) for large nymphs (3^rd or 4^th instar) per quarter-sized leaf disk (3.88 cm²) over five years of replicated, large-scale assessments of IGRs in comparison to the UTC in cotton, Maricopa, Arizona, USA (P = 0.02). The properly timed usage of IGR sprays significantly lowered the maximal seasonal density of whiteflies compared to the UTC. Severe economic loss (reductions in yield and quality) is common at levels in excess of 4 large nymphs per disk⁸⁶.