Fig. 4

Comparisons of the thoracic and abdominal widths of unfed and fed C. lectularius of two strains. The thoracic (Tx) and abdominal (Ab) widths of second, third and fifth instars, as well as adult males and females (20 bed bugs per stage), were measured at both unfed (orange) and fed (blue) states for both the Harlan (insecticide-susceptible, a) and Fuller Mill (pyrethroid-resistant, b) strains. The results show increases in both thoracic and abdominal widths throughout development and general decreases in abdominal width in fed bed bugs. The mean is represented by x within each box plot. The average largest linear dimension of mesh holes in the three bed nets are represented by red dashed lines. Significant differences (Student’s t-test) in width between fed and unfed bed bugs are denoted by *P < 0.05; **P < 0.01; ***P < 0.001