What is their lifecycle?
After mating, a female Brown marmorated stink bug can produce between 50–150 eggs in light green egg masses of 20–30 eggs on the undersides of leaves (Figure 3), which depending on the temperature, hatch within 3–4 days (Wermelinger et al. 2008; Leskey et al. 2012).
Figure 3: A Brown marmorated stink bug egg mass with hatched first instars (DAWR 2015).
After hatching, juvenile Brown marmorated stink bugs, known as nymphs, go through five stages called instars (Figure 4; Leskey et al. 2012). Brown marmorated stink bugs typically produce one generation per year; however, up to six generations in one year have been recorded in southern China (Hoffmann 1931 cited in Leskey et al. 2012). Decreasing day length and reductions in temperature trigger adults to assemble in large numbers on hosts prior to entering overwintering sites, including natural and human-made structures until spring returns (Hoebeke & Carter 2003; Leskey et al. 2012).
Figure 4: The lifestages of the Brown marmorated stink bug from left to right through four stages (2nd, 3rd, 4th and 5th instars) adult male and female (DAWR 2015).