5.) Seed-feeding Insects
Southern green stink bug is the major seed-feeding insect which annually causes damage in soybean fields. Damage this pest causes could be described by equation
4.
D- I (T-86) 0.42 Y Z + 0.43 (Eq. 4)
D- reduced dry-matter accumulation by the seed
I= insect population per area T= time from planting in days
Y- number of seed destroyed per insect per day
Z= dry-matter weight of one seed
Reduced dry-matter accumulation by seed (D) is removed directly from the accumulation of any one day after 86 days from planting. Eighty-six days from planting is suggested as a reference point because this is where a published linear equation describes the seed dry-matter accumulation (28), and my data (Table 15) are in good accord. Appearing in equation 4 is a 0.42 factor which describes the plant dry-matter accumulation per day for the seeds after 86 days from planting, in grams. Also appearing in equation 4 is a 0.43 factor added for the Y-intercept value, in grams, from the linear equation (Table 15). The number of seed destroyed per insect per day (Y) would have to be determined experimentally. The