— by Dr. Jeff Whitworth, Dr. Holly Schwarting and J.R. Ewing
Much sorghum throughout north central Kansas is at least in the soft dough stage and thus has passed through the most susceptible stages for sorghum headworm infestations. However, any sorghum yet to head out will still be susceptible to these headworms as there will still be at least one more generation.
All four aphids species, corn leaf, greenbugs, sugarcane, and yellow sugarcane, are still in every sorghum field we sampled throughout north central Kansas. All populations seem to be increasing but there are relatively healthy populations of beneficials present as well.
–by Dr. Jeff Whitworth and Dr. Holly Schwarting
Double cropped sorghum may still have some ragworm feeding during the whorl stage (see photo). In addition, there will probably be at least one more generation of headworms and thus later planted sorghum needs to be monitored for headworms between flowering and soft dough when it is vulnerable. Also, continue monitoring for aphids as there still seems to be a pretty good mixture of greenbugs, corn leaf, yellow sugarcane, and sugarcane aphids. Some of the fields treated for headworms have reduced numbers of beneficials so they may not be there in sufficient numbers to help control these aphids. However, some of the fields sampled this week that were sprayed for headworms at least 2 weeks ago had pretty good populations of beneficials already building back up.
— by Dr. Jeff Whitworth and Dr. Holly Schwarting
The situation seems about the same throughout north central Kansas with regard to insect pests. Still finding mixed populations of aphids (greenbugs, corn leaf, yellow sugarcane, and sugarcane) but beneficial insect populations (mainly green lacewings, lady beetles, parasitic wasps, and occasionally syrphid fly larvae) still remain plentiful. Headworms are also plentiful in just about every field that is not yet at soft dough. Remember, expect 5% loss/worm/head between flowering and soft dough. Chinch bugs, both adults and nymphs, are also plentiful at the base of most plants but can also be found feeding on young developing berries in the heads.