–by Dr. Jeff Whitworth
Much disparity in sorghum development exists throughout north central and south central Kansas, mostly due to weather-caused delays in planting. So, there are many different levels of “worms” infesting this sorghum from whorl stage to some that is already soft dough stage. Therefore, there are also different stages of “headworms” (see pic) from small 2nd instar larvae to almost mature 5th instar larvae. Sampling needs to be initiated as soon as plants start flowering to determine infestation levels.
Different headworm instars
Additionally don’t forget about chinch bugs (see pic). These don’t usually affect plants as much under good growing conditions, which we have had for the most part, but there are still significant populations present which may affect plants if growing conditions become more stressful.
Chinch Bug Nymph
Also, some fields throughout north central Kansas have significant infestations of cattail caterpillars (see pic). These are often confused with corn earworms or fall armyworms, but they are leaf feeders, not part of any “headworm” complex.
Cattail Caterpillar