By John Tooker
Notable pest observations in specific locations provide guidance for the rest of the state.
As we reported a few weeks ago, soybean aphid is colonizing Pennsylvania soybean fields. Yesterday, we received our first report of fields in central Pennsylvania (Clinton County) with populations of aphids exceeding the economic threshold of 250 aphids per plants—these fields are scheduled to be sprayed.
In light of this finding, I encourage soybean growers to scout their own fields for soybean aphids to determine current populations. Recall that natural-enemy populations (lady beetles, minute pirate bugs, lacewings) in soybean fields often suppress aphid populations, so avoid unnecessary insecticide applications to give the natural enemies a chance to contribute to control. However, if aphid populations build to the economic threshold of 250 aphids per plant, they should be treated to protect yield.
Earlier this summer in this newsletter, I mentioned that we are again monitoring populations of western bean cutworm across the state. For the most part, we have only captured a limited number of moths across Pennsylvania, but last week moth activity in northwestern PA, and in Erie County in particular, really exploded. Our cooperator just west of Erie captured 450 moths at one trap over seven days. So while western bean cutworm populations appear to pose little threat to corn or snap bean growers in most of the state, those of you in the northwest corn might get out and scout for eggs and young caterpillars.
Source:psu.edu