In southern and southwestern orchards, as well as at Urbana, first generation flight has been spread over several weeks, and separate early and late peaks have occurred. Egg hatch begins at about 240 degree days after eggs are laid, and a cover spray should be in place on fruit when hatch occurs. When counts drop to 1 or 2 moths per week, the insecticide spray that should be in place about 240 DD later is not so critical. If it goes on a day or two late because other jobs need to be done, it's still unlikely that significant damage will show up. And in such circumstances an alternate-middle spray program is likely to work fine.
Dogwood borers are caterpillars that grow up to be clearwing moths.
They tunnel beneath the bark of trees, and in young trees are active especially in the burrknot. Pheromone traps are available to monitor flights and guide in timing sprays. However, with the dramatic change in the weather, I think that particular threat is no longer a concern. I had received a report from Arkansas that levels of common rust were reaching fairly high levels even on field corn. Common rust does not overwinter in Illinois, but is carried up from the south on air currents, and usually arrives here in late June or early July.