As an aside, if you enjoy the outdoors and like to spend time in the field, start looking at insects if you don't already. As mid-summer rolls into early autumn, the bugs increasingly proliferate and their variety is staggering. Many are beautiful, and they all have fascinating life histories. Besides, insects are the fuel that makes much of the songbird world go 'round, and one can only get a better grasp of the feathered crowd by knowing more about their food!
Last Sunday, Kelly Williams-Sieg and I ventured into Scioto Trail State Forest, and the very first stop proved to be quite productive. Upon exiting the vehicle, we quickly noticed that a nearby stand of Gray Dogwood, Cornus racemosa, was under siege by beautiful white and yellow "caterpillars".
Growing side by side with the Gray Dogwood were several plants of Silky Dogwood, Cornus amomum. Fascinating to me was the fact that the sawfly larvae completely shunned this species, even though it is very closely related and was readily accessible. This just shows the great degree of chemical specificity required by many plant-eating insects.
Adult sawfly - not Dogwood Sawfly, though - courtesy of the University of Minnesota entomology department. The larvae above will probably grow into something similar, at least the ones that make it to adulthood.