Ron Hammond and Andy Michel, Ohio State University, reported the lack of eggs at most buckthorn sites last fall, but they did find lots of eggs on buckthorn at Mirror Lake on the OSU Campus in Columbus. They sampled these various sites over the past few weeks and did not find any aphids following the leafing-out of the buckthorn, including the Mirror Lake buckthorn where masses of eggs were found. However, in looking at the eggs that were still there, it was observed that the eggs, while still present, were all shriveled.
Having talked with people more in the know, these eggs were perhaps not fertilized last fall, maybe from a lack of males. Based on these observations and past history, Hammond and Michel predict that Ohio, and only speaking for Ohio, will experience a "low aphid" year. Aphids are expected to be hard to find through most of the summer, and will only rise in numbers in late summer/early fall prior to migrating to buckthorn. In essence, the two-year cycle of "high - low" aphid years is expected to continue this year, with 2012 being another low year.
However, this cycle, because of unknown reasons, could change at any time. Thus, continue to scout for this insect pest and to read this C.O.R.N. newsletter throughout the summer for updates and possible changes in the situation.