Treesearch

In this presentation I will address three points associated with pear thrips damage and sugar maple. First, I will describe the impact of pear thrips on sugar maple in Massachusetts, in both the sugarbush and the natural forest stand, based on root starch assays that were completed this fall (1988). Secondly, I will discuss the relationship between tree health and thrips damage, specifically addressing the question of whether this insect preferentially selects trees or stands of trees having high or low vigor. Finally, I will offer some speculative comments concerning the influence of air...

Writing a magazine article on thrips in November for an issue of Country Journal that would appear three months later was a considerable challenge, and I apologize now for any mistakes you may find in it. Yet in the process of researching it, I talked to dozens of farmers who count heavily on their annual maple syrup production to supplement their incomes. It is this research into the micro-economics of the small-scale sugarmaker, I think, that prompted Bruce Parker to ask me to speak here.

Sugar maple root starch evaluations were done in 1987 and 1988 as a service to Vermont sugarmakers concerned about tree health. Trees were rated for starch content in late fall, using a visual iodine-staining technique. On the average, trees with heavy pear thrips damage in the spring of 1988 had higher levels of root starch the following fall than trees with light or moderate damage. Trees with heavy damage actually had more starch in 1988 than they had the previous fall. Starch in trees with light and moderate defoliation did not increase. Possible explanations for higher starch in...

I am a sugarmaker from southern Vermont. I became a sugarmaker because I wanted to establish a long-term project on my property from which I could make a living. The trees on my land are very healthy, as evidenced by the high volume of syrup I am able to produce. I have noticed the thrips damage for a number of years, but didn't know the cause until 1987. I would like to give you a brief history of what I have observed.

Kriging is a statistical technique that provides predictions for spatially and temporally correlated data. Observations of thrips distribution and density in Vermont soils are made in both space and time. Traditional statistical analysis of such data assumes that the counts taken over space and time are independent, which is not necessarily true. Therefore, to analyze these data correctly we must account for the correlation structure in the data, which can be done with Kriging. The Kriging technique is reviewed and its use illustrated in determining the pattern of thrips distribution and...

The defoliation from pear thrips, Taeniothrips inconsequens (Uzel), in 1988 caused a great deal of public concern throughout the entire State of Vermont and the New England region (Parker et al. 1988).

The information I am going to present today is a conglomeration of some of the research on the effects of defoliation that has been done on sugar maple and oak. It involves work done by Drs. David Houston, Johnson Parker, Robert Gregory and me. Dr. Houston, a plant pathologist, and Dr. Parker, a plant physiologist, work with the USDA Forest Service in Hamden, Ct.; Dr. Gregory is a plant physiologist who is retired from the Forest Service in Burlington, Vt.

The vertical and horizontal distribution of pear thrips in Vermont sugar maple forest soils was investigated. In the fall, about 86% of the thrips were found in the upper 10 cm of soil, though a few were found as deep as 20 cm. No thrips were found in the leaf litter. Soil sampling tools to determine thrips populations within an entire forest were tested and a standard hand-held bulb planter was found to be the most effective. No consistent pattern in thrips distribution around individual sugar maple trees was found. Pear thrips distribution within a forest stand predominating in sugar...

What is a sugar maple worth? This is an interesting question and not one which is easy to answer. I have some thoughts on this subject to share with you. Many of these have been discussed with county and district foresters, sugarmakers and people from the community who appreciate the maple tree very much.

As entomologists, we sometimes like to think of an insect pest problem as simply a problem with an insect and its host. Our jobs would be much easier if that were the case, but of course, it is never that simple. There are many other factors besides the insect, and each one must be fully considered to understand the problem and develop effective management solutions. In this case I see many factors facing us besides the pear thrips and the sugar maple tree.