Three Entomologists

Associate professor of Entomology, Bob Lewis, teaches graduate courses and is conducting systematic studies of fleas and other ectoparasites, arthropod, and their hosts. Bob is a member of the departmental committee, establishing operations policy for use of Iowa State's new scanning electron microscope. We at Iowa State University have been fortunate to recently acquire a [unclear] scanning electron microscope. Scanning electron microscopy is still in its infancy, but it permits the investigator to examine the surface structures of surface, topography of small animals, especially insects in a three-dimensional way which has not been possible before. We hope that this machine will be useful in improving our research programs here at ISU and also serve as a helpful aide in our teaching programs. :et me show you how it works. This vacuum evaporator is used in specimen preparation while even living insects may be studied with the scanning scope better results are obtained when specimens are coated with a conductive material prior to examination specimens are placed in the bell jar the machine is pumped down to a high vacuum and a gold palladium alloy is condensed on their surfaces before this can be done the material must be mounted on specimen steps using ducros cement silver paint or double-sided sticky tape here you see a number of fleas mounted on a stub ready for study the stub is then placed in the specimen chamber the chamber closed and the column pump down four control knobs outside the specimen chamber control the orientation of the stub on x and y-axes rotation 360 degrees and inclination from minus five to plus 45 degrees focusing the image requires at least partial darkness for detail to show up on the cathode ray to initial focus is obtained by use of the focus knob but additional detail and clarity is obtained by balancing the image brightness and contrast the simplified console of the jsm s1 contains only a few more controls and a color television set and greatly reduces the time required to train an experienced persons to operate the machine when the proper focus is obtained a single slow scan registers the image on Polaroid pn5 five film in 20 seconds the film is developed and the operator is provided with a positive picture as well as a negative from which additional prints can be made by conventional photographic techniques Wilbur Budd Guthrie is an associate professor of entomology at Iowa State and full-time researcher at the USDA's European corn borer research lab in Ankeny since 1964 but has been leader of the Ankeny lab successful research in the area of host plant resistance to the European corn borer we are deficient infesting corn plants today to simulate a first root infestations in the field we have two problems in host plant resistance research one to greed for resistance to the first brood and two to breed for resistant to the second root now unfortunately inbred lines of corn resistant to the first group are not necessarily resistant to the second group we now know a great deal about the genetics of first group resistance and breeding procedures for transferring this type of resistance to susceptible material we have several inbred lines with a high level resistance or at least with an intermediate level resistance that are being used in hybrid combinations we have always had a good source of laws for egg production our first brood work but not in our second root research we can now rear the larvae on a ridic diet and this new technique has allowed us to increase our research on the second route during the past three years we have determined the type of gene action involved in second brood resistance and during the next several years we will determine breeding procedures for selecting for both first and safe food resistance in the same plant population Harold tiny Gundersen standing six feet six tiny Gunderson has been mister extension entomologist to Iowa farmers businessmen and homemakers for more than 30 years born in Butte Montana tiny received his PhD in entomology at Iowa State in 1939 and has since that time driven literally thousands of miles every year carrying the word throughout Iowa extension workers do their educating mostly away from the campus and as an extension entomologist at Iowa State University I spent about 150 days a year away from the campus conducting educational meetings setting up and evaluating result demonstrations and in the growing season of course keeping track of insect activities we need to do all of these things because we have an interested and educated audience the meetings that I've had this past winter have been as good as well attended as any I've held in the past and I think part of this is due to the greater knowledge on the part of both farm people and town people and a greater awareness of insect losses they asked some pretty searching questions and the Extension entomologist have to run pretty hard just to keep up so that we have good answers for our clientele