European Corn Borer Control with Granular Formulations of Endrin, Heptachlor, and Toxaphene Mahlon Lowell Fairchild Iowa State University
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Iowa State University Capstones, Theses and Retrospective Theses and Dissertations Dissertations 1959 European corn borer control with granular formulations of endrin, heptachlor, and toxaphene Mahlon Lowell Fairchild Iowa State University Follow this and additional works at: https://lib.dr.iastate.edu/rtd Part of the Zoology Commons Recommended Citation Fairchild, Mahlon Lowell, "European corn borer control with granular formulations of endrin, heptachlor, and toxaphene " (1959). Retrospective Theses and Dissertations. 2152. https://lib.dr.iastate.edu/rtd/2152 This Dissertation is brought to you for free and open access by the Iowa State University Capstones, Theses and Dissertations at Iowa State University Digital Repository. It has been accepted for inclusion in Retrospective Theses and Dissertations by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. EUROPEAN CORN BORER CONTROL WITH GRANULAR FORMULATIONS OF ENDRIN, HEPTACHLOR, AND TOXAPHENE by MaliIon Lowell Fairchild A Dissertation Submitted to the Graduate Faculty in Partial Fulfillment of The Requirements for the Degree of DOCTOR OF PHILOSOPHY Major Subject: Entomology Approved: Signature was redacted for privacy. Signature was redacted for privacy. Heati of Major department Signature was redacted for privacy. Iowa State Col 1ege Ames, Iowa 1959 I I TABLE OF CONTENTS INTRODUCTION REVIEW OF LITERATURE METHODS AND PROCEDURE DISCUSSION AND RESULTS SUMMARY AND CONCLUSIONS LITERATURE CITED ACKNOWLEDGMENTS APPENDIX ] INTRODUCTION The European corn borer (Pyrausta nubi la 1 is (libn. ) ) was first re ported in this country by VinaI (1917). He suggested that it might have been imported in broomcorn from Europe. Since then it has moved west ward and southward until now it covers a major part of the corn growing area in the United States and Canada and has become one of the major economic pests on corn. Bradley (1952) reported that the corn borer caused an estimated loss of 314,000,000 bushels of dent corn in 1D'lD alone. Such sizeable losses have necessitated the development of control measures to keep this pest in check. Many insecticides have been tested and recommended for duropcan corn borer control. The first insecticides suggested were the inorganic insecticides such as the arsenical and fluorine compounds. These were re placed by rotenone, nicotine tannate, and ryania. ..'ith the advent of the chlorinated hydrocarbons, DDT was added to the list. In spite of the progress made in the development of insecticides for use against the corn borer, there is a need for continuing research in this area. The materials recommended when the work was started gave er ratic control or left undesirable residues on the corn stover. Therefore, the purpose of this project was to test various rates of granular endrin, hep tachlor, and toxaphene in a search for an insecticide which would con sistently give satisfactory control without leaving undesirable residues. 2 REVIEW OF LITERATURE History of Insecticides Entomologists have tested many types of insecticides for control of the European corn borer. Some of the early work was reported by Worth!ey and Caffrey (1927). Investigations from 1918 to 1926 proved that appli cations of insecticides were ineffective in protecting growing corn or other plants from injury by the European corn borer. These workers tested various rates and formulations of the following insecticides : lead arsen ate, magnesium arsenate, calcium arsenate, nicotine, hydrated lime, and sulfur. In addition to the attempt to kill the larvae during the period of establishment, attempts were made in 1925 to kill them in the period of hibernation. Both laboratory and field experiments of a preliminary nature were conducted on insecticides for European corn borer control and reported by Huber £t aj_. (1928). The laboratory work was designed to determine the toxicity of the various dusts to the newly-hatched larvae. In the field 80 percent sodium fluosi1icate was applied at 10 pounds of dust per acre at five-day intervals until six treatments had been made. Final infesta tion and borer population counts were made in the fall. These counts showed a reduction of 83 percent in the number of plants infested. Borer population was reduced 58 percent on infested plants by the insecticide treatment. A number of insecticides were tested by Batchelder and Questel (1930- Neither acid lead arsenate nor any oil emulsion investigated gave satis factory control under field conditions when used a 1 one. Insecticides in volving the use of nicotine and pyrethrum as well as several other ma terials of the contact insecticide type were not found practical for use against the European corn borer. Simanton eit aj_. (1331) round that lead arsenate did not cause a high mortality unless applied in excessive quantities. Calcium arsenate was no better than the lead arsenate. Some samples of barium fluosi1icate were very toxic to corn while others were not. Mos11 y the kill was good but the corn was more or less injured. Calcium fluosil icate consistently gave satisfactory kills with a minimum of corn injury. Consistent high kills were obtained with sodium fluosilicate but the corn was seriously injured. Nicotine was not sufficiently toxic to justify its use. Thir teen fluorine compounds tested in 1330 gave satisfactory kill. According to Ficht (1333), certain insecticides were tested from 1923 to 1932 to determine their value for curopean corn borer control. Barium fluosi!icate, calcium fluos!licate, and sodium fluosilicate were tested. Considerable phytotoxicity was observed after application of barium fluo- silicate. Calcium fluosilicate also had a tendency to injure the plants but was considered as one of the most satisfactory insecticides for corn borer control up to that date. Acid lead arsenate in combination with oil emulsions gave satisfactory control and little plant injury. Mydrated lime and talc were used as barriers to young larvae without success. Hicotine and pyrethrum used a 1 one and with derris gave unsatisfactory rcsu1ts. Of the materials tested by Turner (193-0 two insecticides were proven 4 to be outstanding and a third slightly less effective for corn borer con trol. Pure ground derris root (4 percent rotenone) and phenothiazine (thio-diphenyl-amine) used in suspension at the rate of 2 pounds in 50 gallons of water with a suitable spreader were very effective. From sprayed plots 85 percent of the ears were borer free whereas on unsprayed plots only 36 percent of the ears were borer free. Tank mixed nicotine tannate was somewhat less effective for about 77 percent of the ears from sprayed plants were free from borers. Baker and Oues tel (1939) studied the effectiveness of fixed nicotine preparations, fluorine compounds, phenoth iza ine and derris in spray and dust formulations. Derris and the fluorine compounds provided a high de gree of protection when used as sprays in a treatment schedule of four ap plications spaced at five-day intervals. The fluorine compounds caused more or - Jess injury to the corn plants which made their use undesirable. A series of tests with various insecticides were conducted by Beard and Turner (1942). Dual fixed nicotine containing 4 percent nicotine was consistently more effective in controlling the European corn borer than dust containing 1 percent rotenone in the form of pure ground derris root. Dust made by impregnating inert material with extract of pure ground derris root or pyrethrum flowers was not significantly less effective than dust prepared by mixing ground root of derris with the carrier. Results of preliminary laboratory and field tests performed by Questel (1944) at Toledo, Ohio in 1943 indicated DDT to be the most promising sub stitute for ground derris spray thus far tested for control of the European corn borer in early market sweet corn. It gave relatively high reduction 5 of borers in both ears and plants without injury to the corn. Batchelder and Questel (1945) conducted experiments in sweet corn near Toledo, Ohio to determine dosage requirements and effectiveness of DDT as an insecticide for control of the first brood of the European corn borer. Four applications of dusts containing 0.75, 1.5, 3.0, and 6.0 per cent of DDT in pyrophy11i te were made 5 to 7 days apart in dosages of 0.3, 0.6, 1.2, and 2.4 pounds per acre. Borer reduction increased with each increase in the dosage rate and at the highest rate provided 95 percent reduction. Ryan ia was tested by Pepper and Carruth (1945) against the European corn borer in 1943 and 1944 under field conditions in New Jersey and New York. In preliminary tests in New Jersey in 1943 the corn borer control accomplished was considered the most effective ever obtained up to that time. When the normal application schedule (four to five insecticide treatments at five-day intervals) was modified by reducing the number of treatments and lengthening the interval between treatments, satisfactory results were obtained. Good control was obtained when 20 to 35 pounds of a 50 percent ryania dust was applied. After experimenting with DDT dust and spray preparations against both hibernating and actively feeding larvae of the European corn borer, Questel (1945) suggested that the percentage of DDT may have less bear ing on the effectiveness of the dusts and sprays than some other factors perhaps related to the physical and chemical character of the diluent. Hibernating larvae thoroughly coated with a powder containing 10.8 percent of DDT in pyrophy11i te or with 50 percent DDT with an absorbent clay were b all killed within three days, whereas very few of those coated with coarsely ground undiluted DDT or powders containing 50 percent DDT micro- pulverized with fibrous talc were killed. Several new insecticides were tested by Decker _et _a_L (1947) in the field in l946. None of those tested showed promise in replacing DDT or ryania.