Corncob Grits Research Articles

Effects and persistence of baygon (Propoxur) and temik (Aldicarb) insecticides in soil

The effects of two carbamate insecticides, Baygon and Temik, on microbial processes in soil were investigated. Total plate counts revealed that Baygon and Temik at field rate applications (5 ppm) did not greatly influence the microbial populations in the soil. At a concentration of 500 ppm the fungal and actinomycete populations showed a marked increase in response to Temik and Baygon. Nitrification was severely inhibited by the granular (formulated) Baygon and Temik at 500 ppm, but was much less inhibited with the technical grade (technical) insecticides. The discrepancy appeared due to metabolism of the corn cob grits carrier, the resulting immobilization of nitrogen causing an apparent ‘inhibition’ of nitrification. At the approximate field rate applications of 5 ppm, only slight inhibition was observed with formulated Baygon or Temik. An accumulation of nitrite was noted, especially with technical Baygon at 500 ppm. Populations of the autotrophic nitrifying bacteria were depressed for 2–3 weeks by application of either Baygon or Temik to the soil at 500 ppm. Pure culture studies on Nitrobacter agilis and Nitrosomonas europaea indicated that Baygon and Temik were toxic to both organisms, but particularly the latter. The toxicity to Nitrosomonas was more severe in pure cultures than in soil. Oxygen uptake studies showed that formulated Baygon (but not Temik) added to soil at 500 ppm resulted in high respiratory activity, mostly due to metabolism of the carrier. The technical insecticides had little effect on respiration as measured by carbon dioxide evolution, although there were indications that Temik was being metabolized during the interval from 16 to 30 days. Baygon was found to be quite resistant to degradation in the test soil. Temik residues decreased by about 50% during the 30-days test period.

Effects of Mirex on Litter Organisms and Leaf Decomposition in a Mixed Hardwood Forest in Athens, Georgia

AbstractMirex (dodecachlorooctahydro‐1,3,4‐metheno‐2H‐cyclobuta [cd] pentalene) in corncob grit bait and in spray form was applied to oak (Quercus alba L.) and dogwood (Cornus florida L.) leaf litter in mesh bags, on 20 5m by 5m plots. Macroarthropod fauna was monitored by capture in pitfall traps, and microarthropod populations were extracted from litter bags and counted. Ant presence on plots was tested by use of blank bait and molasses.Mirex in bait and spray form, and at the two levels applied, caused a significant acceleration in litter decomposition. The two leaf species as expected showed significantly different decomposition rates, and the slope of the ground surface on which the bags were placed was found to influence the decomposition process. The two leaf species differed in the amount of decomposition shown with mirex treatment, dogwood being more affected than oak.Ants were essentially removed from bait and concentrated spray plots up to 79 days, but ants had returned to all plots by the 334th day after treatment. The low spray treatment had no effect on the ant populations.Macroarthropods captured were spiders (Araneida), beetles (Coleoptera), millipedes (Orthomorpha gracilis), scorpions (Scorpionida), and centipedes (Scutigerella immaculata). Little difference was observed with treatment except with centipedes whose numbers appeared to decrease on the bait and concentrated spray plots.Microarthropod populations showed significant differences with treatment, at different times during the experiment, but no overall pattern could be detected that might explain the leaf decomposition acceleration noted with all treatments.Since microarthropod, macroarthropods and microflora are known to be involved in the decomposition, and since neither the microarthropods nor the macroarthropods could account for the change in decomposition then by extrapolation the groups most probably affected by the mirex would be the bacteria and fungi. These organisms were not monitored.It is speculated that mirex could have accelerated decomposition through its ability to induce mixed‐function oxidase systems in the microorganisms. These enzymes are responsible for the breakdown of numerous xenobiotics or foreign compounds. If synthesis of more of these enzymes by fungi and/or bacteria allowed faster metabolism of the plant inhibitor, tannic acid, then decomposition could have received an early boost due to the growth of microorganisms usually limited by tannic acid.

An Improved Mirex Bait Formulation for Control of Imported Fire Ants 123

A new method was developed for formulating mirex bait for control of Solenopsis richteri Forel and Solenopsis invicta Buren. The mirex is incorporated into the outer layer of soybean oil on the corncob grits and the bait is coated with an acrylic latex. The oil content of the formulation can be increased by one-third, thus more oil or food attractant is available to the ants. Incorporation of the mirex in the oil on the surface of the grits makes a greater percentage of the insecticide available to the ants (89 vs. 55% in the standard bait). Field tests in Georgia with aerial applications of the new formulation against S. invicta showed that the coated bait containing 0.1% mirex and applied at 1.0 1b per acre gave control comparable to standard bait containing 0.3 % mirex applied at a rate of 1¼ lb per acre (99.6 vs. 99.1%, respectively).

Four mirex bait formulations for control of the red imported fire ant.

Mirex bait (soybean oil and mirex) formulated on corncob grits (the standard), mirex bait formulated on corncob grits or Fur-Ag® granules and treated with latex, and microencapsulated mirex bait all gave control of Solenopsis invicta Buren ranging from 84 to 100% in 4 field tests.

Field Evaluation of Three Formulations of Aldicarb for Control of Cotton Insects12

Formulations of aldicarb on charcoal and on corn cob grits were equally effective in controlling the cotton fleahopper, Pseudatomoscelis seriatus (Reuter); the cotton aphid, Aphis gossypii Glover; and thrips in a field test. The charcoal formulation of aldicarb was less damaging to plant stands and had less adverse effect than the corn cob formulations on beneficial insects.

Microencapsulated Oil Bait for Control of the Imported Fire Ant12

Microdroplets of vegetable oil which contain 2% mirex Encapsulated in thin gelatin or plastic coats are very attractive to Solenopsis saevissima richleri Ford and give high degrees of control. The ability of microencapsulated bait to withstand weathering makes it superior to corn-cob grits bait in controlling the ant during-certain seasons. Aerial application of microencapsulated bait is feasible.

A Low Agar Casein-Wheat Germ Diet for Rearing Tobacco Budworms123

The amount of agar in the casein-wheat germ diet fed to larvae of Heliothis virescens (F.) was reduced from 75 to 20 g/3.4 liters of diet by adding 350 g of corn cob grits as a filler. The change did not affect growth of larvae when they were reared in cell units but did delay the time to pupation by 2 days when the larvae were reared in 3/4-oz plastic cups. Cost of the diet was reduced 25% when the corn cob grits were used.

Fur-Ag®: An Alternate Carrier for Soybean Oil-Mirex Bait for Control of the Imported Fire Ant13

Results of studies to develop toxic baits for control of the imported fire ant (IFA), Solenopsis saevissima richteri Forel, have been reported (Bartlett and Lofgren 1961; Lofgren et al. 1961, 1963, 1964; Stringer et al. 1964). It was found that a bait composed of once-refined soybean oil (the food material), mirex (the toxicant), and corncob grits (the carrier) was effective in reducing or eliminating infestations.

Tests with Three Formulations of Aldicarb for Control of the Citrus Red Mite123

Three formulations of 10% aldicarb (as a coke powder, as a granular coke, and as granular corncob grits) were applied, at doses that were 1/4 and 1/2 the manufacturers’ recommended rate, to soil around potted sweet orange seedlings in the greenhouse and under 1-year-old navel oranges in the field, respectively, to suppress Panonychus citri (McGregor). The biossays with the greenhouse seedlings did not show statistically significant difference in mortality of mites for the 3 formulations, and all caused better than 82% mortality for 16 weeks. In the field where the populations of mites were small, the mean suppression by all 3 formulations was 95% for 52 weeks.

Individual Mound Treatments for Control of the Western Harvester Ant, Pogonomyrmex occidentalis, in Wyoming1

Research on the control of the western harvester ant, Pogonomyrmex occidentalis (Cresson), by treating mounds individually was carried out in 1962 and 1963. Of the insecticides tested, fenthion and Bayer 39007 (o-isopropoxy phenyl phethyl methylcarbamate), in water, when poured down the entrance of the mounds gave less than 70% control. Bayer 38920 (6,7,8,9,10,10-hexachloro-1,5,5a,6,9,9a-hexahy-dro-3-methyl-6,9-methano-2,4-benzodioxepin) provided no control. Mirex and ENT 27005 (1,2,3,4,5,6,7,8,8-nonachloro. 3a,4,7,7a-tetrahydro-4,7-methanoindane) on corncob grits mixed with soybean oil provided excellent control in southeastern Wyoming. Niether mirex (0.075 and 0.15%) nor ENT 27005 (0.075%) gave acceptable control in central Wyoming. Later tests in central Wyoming with Kepone® (decachlorooctahydro-1,3,4-metheno-2H-cyclobuta [ cd ]pentalen-2-one) Ant and Roach bait (0.125%) and mirex (0.125%) with peanut-meal base provided better control than was obtained with other bases. Excellent control was obtained with mirex when tallow was substituted for soybean oil on the corncob-grit bait.

Individual Colony Control of the Western Harvester Ant, Pogonomyrmex occidentalis1

Colonies of the western harvester ant, Pogonomyrmex occidentalis (Cresson), treated individually, were more effectively controlled with Kepone®(decachlorooctahydro- 1,3,4-metheno-2 H -cyclobuta[ cd ]pentalen-2-one), aldrin, or dieldrin baits than with heptachlor or CS 202 [3 parts chlordane (100% assay) to 2 parts heptachlor (72% assay)] baits. Insecticide concentrations or 0.05%, 0.07% and 0.10% on the bait were more effective for colony control than the stronger concentrations; 0.12%, 0.25% or 0.50%. This result was due to rejection of the stronger baits by the ants. Colony control was equally good at bait rates ranging from 6.7 g to 40 g per mound and poorest at the 3.3 g per mound rate. In a second experiment mirex + corncob grits + soybean oil baits were more effective for P. occidentalis colony control than similar baits made with Kepone, sodium fluoroacetate (1080”), heptachlor or CS 202.

Imported Fire Ant Toxic Bait Studies: Further Tests with Granulated Mirex-Soybean Oil Bait

Additional tests with granulated mirex-soybean oil bait for control of the imported fire ant, Solenopsis saevissima richteri Forel, were conducted. An aerial application was made to a 960-acre plot containing land of variable terrain and ground cover. Eight months later 1 colony of ants was found on 1 of thirty-three ½- to 1½-acre observation plots. The total pretreatment count of ant colonies on these plots was 750, or an average of 23 per plot. Applications of bail made during the cooler part of the year (November-April) to open land in sunny weather gave good control (96-100%). However, fast and complete kills of ants was dependent upon warm weather. The bait in the previous tests contained 0.075% mirex, 14.925% soybean oil, and 85% corncob grits, and was applied at the rate of 12½ lb/acre. Bait containing 0.075, 0.15, or 0.3% mirex and applied at the rates of 3, 5, or 10 lb/acre all gave excellent control of ants. In general, observations have shown that areas treated with bait in the first half of the year become reinfested the next fall, while areas treated during the last half of the year will not become reinfested until the fall of the next year. In either case, the actual reinfestation appears to coincide with the period of greatest mating flight activity (May-June).

Control of the Western Harvester Ant, Pogonomyrmex occidentalis, with Poisoned Baits1

The western harvester ant, Pogonomyrmex occidentalis (Cresson), is considered a pest of low-rainfall rangeland in the Western States. Trials with Kepone®(decaehlorooctahydro-1,3,4,-metheno-2 H -cyclobuta[cd]pentalen-2-one)-peanut meal-peanut oil bait and mirex (dodecachlorooletahydro-1,3,4-metheno-2 H -cyclobuta ( cd ) pentalene)-corncob grit-soybean oil baits were successful, but only when the materials were applied during the summer when the ants were actively foraging for seeds. These bait materials, as also Bayer 38920(6,7,8,9,10,10-hexachloro-l,5,5a,6,9,9a-hexahydro-3-methyl-6,9-methano-2,4-benzodioxepin (chlorinated to contain 70% total chlorine content)) on corncob grits’ were readily accepted and carried into the nests by the ants. Results of individual hill tests can be confounded by the over-lap of foraging ants from different hills and by colonies moving their brood from one mound into another. Application of a 2× mirex fire ant bait (0.15% mirex) was tested successfully on 50-acre plots of rangeland, a 3-pound-per-acre rate being as effective on land averaging 23 hills per acre as 5 pounds of bait per acre on land averaging 37 hills per acre.

Imported Fire Ant Toxic Bait Studies: Evaluation of Carriers for Oil Baits

Wheat bran, puffed barley grits, corncob grits, corncob pith, okra and kenaf hurds, sawdust, vermiculite and various clay granules were evaluated as carriers for oil baits for the imported fire ant, Solenopsis saevissima richteri Forel. While satisfactory baits were made with several of the carriers, the corncob grits baits were the most practical and the easiest to formulate and distribute with conventional equipment. The most effective formulation tested consisted of corncob grits 85%, soybean oil 14.925%, and mirex, formerly called GC-1283, (dodecachlorooc-tahydro-1,3,4-metheno-2H-cyclobuta [cd]pentalene), or Kepone® (decachlorooctahydro-1,3,4-metheno-2H-cyclobuta [cd]pentalen-2-one) 0.75%. Field tests with this bait consistently gave more than 95% control at rates of 5 to 20 pounds per acre (1.7 to 6.8 gm. of insecticide per acre). Other tests showed that this bait did not lose its effectiveness when aged up to 48 days and that peanut oil, tallow, tallow oil, yellow grease, and grease oil compared favorably with soybean oil as the food attractant.