Studies on the Sterile-Insect Technique as a Means of Controlling the Stable Fly, Stomoxys Calcitrans (L.), in a Beef Cattle Feedlot in Brookings, South Dakota

The stable fly is usually the only biting, blood-sucking fly breeding in appreciable numbers in and around confined animal facilities. An average number of 50 flies per animal can reduce the weight gains of calves on a growing ration by 0.9 kilogram per day. At present, the level of 5 stable flies per front leg of confined beef cattle is used as an indicator of the economic threshold when control measures must be instituted. Since the immature stages of the stable fly develop in decaying organic matter, the most practical control measure has been sanitation or the proper storage and management of grains, silage, haylage, and manure which can support breeding in the feedlot. Campbell and McNeal in Nebraska found chemical control to be of value when residual sprays I were applied to fly resting areas such as the feed bunks, farm buildings, or vegetation surrounding the feedlots. The sterile-insect technique as a method of controlling or eradicating harmful insects gained popularity after the successful eradication of the primary screw-worm fly in the United States by the U.S. Department of Agriculture. It involved the mass-production of the fly, sterilization by gamma radiation, and release of the sterilized flies over infested areas. This resulted in total elimination of the screwworm fly over large geographical areas. Several workers subsequently employed the sterile-insect technique against other insect pests such as the melon fly and the stable fly. Compared to chemical control, the sterile-insect technique is highly selective and does not cause insect resistance. Sterilization is also the only proven pest control method that can actually eradicate an insect species over large areas. The main requirements for the technique to work according to Knipling are: (I) The availability of a method for producing sterility without serious adverse effects on the mating behavior and competitiveness of the insect, (2) A practical method for rearing the insects in large numbers, and (3) Quantitative information on the natural population density. Williams et al., demonstrated that the stable fly can be easily mass-produced and sterilized by 2 kR gamma radiation without affecting its competitiveness and longevity in the field. Previous studies in Florida and on St. Croix, U.S. Virgin Islands indicated that the sterile-insect technique shows promise against the stable fly. This research was initiated to investigate the feasibility of controlling a stable fly population in a beef cattle feedlot in Brookings, South Dakota using the sterile-insect technique. The objectives of the studies were: (1) To determine the population dynamics of the stable fly in the feedlot during the summer season of 1986, (2) To design a practical method of mass-producing the flies in the laboratory, (3) To determine whether actual releases of sterilized flies will have an effect on the reproductive potential of the wild population in the feedlot, and (4) To evaluate a chemosterilant, bisazir, as a possible substitute for gamma radiation in producing sterility in flies to be released in the field. All experiments in this study were carried out at the SDSU Cattle and Sheep Nutrition Research feedlot and at the Physiology Laboratories on SDSU campus from May, 1986 to July, 1987

Pesticides Registered for Mosquito Control in South Dakota

Pesticides alone will not eliminate all mosquitoes. The use of pesticides to control mosquitoes around the home and yard must be part of a multifaceted approach that includes the following non-chemical tactics: • Eliminate standing water. • Fix broken window screens. • Use outdoor bug lights. • Installing carbon dioxide-baited traps. Some mosquitoes will always “get through.” If you will be outdoors, it is recommended that you wear a mosquito repellent of your choice, avoid being outdoors around sunset and sunrise, and cover as much skin as possible with appropriate clothing. For more information on selection and use of insect repellents, refer to FS 920 Personal Mosquito Repellents available at your local Extension office or online at http://sdces.sdstate.edu/westnile/publications.htm. This publication lists the most common insecticides that are registered in South Dakota for use around the house and yard. The products are arranged by the active ingredient. The active ingredient is usually listed prominently in the first section of the label. This section will list the chemical name and/or the common name of the pesticide and also the concentration. This list was current as of June 2004, but label uses and registrations change. Before using any pesticide, be sure to read the entire label to ensure that the product can be used for mosquitoes, can be applied around the home and yard, and to be sure all safety restrictions are followed. For more information, refer to FS 923 Controlling Mosquitoes Around the Home and Yard

Personal Mosquito Repellents Available in South Dakota — 2004

The most commonly available insect repellents contain either DEET or permethrin. This publication provides information on specific repellents that are registered for sale in South Dakota in Spring 2004. Personal mosquito repellents are products that can be applied directly onto the human skin or clothing for the purpose of repelling or killing adult mosquitoes. While repellents containing the chemical DEET can be applied directly on human skin and clothing, products containing the insecticide permethrin cannot. Permethrin must be applied only on clothing or related apparels such as hats,shoes, and overalls several hours before being worn. Organic alternatives to DEET or permethrin are also available for chemically-sensitive individuals. There appears to be a limit in the duration of protection time that increasing DEET concentrations may provide. For example, a product containing 100% DEET may provide no more than 10 hours of protection from mosquito bites. The duration of protection time provided by products containing 35% and 100% DEET may not be significantly differen

Alfalfa Production and Pest Management in South Dakota

Alfalfa is a herbaceous perennial forage crop in the plant family Medicago. Alfalfa is well adapted to growing conditions in South Dakota if a variety with good winter hardiness has been selected. Several vegetative stems are produced from the crown during each growth cycle, and the plant has a deep, branched taproot system that allows it to produce acceptable forage yields, even under relatively dry conditions. South Dakota is one of the leading alfalfa growing states in the U.S., annually producing more than six million tons of alfalfa hay for all uses

Insecticide Use and Crop Selection: A South Dakota Case Study

South Dakota has recently experienced a significant increase in the proportion of acres treated with insecticide. Unfortunately, data on insecticide usage by crop at the county level is not available. The following case study seeks to uncover the reasons for this increase by analyzing county-level data in South Dakota with a fixed effects panel regression. The study links the proportion of acres planted for a specific crop to the proportion of total acres treated with insecticide. This approach provides insight on how changing cropping patterns in South Dakota have influenced insecticide use.Variance Risk Premium, Variance Swap, Model-free Variance, Implied Variance, Realized Variance, Corn VIX