This information was provided by state coordinators and was collected from surveys of county agents, extension specialists, private consultants and research entomologists. All data are averaged over a total reporting unit. For example, if a unit report represents 100 acres and an 8% loss on 25 of these acres, then in the table summary this shows up as a 2% loss. ((.08 .25)/100). This type of averaging is used for all data reported including yields and costs of control. Because of averaging and rounding some individual state summary numbers listed as `0' are slightly larger. Costs are averaged to the nearest cent, bales and acres to the nearest whole number, other numbers are rounded to the nearest .001. Bales are calculated at 480 pounds, and a cost of $0.65 per pound of lint is used in figuring costs.
Arthropod pests reduced overall yield by 7.98% in 1998. Both acreage and yields were down, partially due to weather. The bollworm/budworm complex, causing 2.71% loss, was the number one arthropod pest of cotton in 1998. Eight-five percent (85%)of US cotton acres was infested by heliothines. Of those, 70% were bollworms, H. zea. Only 55% of US acreage is reported infested by boll weevils but they are 1998's second worse pest at 2.3% loss. Lygus at 1.04% loss is the only other pest to exceed 1% reduction in yield. Thrips (0.352%) and aphids (0.333%) complete the the top five insect pests of 1998. Beet and fall armyworms (0.281 and 0.221%) also contributed heavily to losses in some areas. Cotton fleahoppers (0.208%) and spider mites (0.241%) were also significant pests in some areas of the belt. Total cost of management and loss to insects to the 1998 crop was $1.22 billion or $114.28 per acre. Of those costs approximately $63 are direct insect management costs.
In an attempt at capturing as many of the costs of insect management as possible, the Cotton Insect Losses estimates have changed in the last few years. They were begun as a simple attempt to arrive at the `average cost of spraying insecticide for control of cotton arthropod pests. We still attempt to arrive at the most accurate estimate possible for spray activities, but have also added some of the other costs which are incurred in cotton insect pest management. These `additional costs increase the bottom line of expenditures for arthropod pest management - but also more accurately reflect true expenditures. We include `at planting insecticide costs,(an estimate of the cost of systemic insecticides applied at planting for control of thrips and other pests of seedling cotton) `Bt cotton costs,(an estimate of the technology fee and the seed surcharge) `eradication costs(which include the maintenance fee in those states which have eradicated the weevil and other eradication projects) and `scouting costs to the traditional `foliar insecticide costs. Bales lost are also given a dollar value using 480 pound bales at $0.65 per pound. Remember, these are estimates and may not totally reflect an individual farm or area, but they do reflect trends and serve as a general comparison.