Cotton aphid (Homoptera : Aphididae) biology, honeydew production, sugar quality and quantity, and relationships to sticky cotton

Cotton aphid, Aphis gossypii Glover, fecundity, nymph development, honeydew production, and honeydew relationships to cotton, Gossypium hirsutum L., l int stickiness were studied in the laboratory and in the field. Apterous ad ult females produced an average of 1.7 nymphs per day and the nymphs (four instars) developed to adults in an average of 4.1 days, in each case at 26. 7 degreesC in the laboratory. Average longevity of adults was 16.1 days. Mo re honeydew drops were produced by one-day old nymphs than three- or four- day old nymphs. There were no significant differences between amounts of gl ucose, fructose, trehalulose, or melezitose produced by nymphs of different ages. But one- and two- day old nymphs produced more sucrose than four-day -old but not three-day-old nymphs. Numbers of honeydew drops produced on a day to day basis by adults and adults plus their nymphs were highly variabl e and did not show a distinct pattern of production. Adults alone and adult s plus their nymphs in leaf cages over 28 and 24 days, respectively, averag ed, For all measured sugars, 1.83 and 2.68 micrograms per day. More honeyde w drops, sugars. (except trehalulose and melezitose) and progeny were produ ced by adults at 26.7 degreesC compared with 15.5 or 32.2 degreesC. Increas ing times of exposure of clean cotton lint to aphids acid the resulting inc reasing amounts of honeydew sugars under laboratory and field conditions we re significantly related to increasing cotton lint stickiness as measured w ith a thermodetector.