The Georgia Weekly Weather and Crops Report for the week ending July 2ND listed the crop as 71 percent squaring and 28 percent setting bolls which is similar to the
5-year averages of 78 percent squaring and 26 percent setting bolls. Hit and miss showers were welcomed but soil moisture remains low in many areas.INSECT SITUATION:
Aphid populations increased significantly in some areas during the last week, and treatment has been needed on some fields. Tobacco budworm and corn earworm moths are also being observed. Armyworm egg masses have been observed in some fields.
Aphids: Aphid infestations increased dramatically in recent days and some fields have warranted treatment. Cotton aphids are very prolific; a new generation may occur every five days. In the
early part of an infestation, winged aphids infest plants and give birth to living young that develop into wingless females. Wingless females will continue to give birth to wingless forms until the host plant becomes crowded
at which time females will give birth to living young that will develop wings so that they may fly to infest other plants. These soft bodied insects range in color from light yellow to dark green or almost black and infest
the underside of leaves and/or tender terminal growth. Damage to the plant occurs as aphids feed on plant juices with their sucking mouthparts. This feeding is an additional stress factor on the plant. Heavy
feeding will cause discoloration or yellowing of the terminal. Aphids secrete a sugar-like substance called honeydew which makes the leaves sticky and slick in appearance. A fungus or sooty mold will develop on
accumulated honeydew.
Aphid trials conducted in recent years have typically shown no yield benefit in treating aphids. However, there appears to be some heavily infested fields in parts of Georgia which
are in need of treatment. The decision to treat aphids is a difficult one and is basically a judgement call which must be made on a field by field basis. Aphids would need to be severe in non-Bt cotton to justify
treatment as beneficials are vitally important in this system. In making the decision to treat aphids I would suggest you consider the following symptoms: heavy honeydew present and some leaves showing sooty mold,
yellowing in the terminal or lower leaves, retention problems on stressed cotton, or limited growth on late planted cotton.
Help is on the way, but when will it get to you. Scott Brown, CEC in Colquitt County,
reported the naturally occurring fungus in a cotton field in the Berlin area. This is the first report of the fungus which will cause aphid populations to crash. Hopefully, the fungus will continue to spread and offer
some relief. This further compounds treatment decisions. How fast will the fungus spread? Infected aphids will be covered by a brown or grayish green fungal mass ("fuzzy" aphids). Once fuzzy aphids are
observed in a field, the population will generally crash in a matter of days.
Several county agents and consultants are participating in a Cotton Aphid Fungus Sampling Service being coordinated by Dr. Don
Steinkraus of the University of Arkansas in cooperation with Cotton Incorporated. Results of samples sent from Georgia and other states will be posted on a web site by the University of Arkansas (
