Sugarcane Aphid


2017 Management

The Sorghum Checkoff co-hosted the research exchange meeting with Dow AgroSciences and Bayer Crop Science to meet your needs and wants as sorghum producers. Early this year, researchers from across the country met to discuss their findings in relation to sugarcane aphid management.

Defense Against the Sugarcane Aphid booklet

sugarcane aphid bookletThe Sorghum Checkoff recently released the Defense Against the Sugarcane Aphid booklet in order to provide more information to growers. The goal of the document is to assist growers in effectively managing the pest to avoid yield and revenue loss. The 20-page document covers topics from identifying the pest and aphid effects to scouting and when to treat.
Downloadable PDF >>

The sugarcane aphid, Melanaphis sacchari, was discovered late in the 2013 growing season in the coastal sorghum regions. The sugarcane aphid is a new pest to the U.S. sorghum industry, and it is capable of causing substantial damage to the crop if left unmanaged. It is important for producers to be proactive and constantly scout for and monitor the pest because early detection is critical to minimize the aphid’s harmful effects.

Sugarcane aphids will only survive and multiply significantly in sorghum genotypes, including Johnsongrass, shattercane, sorghum-sudangrass, sudangrass, forage sorghum and grain sorghum. Sugarcane aphids will not survive on any of the major crops such as corn, cotton, soybeans or wheat. However, sugarcane aphids are distributed by the wind, so small colonies can be found in these crops, but at this time, they have not been found to be of economic importance.

Aphid Effects

Heavy infestations of the sugarcane aphid cause leaves to be covered with a sticky, shiny substance called honeydew. This honeydew is made up of plant sugars and water, which are harmless to animals. Honeydew is water soluble and washes off of the plant by rain or sprinkler irrigation. If honeydew is left on the plant, it eventually dries into a harmless residue.

Black sooty mold will often begin growing on the honeydew of sorghum leaves. This black sooty mold blocks out sunlight and decreases the plant’s ability to produce sugars through photosynthesis. Over time, black sooty mold causes leaves to turn yellow and eventually the leaf tissue dies.

Loss of plant sap from the sugarcane aphid feeding on sorghum leaves takes away nutrients from the plant that could otherwise be utilized for plant health and grain yield. Plant stress caused by the sugarcane aphids can also lead to uneven and lack of head emergence, poor grain set and will likely contribute to an increase in lodging.

Scouting

aphid scouting

  1. Fields should be scouted once a week for signs of the aphid. Once they are found, begin scouting at least twice a week.
  2. The first sign of sugarcane aphid buildup in a field is usually honeydew on lower leaves. 
  3. To determine if an insecticide treatment is needed, note the presence and number of aphids on leaves in at least four areas of the field. 
  4. In each area of the field examined, collect a leaf from the bottom and top of 20 plants, and observe the presence and number of aphids.

When to Treat

Threshold levels change and vary between regions. It is important to check with local experts to determine regional thresholds and scouting procedures. In general, two methods are currently being utilized to determine when to apply an insecticide to treat for sugarcane aphids.

Texas A&M University entomologists recommend threshold has been reached when 25 percent of the plants are infested with 50 aphids per leaf.

Mississippi State has explored thresholds by growth stage, which are described in the following table. Regardless of the threshold level used, it is critical that insecticide application occurs as soon as possible. Otherwise, severe loss can occur.

Growth Stage

Threshold

Pre-boot & Boot

20 percent of plants infested with localized area of heavy honeydew and established aphid colonies.

Heading, Soft Dough & Dough

30 percent of plants infested with localized area of heavy honeydew and established aphid colonies.

Black Layer

Heavy honeydew and established aphid colonies on the flag leaf or in the head. Only treat to prevent harvest problems. Observe preharvest insecticide intervals.

2016 Texas High Plains Sugarcane Aphid Management Guide

Best Management Practives to Combat the Sugarcane Aphid

Sugarcane Aphid: Management Guidelines for Grain and Forage Sorghum in Texas

KSU Sugarcane Aphid Information

Insecticides

There are several possible insecticide options available to control the sugarcane aphid, but in 2015 Sivanto Prime and Transform WG proved to be the most effective labeled products. Sivanto Prime, flupyradifurone, is sold by Bayer CropScience under a federal 2ee label for use on grain sorghum. Sivanto Prime also has a section 18 label for use on sweet sorghum in Arkansas, Kentucky, Mississippi, North Carolina and Tennessee. Transform, a Dow AgroSciences product, has been approved for use on grain sorghum in 2016 under a section 18 label in Alabama, Arkansas, Arizona, Colorado, Georgia, Kansas, Kentucky, Louisiana, Mississippi, Missouri, Nebraska, New Mexico, North Carolina, Oklahoma, South CarolinaTennesseeTexas and Virginia. The 2016 authorization includes new restrictions related to preventing exposure to bees, including a prohibition on the application of Transform from three days prior to bloom to seed set. 

One of the benefits of Transform and Sivanto Prime is they are not harmful to beneficial insects, which is important for the control of sugarcane aphids. Care should be taken in adding other insecticides to the mix that could be harmful to beneficial insects. Additionally, movement of Sivanto Prime and Transform in the plant is minimal, making coverage essential for adequate control.

Insecticide Application

When applying insecticides, it is important to read the full product label and follow instructions carefully. In general, ground rig application tends to work better than air application. Insecticide coverage is critical for sugarcane aphid control. Use spray nozzles and a spray pressure that maximizes coverage. Increasing the volume of water above the minimum requirements listed on the insecticide labels is recommended. Control will be lessened if insecticide application is made under cool conditions, including temperatures into the low 60 degrees Fahrenheit. The duration of control will depend on many factors, but under heavy infestation levels, expect anywhere from 5-14 days with 10 days being the most common length of control. Check with local experts on the use of adjuvants. Research on their effectiveness has been mixed.

Hybrids and Resistance

Several commercial hybrids are being sold that have shown some degree of tolerance to the sugarcane aphid. In most cases the hybrids have exhibited the ability to withstand higher infestation populations of aphids without affecting yield or the aphids have been shown to increase in number much slower than in susceptible hybrids.

Sound, integrated pest management strategies must still be utilized with these hybrids and the application of an insecticide may still be warranted if action thresholds are reached.

The list below has been put together after visiting with seed company representatives and reviewing various university data. Check with your seed company for other hybrids that they may consider as having some degree of tolerance to the sugarcane aphid.

Company/Brand

 Hybrid*

Maturity 

 Pioneer

 83P17

Med-Full

 Pioneer

 83P56

Med-Full

 DEKALB

37-07

Med-Early

 DEKALB

 Pulsar

Med-Early

 Sorghum Partners

 SP 7715

Med-Full

 Sorghum Partners

SP 78M30

Med-Full

 Sorghum Partners

 SP 73B12

Med-Full

 Richardson

 RS260E

Med-Full

 Richardson

 Sprint W FG

Med-Early

 Richardson

 Jowar I

Full

 Richardson

 Swift

V. Early

 Alta

 AG1201

Early

 Alta

 AG1301

Med-Early

 Alta

 AG1203

Med-Early

 Mycogen

 627

Med-Early

 Mycogen

 1G688

Medium

 B-H Genetics

 BH 4100

Medium

 B-H Genetics

 BH 3400

V Early

 Warner Seed

 W-844-E

Med-Full

 Warner Seed

 W-7051

Med-Full

 Golden Acres

3960B

Med

*All of these hybrids may need to be treated with an insecticide if the action threshold is reached

Louisiana State University Sugarcane Aphid Hybrid List

Private companies and university sorghum breeders continue investigating resistance. They have identified better sources of sugarcane aphid resistance and tolerance, and are working to incorporate these qualities into commercially available hybrids.

Ask your seed company representative or check the Sorghum Checkoff website for hybrids with some tolerance to the sugarcane aphid.

Pre-Plant Considerations

To protect sorghum from potential early season infestations, growers should consider planting seeds treated with an insecticide seed treatment. Acceptable seed treatments include Cruiser (thiamethoxam), Poncho and Nipsit (clothianidin) and Gaucho (imidaclorprid), which should give up to 40 days of sugarcane aphid control.

Harvest Considerations

If sugarcane aphids are in significant numbers in the sorghum head or on the upper leaves, harvesting can be impeded due to honeydew. There is not a good threshold level at this time for when to spray sugarcane aphids to assist in harvest.

If sugarcane aphids are present and produce a significant amount of honeydew that can gum up the combine, many producers are opting to spray an insecticide to eliminate the risk of harvesting issues. In 2015, Transform was the insecticide of choice, since it had a shorter harvest interval after application of 14 days compared to Sivanto prime with 21 days. If used in Texas, Kansas, Nebraska, Arkansas and Oklahoma in 2016,  Sivanto prime's preharvest interval is 14 days. If desired, these insecticides can be mixed with preharvest desiccants.