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Sorghum Midge and White Sugarcane Aphid Concerns

Sorghum Midge and White Sugarcane Aphid Concerns published on 3 Comments on Sorghum Midge and White Sugarcane Aphid Concerns

David Kerns and I have been receiving numerous phone calls this week about problems with applications of pyrethroids tank mixed with Transform for control of midge and white sugarcane aphid. The use of a pyrethroid for control of sorghum midge is a common practice in Louisiana; however, pyrethroids are very toxic to beneficial insects and are very likely to flare white sugarcane aphids in grain sorghum. Co-appliations of Transform and a pyrethroid have led to white sugarcane aphids recolonizing fields very rapidly and often resulting in poor control of aphids overall.

Therefore, automatic insecticide applications for midge should be avoided, and applications should only be made if midge are present.  The Louisiana threshold for midge in sorghum is at 25 – 30% bloom, treat for one or more midge per head.  If midge and sugarcane aphids are present, tank mixed applications of chlorpyrifos and Transform will offer good midge control while also reducing the risk of flaring aphids. Chlorpyrifos may not be quite as effective as a pyrethroid for sorghum midge and large populations may require a second application 3 – 4 days later.  Transform tank mixed with Dimethoate is another option for midge and aphid control; however, producers should be prepared to follow up with a dedicated midge application 3 – 4 days later.

Also, pyrethroid applications for the headworm complex in grain sorghum are strongly discouraged. Pyrethroid resistance is very common in sorghum webworm and corn earworm in Louisiana, and insecticides such as Belt or Prevathon should be used for headworms. These chemistries are Lepidopteran specific and will not harm beneficial insects or flare sugarcane aphids.

 

Sugarcane Aphids in Sorghum

Sugarcane Aphid Numbers Increasing in Grain Sorghum

Sugarcane Aphid Numbers Increasing in Grain Sorghum published on 1 Comment on Sugarcane Aphid Numbers Increasing in Grain Sorghum

Infestations of sugarcane aphids in boot to heading grain sorghum are increasing in Louisiana. Many of these populations start off small and exponentially increase in a span of 5 to 7 days. Pyrethroid applications for midge control can reduce natural enemy numbers allowing sugarcane aphids to reach damaging numbers faster.  Honey dew produced by sugarcane aphid feeding will give the crop a glossy appearance and large accumulations will often result in sooty mold growth and harvesting issues later season.

Sugarcane Aphid Damage to Pre-boot Sorghum
Sugarcane Aphid Damage to Pre-boot Sorghum

Sugarcane aphids are difficult to control with currently labelled insecticides; however, Louisiana was granted a section18

Sugarcane Aphids in Sorghum
Sugarcane Aphids in Sorghum

emergency exemption for the use of Transform 50WG for the 2014 production season.  Transform applications should be initiated before grain sorghum becomes heavily infested and producers in Texas are making applications at 30% infested plants with 100 to 250 aphids per leaf present. Use lower aphid numbers with increasing stress due to plant water deficit. This treatment threshold appears to be working for Texas growers; however, these recommendations are not supported by university research due to the recent introduction of this pest to grain sorghum in the United States. Transform applications of 1 oz/acre should be used on medium to high sugarcane aphid populations with the largest gallonage per acre (GPA) feasible for applicators (5 GPA by air or 20 GPA by ground). If 1 ounce applications of Transform are not providing adequate control the rate should be increased to 1.5 oz/acre.

2014 Northeast Research Station Pest Management and Crop Production Field Day

2014 Northeast Research Station Pest Management and Crop Production Field Day published on No Comments on 2014 Northeast Research Station Pest Management and Crop Production Field Day
NERS Field Day Flyer
NERS Field Day Flyer

Transform Granted Section 18 for Control of Sugarcane Aphid in Louisiana Sorghum (Forage, Grain or Stover)

Transform Granted Section 18 for Control of Sugarcane Aphid in Louisiana Sorghum (Forage, Grain or Stover) published on No Comments on Transform Granted Section 18 for Control of Sugarcane Aphid in Louisiana Sorghum (Forage, Grain or Stover)

Transform WG Sec 18 Label for Sorghum                                                     Approval Letter With Effective/Expiration Use Dates

Please follow the link above to access the section 18 label.  The link to the approval letter outlines the effective and expiration dates for the use of Transform in sorghum, as well as specifics regarding number of applications and maximum acreage treated in Louisiana.

If you have any questions or concerns about sugarcane aphids or use of Transform in Sorghum please contact:

Sebe Brown at 318-498-1283 (cell) or 318-435-2903 (office)

Dr. David Kerns at 318-439-4844 (cell) or 318-435-2157 (office)

Dr. Julien Beuzelin at 337-501-7087 (cell) or 318-473-6523 (office)

Mid-South Tobacco Thrips Resistant to Thiamethoxam

Mid-South Tobacco Thrips Resistant to Thiamethoxam published on No Comments on Mid-South Tobacco Thrips Resistant to Thiamethoxam

Syngenta has confirmed resistance to thiamethoxam, the active ingredient in Cruiser, Avicta Complete, Avicta Duo and Acceleron N seed treatments in four populations of tobacco thrips collected in the Mid-South.  Early indications suggest that this resistance is confined to the Mid-South.  Thiamethoxam is a widely used seed treatment for cotton, corn, soybeans and rice in Louisiana; however, thrips rarely inflict enough injury to corn and soybeans to cause economic losses

Over the past three years we, as well as our colleagues around the Mid-South, have seen a decline in efficacy of thiamethoxam treated cotton seed against tobacco thrips.  Based on limited information, resistance appears to be confined to thiamethoxam and has not been detected with imidacloprid.

Additionally, current data suggests that resistance to thiamethoxam is limited to tobacco thrips; thus western flower thrips, which occur in high numbers some years in Louisiana, still appear to be susceptible.

A larger resistance screening program will be conducted in 2014 and more information and specifics will provided as production meetings commence in the winter and spring.

Please see the following link by Gus Lorenz for additional information.

http://www.arkansas-crops.com/2013/11/08/cruiser-thiamethoxam-seed-treatment-may-be-ineffective-on-tobacco-thrips-in-cotton/

If you have any questions or concerns, please contact the Sebe Brown or  David Kerns for more information.

Sebe Brown     Cell: 318-498-1283       Office: 318-435-2903

David Kerns    Cell: 318-439-4844     Office: 318-435-2157

 

Section 24c Granted for Acephate in Louisiana Soybeans

Section 24c Granted for Acephate in Louisiana Soybeans published on No Comments on Section 24c Granted for Acephate in Louisiana Soybeans

This special local need label allows soybean producers to apply a maximum of  2lbs (ai/acre) of acephate  per season. The previous maximum was 1.5lbs (ai/acre)  per season.

For more information or if you have any questions or concerns, please contact:

Sebe Brown at 318-498-1283 (cell) or 318-435-2903 (office)

Dr. David Kerns at 318-439-4844 (cell) or 318-435-2157 (office)

Dr. Julien Beuzelin at 337-501-7087 (cell) or 318-473-6523 (office)

Dr. Jeff Davis at 225-747-0351 (cell) or 225-578-5618 (office)

 

Corn Leaf Aphid

Aphids in Grain Sorghum

Aphids in Grain Sorghum published on No Comments on Aphids in Grain Sorghum

Recently, David Kerns and I have been receiving more calls about aphids in grain sorghum. Three species of aphids colonize grain sorghum in Louisiana – corn leaf aphid, yellow sugarcane aphid and green bug.

The corn leaf aphid is blue to grayish green in color with black cornicles (twin exhaust pipes on rear of the body). Corn leaf aphids are typically found in the whorl, and development occurs sporadically throughout the growing season. Large populations can develop on larger plants; however, their effects on the crop are often negligible. As a general practice, control of corn leaf aphid is not recommended because this insect is seldom an economic pest.

Corn Leaf Aphid
Corn Leaf Aphid: Iowa State

The yellow sugarcane aphid has a lemon yellow body with a double row of dark spots down the back and is covered with small spines. Yellow sugarcane aphids will occasionally infest grain sorghum and can cause an issue due to the injection of a toxin when feeding. Areas of intense feeding will often result in purpling of young plants or chlorotic discoloration in older plants. Yield losses are most likely to occur in seedling infestations of this insect, but high numbers infesting older sorghum shouldn’t be ignored.

 

Yellow Sugarcane Aphid
Yellow Sugarcane Aphid: Kansas State

The green bug has a bright lime green body with a dark green stripe running down the middle of the back and cornicles with black tips at the end. Green bugs typically congregate on the underside of fully expanded leaves, and infestations are rare in Louisiana. This insect is a serious threat to grain sorghum because it will inject a toxin while feeding. Large numbers are capable of reducing yields and in extreme cases will cause plant mortality. If a green bug population does develop, consider the size of the plants, growing conditions, crop maturity and presence of beneficial insects when determining if an application is warranted. Applications may be justified when larger to preboot stage sorghum is exhibiting symptoms of red spotting or yellowing of leaves prior to leaf death. In preboot to mature sorghum, an application may be justified when green bugs cause desiccation of more than two of the lowest fully expanded leaves.

 

Green Bug
Green Bug: University of Tennessee

For more information or if you have any questions or concerns, please contact:

Sebe Brown at 318-498-1283 (cell) or 318-435-2903 (office)

Dr. David Kerns at 318-439-4844 (cell) or 318-435-2157 (office)

Dr. Julien Beuzelin at 337-501-7087 (cell) or 318-473-6523 (office)

 

ULV Malathion

ULV Malathion published on No Comments on ULV Malathion

I have been receiving more calls about ULV malathion and its use on cotton. Outlined below are the rules regarding the use of ULV malathion and application intervals outlined by the LDAF.

Courtesy of Bobby Simoneaux:

An ultra-low volume (ULV) malathion and a ULV pyrethroid insecticide (tank mixed) may be applied to control plant bugs in cotton only between sunrise on May 15 through sunrise on September 15 of each year, subject to the following.

1.     Applications shall be made at no less than seven day intervals at an application rate not to exceed the individual pesticide product labels and with no other dilutions or tank mixes.

2.     Each application shall be reported, in writing and within 24 hours of the application, to the appropriate Boll Weevil Eradication Program district office by the farmer, agricultural consultant or owner/operator.

3.     The report shall include the names and addresses of the farmer, agricultural consultant (if appropriate), owner/operator and applicator; the applicator’s number issued by the department; the field name or number; the number of acres treated; the name and EPA registration number of the pesticide product; and the application date and time.

If you have any questions or concerns, please contact the LDAF, Sebe Brown or Dr. David Kerns for more information.

Bobby Simoneaux:  225-925-3763

Sebe Brown     Cell: 318-498-1283       Office: 318-435-2903

Dr. David Kerns    Cell: 318-439-4844     Office: 318-435-2157

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