Sugarcane Aphid: A New Threat to Sorghum in Arizona

Ayman M. Mostafa and Peter Ellsworth

University of Arizona, College of Agriculture and Life Sciences, Cooperative Extension

Over the last two weeks the UA Cooperative Extension IPM team received reports from pest control advisors of an aphid heavily infesting sorghum in many fields. The UA members of the Arizona Pest Management Center collected and field identified several samples from the Maricopa / Stanfield areas. The identification by Gene Hall UA Insect Diagnostician confirmed this invader as sugarcane aphid, Melanaphis sacchari. This is a new pest report for our state.

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External identification characteristics of sugarcane aphid.

The infestation in many fields was overwhelming with the plants completely covered in stickiness from the honeydew excreted by the aphids.

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Given this heavy infestation, it is likely this aphid has been in the state for longer than just this year, although reports extended only as far west as eastern New Mexico last year. The sugarcane aphid is distributed over the South, Texas and New Mexico; where it is one of the most important insect pests of grain and forage sorghum. Until recently the sugarcane aphid fed only on sugarcane in the US, but in 2013 it was found feeding on sorghum in southeast Texas near the border with Louisiana. This sorghum-feeding sugarcane aphid biotype spread over north Texas, southern Oklahoma, Louisiana, and Mississippi. Sugarcane aphids survived the 2013 winter in south Texas and spread throughout much of Texas and 12 other southern states during the spring and summer of 2014. In 2015, the sugarcane aphid spread through Texas into Oklahoma and Kansas, eventually infesting 17 states. This area encompasses 90 percent of the US sorghum acreage (Click here for 2015 distribution of sugarcane aphid). Giving the severity of this infestation and the rapid distribution of sugarcane aphid in Texas, this could become a serious impediment to sorghum production in Arizona with serious consequences on forage and dairy industries in the state. Giving the challenges facing forage crops, like alfalfa and now sorghum, in the last few years, it is important to bring different interested parties in the forage and dairy industry together for discussion.

Click here for more information from Texas A&M Agrilife Extension and Research about identification biology, damage, sampling and management.

Cutworms in Alflafa

Ayman Mostafa

There have been many cases of cutworm infestations in alfalfa in central Arizona over the last few weeks. Cutworms are frequent pests in the low desert of Arizona. The granulate (Feltia subterranea) and the variegated (Peridroma saucia) cutworms are the two most common species in alfalfa.

Full grown caterpillars are about 1.5 to 2 inches long and vary in color and patterns. Larvae frequently roll into a C-shape when disturbed. Cutworms feed at night and hide during the day in soil cracks and under debris.

 

Cutworm populations may develop in weedy areas and migrate into seedling or mature stands.

Established fields are damaged when cutworms cut off new growth or feed on the alfalfa foliage. Established alfalfa fields can be severely injured when cutworms cut off new shoots at or below ground level following harvest. The pest often goes undetected after cutting and hay removal but the problem becomes apparent when the field is irrigated and there is little or no regrowth.

Seedling alfalfa stands can be severely damaged by cutworms cutting the seedlings off at or just below the soil surface. Cultural control is important in managing cutworms in alfalfa, especially for new stands. Cutworms are most injurious in fields with high plant residue. Tillage helps to limit cutworm populations; seedlings in well-tilled fields, especially when there is an interval between crops are less likely to have cutworm problems. Keep the field and field edges weed-free. Flood irrigation can drown many cutworm larvae. Flood irrigation during the day will attract many birds that prey on the cutworms as the advancing water forces larvae from hiding. When damage is severe in seedling fields, apply an insecticide bait.

Treatment guidelines have not been established in Arizona. Check for cutworms by looking under duff and carefully digging to a depth of 1 inch in loose soil near alfalfa crowns. When cutworm numbers exceed one or two per foot of row or severe damage is apparent, it may be necessary to treat. If treating with baits, apply baits in late evening or at night when cutworms are on plants.

References:

http://ipm.ucanr.edu/PMG/r1300911.html

http://alfalfa.ucdavis.edu/+symposium/proceedings/2005/05-111.pdf

http://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=10705

http://alfalfa.ucdavis.edu/+symposium/proceedings/2006/06-113.pdf

 

EPA Proposal “to Mitigate Exposure to Bees From Acutely Toxic Pesticide Products”

Al Fournier and Peter Ellsworth

To Growers, Beekeepers, and Other Concerned Stakeholders:

EPA is seeking comment on a proposal to adopt mandatory pesticide label restrictions to protect managed bees under contract pollination services from foliar application of pesticides that are acutely toxic to bees on a contact exposure basis. These label restrictions would prohibit applications of pesticide products, which are acutely toxic to bees, during bloom when bees are known to be present under contract. (The proposed label restrictions will not apply to situations where contracted pollination services are not in use.) EPA is also seeking comment on a proposal to rely on efforts made by states and tribes to reduce pesticide exposures through development of locally-based measures, specifically through managed pollinator protection plans. (More Details Below, including proposed label language and an extensive list of affected active ingredients.)

Comments must be received on or before June 29, 2015.

You may provide comments directly to EPA at www.regulations.gov in docket EPA-HQ-OPP-2014-0818. http://www.regulations.gov/#!docketDetail;D=EPA-HQ-OPP-2014-0818

The Arizona Pest Management Center is developing a coordinated response for the desert southwest on behalf of the Western IPM Center. We will be glad to incorporate into our response any comments, concerns, feedback or relevant data from interested stakeholders. Please forward your comments to me at fournier@cals.arizona.edu or contact me at one of the phone numbers below. Individuals may also comment directly on the public docket linked above.

Your input on this important issue affecting agriculture is strongly encouraged! We have requested a 30-day extension of the June 29 deadline, but it is not clear at this time if an extension will be granted. Links to more information are at the bottom of this notice.

Important Considerations (extracted from EPA proposal):

“EPA encourages pollination service contracts established between growers and beekeepers that take into account the increased likelihood of bee colony exposure by including provisions to ensure that colonies will be protected and pollination services secured. If EPA receives evidence during the public comment period and/or through outreach at stakeholder meetings that such contract provisions are common or that there are other effective and mutually agreed upon stakeholder (i.e., beekeeper-to-grower) practices indicating that application of acutely toxic pesticides is not of risk concern for bees under contract, then EPA will consider this evidence in determining whether this scenario needs the mitigation indicated in the proposed language.” (From second paragraph on p 11 of the .pdf; last paragraph of section 5.2)

“EPA understands that there are some flowering crops and ornamentals that have an indeterminate period of bloom, i.e., these crops flower, set fruit and continue to flower throughout the year, and that for these crops bees are present under contract for pollination services for extended periods of time. Examples of indeterminate blooming crops which involve commercial pollination services include: cucurbits, strawberries, etc. EPA recognizes that the proposed prohibition on application of acutely toxic pesticides during the time when bees are present under contract may cause significant issues for the growers of these crops. Therefore, EPA requests input during the comment period on alternative mitigation approaches for these pollinator-attractive crops with indeterminate periods of bloom.” (From p 14 of the .pdf; Section 6.4, “Indeterminate Bloom”)

From EPA’s Proposal, here is the proposed Label language:

Appendix B – Proposed Labeling

DIRECTIONS FOR USE

It is a violation of Federal law to use this product in a manner inconsistent with its labeling.

FOR FOLIAR APPLICATIONS OF THIS PRODUCT TO SITES WITH BEES ON-SITE FOR COMMERICAL POLLINATION SERVICES: Foliar application of this product is prohibited from onset of flowering until flowering is complete when bees are on-site under contract, unless the application is made in association with a government-declared public health response. If site-specific pollinator protection/pre-bloom restrictions exist, then those restrictions must also be followed.

From EPA’s Proposal, here is the list of active ingredients that are affected by the proposed Label changes:

“Appendix A – List of registered active ingredients that meet the acute toxicity criteria

Abamectin Dicrotophos Momfluorothrin
Acephate Dimethoate Naled
Acetamiprid Dinotefuran Oxamyl
Aldicarb Diuron Permethrin
Alpha-cypermethrin D-trans-allethrin Phenothrin
Amitraz Emamectin benzoate Phorate
Arsenic acid Endosulfan Phosmet
Azadirachtin Esfenvalerate Pirimiphos-methyl
Bensulide Ethoprop Prallethrin
Beta-cyfluthrin Etofenprox Profenofos
Bifenazate Fenazaquin Propoxur
Bifenthrin Fenitrothion Pyrethrins
Carbaryl Fenpropathrin Pyridaben
Carbofuran Fipronil Resmethrin
Chlorethoxyfos Fluvalinate Rotenone
Chlorfenapyr Fosthiazate Sethoxydim
Chlorpyrifos Gamma-cyhalothrin Spinetoram
Chlorpyrifos methyl Imidacloprid Spinosad
Clothianidin Imiprothrin Sulfoxaflor
Cyantraniliprole Indoxacarb Tefluthrin
Cyfluthrin Lambda-cyhalothrin Tetrachlorvinphos
Cypermethrin Malathion Tetramethrin
Cyphenothrin Metaflumizone Thiamethoxam
Deltamethrin Methiocarb Tolfenpyrad
Diazinon Methomyl Zeta-cypermethrin
Dichlorvos”

MORE INFORMATION:

A summary of EPAs proposed action is available at: http://www.regulations.gov/#!documentDetail;D=EPA-HQ-OPP-2014-0818-0003

The full Proposal is available at: http://www.regulations.gov/#!documentDetail;D=EPA-HQ-OPP-2014-0818-0002

A fact sheet about the proposal is available at: http://www2.epa.gov/pollinator-protection/proposal-protect-bees-acutely-toxic-pesticides

Dr. Al Fournier
IPM Program Manager
University of Arizona
Maricopa Agricultural Center
37860 West Smith-Enke Rd.
Maricopa, Arizona 85238
office    520-374-6240
mobile 520-705-9903
fax        520-568-2556

Peter C. Ellsworth, Ph.D.
Full Specialist / Professor, IPM Coordinator &
Director, Arizona Pest Management Center
University of Arizona
Department of Entomology
Maricopa Agricultural Center
37860 W. Smith-Enke Road
Maricopa, AZ 85138
peterell@ag.arizona.edu
Tel: 480-331-APMC
http://cals.arizona.edu/crops