Lettuce Aphids Showing Up on Late Produce

Lettuce Aphid Pressure Has Been Steady

By John Palumbo, University of Arizona Professor/Extension Specialist, Department of Entomology

This season has been a banner year for aphids in the desert. Aphid pressure has been steady on most crops throughout the spring. Consistent with the warm weather we have been experiencing lately, Lettuce aphids, Nasonovia ribisnigri, (aka., Red aphid) have shown up in desert lettuce again.

The last time lettuce aphid was this abundant on desert produce was the spring of 2012. However, in the past couple of weeks, I’ve identified lettuce aphid appearing on both head lettuce and romaine in Roll and Wellton. I’ve also had reports of the aphid showing up in the Imperial Valley.

At the Yuma Ag Center, we began seeing lettuce aphid a couple of weeks ago on untreated lettuce, and they have recently built up to high numbers. Previous experience has taught us that daytime high temperatures in the 80’s are ideal for population growth. A few things to remember about lettuce aphids relative to the other aphids we commonly see.

First, the immature nymphs are small and have a red appearance, whereas the apterous adults are typically a large brown colored aphid with dark bands running across the abdomen. Second, among the crops we grow locally, lettuce aphids are only found on the lettuce types(Lactuca spp.)

Lettuce aphids prefer to colonize the terminal growth, and can often be found in heads or hearts, whereas green peach aphids are often found on the frame leaves in high numbers before moving into the heads. Sampling should be focused on the terminal growth of young plants and in the heads and hearts of older plants. Third, they can reproduce prolifically, producing many more winged alates than other species, which can quickly lead to widespread abundance throughout a field or a growing area. Finally, as the saying goes “he who hesitates is lost”.

If lettuce aphids are found on your lettuce, it is recommended that you respond quickly with an insecticide treatment. The product of choice is Movento at 5 oz/ac. Because of its systemic activity, Movento will reach aphids in the protected terminal growth.

Be sure to include a penetrating adjuvant for best results at a rate of at least 0.25% v/v. It normally requires 7-10 days of activity before a significant reduction in the infestation is observed. For more information on lettuce aphid please refer to Lettuce Aphid on Late Season Produce. If you’re finding lettuce aphid on organic lettuce, you’re out of luck; none of the registered biopesticides will control this aphid.

California Ag Today2021-05-12T11:01:49-07:00April 9th, 2019|

2018 Cotton Crop Proceeding Well

Late Season Pests Can Be a Challenge

By Patrick Cavanaugh, Editor

The 2018 cotton harvest will be starting in the southern part of the Central Valley later this month, and some growers will be facing pressure from pests.

California Ag Today recently spoke about the topic with Dan Munk, a UC Cooperative Extension Farm Advisor in Fresno County specializing in irrigation crop nutrient management and cotton production systems.

“The crop looks very good and loaded with cotton bolls. We don’t have a lot of boll losses, and that’s a real positive thing, so very excited about the potential for fairly high yields in the 2018 season. The biggest concern right now is pest management, press pressures as we approach the latter part of the season,” Munk explained.

The main issue this time of year is the honeydew that pest leave on the cotton. Honeydew is the exudate extracted by the insect as it feeds on the leaves.

“Because we have the bolls on the plant that have opened, we now have exposed lint and need to protect that lint from stickiness that’s created from whitefly and the aphid honeydew, which is basically the added sugars that those insects that feed on the leaves of the plant, and they excrete them and deposit them on the lint,” Munk said.

Munk explained that the big concern right now is dealing with pest pressures in terms of whitefly and aphid—both sucking insects. “The problem right now [is] where we’re seeing pest pressures—particularly from whitefly as we get later in the season—will build in many fields.

There are several approaches to controlling whitefly and aphids. One is to deal with the eggs that they produced. And then there’s a certain class of materials to deal with the eggs.

“There’s another class of materials that deal with the juveniles—that early form of the insect—and then there are ways to control the adults,” Munk said.

“A number of insecticides have been applied to deal with those various levels of insect populations based on the individual field situation,” he explained.

California Ag Today2021-05-12T11:01:53-07:00October 3rd, 2018|

BioSafe Systems Offers Biological Control Products

BioCeres Beneficial Fungi Kills Important Pests

By Patrick Cavanaugh, Farm News Director

California Ag Today recently interviewed Jay Sughroue, Ph.D. with BioSafe Systems about the new BioCeres WP Biological Pesticide.

BioCeres is new strain of the fungi Beauveria basiana discovered in Italy in 1815. There was a sharp decline in silkworm production and the entomologist back then, Antonio Basiana, discovered the fungi that was responsible for white muscarsdine disease causing the decline of silkworm production.

“The new strain, ANT-03, is different from commercially available strains is that it’s more aggressive and more resilient, so it lasts longer in the environment. And it’s more pathogenic when it comes in contact with insects that you want to control,” Sughroue said.

“Fast forward several decades, and now, we have commercially available products that are controlling very important agronomic pests, such as thrips, aphids and white flies,” Sughroue said.

Sughroue noted that it’s important to follow important application strategies.

“You want to apply this prior to high population development. It’s not a knockdown, so you want to be out there scouting fields. As soon as you start to see numbers that are indicative of causing damage, you want to start a spray program that contains BioCeres, and then after about 5 to 7 days, you’ll start to see the pests decline in population.”

The fungi spore germination is the key to the effectiveness.

“The spore lands onto an insect. It doesn’t matter if it’s an egg, a nymph, a larva or an adult. It starts to germinate, and through enzymatic activity and mechanical pressure, it grows inside the insect, and it will start to sporulate so the insects come down with a severe case of the flu. They stop feeding immediately.

Sughroue said while it takes about 3 to 5 days for the pest to die, it stops feeding very soon after the spore germinates inside them.

Sugroue said the list of the pests will only become larger as time goes by

“We’re going to expanding that list to include other important insects, but this is the first generation of this product,” he said.

California Ag Today2021-05-12T11:01:58-07:00October 11th, 2017|

Lorsban Under Scrutiny

Chlorpyriphos (Lorsban) Must be Used More Carefully

By Patrick Cavanaugh, Deputy Editor

California Department of Pesticide Regulation (DPR) reports an important, broad-spectrum organophosphate insecticide known as Chlorpyriphos, or Lorsban, may be further restricted due to evidence of potential human health and environmental risks, presence (parts per billion) in some California waterways, and pressure from the EPA. Brian Leahy, director of the California Department of Pesticide Regulation, said, “Chlorpyriphos is an important tool and we know there are important times when you have to use it.”

Registered and widely used in agriculture across the nation for more than 40 years, DPR has made it a restricted-use material. Leahy said, “We are trying to work with the grower community to improve how they use it. We are also working with UC IPM to look at essential needs, but we know that as we look at Chlorpyriphos, we are going to have to put additional restrictions on it.”

“We simply need for it to stay on target, and not be getting into the human body. We are seeing that it is, and we are going to continue to make sure that people use it thoughtfully and wisely,” he said.

And Leahy is very confident that growers can use this material and keep it on target, “I have seen farms that use it only when they really need it, and that is what we want. We can’t lose this tool and we are going to keep it only by showing we can greatly reduce off-site movement to the human body and watersheds,” he noted.

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Resources:

According to the University of California Agriculture and Natural Resources 2014 Chlorpyrifos Report entitled, “Identifying and Managing Critical Uses of Chlorpyrifos Against Key Pests of Alfalfa, Almonds, Citrus and Cotton“:

Chlorpyrifos plays a critical role in many IPM programs for controlling pests that threaten the productivity and economic well-being of California producers and in maintaining the high quality standards required by consumers and international export markets. This active ingredient also allows production of animal feed to support the important dairy industry in California. For some pests, chlorpyrifos is one of the last effective organophosphate insecticides available and may provide an important alternative mode of action for insecticide rotations to prevent the development of resistance to newer insecticide products. For others, this product is one of very few products with international registrations with established maximum residue limits (MRLs) that allow unhampered trade. Chlorpyrifos may also be a key tool for controlling invasive pests as well as endemic pests occasionally found in extremely high population densities.

The California Department of Pesticide Regulation reports that the combined use of chlorpyrifos in alfalfa, almonds, citrus, and cotton has decreased since 2006.

Although newer insecticides are also available to manage some pests in these four crops, there is a continued need to preserve the availability of chlorpyrifos for specific situations.

“Assessing the Health Risk of Pesticides,” California Department of Pesticide Regulation

California Ag Today2021-05-12T11:03:04-07:00February 16th, 2016|

New UC IPM Program Director

Jim Farrar Named Director of UC Statewide IPM Management Program

By Pam Kan-Rice, UCANR Assistant Director, News and Information Outreach

Jim Farrar has been named director of the Statewide Integrated Pest Management Program for the University of California’s Division of Agriculture and Natural Resources. He will begin as new uc ipm program director on Oct. 1.

UC IPM works with growers and residents to protect human health and the environment by reducing risks caused by pests and pest management practices.

Farrar is currently director of the Western IPM Center, where he has served since 2013. He succeeds Kassim Al-Khatib, UC IPM director since 2009, who is transitioning to a UC Cooperative Extension specialist position located in the Department of Plant Sciences at UC Davis. There Al-Khatib will focus on his research in weed management.

“UC IPM is a widely recognized national leader in integrated pest management,” Farrar said. “I am excited to continue efforts to make IPM the standard practice for managing pests in agriculture, communities and natural areas in California.”

Prior to joining the Western IPM Center, Farrar was a professor of plant pathology in the Department of Plant Science at California State University, Fresno for 12 years.

At Fresno State, Farrar received three teaching awards. He taught courses in plant pathology, plant nematology, diagnosis and control of plant diseases, crop improvement, aspects of crop productivity, mycology, sustainable agriculture and advanced pest management. His research centered on fungal diseases of vegetable crops, including management strategies for cavity spot of carrot. During his Fresno State tenure, he served four years as chair of the Department of Plant Science and a year as interim chair of the Department of Food Science and Nutrition.

From 1995 to 1997, Farrar taught in the Botany Department at Weber State University in Ogden, Utah. At Weber State, he conducted research on rock cress plants infected with a rust fungus that causes false-flowers. This rust is closely related to a species that is a potential biological control agent for dyer’s woad (Isatis tinctoris), an invasive weed.

Farrar has published scientific papers, extension newsletter articles, and articles in agricultural industry magazines. He also wrote a chapter in the book Tomato Health Management and five disease descriptions in the book Compendium of Umbelliferous Crop Diseases. He recently completed a three-year term as senior editor for feature articles in the journal Plant Disease and was senior editor for the online journal Plant Health Progress for three years. Farrar is a member of the American Phytopathological Society and the Pacific Division of the American Phytopathological Society.

The Wisconsin native completed his Ph.D. in botany and B.S. in plant pathology at the University of Wisconsin, Madison, and his M.S. in plant pathology at UC Davis.

California Ag Today2016-05-31T19:28:05-07:00September 10th, 2015|