Are We Creating Super Bugs?

Are We Creating Super Bugs?

Normally, you will have one of four answers:  “yes”, “no”, “I don’t know” or “what are super bugs?”  The answer to the last one is an insect or other pest that has become resistant to chemical treatments through either natural selection (genetics) or an adaptive behavioral trait.

The next question is do you treat insect or pest problems at home with a purchased EPA registered chemical (one purchased from the nursery or other retailer)?  If you answered yes, then the next question is how many times in a row do you apply the same chemical?  If you only use one chemical until the product is used up, then you might be creating super bugs.  Do you ever alternate chemicals and if you answer yes, do you understand chemical Modes of Action (how the pesticide kills the pest)?  If you do not, then chances are the rotating chemicals might act in the same way.  Thus, you are creating super bugs because in essence you are applying the same chemical with different labels.

MoA resistance diagram

Click on image for a larger view. Taken from https://edis.ifas.ufl.edu/in714.

One of the first ways to reduce creating super bugs is to practice Integrated Pest Management (IPM).  The very last step of an IPM philosophy is chemical control. You should choose the least toxic (chemical strength is categorized by signal words on the label:  caution, warning, and danger) and most selective product.  A chemical label advertising it kills many pests is an example of a non-selective chemical.  You want to choose a chemical that kills your pest or only a few others.  In Extension education, you will always hear the phrase “The label is the law.”  To correctly purchase a chemical, you must first correctly identify the pest and secondly the plant you want to treat.  If you need help from Extension for either of these, please contact us.  Before purchasing the chemical, always read the whole label.  You can find the label information online in larger print versus reading the small print on the container.

IRAC app

IRAC phone app.

You now have the correct chemical to treat your pest.  Wear the recommended personal protective equipment (PPE) and apply according to directions.  If your situation is normal, the problem is not completely solved after one treatment.  You might apply a second or third time and yet you still have a pest problem.  The diagram explains why you still have pests or more accurately super bugs.

Now the last question is how do we really solve the problem given that chemicals are still the only treatment option?  A bit more work will greatly help the situation.  You need to download the Insecticide Resistance Action Committee (IRAC) guide and find the active ingredient on your chemical label (http://edis.ifas.ufl.edu/pi121 or https://irac-online.org/modes-of-action/ and select the pdf).  If you are like me, you can just download the IRAC MoA smartphone app and type in the active ingredient; otherwise, Appendix 5 in the pdf has a quick reference guide.  Either way, you will know the Group and/or Subgroup.  A lot of commonly purchased residential chemicals fall within 1A, 1B or 3.  The successful treatment option is to select chemicals from different group numbers and use them in rotation.  If you start practicing this simple strategy, your treatment should be more successful.  Then when someone asks if you are creating super bugs, your answer will be no.

If you have any questions about rotating your chemical Modes of Action, please contact me or your local county Extension agent.  For more resources on this topic, please read Managing Insecticide and Miticide Resistance in Florida Landscapes by Dr. Nicole Benda and Dr. Adam Dale (https://edis.ifas.ufl.edu/in714).

Biological Control of Air Potato by a Beneficial Beetle

Biological Control of Air Potato by a Beneficial Beetle

Article by Jessica Griesheimer & Dr. Xavier Martini, UF/IFAS North Florida Research and Education Center, Quincy

Dioscorea bulbifera, commonly known as the air potato is an invasive species plaguing the southeastern United States. The air potato is a vine plant that grows upward by clinging to other native plants and trees. It propagates with underground tubers and aerial bulbils which fall to the ground and grow a new plant. The aerial bulbils can be spread by moving the plant, causing the bulbils to drop to the ground and tubers can be spread by moving soil where an air potato plant grew prior. The air potato is commonly confused with and mistaken as being Dioscorea alata, the winged yam which is also highly invasive. The plants look very similar at first glance but have subtle differences. Both plants exhibit a “heart”-shaped leaf connected to vines. The vines of the winged yam have easily felt ridges, while the air potato vines are smooth. They also differ in their aerial bulbil shapes, the winged yam has a long, cylinder-shaped bulbil while the air potato aerial bulbil has a rounded, “potato” shape (Fig. 1).

In its native range of Asia and Africa, the air potato has a local biocontrol agent, Lilioceris cheni commonly known as the Chinese air potato beetle (Fig. 2). As an adult, this beetle feeds on older leaves and deposits eggs on younger leaves for the larvae to later feed on. Once the larvae have grown and fed, they drop the ground where they pupate to later emerge as adults, continuing the cycle. The Chinese air potato beetle will not feed on the winged yam, as it is not its host plant.Current methods of air potato plant, bulbil, and tuber removal can be expensive and hard to maintain. The plant is typically sprayed with herbicide or is pulled from the ground, the aerial bulbils are picked from the plant before they drop, and the underground tubers are dug up. The herbicides can disrupt native vegetation, allowing for the air potato to spread further should it survive. If the underground tuber or aerial bulbils are not completely removed, the plant will grow back.

The Chinese air potato beetle is currently being evaluated as a potential integrated pest management (IPM) organism to help mitigate the invasive air potato. The beetle feeds and reproduces solely on the air potato plant, making it a great IPM organism choice. During 2019, we studied the Chinese air potato beetle and its ability to find the air potato plant. It was found the beetles may be using olfactory cues to find the host plant. Further research is conducted at the NFREC to increase natural aggregation of the beetles on air potato to improve biological control of the weed.

Chinese Air Potato Leaf Beetle.

If you have the air potato plant, or suspect you have the air potato plant, contact your local UF/IFAS Extension Agents for help!

 

‘Patio Baby’: An Eggplant for Any Space

‘Patio Baby’: An Eggplant for Any Space

In my ongoing search for low-maintenance vegetable varieties that perform well in small spaces, like my raised bed garden, I decided to try a newish Eggplant variety called ‘Patio Baby’ this summer.  Developed by PanAmerican Seed and winner of the 2014 All-American Selections Vegetable- edible category, I was drawn to ‘Patio Baby’ due to the advertising claims made that it was a true miniature variety, perfect for growing in containers, only reaching 20” or so in height and producing both “early” and abundant fruit.  I’ve been very pleased with the performance of this extremely unique variety so far in my informal backyard trial and definitely think it deserves consideration in your garden too!

‘Patio Baby’ fruit ready for harvest in September 2020. Photo courtesy of Daniel Leonard.

The first observation when seeing a mature ‘Patio Baby’ is how small the plant is, leaves, flowers, fruit, everything.  Compared to a standard ‘Black Beauty’ variety, ‘Patio Baby’ plants measure maybe a third as tall and wide.  Where a “normal” eggplant fruit might be slightly larger than a softball and often have spines on their calyxes (the green part that connects the purple fruit to the stems), ‘Patio Baby’ fruit are roughly the size of a large chicken egg and totally spineless!  I find this smaller plant and fruit size to have several perks.  Vegetable plants that grow 2’ tall and wide are just about perfect for raised bed gardening.  If you don’t require a large quantity of eggplant, you won’t have to sacrifice an entire bed’s space to ‘Patio Baby’ like you would with the standard varieties. Also, ‘Patio Baby’ fruit won’t bend or break branches and are held strongly on the plants, with no need for staking, another bonus when space is at a premium.  Finally, I find it much easier to harvest, handle and prepare the small, spineless ‘Patio Baby’ fruit in the kitchen.  Think of them as a “personal pan” eggplant.  As I’m the only one in my house who eats much eggplant, I waste a lot less fruit cooking these little guys!

‘Patio Baby’ mature fruit. Standard house key used as a size reference. Photo courtesy of Daniel Leonard.

‘Patio Baby’ Eggplant also lives up to its reputation of being exceedingly easy and quick to grow.  I purchased a packet of ‘Patio Baby’ seed from Johnny’s Selected Seeds in June and planted three in a 20” diameter decorative pot next to my raised bed garden during the first week of July, behind summer squash that had recently expired in the heat of late June.  After sprouting, the plants grew strongly and, true to form for most Eggplant varieties, were bothered by no serious pest or disease issues other than the normal stinkbugs and occasional caterpillar that plague summer gardens in Florida.  Around 8 weeks from sowing seed in the soil, cute, egg-shaped fruit were ready for harvest!  Over the next three or four weeks, my single plant produced around 50 of the cute little fruit.  More than enough for me and plenty to share, the goal of my gardening endeavors.

‘Patio Baby’ produces lots of fruit in a small package! Photo courtesy of Daniel Leoanrd.

If you’ve run out of space in your raised bed garden, just want a single plant for your back porch or simply want to try a novelty vegetable variety, my experience this summer deems ‘Patio Baby’ Eggplant is an excellent option!  For an eggplant that is space-efficient, very early and heavy producing, and comes in a more easily harvestable, kitchen-friendly package, try ‘Patio Baby’.  For more information about raised bed gardening, vegetable varieties or any other horticultural topic, contact your local UF/IFAS County Extension Office.  Happy Gardening!

Whiteflies, Whiteflies, Whiteflies

Whiteflies, Whiteflies, Whiteflies

Whitefly adults and eggs.

Whitefly adults and eggs. Photo Credit: James Castner, University of Florida, IFAS.

Whiteflies are a pest we typically see in the fall but if you look around, you’ll notice high densities of them now. Despite their name, whiteflies are more closely related to an aphid or scale insect than a fly. They are 1/16 of an inch long (about the size of a gnat) and resemble small moths. They can be found on the undersides of host plant leaves and their behavior is easily recognizable as they scatter from the leaves when they are disturbed.

Silverleaf Whitefly. Photo by Lyle Buss, UF/IFAS

You’ll find whiteflies on a variety of plants ranging from ornamentals such as ficus, poinsettia, hibiscus, and ivy to vegetables like tomato, pepper, eggplant and okra. Some species feed on sweet potatoes, vegetables in the cabbage family, and citrus.

There are several species of whiteflies in Florida but the three main species of agricultural and horticultural concern are the silverleaf whitefly (also known as the sweet potato whitefly), citrus whitefly, and the ficus whitefly. Whiteflies have piercing-sucking mouthparts with which they feed on plants. The top side of leaves on infested plants may become pale or spotted due to whiteflies feeding on the undersides of leaves. It’s not uncommon for an infestation of whiteflies to go unnoticed until leaves turn yellow or drop unexpectedly. Some whitefly species can cause greater damage by transmitting plant viruses.

Whiteflies, along with aphids, scales and mealybugs excrete a sugary substance known as honeydew. This honeydew coats the surface of the plant where the insect feeds and facilitates the growth of a black fungus called sooty mold. Ants and wasps also feed on the honeydew secreted by these insects and may serve as an indicator that a plant is infested with whiteflies or other honeydew secreting insects.

Adult female whiteflies can lay anywhere from 200-400 eggs in her lifetime. The eggs are laid on the undersides of leaves. These eggs hatch into nymphs (also known as crawlers) after 4-12 days. From there, the crawlers will insert their mouthparts into the leaves of host plants where they will molt, pupate and then become adult whiteflies. This process takes anywhere from four weeks to six months, depending on temperature and humidity.

Whiteflies are difficult to control due to their prolific reproductive cycle. It is difficult to get rid of whiteflies once there is an infestation. As with dealing with most insects, proper plant selection, irrigation, and fertilization are critical for managing whiteflies. Removing sources of infestation such as weeds around the garden or old plant debris around the yard can help prevent whitefly populations from carrying over to the next season. Natural predators such as lady beetles, lacewings and predatory mites can help keep whitefly populations in check.

Insecticides such as insecticidal soap or horticultural oil can be used to help reduce whitefly populations. Be sure to always read the label for instructions. For more information on whiteflies, please contact your local UF/IFAS Extension Office.

Video: How to Control Azalea Caterpillars on Azalea Bushes

Video: How to Control Azalea Caterpillars on Azalea Bushes

In late July, Larry Kinsolving, a Jackson County Master Gardener, noticed an insect pest in the beautiful, large azalea bushes that frame the front entrance to his home in Marianna, Florida. The azalea caterpillar is found in Florida from late summer to early fall on azaleas and other plants including blueberries. If left undetected, the caterpillars can defoliate (eat up the leaves) of much of a plant. In general, caterpillars seldom kill the plants they feed on, but the stress caused by defoliation can reduce flowering or fruiting the following spring, if it becomes a serious problem. Larry shows you how easy it is to find and remove this pest from your azalea bushes. While the caterpillar appears hairy, it is harmless to humans and can be handled without concern.

Aphids & Milkweed

Aphids & Milkweed

Perennial milkweed, Asclepias perennis, with oleander aphids; notice the brown aphid mummies that have been parasitized. Photo credit: Mary Salinas UF/IFAS Extension.

Milkweeds are appreciated for their beauty, but often we cultivate it for the benefit of the monarch butterflies who lay their eggs only on this plant genus. Avid butterfly gardeners want the monarch caterpillars to eat up the milkweed and become beautiful butterflies. Often instead, thousands of aphids show up and compete for space on the plants. These bright yellow aphids are known as oleander aphids.

Just how do aphids build up their populations so quickly? It seems that one day you have a small number on a few plants and then a few days later, thousands are all over your milkweed. Oleander aphids have a few advantages for quickly building their populations:

  • All oleander aphids are female and do not need to mate to produce their young
  • Aphids give birth to live young who immediately start feeding on the plant
  • Aphids start reproducing when they are 4 to 10 days old and keep reproducing during their one-month life span
  • When populations get heavy or the plant starts to decline, winged individuals are produced to migrate to new areas and plants.

Parasitic wasp and aphid mummies. Photo credit: University of California.

 

What can or should you do to control this pest?

One option is to do nothing and let the natural enemies come in and do their job. One of the best is a very tiny wasp that you will likely never see. This parasitoid lays its eggs only inside aphids. The wasp larva feeds on the inside of the aphid and turns it into a round brown ‘mummy’ and then emerges when mature by making a round hole in the top of the aphid. Look closely with a hand lens at some of those brown aphids on your milkweed and you can see this amazing process. Another common predator I see in my own garden is the larvae of the hover fly or syrphid fly. You will have to look hard to see it, but it is usually there.  Assassin bugs and lady beetles also commonly feed on aphids. The larvae of lady beetles look nothing like the adults but also are voracious predators of aphids – check out what they look like.

Lady beetle larva feeding on aphid on tobacco. Photo credit:
Lenny Wells University of Georgia Bugwood.org.

If you think your situation requires some sort of intervention to control the aphids, first check carefully for monarch eggs and caterpillars, keeping in mind that some may be very small. Remove them, shoo away any beneficial insects, and spray the plant completely with an insecticidal soap product. Recipes that call for dish detergents may harm the waxy coating on the leaves and should be avoided. The solution must contact the insect to kill it. Always follow the label instructions. Soap will also kill the natural enemies if they are contacted. One exception is the developing wasp in the aphid mummies – fortunately, they are protected inside as the soap does not penetrate. Oils derived from plants or petroleum can serve the same purpose as the insecticidal soap.

Syrphid fly larva and oleander aphids. Photo credit: Lyle Buss, University of Florida.

You also can squish the aphids with your fingers and then rinse them off the plant. If you only rinse them off, the little pests can often just crawl back onto the plant.

There are systemic insecticides, like neonicotinoids, that are taken up by plant roots and kill aphids when they start feeding on the plants. However, those products also kill monarch caterpillars munching on the plant and harm adult butterflies, bees, and other pollinators feeding on the nectar. So those products are not an option. Always read the product label as many pesticides are prohibited by law from being applied to blooming plants as pollinators can be harmed.

In the end, consider tolerating some aphids and avoid insecticide use in landscape.

Happy butterfly gardening!