Vacation Hitchhikers

Vacation Hitchhikers

Photo from USDA APHIS

Remember last year’s vacation trip?  You picked the perfect location, checked into the hotel and made sure to check every mattress corner for bedbugs.  Bugs can hide in the strangest places.  Now with COVID-19 those people insisting on still taking a vacation are flocking to Northwest Florida.  While some are still utilizing hotels, the majority are pulling into the RV park or campground. They are bringing anything and everything anyone could possibly need for the week, from firewood to camp chairs.  That way no one will have to go to the store.  Somewhere on the vehicle or within all the stuff there may be some hitchhikers, insect stowaways. The problem is that these bugs may be staying even after the human beings head back north.  Florida is notorious for invasive species.  With 22 international airports and 15 international ports in the state, hundreds of foreign insects are intercepted each month.  But, not all the problem creepy crawlers are coming from the south.  Many have been introduced to northern states and work their way here.

One to keep an eye open for is spotted lanternfly (Lycorma delicatula).  The Asian native was first detected in Pennsylvania in 2014.  Since then it has spread to the east and south.  While the insect can walk, jump, or fly short distances, the quickest way for the spotted lanternfly to relocate is to lay eggs on natural and man-made surfaces.  Some of those egg masses may fall off and get left at the park. Next spring after the eggs hatch the nymphs will begin feeding on the sap of numerous plants, often changing species as they mature.  Host plants include grape, maple, poplar, willow and many fruit tree species.

Nymphs in the early stages of development appear black with white spots and turn to bright red before becoming adults.  At maturity spotted lanternflies are about 1 ½ inches wide with large colorful, spotted wings.

Photo from USDA APHIS

At rest their forewings are folded up giving the lanternfly a dull light brown appearance.  But when it takes flight its beauty is revealed. The bright red hind wings and the yellow abdomen are very eye-catching.  Remember, in nature bright colors are often a warning.  Though spotted lanternflies are attractive, they pose a valid threat to native and food-producing plants. The adults feed by sucking sap from branches and leaves.  What goes in must come out.  Sugar in, sugar out. Spotted lanternflies excrete a sticky, sugar-rich fluid referred to as honeydew.  Black sooty mold often develops on honeydew covered surfaces.

Spotted lanternflies are most active at night, steadily migrating up and down the trunk of trees.  During the day they tend to gather together at the base of the plants under a canopy of leaves.  So, you may need your lantern (or head lamp) to locate them.  If you find an insect that you suspect is a spotted lanternfly, please contact your local Extension office of the Florida Department of Agriculture and Consumer Services Division of Plant Industries.

Photo by USDA APHIS

False Potato Beetle:  An Overlooked, Destructive Pest of Eggplant

False Potato Beetle:  An Overlooked, Destructive Pest of Eggplant

August is awful.  Its heat makes one miss the relative cool of July.  Its rain is so sporadic that it invokes nostalgia for the rainy afternoons of early summer.  But if there is a silver lining in August for gardeners, it is the simplicity that it brings.  The weaker spring crops, tomatoes, squash and the rest, are all gone now, destroyed or rendered fruitless by insects, disease, and heat.  This leaves only the hardened, usually pest and disease-free survivors Okra, Pepper, Sweet Potato and Eggplant.  I say usually because, this year, my eggplant bed is under attack by a new-to-me pest, the False Potato Beetle!

I’ve dealt with Colorado Potato Beetles (CPB) before.  Those orangish, black-striped terrors often attack my spring potato crops and occasionally bother early tomatoes.  However, I’ve never seen them in late summer on Eggplant.  This raised suspicion.  Also, I spotted unusual, round, whitish purple creatures munching on leaves from the same plants; these appeared to be the larval stage of the unidentified beetle. A little digging led me to identify these garden pests as the lesser known, lookalike cousin of CPB, the False Potato Beetle.

False Potato Beetle munching on an Eggplant leaf in the author’s garden.

False Potato Beetle (FPB) looks nearly identical to its cousin in the adult stage.  They are similarly shaped and colored, though a close look reveals subtle differences between species.  While both have yellowish-orange heads and pale-yellow backs with dark stripes, the FPB’s back is slightly lighter hued, more of a whitish, cream color.  Also, the CPB’s underside and legs are a very dark orange to brown, with the False Potato Beetle having lighter colored legs and underside.  If you’re saying, “These old eyes will never be able to tell the difference, County Agent.  Cream and light-yellow look the same to me.”, I get it.  Fortunately for those of us with poor vision, the larval stage (babies) of the two beetles looks very different and is the key to correct ID!  FPB larvae are larger and have a whitish coloration.  CPB larvae, in contrast, are a similar burnt orange color to the adult beetle.  I promise, the difference is very distinguishable!

False Potato Beetle is considered a minor garden and agronomic pest as they typically only bother Eggplant, and they don’t usually destroy entire plants.  However, if you get a FPB outbreak in your Eggplant garden, they can still be pretty destructive.  These beetles feed in the same manner as caterpillar pests, chewing away entire sections of leaves and stems.  Unchecked infestations can defoliate entire sections of plants.  So, if you find these little beetles eating away at your eggplant garden, what can you do?

False Potato Beetle larvae. Photo courtesy of the author.

First, if you scout regularly, you’ll notice the beetles and their larvae in relatively small numbers before outbreaks become widespread.  I had pretty good success this year just catching infestations early and picking off the beetles I saw and squishing them.  Continue scouting and squishing for a few days and pretty soon,  the population is reduced to a manageable level.  However, if squishing makes you squeamish, you also have some common pesticide options at your disposal.  I normally encourage clients to start their chemical pest control strategy with “softer” products like Pyganic, a pyrethrin make from an extract from the Chrysanthemum plant.  Pyganic works great but is a little harder to find; you may have to order online or ask your local retailer if they can get it for you.  If you are unable to find Pyganic or it doesn’t perform for you, the old standby products with carbaryl or pyrethroids (Sevin, Ortho Bug-B-Gone, and others) also work well.

False Potato Beetle can be a late summer garden pain, but with regular scouting, proper insect ID, lots of squishing, and maybe a timely pesticide application or two, you should be able to continue to harvest eggplant deep into fall!  If you have FPB in your garden or have another horticultural question, give your local UF/IFAS County Extension office a call!  Happy Gardening!

Camouflaged Critters

Camouflaged Critters

Nature is full of examples of animals that use camouflage to protect themselves, and some of the best examples are found in the insect world. They may appear to be leaves, sticks, thorns, or flowers; there are insects that disguise themselves as snakes, bird poop, or other more dangerous insects. While many of these adaptations protect them from predators such as birds or spiders, they may also make it difficult to identify a bug that’s causing a problem in the garden!

There are several insect pests of plants that may not appear to be what they are at first glance. This can make frustrating to figure out what’s harming a plant, and identification is a very important first step in solving any problem. Here are some of the more common critters that wear disguises in our area, though.

The ants in this picture are attracted by the scale insects, which look like oval bumps on the stem of the plant.

Scale Insects vary in shape, but many of them appear to be simply another bump on the stem or leaf of a plant. They often form a waxy covering over their bodies and stay put, simply feeding in place on the juices within the plant. Ants may notice them, however, and are attracted to the sticky, sugary substance that they exude called honeydew. This honeydew drips onto other stems and leaves, and may grow sooty mold, a black or gray coating that might make one think the problem is fungus. Look for scale insects if you notice these signs (and be aware that other insects such as aphids or mealybugs also produce honeydew).

 

Some psyllids or immature planthoppers cover themselves in white fuzz as protection.

 

Psyllids, mealybugs, and aphids are all different insects, but some species of each use a waxy coating to protect themselves. This gives them a white, fuzzy appearance that may appear at first glance to be a fungal growth. A close look can reveal the truth – that the fuzz is hiding a plant pest within.

 

Planthoppers and sharpshooters can be pests of certain plants, including grapes. They may appear to be bumps or thorns on a stem, but usually move or jump if approached.

Caterpillars may disguise themselves in a number of ways. Some may blend in with the foliage that surrounds them, while others appear to be twigs or even the aforementioned bird poop (in the case of the giant swallowtail butterfly, whose larvae enjoy feeding on citrus leaves). It is typically the damage to the plant that is first noticeable. Unlike the other insects mentioned here which feed by piercing into a plant and sucking out the juices, caterpillars have chewing mouthparts. Leaves with holes in them are a good sign that you might have a caterpillar problem.

Remember that not every insect is a pest, and not all pests do enough damage to warrant controlling them. If you need help determining if an insect you’ve seen in your garden or landscape is a problem, contact your local Extension office. You can also find more information on all of these insects and more in our EDIS publications, a few of which are listed below:

Scale insects: https://edis.ifas.ufl.edu/pdffiles/MG/MG00500.pdf

Mealybugs: https://edis.ifas.ufl.edu/in1149

Caterpillars: https://edis.ifas.ufl.edu/topic_landscape_caterpillar_pests

by Evan Anderson, Walton County Horticulture Agent

Beneficial Insects Work Hard in Summer Gardens

Beneficial Insects Work Hard in Summer Gardens

I know this is going to come as a shock to some readers, but not all bugs are bad.  In fact, while there are over 1 million species of insects worldwide, less than 1% are problem pests!  This problem 1%, composed of common garden pests, including aphids, stinkbugs, nuisance caterpillars, and scales, get all the attention and for good reason; they can be extremely destructive to home and commercial crops.  However, the good guys, beneficial predatory insects, are out there too, providing valuable pest control day and night and should be considered in part of a quality garden pest management strategy.

Beneficials come in many shapes and sizes.  Some are commonly known predators, such as spiders, Lady Beetles and Praying Mantids, while others are lesser known pest nemeses, like Paper Wasps, Pirate Bugs, and Lacewings.  Regardless, gardeners should do their homework and be able to identify beneficials when they see them and allow them to do their jobs. The presence, or not, of a handful of Lady Beetles or Lacewings on the attack can be the difference between needing to treat with insecticides for an aphid outbreak or just letting nature take its course.  Studies have shown that just one individual Lady Beetle in the larval stage can consume as many as 500 aphids; adult Lady Beetles are even hungrier aphid eaters!  Paper Wasps, you know the ones who make the large “papery” nests around eaves of house and other structures, play an important beneficial role, frequently preying on caterpillars.  If their nests aren’t near highly trafficked areas around your home and you don’t have family members allergic to wasp stings, your garden will thank you for leaving a few paper wasp colonies as caterpillar insurance!

Lacewing eggs on a Jade plant in close proximity to the author’s vegetable garden.

In many instances, beneficial insects can keep pest insect infestations at bay, allowing gardeners to spot treat outbreaks when they get out of hand or even prevent the problem from needing chemical intervention altogether. 

As helpful as they are, beneficial insects in the garden won’t totally negate the need for chemical treatment entirely.  From time to time, garden pest populations outpace the beneficials’ abilities to kill them and intervention from humans is needed.  In these times, it is advisable to use a couple of best practices to limit exposure to beneficial insects.  First, try to use selective insecticides that only target specific pests and are nontoxic to other bugs, like the product Bt for caterpillar pests (sold under many brands like Dipel, Garden Safe Bt Worm and Caterpillar Killer, Thuricide, etc).  However, if a nonselective, general insecticide, like the Pyrethroids (many common homeowner insecticide brands) and carbamates (Sevin and others), is needed, timing these broad spectrum sprays for early in the morning and late in the evening when many beneficials are not very active can help reduce friendly fire casualties.  Care should also be taken to only spot treat infested plants and not the entire garden, this helps reduce beneficial exposure to these broadly toxic pesticides.

Every gardener should have a plan for pest control and beneficials can play an important role in this overall strategy.  Gardeners can help ensure that nature pulls its weight in controlling problem pests by taking a little time to scout for beneficial insect populations, keeping a close eye on developing pest outbreaks, using selective insecticides when you can, and only spraying broad spectrum products as spot treatments when necessary and timing those applications for very early or late in the day.  If you have a question about whether or not a garden insect is a good guy or a pest or want more information on garden pest control strategies, contact your local UF/IFAS County Extension Office!  Happy Gardening!

The following resources were used in the development of this article:

https://gardeningsolutions.ifas.ufl.edu/care/florida-friendly-landscapes/beneficial-insects.html

https://sfyl.ifas.ufl.edu/sarasota/gardening-and-landscaping/horticulture-commercial/integrated-pest-management/beneficial-insects/

http://www.missouribotanicalgarden.org/gardens-gardening/your-garden/help-for-the-home-gardener/advice-tips-resources/pests-and-problems/other/beneficial-insects.aspx

Video: Diagnosing a Black Twig Borer Problem

Video: Diagnosing a Black Twig Borer Problem

The bay laurel tree in the Escambia County Demonstration Garden had some dead branches on the outer canopy.  Further investigation led us to the culprit, the black twig borer. Learn more In the Garden with UF IFAS Extension Escambia County.