With every season comes a new set of bugs, pests, and insects ready to invade our gardens and homes. However, some are good guys.
Between the chewers, suckers, and lawn ants, Molly Keck, senior program specialist for the integrated pest management program for Texas A&M AgriLife Extension Service, previously broke down which ones every San Antonian should watch for last fall during a seminar. And, she said it’s likely the same for this fall.
Keck also added how you’re probably already seeing high loads of aphids at the moment due to the rain the city saw a few weeks back. Aphids love humidity and moisture and lack of airflow. Rain means more moisture, but it’s also getting the plants full and lush so that’s clogging up the airflow between and among plants.
Aphids consume leaves, ingesting far too much sap for their tiny bodies, thus excreting a sticky substance that lands across yards, patios and cars.
“Also, high aphid loads are a sign that plants are on their way out,” Keck said. “So plants that are at the end of the veggie garden are showing them, plants that will be dropping leaves soon are seeing them as well.”
Scroll below to read about the 30 bugs every San Antonio resident should expect in the fall:
Pill Bug or Woodlouse is normally found in rotting wood or vegetation.
Isopods (pillbugs) and millipedes
Grasshoppers, caterpillars, and beetles are the main chewing insects gardeners generally find damaging their plants during the fall. Keck said isopods, also known as pillbugs, and millipedes are insects you’ll see in vegetable plants. Both are moisture lovers and gravitate towards an overcrowded situation where many veggie plants are potted, like redbud basil or herbs.
The best way to try to control them if they are damaging your plants is to try to reduce the moisture, Keck said. They will likely move away if you turn the mulch over and cut back on watering the plants. In some cases, the insects will invade a house and eat wood, but Keck said not to worry. They are just wandering and won’t hurt humans or pets, she added.
“While you’re probably going to see them as the weather cools off and the moisture increases, I wouldn’t be overly worried unless you’re seeing hundreds upon hundred,” Keck said.
The big green caterpillar on a leaf.
If you’re planting cold crops such as broccoli and cauliflower, Keck said to expect some cabbage loopers, which are little bugs that look like worms and inch along when they move. Cabbage loopers generally chew holes in the cold crops, near the outer leaves. If you’re watering and fertilizing well, cold crops will tend to outgrow the damage and photosynthesize just fine, Keck said.
However, if the plants are wimpy and not happy, the loopers can stop the growth of the vegetable.
To manage them, Keck recommends using Bacillus thuringiensis, also known as Bt. It is a naturally occurring, soil-dwelling bacteria and a common active ingredient in organic biological pesticides.
“They basically die of a bad stomachache and then their guts explode on the inside,” Keck said.
A tobacco hornworm in the tomato garden.
Tomato hornworms are very large caterpillars with horn-like tails. Their favorite plant is the tomato. Hornworms chew leaves and can completely defoliate plants.
“On your tomatoes, you really don’t want those guys because they chew up all the leaves…you almost have to pull them up and start with a bigger plant or just give up for tomatoes that season,” Keck said.
The best way to contain them is to handpick them and smash them far away from the garden, Keck said. They tend to camouflage in the garden so they might be hard to see. However, at night, it’s easier to spot the hornworms as they illuminate with a blacklight flashlight.
Or, Keck said Bt or Spinosad can get rid of them, but she still believes handpicking is the easiest option.
Grasshoppers are a struggle in the fall, Keck said. Warm, dry fall weather allows grasshoppers more time to feed and lay eggs. Unfortunately, Keck doesn’t have a trick to get rid of grasshoppers. She said they can feed on almost anything but prefer waxy plants that could have a bitter taste. If there are holes in a plant, the grasshoppers are probably to blame, Keck noted.
Keck recommended covering favorable plants or turning the soil over to get those eggs out the grasshoppers love to lay.
“By the time we’re worried about grasshoppers, it’s almost too late,” she said. “…grasshoppers are just tough, unfortunately.”
Squash vine borer
Squash vine borer is a type of moth that lays its eggs at the base of squash plants. When the eggs hatch, the larvae burrow into the lower stems, weakening or killing the plant outright.
“They’re really aggravating,” Keck said. “They’re a daytime flyer and can be really zippy, like a wasp … Once it’s inside your vine, there’s nothing you can do about it. You just have to pull that plant out.”
To control them, Keck suggested tilling soil, planting trap crops, like Hubbard squash as a diversion, or applying pesticides when eggs are being laid.
Sap-sucking insects have mouthparts that don’t chew but will pierce into plant tissue and suck the juices out of it. Oftentimes, the damage from these insects will leave some dead spots or discoloration on the leaves.
The squash bug is a sucker that loves melons, pumpkins, cucumber, and squash. They leave a yellow flake look on leaves that will start to die off. The bug tends to lay its eggs on leaves as well. Keck said it’s best to handpick and smash the eggs and bugs when you see them.
“This is one of those insects that if you have the patience, you can successfully eliminate them from the plant, or at least suppress the population enough that the plant is happy, just by handpicking, not having to use pesticides at all,” Keck said.
Leaf-footed bugs are brown stink bugs with piercing-sucking mouthparts that extend more than half of the length of their narrow body.
The bugs love tomatoes and are everywhere right now, Keck said. Their offspring congregate on a plant and cluster together – and that’s never a good thing for a plant, Keck noted.
Keck recommended filling a cup with rubbing alcohol and just flicking them in there to let them fall and die. If they are all over a plant, she recommends repeating the same method but in a large shallow pan instead.
Aphids are small, soft-bodied insects that suck plant sap from leaves, stems, or even roots of herb and vegetable plants.
“They really become an issue as we get into fall when plants and trees are about to lose their leaves near the end of the season and become stressed out,” Keck said. “Aphids come in because the plant doesn’t have the ability to fight those insects off.”
In that case, Keck said she tends to not worry so much about them because those plants have already bloomed and served their purpose. She added the aphids will also die anyway once it gets cold.
If there is a big problem, she said they are pretty easy to kill by using insecticidal soaps.
Wooly aphids eating sap from a beech tree in the woods.
Cyndi Monaghan/Getty Images
Wolly aphids are small, delicate sap-sucking insects, that leave a sticky honeydew on surfaces they are under, Keck says.
They are on lots of trees and ornamental plants but don’t cause a ton of damage. Keck said to wait them out and they will go away on their own eventually.
Adult and immature lace bugs feed on the undersides of the leaves of deciduous trees and shrubs. The feeding can discolor leaves but does not normally affect the health of happy plants.
Management is normally not necessary but gardeners can control the problem by moving plants to shade and watering them often, Keck said.
If they are on trees or large established plants, Keck said to hose and spray them so they can fall off the plant.
Spider mites are one of the more common houseplant pests. Getting rid of spider mites is not always easy, because they are so small and hard to find.
The mites will get into your eggplants, peppers, ornamentals, and okra, Keck said. Spider mites feed on plant tissues and sap. They pierce the cell wall of the back of leaves and literally suck the juices out of the leaf, causing it to spot. Over time, this goes from tiny yellow spots to complete yellowing of the leaf, and a large population can decimate a plant quickly.
To control, Keck said to reduce drought stress and decrease soil temperatures. Or, she added gardeners can use miticides.
Green June bugs
Adult green June beetles are about an inch long, with dull metallic green wings, gold or brownish highlights on their head and sides, and shiny green underparts.
Keck said she’s been seeing them around the city, but they aren’t bad guys during the fall season as the bugs normally feed on springtime fruits. Keck said these aren’t ones to worry about for the fall but will be around frequently.
“They’ll buzz around the ground, hit the side of your house or window, and bump into something, but all they care is about finding a girlfriend to lay their eggs,” she said. “They don’t want to feed on anything. They are also very pretty to look at.”
Green darner dragonflies
Another insect that won’t cause harm but is nice to see in the fall are green darner dragonflies, Keck said. The pretty blue dragonflies typically migrate during September and October.
“When they die, they just turn all brown and lose their color,” Keck said. “So you should enjoy dragonflies in nature while you can.”
Green darners are often found around ponds, lakes, and wetlands, but sometimes get confused and hover over lawns, Keck said.
Galls are abnormal growths that occur on leaves, twigs, roots, or flowers of many plants. Most galls are caused by irritation or stimulation of plant cells due to feeding or egg-laying by insects such as aphids, midges, wasps, or mites. Galls aren’t harmful.
Most people will see them and believe the galls resulted in the leaves falling, but Keck assures plants are fine and that there’s nothing anyone can do about them.
Courtesy Texas A&M AgriLife Extension Service
The desert termite has a light brown exoskeleton with wings that are twice the size of its body. Keck said she’ll get more and more calls about the pests following the October rains.
“These agricultural and desert termites are the ones you want to have,” Keck said. “They don’t feed on wood. They feed on grasses, forbs, roots, and other things that are below the surface.”
If you see them on the lawn, Keck suggested raking them over or stepping on their mounds as there are no pesticides to use to control them.
“They’re so short-lived, but persist in the environment for so long that they’re just not worth doing anything,” Keck said.
Last week’s rains mean this week’s fire ant mounds.
Jerry Lara /Staff file photo
Fire ants are social insects that build nests, called mounds, by pushing up the soil as they tunnel into the earth. Fire ants can be identified by their dull red body coloration, which ranges from reddish-brown to reddish-black.
Don’t kick a fire ant mound as fire ants are aggressive, Keck said. She added the first one that stings you will release a pheromone that tells the others to sting you as well. If you aren’t sure if you have fire ants, put a stick in the ground and if they go up vertically, they are fire ants.
Only a very small portion of the population, around 1 percent, are hypersensitive to ant venom and will experience lethal allergic reactions. Very young and old people and those with suppressed immune systems are most likely to react severely to one or more stings. However, even healthy individuals may experience severe reactions such as anaphylactic shock if they suffer from a multiple-stinging incident.
To control, Keck recommended using a broadcast fire ant killer, like Orto (can be found at H-E-B).
Why is it called a paper wasp? The paper wasp builds a honeycomb shaped paper nest, made from wood fibers gathered and chewed by the insect into a paste-like pulp which it uses with its saliva to build up the hexagonal cells in the structure.
Anton Petrus /Getty Images
Paper wasps get their common name from the paper-like material out of which they make their nests. Paper wasps are sometimes called umbrella wasps, after the shape of their distinctive nests.
Paper wasps generally have a similar body shape to yellowjackets, but are somewhat slimmer with a thin “waist,” six long legs, and an almost triangular side view, as well as two wings and antennae.
Keck said they will sting you when they perceive that their house is being threatened. If you’re slamming a door outside and it jiggles their nest, they will most likely sting you every time, she said.
If they are high up on trees, Keck suggested leaving them alone as they are predators that can eat caterpillars on trees and are pollinators. However, if they are a bother, she said any wasp spray will work. The best time to spray is in the nighttime, she said.
Once you’ve sprayed, knock down the nest as some might come back and rebuild.
Grass carrying wasp
In the fall time, Keck said she gets lots of calls about the grass-carrying wasp.
Grass-carrying wasps are predators of crickets and katydids. Females sting their prey in the head or thorax which causes paralysis. However, they aren’t harmful to humans. They are not aggressive and do not actively defend their nests.
Keck said these are some of the “coolest” wasps because of how they weirdly use grass. The females will grab grass to lay their eggs, then the offspring build a cocoon, and take all the grass to glue it to their bodies.
You’ll mainly see the grass and cocoons on the edges of windows, Keck said.
“They’re not harmful or hurting the window at all,” she said. “If you don’t like them, just pull them out. I mean I think it’s kind of cool we’ve provided a little ecosystem for them by simply just having window sills.”
Mexican honey wasps.
Mexican honey wasps
Mexican honey wasps are so tiny you have probably never seen one. They are, however, the only wasp species that produce honey and are useful pollinators that eat insects that harm citrus crops.
Mexican honey wasps form paper nests that are usually found in trees and shrubs. You won’t really start to see it until the leaves start falling on the trees. The wasps are not aggressive unless actively disturbed.
Keck said it’s best not to bother them as they usually migrate to another tree and area every year.
Close up of cicada killer wasp, Sphecius speciosus, resting on plant.
Cicada killer wasp
Many people confuse the cicada killer wasps with the “murder hornets,” which are known as Asian giant hornets.
Cicada killer wasps only eat cicadas and are not harmful to humans or dogs, Keck said. A female will use her stinger to paralyze the cicada and then take it to her burrow so her offspring can have something to feed on.
The females aren’t aggressive or territorial, but the males may buzz around your head but they won’t sting you because they don’t have a stinger, Keck said.
“They may look scary, but they are harmless,” Keck said.
Don Blakes Prairie Wind Photography
Green lacewing is widely used in various situations to control many different pests. Keck said these are awesome predatory insects to see in the garden.
The adult lacewing lays her eggs on foliage where each egg is attached to the top of a hair-like filament. After a few days, the eggs hatch, and a tiny predatory larva emerges ready to eat aphid pests.
“They are everywhere,” Keck said. “You’ll see evidence of them at your porch or near your plants at night.”
Keck said to let these guys be as they are doing more to your landscape without you even knowing.
Spiders are beneficial predators and serve a significant role in keeping populations of many insect pests in check. Spiders are oftentimes the most important biological control of pests in and around homes, yards, gardens, and crops, Keck said.
Although many spiders produce venom for use in capturing prey, few species are toxic to humans. Spider season lands during the fall which Keck said is kind of ironic since it’s around Halloween time when she’ll get the most calls about them.
“What’s cool about these guys is that they are very tough animals,” she said. “They can survive cold temperatures because they hunker down in warm places.”
While all spiders can bite, Keck said they will only fight if you try to pick them up with your fingers and aggravate them.
Black widow and brown recluse spiders
The only two spiders in Texas that are harmful to humans are the black widow and brown recluse spiders, Keck said. Both are very reclusive and often found in areas many don’t mess with often, Keck said.
Black widows are super common outside underneath hardly used barbecue pits, boat covers, and places people typically don’t hang out. The widow has a neurotoxin. If it bites you, you’re not going to die right away. You probably won’t notice until you can’t breathe or your heart starts beating like crazy, Keck said. That’s when you should see a doctor right away.
Brown recluses are more common indoors, near cluttered places like basements and attics. She noted most of the sightings come during the holidays when individuals take out their Christmas trees and decorations from storages or attics.
A brown recluse has a rare venom that’s more potent than a rattlesnake, and it’s necrotic, meaning it eats away at the tissue. Keck said it really becomes an issue if you’re bitten in an area with a lot of tissue, like your butt. If you’re bitten in the knuckle, then you’re probably not going to react to it, Keck said.
SweetyMommy – Getty Images
A ladybug is a good sign in a garden because it can mean fewer problems due to pests, particularly aphids. Aphids feed on plant tissues and can also transmit viruses to plants, but an adult ladybug may consume hundreds of aphids a day and thousands in its lifetime, Keck said.
If ladybugs end up in your house, Keck said just to sweep them outside and let them go.
Syrphid fly or hoverfly
Flies are among the most frequent visitors to flowers and important pollinators for a wide range of plants. Syrphid flies are often referred to as flower flies. They are beneficial insects, Keck said.
In their larval stage, they prey on aphids. Each larva that hatches can consume hundreds of aphids. Syrphid fly larvae are aggressive aphid predators. They are commonly considered to be the most important aphid predator in vegetable crops.
If you want to draw them into your garden, Keck said to let your herbs bloom to lure them in.
Assassin bugs are predatory insects that are of great benefit to gardeners, Keck said. They are proficient at capturing and feeding on a wide variety of prey including other bugs, bees, flies, and caterpillars. Prey is captured with a quick stab of the assassin bug’s long mouthparts.
These critters may attack and bite humans if provoked, piercing the skin with that sharp beak. Most species of assassin bugs are gray to black or brownish in color, though some are brightly colored.
American snout nose butterflies
The American Snout Nose Butterfly is the one you may have hit with your car many times. It is named for its long nose. It’s small, orange, black, and brown and mimics fall leaves.
This butterfly isn’t threatened or endangered like some other butterflies because of the abundance of the spiny hackberry plant that they eat, Keck said. They migrate to San Antonio yearly, Keck said. She anticipated they will migrate into the area by October.
“Don’t feel too bad when you hit them with your car, chances are there are plenty more out there,” she said. “The migration lasts for about three to four weeks, so don’t wash your car until they leave.”
They are beneficial as they pollinate more of the native, brushy plants other butterflies don’t go after, Keck said.
The pollinator garden is designed to provide a sanctuary for Monarch butterflies during their international migration, as well as crucial habitat for a myriad of other pollinators and migratory species.
Kin Man Hui/Staff photographer
Butterflies are great for your garden as they are attracted to bright flowers and need to feed on nectar. They act as a pollinator and food sources for other species. Keck said fall is the best time of year to observe butterflies.
“I’d say to just stop and observe them. They are really breathtaking,” she said.