Beneficial Insects

If you love spending time in your garden, you must also love spending time with a few creepy, crawly critters. Right? For me, this is a true statement. I even keep a few creepy crawlies as pets at home. However, I know from working here at the nursery that there are quite a few gardeners who are not fans of the small beasts that make their homes in our yards. Well, not every bug or critter you see (and lots you can’t) in your garden is out to eat your plants or harm you. Some are quite beneficial to the plants in your garden and some we even sell at the nursery to help control true garden pests. This is by no means a complete list of garden helpers, but these are common in the Houston/Galveston area.

First, the organisms you can’t see:

Bacillus thuringiensis(or Bt) – Bt is a bacterium that is lethal to caterpillars, beetles and mosquito larvae. In the home garden with a severe infestation of caterpillars, Bt can be quite useful.However, if you are trying to attract butterflies, this is probably not the beneficial organism for you. Bt will kill all the caterpillars that are sprayed. There is currently some controversy surrounding Bt and plants engineered to have Bt in their tissues. A one time, home garden application is completely different than growing whole fields of engineered plants. We do sell Thuricide Concentrate, currently priced at $12.99 +tax for 16 oz.

Mycorrhizal Fungi –  Mycorrhizae are tiny fungi that attach to plant roots (of approximately 95% of all the plants on Earth) and help plants use water and nutrients from the soil. Plants with good mycorrhizal root systems are better able to survive drought and resist disease. Be careful when using fungicides if you are trying to promote growth of mycorrhizal fungi. In my opinion we should all be trying to promote Mycorrhizal fungi in our gardens and lawns. Read up on these important fungi. You won’t believe how all living organisms rely on the tiniest of beings.

Streptomyces lydicus –  This bacterium is commonly found in soil. It is the active ingredient of Actinovate, a very effective lawn and garden fungicide. It is perfect for the home organic gardener in controlling powdery mildew, leaf spot, rusts, brown patch and more. It is easy to apply as a powder mixed with water.   Our current price is $27.99 for 2oz (treats up to 550 plants or 5,000 sq ft of turf).

Nematodes –  Nematodes are non-segmented roundworms that feed on grubs and the larval stages of many insects living underground. They are safe to use around humans and pets. These are easy to apply. You simply mix them with water and spray. A package of 1,000,000 nematodes treats 2000 sq ft of garden or lawn. I must note that some nematodes can be plant pests themselves, but not the ones you can purchase for home garden usage.

And now, the organisms you can see:

Ladybug (aka Ladybird beetle) –  Most gardeners know about these beneficial insects. They are famous for eating aphids and other soft-bodied insects. We sell lady bugs in bags of 1500 (recommended to treat 800 to 1000 sq ft) currently priced at $15.99 +tax. To get the most out of your ladybugs, you want to do what you can to keep them in your garden.   Here are a few tips to help them stick around: (1) Water your garden before release. (2) Release before sunrise or after dark (they use the sun to navigate). (3) Keep them in a refrigerator before release (a cooler ladybug is less active and less likely to fly away). You may have to release ladybugs 2-3 times in a season to get a colony established in a yard, and there really are no guarantees you will. But, releasing ladybugs sounds like a fun family activity to me!

Earthworms –  Earthworms are “nature’s plow” or in other words, they help aerate and turn the soil as well as enrich it with nutrients from their castings. The presence of earthworms generally indicates healthy soil. All you have to do to get more earthworms is provide them with moist soil and decaying plant matter. They will do the rest. From what I have read, it is really not worth trying to supplement your garden with earthworms from a bait shop. They generally don’t survive.

NOTE – Bees and Wasps are next on my list of beneficial organisms. If you are allergic to bee or wasp stings, I don’t recommend that you attempt to attract them to your yard. Though some may choose to make their home there anyway. However, most will not aggressively attack unless they or their nests are disturbed. Bees and Wasps are wonderful garden helpers, but attracting them is not a good idea if you develop an allergic reaction to their sting.

Also, Only female bees and wasps have the ability to sting.

Bees –  Bees (with Honey Bees being key) are beneficial in a most significant way. They are very important pollinators in our gardens. Without bees, many crops could not exist (ex. blueberry, cucumber, watermelon, and more than 100 other agricultural crops grown in the US). To attract more bees to your garden, add plants they will love. As a bonus, most of the plants bees would love to visit in your garden are native and drought tolerant. Plant things like: bee balm, borage, columbine, coreopsis, lemon balm, and rosemary. Also, bees need water, but provide it to them in a shallow container so they don’t drown. Many bees actually make their nests in the ground and mulch prevents them from being able to do this. Go light on the mulch if you can.

Parasitic Wasps –  This is a very diverse group of wasps that parasitize other insects to house and feed their larvae. These wasps commonly lay eggs in or on their hosts and once the larvae hatch, they usually devour their host from the inside out. Now that’s the Hostess with the Mostest! If you have the time and an interest in entymology, there are some very interesting articles on the WWW about the saliva of some caterpillars mixing with plant sap to make an aromatic compound that actually attracts parasitic wasps. Mother Nature is so amazingly complex!

Predatory Wasps –  All wasps are predatory, meaning they hunt and kill their prey and will eat a great variety of insect pests. One such wasp is the Cicada Killer Wasp. These wasps are impressive with adults reaching 2 inches in length. And, as their common name indicates, they prey on cicadas. They are generally not aggressive, but will defend themselves and their nests. They tend to be more common in late Summer and I have actually seen quite a few on my patio this year. Just another reason my girls won’t go outside.

Assassin Bugs –  Assassin Bugs are excellent insect predators with a wide variety of prey including caterpillars, flies and mosquitoes. There are many different Assassin bugs, but the most common in our area is the Milkweed Assassin Bug.   To attract assassin bugs to your garden, plant Queen Ann’s lace or other flowering plants with small flowers (Assassin bugs can’t reach too deeply for their nectar). Assasin bugs can bite, but usually don’t unless being bothered.


Big-Eyed Bugs – There are several species of Big-Eyed bugs found naturally in our landscapes. They are general predators and will eat a variety of pest insects including mites, thrips and white flies. They will feed on seeds and sap, but not to the detriment of your plants.

 Green Lacewings –  Lacewings feed on a variety of soft-bodied pests like spider mites, thrips, mealybugs, aphids, and the eggs of caterpillars. Green lacewing larvae are absolutely voracious and are known as “Aphid Lions.” ROAR!

Predacious Ground Beetles  – This is a very large group of ground dwelling beetle species. Ground beetles vary greatly in size and appearance, but all are great garden pest predators. Some common ones we have in our gardens are: Tiger Beetles and Caterpillar Hunter Beetles. Truly amazing looking creatures.


Praying Mantis –  Praying Mantis have to be my favorite garden insect predator. And, we do have them naturally in our area. I have researched buying some to put in my own garden, but from what I have read, it is hard to have enough of them to really put a dent in your pest problems. But, I still would not mind having one of these guys make a home in my yard. I may purchase an egg case (it looks like someone from the construction crew let their spray foam can leak a bit) just to see if I can successfully raise them. I do love my creepy crawlies. 


 Spiders –  OK. So here is another group of garden crawlers that will surely have some folks fleeing their yard. Me, I love having spiders around. I have always said, “I would rather have a spider in the corner than flies in my pudding.” That may sound silly, but it’s true. Spiders are great at controlling garden pests. 

Spiders can and will bite when threatened and there are two species you want to avoid in our area: the Black Widow and Brown Recluse. Other spider species in Texas are not considered medically important, but people can be allergic to their venom much like bee or wasp stings. So, maintain a healthy respect for spiders and their space. Some spiders that you may have waiting in your garden for a tasty treat are: the Orb Weaver and Spiny Orb Weaver. I think they are magical looking!

Lizards –  Now we are getting to some larger predators. Anoles and Geckos and Skinks – Oh My! Lizards are great at controlling some garden pests and they are truly amazing to watch. Anoles can be green or brown and prefer, like the Mediterranean Gecko, to be climbing on something. Skinks will be found on the ground, usually under a limb. All three groups of lizards will drop their tails in response to threat, so just warn your kiddos before they pick one up.

Birds –   This is probably one we can all agree on. Attracting insect eating birds to your garden is an excellent way to control some garden pests. Cardinals, Sparrows and Woodpeckers are superb predators of common insect pests. Attract birds to your yard by providing a shallow source of clean water. Supply them with bird seed throughout the year. Even insect eaters like Sparrows and Cardinals will sometimes snack on seed. And lastly, provide places for birds to hide in your garden.

 So, that’s it for my list and I barely scratched the surface of beneficial garden organisms. I could probably

write a thesis on each one of these individually. So, if you want to introduce or attract beneficial organisms into your yard, turn on your computer and start Googling. A great place to go is this Texas A & M site – And, please remember to be very sparing and careful with the use of systemic pesticides. These kill beneficial organisms too. Try to go Organic if you can. If you need help learning how to do this, just give us a call. We all benefit from our gardens and the beasties that make their home in them.