Should You Buy Ladybugs as Natural Pest Control?
Ladybugs are voracious predators of garden pests, but purchasing these beneficial insects may not be the best form of pest control. Garden expert and former organic farmer Logan Hailey explains how ladybugs can help control pests and why you don’t need to buy them.
Contents
Ladybugs are one of the most popular and renowned garden predators. An adult ladybug can consume over 50 aphids per day, and larval lady beetles eat hundreds of pests daily.
Many garden stores and online shops sell ladybugs as a biocontrol agent to release into your garden, but must you buy these beneficial insects in order to reap their benefits? And could introducing store-bought predators actually do more harm than good?
Let’s dig into everything you need to know about buying ladybugs as natural pest control.
The Short Answer
Buying ladybugs and introducing them into your garden can temporarily cut down on pest pressure, but 95% or more will fly away within a few hours. In order to provide long-term biocontrol solutions, you must create a habitat for the ladybugs to stay and reproduce. Flowers like yarrow, dill, marigolds, cosmos, sweet alyssum, and any regionally native wildflowers naturally attract ladybugs.
It is much more ecological and economical to lure native ladybugs rather than import the predators from store-bought sources. Some lab-reared ladybugs can even be invasive because they come from ladybeetle (Coccinellidae family) species native to other parts of the world. When these insects are released in gardens, they may invade and outcompete indigenous species.
The Long Answer
If you’re facing a crazy outbreak of pests like aphids, spider mites, mealybugs, or ear worms, you may be tempted to buy ladybugs to rapidly deal with the problem. This is a form of biological control that is more eco-friendly than spraying pesticides.
The biocontrol agent (a predator insect) is used to cut back on pest populations by feeding on the smaller insects. Lady Beetles are excellent predators, especially because they only dine on insects and won’t harm your crops. They can eat hundreds of pests per day and proliferate in the garden for long-term control.
However, there are many drawbacks to buying and importing predator insects into your garden. Larval ladybugs are much more voracious predators of aphids, and adult beetles may quickly fly away if released in an open area without many resources. Moreover, there are some types of invasive beetles that can harm the local ecosystem.
If you want to save money and create more sustainable, long-lasting pest control, here are the key reasons why you should plant a beneficial insectary to attract native predators rather than buying and releasing insects.
Are Ladybugs Natural Pest Control?
Ladybugs are natural pest controllers and voracious predators of garden pests like aphids, scales, midges, spider mites, leafhoppers, corn earworms, and mealybugs. These beneficial insects are found all over the world in native ecosystems.
They can help gardeners eliminate pesticide use, but it is best to avoid introducing them from an external location. Buying ladybugs for pest control is no longer considered eco-friendly. Instead, attract native ladybugs by planting beneficial flowers like white alyssum, dill, and yarrow.
The Basics of Biological Pest Control
Biological pest control, or biocontrol, is a form of pest management that uses the natural predators of a pest to control populations. Instead of eradicating a pest with chemical or manual means, biocontrol aims to create ecological “checks and balances’ ‘ that prevent populations from getting out-of-hand.
Predator vs. Pest Species
Generally, predator species are larger and slower to reproduce than “pest” species. Pest species expand their populations very rapidly and can cycle through many generations in a single season.
For example, mountain lions and coyotes can naturally keep rabbits in check because a single large feline or canine may eat several rabbits in a week. But if all the predators are eliminated from an ecosystem, the rabbits will run rampant like they do in suburbia. There won’t be any natural predators to balance the population.
The exact same mechanisms are at play in your garden. For example, a single female aphid can give birth to 60-100 live nymphs in her lifetime. Each aphid completes its life cycle in 5-10 days, and the next generation begins laying eggs. You can see how pest populations can blow up so quickly! You may spot a few aphids, and then, all of a sudden, your vegetable leaves are completely infested.
If you don’t have any local predator insects living in the garden, the aphids will run wild like the rabbits in suburbia. But if you maintain a beneficial insectary habitat, resident predators like lady beetles, lacewings, hoverflies, and parasitoid wasps can keep pests under control.
Pesticides vs. Biocontrol
Ecological balance is the key to successful biocontrol, but many people are so focused on eradicating a pest immediately that they neglect to look at the larger picture. If you spray pesticides to knock out the pest, you can also kill beneficial predators that would’ve been helpful for controlling future problems. Unfortunately, pests return more quickly and develop pesticide resistance much more quickly than their predators.
This creates an ecological disaster where gardens and farms get stuck on a “pesticide treadmill” where they must continuously spray stronger chemicals to keep unwanted bugs away. If you want to grow organically and avoid the harsh chemicals, conservation biocontrol offers a much more promising and sustainable solution.
Conservation vs. Classical Biocontrol
You are likely reading this article because you don’t want to spray pesticides and instead wish to use ladybugs as pest control. First, it helps to understand how biocontrol really works in the garden. There are three main types of biocontrol used by gardeners and farmers:
- Conservation Biocontrol: Conserve and enhance existing, native natural predator insects already living in the garden and surrounding area.
- Classical Biocontrol: Buy and introduce new insect enemies to control pests and create a permanent population.
- Mass Rearing: Buy predator insects and periodically release them when pests get out of hand.
Notice how the first type of biological control makes use of the insects already living in the area. This involves planting flowers and creating a habitat for predators to take up residency in your garden, which means they can provide pest control services for many seasons to come.
The latter two types of biocontrol are focused on buying predators and releasing them. Of course, anyone can buy ladybugs and let them fly into their garden or greenhouse, but how many of them will stay around to eat the pests in your landscape?
Many studies indicate that the bulk of purchased and released ladybugs actually fly away without providing any long-lasting pest control in the desired crop. In fact, about 95% of released beetles fly away within just a few hours. This is because lab-reared ladybugs are often refrigerated during hibernation and naturally wish to migrate away once they come out of their dormant state.
The Ultimate Goal
Don’t get me wrong: Ladybugs are beneficial predators that eat lots of pests! The predicament here is based on where the ladybugs come from and how they arrive in your garden.
Conservation biocontrol is the ultimate goal— plant beneficial insectary plants and magnetize the predator insects to live in your garden for generations to come. Every year, the ladybug populations will get stronger, and they will live like locals, perpetually keeping aphids and other pests under control. Luckily, most flower seeds favored by ladybugs are far cheaper than buying lab-reared beetles for release.
Releasing Ladybugs: Pros and Cons
Natural predator release has some notable benefits and drawbacks, which you should consider before buying a package of insects and letting them fly into your garden. For many, the cons outweigh the potential benefits.
Pros
Buying and releasing ladybugs may seem like a short-term quick fix for a pest issue, but this isn’t often the case. More than 95% of purchased ladybugs can fly away within the first few days of release, often not even putting a dent in pest populations.
Greenhouses are the only places where ladybird beetle release is proven effective. Because greenhouses are a mostly closed ecosystem, you can let the predators fly into the crop, and they will do their work without flying away. Studies show that greenhouse aphid populations were reduced by over 50% when ladybugs were released.
Cons
The drawbacks to buying and releasing natural predators include:
- A lot of ladybugs are required! About 1,500 are needed just for one aphid-infested rose bush.
- It can be very expensive to keep buying ladybugs.
- 95% of the predators fly away from your garden, especially if released in the heat of the day.
- Many lab-reared ladybugs are either poor predators or not hungry for the pests you have on offer.
- The lady beetles deteriorate rapidly if they are left at room temperature or become dehydrated.
- Released beetles are unlikely to lay eggs in your garden.
- Many purchased predators are non-native or invasive species.
Why Native Ladybugs Are Better
Entomologists (people who study bugs) are widely recommending ditching the store-bought ladybugs and instead attracting native predators to your garden. Ladybug beetles belong to the Coccinellidae family of insects, which includes over 5,000 species of ladybird beetles. The most commonly known North American ladybug is the 7-spotted ladybug (Coccinella septempunctata), with the iconic shiny red body, black head, and black spots. Attracting this predatory beetle is easy using the tactics described below.
However, their cousins, Asian lady beetles (Harmonia axyridis pallas) are invasive but often used as classical biocontrol. These beetles are often solid orange or orange with black spots and are equally voracious predators of aphids and mites. However, they can become a huge nuisance if they overwinter in buildings or homes and are highly problematic compared to their native cousins.
Commercially sold ladybugs are often captured from the wild or “farm-reared” in insectaries. Species can vary, but they are most often the 12-spotted ladybug (Coleomegilla maculata). This species is native to the U.S., but the farmed beetles may be fed alternative food sources that make them poor garden predators. In other words, they are a bit like zoo-raised wolves; they don’t have the natural prey drive that a wild-born wolf has.
Overall, lady beetles are a positive thing in the garden regardless of the species. However, there is no need to release more into the environment when native lady beetles are already abundant. All you need to do is lure them into your garden.
How to Attract Native Ladybugs
No need to buy any more insects! These steps are sure to attract an abundance of native lady beetles to your garden to help naturally control pests:
1. Don’t Spray Pesticides
Pesticides kill more than just pests. Most insect-killing chemicals also kill beneficial insects. It’s very important to avoid synthetic pesticide sprays on all parts of your garden, especially floral areas and vegetables that are prone to pest infections.
If you spray the crop with pesticides, lady beetles will suffer and won’t be able to help control future pests. Fortunately, organic options like neem oil and horticultural soap do not harm lady beetles. However, it may harm their food sources, leading to an imbalance in the garden. Use even organic pesticides sparingly.
Plant Beneficial Flowers
Beneficial insectaries aren’t only for butterflies and bees! Flowers provide vital nectar resources for adult ladybugs, luring them to lay their eggs near pest-infested plants. When the eggs hatch, the larval lady beetles can devour nearby pests. Ladybugs need both nectar (floral sugary carbs) and pollen to give them the energy to hunt their main protein source— pests!
The best ladybug-attracting flowers include:
- Yarrow
- Angelica
- Dill
- Fennel
- Sweet alyssum
- Calendula
- Marigolds
- Flowering cilantro
- Caraway
- Tansy
- Scented geraniums
- Coreopsis
- Cosmos
You can intersperse these blooms throughout your vegetable garden as companion plants or grow them in strips along the borders to create an undisturbed area for ladybug habitation.
3. Create Beetle Habitat
It’s important that the floral resources remain a bit wild— no need to excessively trim or manicure the area. The beetles need places to hide and shelter. “Beetle banks” are easy to create by mounding piles of wood chips or small twigs in the borders of your garden to provide nesting spaces as well as habitat for other predators like ground beetles.
A small buried dish of water or a garden water feature will provide a space for ladybugs to stay hydrated. This is also beneficial for bees and butterflies. A bird bath can also do the trick! Regularly change the water or add an aerator to prevent mosquitoes from laying eggs in the water source.
4. Do Not Expect 100% Eradication
While lady beetles are excellent predators, it is unrealistic to expect them to eliminate every aphid or thrip in your garden. After all, 100% eradication would mean no more food left for future ladybug populations. An ecological balance is necessary for a biocontrolled garden, so complete pest elimination is not our goal. Instead, we want to maintain pests at a much lower level to prevent damage to our plants.
You may not see immediate results in the first season, but several consecutive years of predator-friendly gardening will build up enough populations of beneficial insects to prevent major pest infestations.
Final Thoughts
Ultimately, buying and releasing ladybugs is an outdated theory. Classical biocontrol methods have had many disastrous consequences, including releasing invasive species in areas where they wreak havoc on local ecosystems. It is much safer, easier, and more effective to use conservation biocontrol to attract predator insects to your garden. Avoid pesticides, plant nectar-rich flowers, and provide space for native beetles to come in and work their magic!