All Things Garden,  Beginner Basics,  Pests

Organic Pest Control, Pt 2: Identify the Top 18 Garden Pests & Beneficial Insects

Welcome to Part 2 of our organic pest control series! Managing pests in the garden is a complex and sometimes challenging task. Trust me – we have our fair share of pest issues here too! They like to keep us on our toes. Dealing with pests is particularly frustrating when you can’t quite figure out who or what is causing damage in your garden! But locating and properly identifying pests is an essential step – before you can take responsible, targeted action against them to protect your crops.

Keep reading to learn how to find and identify pests in your garden. For easy reference, photos of the top 18 common garden pests, along with a brief description of each, are included below. Last but certainly not least, let’s get familiar with some beneficial insects that you should be happy to see around your garden – so we don’t accidentally do them harm!


Before we get started, please keep in mind that an organic garden should not be free of all insects or pests. That simply isn’t natural! Furthermore, organic produce shouldn’t be expected to be blemish-free. Accepting those things is the first step in being a true organic gardener. Be proud of your holy greens! I am. Perfection is not the goal.

Additionally, prevention is a huge part of organic pest control. “Prevention before action” is central to the concept of Integrated Pest Management, which is what we basically follow here on this homestead. As we explored in Organic Pest Control Part 1, there are many ways to prevent pests in the garden, such as through careful plant selection, crop rotation, companion planting, polyculture, improved soil health, and diligence. If you haven’t already, be sure to check out that article – then come back here of course!


An image of a garden, with raised beds, vegetables, and flowers all around.
Our gardens are productive, lush, and wild. But they are not “perfect”. Instead, we have created a balanced ecosystem; one where pests are absolutely present – but so are plenty of beneficial insects that help us keep them in check, naturally! We do have to intervene at times, but it is not a constant battle.


GARDEN PEST IDENTIFICATION


So, who’s “bugging” you?


When you have a pest problem on your hands, the first and most important thing you need to do is identify exactly who or what you are dealing with. I can’t tell you how many times I have received messages like: “Help! Something is eating my plants! What should I do?!” In response, I always ask, “Do you know what is causing the damage?” More often than not, the answer is “no”. Well, I’m sorry, but I really can’t help you… until we do know!


Properly identifying your pest helps you decide the next step and right course of action. Any respectable organic pest management strategy will use techniques or products that impact only the targeted species, while minimizing risk to others and the environment.


The approach to manage a specific pest will vary tremendously – depending on whether it is aphids, caterpillars, rats, or other buggers in your garden! This is because their biology and behaviors are different. For example, organic soap-based sprays are effective against aphids, but not for caterpillars. Unless you’re bombing your yard with gnarly broad-spectrum pesticides (puh-lease don’t, for everyone’s sake!) there really isn’t a one-size-fits-all solution to deal with pests.

Furthermore, as an organic gardener, it is crucial that you familiarize yourself with ALL the common insects in your garden – so you can distinguish between the “bad guys” and beneficial insects! Some insects are in between. They may cause a little harm, but also do something good for your garden, which we’ll explore more below. Maybe the good outweighs the bad, and you can choose to leave them be.



So, what if you see damage on your plants, but can’t tell who or what is doing it?



How to Locate Pests in the Garden


Finding and identifying pests can be tricky, especially insects. They’re really good at hiding! But if you look closely enough and do some research, you can usually figure it out.

Here are some tips to help you find the pests in your garden:


Be a detective –  inspect those plants, regularly and closely!

  • Lightly sift through the top layer of soil around the base of a plant. Many critters hide close by, but out of sight. Cutworms and pillbugs are especially good at this.
  • Flip over debris on the garden soil surface, such as fallen leaves or rotting bits of wood. Many pests like to congregate there during the daytime.
  • Look closely at the underside of leaves, and frequently. That is where many pests like to hang out, or lay their eggs. Aphids, caterpillars, whitefly, and squash bugs often gather on the underside of leaves.
  • Check among the very center, newest growth on a plant. This particularly applies to greens like swiss chard, kale or collards. Aphids love to cluster on the new tender curled leaves in the middle of a head of leafy greens.
  • Also inspect along the ribs of the stems. Cabbage worms and other caterpillars often lay straight along the center rib of a stem, such as on a leaf of kale, perfectly disguised among it. It can be easy to miss them at first glance!
  • Watch out for poop! Caterpillars in particular are prone for leaving behind little presents. These appear as little black or green specks on the leaves. The bigger the caterpillar, the bigger the poo. If you see a dusting of poop, a caterpillar (or other insect) can’t be too far off! Use poop to narrow down your hunt.
  • If you see holes in your leaves, check the leaf area immediately around the hole. Again, especially on the underside of the leaf. The pest may still be right around the border of the hole, munching away. Cabbage worms are notorious for this, and you can squish them right then and there!


A fat cabbage worm was found nestled among the centermost tender leaves of this large head of otherwise healthy-looking collard greens. There is a lot of black dots of poop around it too.
Look at all that poop! A fat cabbage worm was found nestled among the centermost tender leaves of this large head of otherwise healthy-looking collard greens. Looking straight in from above, it was invisible. Chicken snack!


Check the garden at various times and conditions

Do your detective work at different times of day to see who is around. This includes going out into the garden in the dark with a flashlight! Different pests are active in various conditions and times, and many are nocturnal. Some are most active after a rain or a good watering. I’m not suggesting that you need to be out on the prowl in the garden 24/7. Yet if you’re noticing problems, definitely go take a look at night – you may be astonished at what you find.

For example, we have spotted hundreds of pill bugs or dozens of snails that were impossible to find during the day! They came out in droves at night, and were incredibly easy to manually round up and dispose of in large numbers. Check out the photo in the snail section below to see what I mean! Repeat this for several nights in a row if you have a big problem on your hands.



Think critically

If there are holes in the middle of your plant leaves, it is safe to assume there probably is a chewing insect at work. On the other hand, if there are ragged rips and tears around the outside edges of the leaves only, or if a large plant experiences significant damage in just one night, it is more likely the work of wild birds, opossums, rats, squirrels, deer, or similar large vertebrate pests.

Keep an eye out for irregularly curled or crumpled leaves. When aphids colonize the underside of a leaf, if often buckles and bends around them. I can spot this from a mile away, before I even see an aphid!

Look for warning signs that signal a pest may be at work, even if you aren’t seeing obvious damage or the pests themselves. For example, foliage may begin to yellow from tiny leaf-sucking insects like whitefly and leafhoppers. However, remember that damage from many different issues may look similar. Curled yellow leaves may be a nutrient deficiency, too much or too little water, the work of a leaf sucking insect, or a disease. Not that this is particularly helpful in narrowing down the issue… but it is useful to keep in mind regardless. Using the other investigation methods described above should help you narrow it down.


Three images showing aphids hiding inside the curl of a collard green leaf, and a hand squishing and removing them. It is important to look under and between leaves for garden pests
I knew what that curl meant. Sure enough, a cluster of aphids – waiting to be squished!


I think I found the bugger! Now what?

If you spot an insect and recognize them immediately as a “bad guy”, I suggest to kill them right away. Personally, I do a ton of squishing by hand. If this creeps you out, grab a leaf as a barrier or knock them into a container. Who knows? If you wait, you might not be able to catch it again. Or, by the time you do, it could have laid a shit ton of new egg babies! Insects reproduce at a rapid rate. Again, make sure you KNOW it is a bad guy though. It would break my heart if you accidentally squashed a precious ladybug larvae because you didn’t know better. Let’s make sure you do. See photos of them in the “good guy” section below!

On the other hand, if you’re able to find a suspect insect but aren’t sure what it is, snap a photo! The same goes for mildew, fungus, other signs of disease or damage. You could also collect it, but not kill it (yet). These actions will come in handy when you work to properly ID the pest.


How to Identify Garden Pests


Check out the photos to follow! I have put together the top 18 common garden pests for you all, including a brief description of where they are found, their habits, damage caused, and other characteristics that may be helpful.

Obviously, I couldn’t include every pest under the sun in one post. I also didn’t go into diseases in this post, such as various types of blight, mildew, or viruses. I’ll have to address that in a separate article.


Other resources to help you ID garden pests

Armed with your photo, collected specimen, or a good memory and description, look up the pest or disease online. Google can be damn good, as long as you feed it the right information! Be specific in your search and provide as many unique descriptors as possible. For example, don’t search “there are bugs on my plants”. This may sound obvious, but you’d be surprised how common this is… Instead, try “black and red beetle on milkweed” or whatever details fit your situation.

In addition to Google, share it with your gardening friends – online or in real life! Our gardening community on Instagram is great for stuff like that. There are also many Facebook gardening groups, possibly local to your area. Post a photo and ask for feedback!

Another great resource at your disposal are the friendly staff at your local garden center or nursery. Bring in a photo (or even a specimen!) and see if they can help identify it. If there is a Master Gardeners program in your area, they can help do the same! Our local MG program even has a hotline that you can call to ask questions – pest related, or for general garden advice! This can be especially useful to ID diseases common to your area.

If you are struggling with a larger nocturnal pest, such as skunks or rodents, but aren’t quite sure what, you could consider setting up a video camera that is equipped with night vision! This rechargeable battery-powered camera is popular for home safety, but could be used for garden pest patrol as well.

Last but not least, feel free to contact me. I will help the best I can!


Without further ado, the mugshots.


THE “BAD” GUYS


Here are the top 18 most common garden pests! I feel just a tiny bit sad, calling them “bad”… Every organism has a place in our ecosystem, but the ones included on this list can wreak havoc in a garden, particularly if their populations aren’t kept in check! And their population numbers are NOT suffering, so don’t feel guilty in killing them. You gotta do what you gotta do to protect your hard work and food supply.  

I have included a few quick tips and tricks for locating and managing them within their descriptions. However, I do not go into detail on all the ways to organically reduce or eliminate their populations in this article. It would have been far too much to cover at once! Therefore, Part 3 of this organic pest control series will cover just that. Hang tight. It is coming soon!

Keep scrolling down to the “good guys” section to check out the beneficial insects! You need to get to know your friends as well.



1) Aphids

Found: There are thousands of species of aphids, which can be found all across the globe. However, aphids are most common and prolific in temperate climates.

Attracted to: Aphids are most attracted to the tender new growth of plants. They can infest and feed on pretty much any type of plant, including tomatoes and squash, though they seem to favor the brassica family. This includes kale, cabbage, collard greens, and broccoli. In our garden, they also seem particularly attracted to milkweed, swiss chard, carrot greens, and leafy greens like spinach or lettuce.

Damage done: The leaf-sucking causes stunting in plants, and will damage and yellow leaves. Serious infestations can cause plant death, particularly young plants. The sucking action also serves as a way to spread diseases from plant to plant. Their sticky honeydew can harbor sooty mildew.

Characteristics: Aphids are soft-bodied insects that are most active in the spring. Some have wings, many do not – especially young aphids. Aphids can be green, white, black, grey, orange – most colors really! They have a sucking mouth piece, which pierces and sucks the sap, moisture, and nutrients from a plant. Aphids produce a sticky residue called “honeydew” that ants love to eat, so you often see the two colonizing together. They are a food source for lacewings and ladybugs, which you can buy and release to keep aphid populations in check! When you come across a cluster of aphids, the quickest and easiest way to get rid of them is squish them, then blast them off with water.

Quick tip: Make a DIY soap-spray for aphids, mealybugs, or whitefly by combining 1 tablespoon of Dr. Bronner’s peppermint castile soap per 1 quart of water, or 5 tbsp per gallon. Apply directly to the insects, in the evening hours to avoid sunburning leaves. Beneficial insects are also less active in the evening.


The photo on the right shows a ladybug larvae eating orange aphids (garden pests) on our milkweed, on the left an adult lady bug eating grey aphids on kale.
Ladybugs aren’t choosy on their color of aphid. They love to eat them all! The one on the right shows a ladybug larvae eating aphids on our milkweed. Don’t mistake ladybug larvae for a bad guy!



2) Whitefly

Found: Can be present year-round in temperate southern and coastal climates, but less so in locations with extremely cold winters. They thrive in warm weather.

Attracted to: A wide variety of vegetables, fruit trees, and ornamental plants. They favor warm weather crops such as tomatoes, peppers, eggplant, and the cabbage family.

Damage done: The damage caused by whitefly is similar to that of aphids, described above. They feed on the underside of plant leaves, depleting the plant of nutrients and spreading disease. Leaves will yellow and possibly drop off. These garden pests are particularly threatening to crops in a greenhouse environment.

Characteristics:  Despite their name, they’re not truly flies. White flies are actually in the same family as aphids and mealybugs, but are named as such due to their apparent wings. But they are tiny. As immature nymphs, they can appear similar to small aphids or mealybugs. Ladybug, lacewing larvae, and dragonflies are natural predators of whitefly. Sticky traps catch these guys fairly easily.


Tiny flies with white wings on the underside of a leaf
Whitefly. Photo from Sustainable Gardening Australia


3) Slugs/Snails

Found: Snails and slugs thrive in wet environments, and will be most prevalent in areas with regular rainfall, high humidity, or in gardens that use overhead sprinklers. They are most active at night, and on moist or overcast days. Look for these guys with a flashlight at night after a rain or watering, and remove them.

Attracted to: Both living and decaying plant matter. Snails and slugs especially like soft, succulent, herbaceous plants.

Damage done: Slugs and snails can be extremely destructive. They’ll chew holes in leaves, or for small tender plants (like seedlings), eat the entire plant down to nothing overnight.

Characteristics: I lumped these guys together because they have virtually the same biology and habits. The obvious difference is that slugs lack the hard outer shell that snails have. While the damage to plants caused by slugs or snails can be easily confused with that from other pests, the telltale sign to watch for is their slimy trail! I suggest hunting and removing these garden pests at night. One mild organic product that only harms slugs and snails is Sluggo. They can also be trapped with beer!


Almost a dozen brown snails on a green leafy plant, the photo taken at night with a flash. These sneaky garden pests can do serious damage overnight!
Invisible in the daytime, a buck-wild snail party in our garden at night!



4) Leafhopper

Found: Leafhoppers are found all across the world, in virtually any climate that has vegetation – even the desert!

Attracted to: Leafhoppers will suck on just about anything. Really! They seem to be the least picky of all leaf-sucking pests.

Damage done: The symptoms of leafhopper damage is similar to that of other piercing and sucking insects like aphids or whiteflies. Leaves are yellow, and may curl or have brown tips. A leafhopper infestation may be very difficult to control.

Characteristics: These garden pests are tiny, wedge-shaped, sap-sucking insects. When they’re disturbed, they will immediately take flight (adults) or hop off (juvenile, lacking wings). They may be green, gray, or brown in color.  


A close up of a green leafhopper resting on a leaf
Leafhopper. Photo courtesy of Royal Queen Seeds


5) Pillbugs & Sowbogs, aka “Rollie Pollies”

Found: Pillbugs are found all over the world, and called different things everywhere too! Different names:

Attracted to: Pillbugs are most commonly and naturally drawn to decaying plant matter, also called detritus. They’re actually very beneficial in this regard, as they turn over organic matter and increase available nutrients in the soil, similar to worms! However, in the absence of adequate detritus to eat, pillbugs will also eat living plants. Small tender plants near the soil line are most at risk, such as new sprouts, tender young seedlings, or leaves dangling on the soil surface.

Damage done: The damage from pillbugs is generally mild – a few munch holes here and there. Yet when there is a large, hungry population, they can do a number on newly sprouting seedlings. Especially in an overly-tidy garden space without other detritus available for them to eat.

Characteristics: Pillbugs are nocturnal. During the day, you can find them hiding under rocks, fallen leaves, under the soil surface, or in other dark locations. I’m sure most of you all know what a dear “rollie pollie” looks like, right? Like a mini armadillo! Cleaning up large leaf and wood piles helps reduce prolific breeding. We find manually squishing them at night helps too.



6) Earwigs aka Pincher Bugs

Found: Earwigs can be found in every climate, though they are most prevalent in Southern zones.

Attracted to: Seedlings, soft fruit, and corn. But earwigs also eat aphids and maggots, so it is a bit of a catch-22 with these guys! They’re present in our garden, but we have never had any significant issues with them. That we know of, at least…

Damage done: The holes in leaves that are caused by earwigs will appear ragged and irregular. Seedlings may be demolished completely.

Characteristics: Like pillbugs, earwigs are nocturnal. These garden pests hide in damp, dark locations such as under decaying wood, and are more difficult to spot during the day. Earwigs have long skinny antennas in front, and two big pinchers on their rear – which, contrary to popular myth, are actually more for mating-purposes than pinching-purposes!


Earwig or "pincher bug".
Earwig or “pincher bug”. Photo via Good Housekeeping


7) Cutworms

Found: Various types of cutworms are found in most all regions of the world. These caterpillars (not actually worms) are the larvae of many species of nocturnal moths.

Attracted to: Any herbaceous plant, especially the stems and foliage of vegetable and grain plants near the soil surface.

Damage done: Cutworms are difficult garden pests to identify because they hide in the soil during the day. Then, they come out at night to feed on plants, creating holes and damage to foliage. Often times, they will chew on the first living plant matter they can find – the stems and stalks of plants. Thus, they chew and essentially chop the plant down at or just below the soil line – hence their name!

Characteristics: Cutworms are soft-bodied caterpillars that can vary slightly in appearance, ranging from brown, black, greenish, or dark grey in color. Sometimes they have stripes. Cutworms will curl up into a “C” shape when disturbed (not to be confused with curl grubs, described below). If you see a cutworm, remove and dispose of it.


Cutworm and a damaged plant. These garden pests are more difficult to identify since they usually hide below soil.
Cutworm image from Farmer’s Almanac


8) White Curl Grubs

Found: Curl grubs are found all over the world, since they are not one specific species. Like others on this list, they are grouped together based on their common appearance and biology – but know that they are the larvae of dozens of different types of beetles, such as an African Black Beetle, June Bug, or others.

Attracted to: Lawns, and the roots of most types of plants – except for beans and peas.

Damage Done: Curl grubs are most recognized for the damage they cause to lawns. I have just the solution for that! #growfoodnotlawns. Ha! Kidding… kind of. You may also find them in your garden beds, where they eat the roots of plants. The affected plants will look yellow, appear unhappy or deficient, or otherwise fail to thrive.

Characteristics: Curl grubs are pearly white in color. They’re shiny in appearance, with an orange-brown head and often bluish hind end. Manually remove grubs as you find them. Beneficial nematodes can also help control populations. The larvae are most active mid-spring to mid-summer.


White fat curl grubs on the soil
White curl grubs. Photo courtesy of My Home Turf


9) White Cabbage Butterfly and “Cabbage Worms”

Found: I think we all know these guys. They’re pretty much everywhere!

Attracted to: As their name suggests, white cabbage butterflies are most attracted to the cabbage and mustard plant family. They lay their eggs on the leaves of cabbage, broccoli, kale, collard greens, and the like. However, that isn’t all! We have found cabbage worms on a wide variety of other plants in our garden as well.

Damage done: As the larvae of cabbage moths emerge from their eggs, the caterpillars begin to feed on the surrounding plant matter immediately. This creates little holes in the leaves, expanding to larger holes or completely demolished leaves and plants as the caterpillars grow in size and population.

Characteristics: Also called “cabbage whites”, the adult form are small to medium sized white butterflies. They have a couple of black dots on their otherwise mostly creamy white wings. Very active during the daytime, cabbage whites are often seen flitting about your garden, laying eggs on anything they can bump their little asses on. The eggs are seen as white to yellow oblong dots, attached to the underside of leaves. If you find and recognize these eggs, squishing them is a great early control method. (Please note that ladybug eggs are also oblong and yellow, but are found in clusters. Cabbage worm eggs are usually sporadic and solo.) Once they emerge into caterpillars, the cabbage worms are most often found on the underside of leaves or new growth of the plant.

Management Tips: We manually remove caterpillars, and squish eggs. For serious infestations, an organic spray containing bacillus bacillus thuringiensis “Bt” can be used – but with care! It only impacts caterpillars, but do not overspray to non-target plants. Keeping crops covered with floating row covers of insect netting is another option. Neem oil is not effective at killing caterpillars, but may deter the butterflies.


A handful of green cabbage worms on a damaged collard green leaf, and the adult white butterfly. Cabbage moths and worms are very common garden pests
Collecting cabbage white caterpillars, aka cabbage worms, from the collard greens and kale. They sure do blend in with the leaves well, making it easy to miss them when you’re on the hunt! Squish those eggs if you see them too.


10) Cabbage Loopers

Found: Cabbage loopers are found throughout the world. In the U.S., you’re mostly likely to see cabbage looper activity during the summer months. They overwinter in only the mild southernmost regions.

Attracted to: Cabbage loopers are named after their favorite meal: cabbage plants. Yet they are not picky. They will feed on any and all cruciferous veggie plants in the cabbage family, along with many others. We find them on our flower and cannabis plants too.

Damage done: The damage to plants from cabbage loopers is virtually the same as cabbage white butterfly larvae, as described above. The looper caterpillar larvae are ravenous leaf eaters.

Characteristics: Cabbage looper caterpillars are often confused with cabbage worms, the green larvae from white cabbage butterflies. However, the adult form of loopers are actually a brown nocturnal moth instead of a white diurnal butterfly. The telltale difference between the similar-looking caterpillars is the way they move. Cabbage loopers move like inchworms, arching and humping along.  Practice similar management methods as described above for cabbage whites.


Cabbage looper caterpillar, small and green, and adult brown moth.
Cabbage looper caterpillar and adult moth. Now, you can see the difference between the looper and the white cabbage worm, right? Photo credit: Epic Gardening


11) Squash bugs

Found: Squash bugs are widely distributed across North America.

Attracted to: As their name would indicate, squash bugs are most commonly found on squash plants, though they’ll feed on any member of the cucurbit family. This includes squash, pumpkins, and cucumbers.

Damage done: Squash bugs are sap-suckers, like aphids and whiteflies. Yet, in addition to sucking on leaves, their piercing mouthparts also inject a toxin into the foliage. This leaves spots that will yellow, then turn brown and crispy. It can also cause wilting foliage. The damage done prevents the plant from adequately using nutrients and water for health.

Characteristics: Adult squash bugs can be up to half an inch long, with a brown or grey flat body. Young baby squash bugs will cluster on the underside of leaves, and look similar to large aphids, with grey bodies and long black legs. The adult beetles are commonly found under damaged leaves. They will also congregate under wood on the soil surface if placed there, and in deep cool mulches of straw or hay. You can create traps with wood by placing it on the soil surface overnight, and scooping them up to dispose of in the morning. I have also heard of people vacuuming them up!


Squash bug life cycle: adults, egg mass, and nymphs.
Squash bugs: adults, egg mass, and nymphs. Photo from University of Massachusetts Amherst


12) Stink Bugs

Found: Stink bugs are most prevalent and damaging in the mid-Atlantic region of the United States, though they can also be found on the west coast. In warm climates, they reproduce all year long. Of all the pests on this list, the Brown Marmorated stink bug (shown below) is the most newly introduced pest to the United States – originating in Asia.

Attracted to: Stink bugs are especially drawn to soft fruit trees like peaches and pear, along with apples, tomatoes, corn, soybean, blueberries, and many ornamentals.

Damage done: The damage caused by stink bugs is very similar to that of a squash bug, described above. They are leaf suckers, but will also eat and damage seed pods and fruit.

Characteristics: Stink bugs and squash bugs are often confused with one another. The adult forms look very similar, with broad, squatty, angular bodies. They also both emit a foul odor when smushed. However, stink bugs are slightly more round than squash bugs. Their eggs are also noticeably different if you compare the images above and below. Those are eggs I found on our squash plant just this week, which look to be laid by a stink bug! (Though cutworm moth eggs look nearly the same, so I suppose it could be either!)


Wide brown beetle-like Stink bug and a close up of it's eggs.
Stink bug and eggs.


13) Squash Vine Borers

Found: I feel guilty writing this, but squash vine borers are found throughout the United States… except for the West Coast. I know – we are very, very lucky. The most heavy populations are found in eastern and southern states.  

Attracted to: Another no-brainer here… Squash vine borers like squash plants, including summer squash, winter squash, and pumpkins. They’ll occasionally affect other cucurbits like melon or cucumber, but not nearly as much.

Damage done: Young borer larvae will cause similar leaf damage as squash bugs, including yellowing and wilting. Adult vine borers burrow into the large hollow stems of squash plants, eating them from the inside out. Wilting of plants is usually the first symptom. Some squash plants wilt naturally in hot afternoon sun, but if it doesn’t spring back in cooler weather, it may be a squash vine borer. Once these garden pests are inside, it is very difficult to treat or help the plant. It will succumb to death.

Characteristics: An adult vine borer insect may be confused with a wasp, with a similar body structure. They are about a half-inch long, orange with black spots, and have long wings. In addition to wilting, you may notice holes in the stems near the base of the squash plant. Also, an accumulation of greenish saw-dust like material may be visible. This is called frass, aka, their poop. Squash bugs are said to only be active during June and July. Therefore, one management technique is to plant out another round of squash crops after early July, once the adult borers are no longer active. Good thing squash grows quickly!


Squash vine borer adult (red and black winged beetle), larvae (large white fat worm), and plant damage shown from the garden pest.
Squash vine borer adult, larvae, and plant damage. Photo courtesy of Farmer’s Almanac


14) Mealybugs

Found:  Mealybugs are found throughout North America, but prefer warm weather. They thrive in locations with mild winters – such as coastal and southern states.

Attracted to: Mealybugs are a known houseplant pest, but can also affect the outdoor garden as well. Citrus is a key target, along with many herbaceous ornamentals. They also love our damn passionfruit vines like crazy.

Damage done:  Like their whitefly cousins, mealybugs suck on leaves. They also emit a sticky honeydew, like aphids. Both actions reduce plant vigor and can lead to decline.

Characteristics:  Mealybugs are small insects, just a tad larger than aphids. They are most often white and fuzzy, and can be found in clusters on the bottom sides of leaves and in the nooks of stem branches. Small populations don’t typically do a huge amount of damage, especially if caught early. For small infestations, the bugs can be wiped away by hand, or with a Q-tip soaked in rubbing alcohol. A soap-based spray or dilute neem oil can also be used. See the soap spray recipe in the Aphid section above, #1 on this list.


Fuzzy mealybugs on the bottom of a leaf, with a black and orange ladybug larvae eating them.
Mealybugs on our citrus. Ladybug larvae to the rescue! One is also in the process of pupating – from larvae to adult ladybug.


15) Leaf Miners

Found: Found throughout the world, especially in temperate climates.

Attracted to: While leaf miners are said to be attracted to a wide variety of garden vegetables and other plants, we most often see their damage on our swiss chard, beet greens, and radishes. Maybe a little on our citrus leaves.

Damage done: Adult forms of leaf-mining insects, such as certain flies, puncture leaves to lay their eggs inside, and to feed from the leaf as well. The larvae is “born” inside the leaf, between layers of plant tissue. They move about, eating the interior of the leaf, leaving long tell-tale burrow trails. Often times, it is a small and mostly cosmetic issue and reduces crop value. Serious infestations of this garden pest cause more damage and loss of crops.

Characteristics: Leaf miners aren’t just a single species. This group consists of many kinds of fly-like garden pests, referred to as leaf miners because of how they behave. Hint: If you see the tracks from a leaf-miner, you can usually feel around that area and locate a little lump within the leaf. Squeeze it, and smash the larvae! Done. Simply cut away that part of the leaf and discard it when you go to use the rest.


Leaves of swiss chard with tracks and damage from leaf miners
Minor versus major leaf miner damage on our swiss chard. When I catch it early, I can squish their little larvae inside the leaf before it gets too bad. Look how large and visible they are on the right! I would still squish those, rip out the damaged area of the leaf, and enjoy the stem and rest of the leaf!


16) Cucumber Beetles

Found: Cucumber beetles are found across the United States, Canada, and Mexico.

Attracted to: Striped cucumber beetles mostly prefer the cucurbit family, including cucumbers (duh), squash, melons, and pumpkins. The spotted cucumber beetle loves the same, along with a wider variety of your garden plants.

Damage done: Cucumber beetles are especially damaging to young tender seedlings. Damage from cucumber beetle leaf-sucking and munching includes holes, yellowing, and wilting of leaves. They may completely eat off stems and decapitate seedlings. Spotted cucumber beetles also carry and spread bacterial wilt, which is more damaging than their munch holes, especially for mature plants.

Characteristics: There are a couple types of cucumber beetles. Both have yellow bodies with either black spots or stripes. If you see one, squish it. When approached, they often drop quickly from where they are, to the soil or leaves below. I have found if I slowly place my hand below them, then go in to manually squish them, I can catch them as they try to drop and escape. Don’t mistake the spotted ones for lady beetles, who look similar in size, shape, and appearance – except that ladybugs are red instead of yellow. Some lady beetles can also be more orange, but not yellow.


Spotted and striped cucumber beetles. Both of these garden pests have yellow with black markings.
Spotted and striped cucumber beetles.


17) Tomato Hornworm & Tobacco Hornworm

Found: The Tomato Hornworm is found across the United States, into Southern Canada and Northern Mexico. However, they are not common in the Southeast. Instead, the closely related Tobacco Hornworm is most prevalent in the South and Southeast states instead.

Attracted to: The Tomato hornworms is most attracted to tomatoes, but will feed on most plants in the nightshade family, including potatoes, peppers, and eggplant. Wild tobacco is the most prevalent host for the Tobacco Hornworm. However, they’ll feed on the nightshade family as well.

Damage done: These massive caterpillars can cause severe leaf damage, along with destruction to the plant’s blossoms and fruit.

Characteristics: Both caterpillars are the larvae of large nocturnal moths, hummingbird or sphinx moths. These moths lay their eggs on the host plant, and as soon as the eggs hatch, the larvae start eating and don’t stop. Hornworm caterpillars are very large, with primarily green bodies and have diagonal white or yellow stripes on their sides, along with red dots. Don’t forget the namesake horn on their hind end. The one benefit of the caterpillars large size is that it is easier to spot them, and manually remove them. Watch for their large poop as a hint! Beneficial parasitic wasps also help control hornworm populations, as well as an organic Bt-based spray.


A large brown moth, green tomato hornworm caterpillar, and egg cluster
The lifecycle of a tomato hornworm. If you see those brown pupae casings in your soil, you may want to dispose of them. Photo from Kansas State University.


18) Spider Mites

Found: Spider mites are found throughout North America, and many other parts of the world, including Australia. Dry and warm conditions are especially favorable.

Attracted to: These tiny little pests have a big appetite, for over 200 varieties of ornamentals, fruit trees, and garden vegetables.

Damage done: Causing similar damage to aphids and whitefly, spider mites use their piercing mouthparts to suck the sap and nutrients from leaves. The result is yellowing and bronzing leaves. Leaves may drop, and with serious infestations, the plant may die. They are especially destructive in greenhouses.

Characteristics: Spider mites are very tiny, ranking in at only 1/50th of inch, and are yellow-orange in color. You will find webbing around their habitat and host plant. They are arachnids, after all!

Tiny orange spider mites in a web on a leaf, common garden pests
Spider mites in their webbing. Photo Courtesy of University of Nebraska-Lincoln


Vertebrate Garden Pests


In addition to insect garden pests, other larger vertebrate pests may bother your garden from time to time. This includes deer, gophers, skunks, opossums, raccoons, birds, rats, mice, squirrels, neighbor cats, rabbits, and more! I figured you all probably know what most of these guys look like, and didn’t need a photo and description of each one.  Yet that doesn’t mean I am undermining their status as pests! Often times, these larger pests can do more swift damage than insect garden pests. I cover the ways to protect your garden from vertebrate garden pests in the next article in this series!


Now that you’re familiar with some of the insects that cause damage in a garden, let’s briefly introduce you to the good guys!



THE GOOD GUYS


I am not going to dive into too much detail about each one of these friends now, as I plan to write a post dedicated to beneficial insects in the near future. However, I want you to be able to recognize and appreciate these members of your garden, if you’re so lucky as to have them around!

I also didn’t include bees, butterflies, and other pollinators in this good guy list. Those are a given, right? They are certainly a huge benefit to the garden, but don’t provide the same predatory mechanisms that the others included below do. If you’re interesting in attracting more pollinators to your garden, check out this post: The Top 23 Plants for Pollinators.


Ladybugs

Ladybugs are known predators of aphids, mealybugs, thrips, leaf-hoppers, and other small soft-bodied insects. Ladybug larvae, shown in the top left photo, are more ferocious aphid-eaters than the adult beetles! One ladybug can eat up to 50 aphids per day, or 5000 in their lifetime! We buy and release ladybugs into our garden each year. If you do this, ensure you’re getting native North American ladybugs, and not the invasive orange-tinted Asian lady beetle.


Four images of lady beetles in all stages of life


Green Lacewings

Adult lacewings are most often seen flying at night or in evening hours, and are attracted to light. Their adult form may feed on honeydew or on small insects. Lacewing larvae look like tiny alligators. The larvae are the best predators, and feed on mites, aphids, caterpillars, leafhoppers, mealybugs, thrips, whiteflies, insect eggs, and more!


The lifecycle of green lacewing. This is a beneficial insect that helps control other garden pests
Photo from UC Davis


Praying Mantis

I am always happy but also a tad worried to find praying mantis in our garden. They’re excellent pest predators, and will eat a wide variety of insect garden pests – including caterpillars. Since we raise monarch caterpillars and butterflies, I always relocate praying mantis away from our milkweed when I find them!


A green praying mantis climbing up a leaf


Parasitic Wasps

Parasitic wasps lay their eggs inside or on top of other arthropods, including caterpillars and their pupae. There are dozens of species and types, so they won’t all look like the one below. Once their eggs hatch, and the wasp larvae feed on the host, killing it.


A wasp sticking its stinging end into a green caterpillar below
Photo from Phys.org


Mealybug Destroyers – Cryptoleamus Lady Beetles

Mealybug Destroyers are a type of lady beetle, as shown on the bottom right image below. They do just as their nickname indicates, and devour mealybugs – along with aphids and other small soft-bodied insects. We buy and release these guys on our passionfruit vines to help with the mealybug issue there.

True to lady beetle form, the mealybug destroyer larvae (left image) is the most ferocious eater of mealybugs (top right image). Please note how similar the mealybug larvae look to their prey, the mealybugs themselves. It is tricky, but you can tell them apart this way: mealybug destroyers are more “furry” and lump, with no tail. Mealybugs that look similar have a long tail and are a little less wooly looking.


A three way image, the first being a close up of a mealy bug destroyer in the larval stage. It is white with many fuzzy strands coming from the main body, resembling the end of a mop. The second image is an even closer image of the larvae, it more closely resembles a crab or crustacean of sorts. Many legs coming from its side with two long antenna type pieces protruding from its rear. The final image shows a close up of an adult mealybug destroyer on a leaf, its head is orangish brown and its body is black, its shape is similar to that of a lady bug or other similar beetle.


Beneficial Spiders

I was a little angry with this Orb Weaver last summer, since he captured and ate a couple of our monarch butterflies. I guess I have to accept that is natural… because these guys are actually very beneficial in the garden! He also captured dozens of cabbage whites, flies, moths, mosquitoes, and other flying insect garden pests.


A yellow and brown orb weaver spider in its web. Spiders are beneficial and usually eat other garden pests.



Monarchs & Swallowtail Caterpillars

Some gardeners get frustrated with Swallowtails, as their caterpillars do feed on dill, fennel, carrot greens, and a few other herbs in the garden. But they will become gorgeous pollinating butterflies one day! You can treat them as a pest if you wish, but some folks also like to take them in and raise them into butterflies – following the same process we do for Monarchs.

Unlike Swallowtails, Monarchs do very little damage to the garden. The ONLY plant they consume is milkweed, which monarch lovers plant just for them. They may wander onto your other plants to rest or pupate, but they will not eat anything but milkweed. DO NOT HARM THEM!


Swallowtail caterpillar (green, black, and yellow spots) on the left, Monarch on the right, yellow black and white stripes.
Swallowtail cat on the left, Monarch on the right. Note that younger swallowtails are more dark in color, often times black with orange spikes.


Beneficial Nematodes

Beneficial nematodes are tiny, tiny “worms” that live in the soil. You won’t be able to see them with your naked eye for the purpose of identification, but they are still worth mention in this article! Beneficial nematodes are hugely important, as they feed on over 200 pests from up to 100 different insect families. They are particularly good at controlling populations of garden pest grubs, fungus gnats, and soil-dwelling caterpillars. These are another that we buy and release into our garden beds routinely!


Microscope images of beneficial nematodes - like tiny, tiny "worms" that live in the soil.
Image from Research Gate




And with that – you now know your garden insects, for better or worse!



In closing, I hope this article will help guide you on your pest investigation and identification journey! Hopefully you won’t come across most of these garden pests in your garden. Yet if you do, you will be prepared to make educated decisions about who to remove or not!


Next up, Part 3 of this series dives deep into pest management strategies, including physical barriers, traps, recipes for homemade organic sprays, and more! Check out that article here.


If you found this article useful, please spread the love and share it with others! As always, feel free to ask questions in the comments. Happy hunting and observing!



DeannaCat's signature, Keep on Growing

36 Comments

  • Shannon

    Hi! Would love advice on specifically treating cannabis for caterpillars! My first year outdoor last year I lost 2 full plants at the end of my season due to a crazy infestation. I tried BT (not on buds) but it got to the point I was pulling off 10-20 every morning and rotted my buds. This year I’m using insect netting but am weary just the same. Any advice? I’m in 9b in Livermore. Thanks Deanna!

    Cheers,
    Shannon

    • DeannaCat

      Hey Shannon! We actually have a cannabis-specific pest post in the works, hopefully coming next week. For caterpillars, Aaron does have to Bt about once every other week or weekly if they are bad. We have the same issues. It is the ONE and only kind of spray that he does use on the buds if needed, since it has such as short residual life and no harsh chemicals. I hope that helps

  • April

    I’m loving all of your blog posts. They are so informative & invaluable for this new gardener. Thank you for sharing all you do!

      • Cecily

        Thanks for this. I am so grateful for how much information you share, I just wish you’d use some metric measurements because I’m in Europe and I struggle with gallons and quarts! But I know that there are plenty of converters about..

        I personally struggle the most with aphids and spider mites. Aphids are easy enough to squish, but spider mites are challenging and have been known to turn my plants to crisps 🙁 at the moment they are hanging out on my tomatillos and physalis, and I am doing my best to spray them with water, neem them, soap them, and squish them, but I’m not sure I’m winning…

        I thought I had pretty much dealt with the aphids on my pea plants, but all the leaves still seem to be turning yellow and drying up. I never have amazing success with peas, but I am growing in containers on a balcony so maybe that is a challenge for them too..

        Any advice is welcome..

        I’m also wondering if it’s normal for my passion fruit vine not to be growing much..

        • DeannaCat

          Hey there! Have you tried releasing lady beetles? They will eat them too. Otherwise it sounds like you’re doing all the right things! You just may need to do things more often, to stay on top of it? Some suggest intervention every 2-3 days to “break the cycle” of their eggs hatching after you killed or removed the adults. And regards to peas – they can be finicky, especially in containers and in direct sun when it is too hot. They usually like cooler weather. I hope that helps!

  • CAROL W

    Awesome post! I just realized that my borage plants are luring in TONS of black bean aphids. They’re saving my other plants! Now that my garden is growing it’s good to know who is good and who is bad news. Thanks!

  • Melissa Daigneault

    Fantastic information, thank you! We struggle with squash bugs every year, and marigolds have been the ticket for us in prevention. Have you shared where you purchase your ladybugs from? I would love to get some this year.

  • Joanne Ardizzone

    Thanks for providing this informative list of garden pests. As you know, this is something I am personally struggling with. Because I keep asking you “what the heck is this??” type questions, and sending you weird pictures.

  • Michelle

    Thank you so much!!! This is an amazingly thorough and extremely helpful post! I have upped my gardening game exponentially thanks to you! I know this took hours and hours to complete and I’m very thankful! My trip around my garden this morning was much more thorough 🙂 I appreciate all you do!

    • DeannaCat

      Aw, thanks Michelle. Yes I was joking that this pest post sure was a huge pest! 🙂 No problem. I am happy to help and share. Thank you for saying thank you, and for the support!

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