Friend or Foe?

Have you ever had an insect in your garden and wondered if it was really eating your plants? Well I'll do my best to answer that question for you. Post your picture and question here, and I'll see what I can do.

I'll also provide some pictures of insects that are often mistaken for "bad bugs" that are actually very beneficial and/or benign.

As a first example, here's a stink bug, but this stink bug is a predatory stink bug. Even though it looks very similar to the ones that eat your plants, as you can see here, it dines on caterpillars instead of your plants. It often eats caterpillars many times its size!

How can you tell if it's a good stink bug? One of the best ways to tell is by looking at the "beak". A predatory bug will have a short, stout beak whereas a plant-sucking stink bug will have a longer slender beak.

Handle the predators with care though - don't squash! The beaks that are good at catching pests can also bite sensitive skin if threatened.

predatory stink bug (family Pentatomidae) and prey.

oh, what a great thread you've started! Thank you!!

I'll add a photo of my own.... Here's one tomato hornworm you don't want to squish! The white things are eggs from a tiny parasitic wasp whose name I've forgotten (maybe Night_Bloom can help me out). This pest will not be munching any more tomatoes; instead, he will be feeding the good guys!

What a wonderful picture, critterologist.

And yes, this is definitely a good thing to have in your garden. Each of those white things is a cocoon out of which a small adult parasitic wasp will hatch.

I'm not sure of the genus and species of this wasp (if I find out, I will add it for you), but they are in the family Braconidae and are commonly called braconid wasps.

Thank you so much for this thread.I'll be reading it every day.

This is a great thread, especially for someone like me that can only identify a bug if it's wearing a sign on it's chest! Since I have only been gardening a year or so, I have seen some mighty strange things that I've never seen before! But, I think I will wait until after coffee to check out this thread, not a pretty sight! *giggle*
Thanks,
Pati

I'm adding this thread to my watched list. Being a beginner, I sure will appreciate the information. I used to think that the only good bug was a dead bug.

Here's one that can easily be mistaken for something it's not. Is it a fungus? Is it a bird dropping? Nope, it's a trash bug. Trash bug is the common name for the nymph of certain types of green lacewings (family Chrysopidae). What a particular bug's "trash" looks like will vary with whatever the nymph picks up, but it often contains the empty skins of its prey, usually aphids. The nymph generally moves along in a jerky fashion, which is usually what gives it away. Otherwise it might be overlooked as not being an insect at all. This first picture is the top of a trash bug.

This message was edited Apr 28, 2005 3:19 AM

This message was edited Apr 28, 2005 3:20 AM

Here's a small trash bug that I've picked up in order to get a shot of the actual insect underneath the trash. As you might be able to see, this trash bug has picked up a different assortment of trash than the one above. Most trash bugs are small - being around 1/4 of an inch or so.

And I'm glad you are all enjoying this thread. If you have any questions about any of these critters, don't be afraid to ask, or to post pictures of yor own critters.

Very cool critter! (especially as it eats aphids!) Great camoflage method there -- reminds me of the "spider crabs" that stick all manner of things to their backs, including bits of leafy algae that they can snack on later!

Alright. It's started. I got a picture of a critter I see every year about this time. This will be the first of many.

I must tell you that this bug gives me the major willies, and I'm surprised I got close enough to it to get a picture. lol I'm really not big on bugs, but for my plants, I'll deal with my fears, but this one looks like it just crawled up out of the pits of hades,,,,but if it's a good bug, I'll try to find a way to co-exist with them.

Hey, night bloom -- is that one of those plant eating stink bugs??

This is a great thread.
Except for ladybugs, I have almost zero knowledge of good bugs.
I hope to learn a lot here.

Question #1 - Could the hole in my rosebud be caused by a plant eating stink bug?

Question #2
Here is an assortment of bugs on the back side of a leaf I removed.
I was wondering if the winged bugs were good bugs?
Are they all bad?

#2 cont
The last photo didn't show the black bug at the top

#2 cont
sorry I hope this isn't overkill
This one shows a better view of the green bug towards the bottom of the photo

Ah, Night_Bloom, you may have bitten off more than you can chew here! I'm heading out to my garden with my camera right now!!! There're about 10 bugs I want to know about, particularly the scary looking red spidery-thing that I always seem to dig up when I'm planting.....

Dovey, that does not look like a happy leaf. While I'm not sure about the other bugs, I'm concerned that those little light colored things that aren't quite in focus might be aphids (which are not a good bug!).

I just had a great idea, which will probably result in Dave giving me my walking papers! Wouldn't it be neat to have a bug file like the plant file? That way when we come across something we can't identify we would have a place to go to try and find out what it is. If it wasn't there, we could then try to identify it (night_bloom?) and add it.

Just a thought
Pati

The hard part there would be devising a key so the bug's name could be found. Might be better if people could just suggest their favorite books for IDing garden good guys / bad guys. Night_Bloom, do you have a favorite reference we could use when/if you get tired of this thread (which we hope won't be any time soon!)?

You're right critterologist, it would have to be a LOT more organized than I envisioned. One of my great joys was finding a phonetic dictionary. If you could say it, you could find it, then it told you how to spell it correctly. I was thinking along the lines of sections with headings like: black bug with wings...black bug , no wings....things with many legs...tiny green things...etc. etc. If you could describe it, you could find it's picture and find out it's real name.

Oh well, now you know why I failed Biology! LOL
Pati

Hi Critter,
Yes the out of focus things are aphids, those little creeps were on my Double Delight.
I do a garden walk every morning to check my roses, I spray off the aphids or flick them off with my hand.
I'm hoping the winged bugs eat aphids.
I really wish I was better at photography, it's not the camera I assure you it's me.

Hee, patischell - that would certainly be user friendly.

critterologist - me get tired of a thread full of bug pictures? Highly unlikely. I do have a great book though - huge, full of pictures, and fairly cheap that I got off the internet for work. Here's the title etc., but I might have to get the site for you guys where I bought it (I have since forgotten).

Garden Insects of North America:
The Ultimate Guide to Backyard Bugs
by Whitney Cranshaw
Princeton University Press
2004
656 pages

It's a soft cover book. Mine was around $25 - $30.

But until then - or for a maybe quicker answer. I'm here to answer your questions when I can. Speaking of which here we go. *Rubs hands together gleefully*


dovey (question #2) - critterologist is correct. The small green guys are aphids. So are the winged critters. That is the aphid form that "migrates" in. What is interesting, however, are the swollen, black aphids without wings. If I am seeing correctly, these aphids are dead, and probably parasitised by a wasp which should eventually pop out of the aphid and kill some more aphids. I think they are dead versions of the green ones beside them. Other types of "mummies" as these dead aphids are called are a tannish color. Most are swollen up like a ballon.

Now I could be wrong about the black ones being "mummies" - I have seen black wingless aphids too, but if you want to check, you could take a pencil and touch them. Dead aphids will be somewhat dried up and won't move away from your prodding.

My suggestion... Keep an eye on your aphids for a bit. In my garden, generally just about the time I think "I better spray those" the lady beetles, lace wing nymphs, and parasitic wasps show up and eat the lot of them in a couple of days. If things start to look grim, pyrtherins or insecticidal soap (like Safer soap) would be more low impact (breakdown quickly) and should do less damage to "good bugs."

a picture of a tan aphid "mummy"...

This message was edited Apr 29, 2005 2:36 AM

jdee - hmmm. That does certainly look like a bug (Hemiptera), but I can't see its mouthparts to know if it is a predator or a plant eating one. I'll give another example of a predatory bug where you can see its "beak".

And here's one where you can (sort of) see a long, thin beak of a plant-sucking stink bug. The beak is tucked under its body and reaches to at least the third set of legs.

This message was edited Apr 29, 2005 2:58 AM

Dovey - question #1. Nope. Stink bugs have piercing sucking mouthparts - as shown above. They can't chew, so in general they can't make holes that large. Stink bug "stings" would look more like pin pricks. This looks like damage from a chewing insect such as maybe a beetle (perhaps a rose chafer?).

I admit to not knowing many rose pests. I only have one rose - a wild, "rambling" rose that has little pink flowers that my hubby brought me from the woods. The regular kind would require me to actually "work" on my flowers - hee. Most of my flowers in the garden get the "if you live, fine. If not, I replace you" treatment. Hee. Beyond giving them a nice hole with some humus and slow-release fertilizer and a watering every once in a while (maybe once a month), most of my flowers are on their own. It's my veggies that I tend to baby a bit.

margu - hmm. How large spidery red things? Larger size and long-shaped, I would guess centipedes (Chilopoda). I don't have a picture of those kind of centipedes unfortunately - they are fast and I usually encounter them when I have gloves on that are covered with dirt (not a camera-friendly situation). If you google centipede and choose the images selection, you might find your guy.

If small and red - like the size of a round-headed pin's head - it might be a predatory or omniverous mite. Picture (a bad one) below. These guys don't stay still either.

night_bloom, if you had been my teacher, I might not have failed Biology. You make it very interesting. This thread is going in my "favorite" box.
Pati

Thanks for that pair of stink bug photos! They make the difference between the good & bad guys obvious, and I'm pretty sure I only saw the bad guys on my tomatoes last year.

I love this thread!! How totally cool that we have our own in-house expert! Thanks, Night_Bloom!!!

critterologist - just to calrify, because I really should have done a better job of that... in the second set of photos above, our "good guy" was a bug (Hemiptera), but not a stink bug (Pentatomidae), so the body shape is very different, too, as well as the beak. That guy is actually in a family called Reduviidae of which most are predators (some bite you if you live in Florida).

But if you compare the plant stink bug to my first example of a stink bug in the second post, you can see how very similar they can look. Both are brown and both are shaped like a sheild. I'll post the picture again here to make it easier. Those who don't mind skipping back up can ignore the picture.

I mostly chose the Reduviidae for the second comparison, because both are in a sideways view (the usual view you will get of their "beaks" if they aren't eating prey), but I should have pointed out that they are not both stink bugs.

And thanks, patischell. Of course in my enthusiasm, I tend to forget to state the important things - like with the examples above - which explains why I am NOT a teacher. That is too organized a career for someone like me - hee. And don't worry, I'll make things even more confusing when I start introducing other predatory bugs that don't always have the fat "beaks." These are identified by their unique looks only. Then we'll really see if I'm good at this or not - hee.

So to clarify - this again is the predatory stink bug (family Pentatomidae). Note the distinctive "sheild" shape that most stink bugs have. And of course the stout, short beak sticking into the caterpillar. Then see how this is similar in shape and color to the plant stink bug five posts above. The main difference is in the beak (which sometimes means you have to get VERY close or even pick the bug up - use gloves if there's a concern, because some predatory bugs may bite if scared - so this may not always be for the faint of heart) and of course in what it eats, which if you are lucky, it will be doing, so as to make your life easier in trying to tell if it's a good or bad bug.

Sorry I couldn't get a close up this time. This computer does not let me crop photos like my computer does. Scroll up to the top if you need to.

This message was edited Apr 29, 2005 2:46 PM

Hi Night_Bloom! This is fun! I didn't go out and take pics like I threatened to, it's actually raining again here in Los Angeles, I love it! Actually makes it seem like a nice place to live! :-> As to the red spider, it's not a centipede, it looks more like the mite that you posted, but I suspect it's bigger, maybe about 1/4 inch with the legs, and looks even more like a spider. It has that wet, transparent kind of bright red look, and it lives under the soil, I only see them when I dig them up. They look dangerous, I guess because of the color. There's another thing that I dig up all the time too, it's big, like an inch or inch and a half with the legs, brown, wet looking too, big legs, big brown body, UGLY!! Sometimes I've found them in the house too, but mostly they live under the soil. I'll take my camera with me this week while I'm planting, maybe I'll be "lucky" enough to dig one up. Yuck!! And I'm with you on tending the garden. If the plants can't get along without me babying them, then tough luck! This year I've planted about 10 antique roses for that very reason. A lot of bang for my lazy buck!

Hi Night Bloom,

Thanks to this thread I went out and inspected my plants. Everything was going great until..... leaf curl on the Viburnum. Bugs and white "fibers" inside the curled leaves. Are these aphids? I know that is not much to go on:) What do you think?

-Kim

Not aphids, Kim, but I'm not sure what they are..... but since the leaves are curling, I'd guess they are *not* good guys! If it's just a few leaves, you could probably pick off the affected leaves.

bluekat, I can't be sure, but it might be phylloxera (family Phylloxeridae). They can cause "galls" (not quite true galls in some cases, because they aren't always closed) on leaves and are sometimes associated with waxy, fibrous balls inside the galls. I don't unfortunately have any pictures of the waxy, fibrous balls, but I do have a microscope picture of a phylloxera gall. This one is a stem gall so yours will look a bit different if this is what you have, but this is what the critters look like anyway.

Other things that might cause leaf curl are thrips and mites... Mites might have "fibers" asscoiated with them if they are spider mites. The fibers look like spider webbing. Thrips shouldn't have any fibers that I know of. I would try searching for information and images of phylloxera first and go from there.

If it is Phylloxeridae, they are related to aphids, so a systemic such as imidicloprid (like Bayer Advanced) will work well and be low impact on other critters. (it should also work on the thrips. The mites, however, probably not.) If you really want to be sure, take some leaves to the local extension office and tell them what things you suspect. They should be able to confirm what you've got.

Since we've been talking about lacewing nymphs, I thought I'd include a picture of another type of lacewing nymph. This one does not use a "trash pile" to conceal itself, and though it is small, up close it looks fearsome, especially to the aphid it has caught in its jaws.

And here's a picture of what a nymph of the predatory stink bug above looks like. Note that it still has the sheild shape of the adult, but it doesn't have wings yet. Like many nymphs of the predatory stink bugs, this one has spots of color. Some species of these nymphs are gregarious which means there can be a whole "flock" of the little critters which of course often makes it look like they are up to no good.

This is what a younger nymph of the predatory bug above looks like. In this case, the nymph is eating a Chrysomellidae, a leaf beetle. This nymph, like the drab brown predatory stink bug above, is called a spined soldier bug.

Night_Bloom,
great idea for a thread. Thank you. Here's my friend or foe question:

they're spiderish little guys.
size: up to 1/4". As small as 1/10th" or so.
legs: I think they've got 6 (black) legs - could be more.
color: most are a dull red (not firetruck red). Some are tan.

I can't do a real close-up with our camera. They congregate like this (and on *this* plant in particular). I saw them last year too. They're on about 3 plants like this, and not on the rest.

they're always moving but don't seem to roam. Drop off the leaf easily if you pick it up etc.

hope this and the pic will be enough to id them.

Night bloom - they don't look like your picture but they do sound like mites. They look like tiny dots with legs. I am going by the extension office tomorrow so I will bring a leaf or two. I did spray with some generic ortho mix the other day.

-Kim

paani - I'm pretty certain those are aphids. The "tan" ones you describe might have been aphid "mummies" - see the picture and explanation above, 16 posts up.

The "dropping off" behavior is common for aphids. They often give off an "alarm pheremone" when disturbed, warning the rest of the aphids of trouble. Sometimes when a lady beetle gets one, it will give off a pheremone - sometimes seen as a drop of clear liquid at the back of the captured aphid - and other aphids around it will drop off the leaf to escape the danger.

That same post 16 posts up has some advice on what to do about the aphids. Depending on if they are affecting the plant - i.e is the plant wilting or loking sick - I generally adopt a wait and see attitude. Usually lady beetles and lacewing nymphs come along and take care of the problem for me before I have to spray, and if you do end up seeing aphid "mummies" that's a good sign too.


bluekat - if the Ortho spray had bifenthrin as the active ingredient, it might do for mites. Mites are tricky and some insecticides don't work well on them. Good luck and please let me know whether they are phylloxera or mites when you find out. You've got me curious now.

"spiderish" does sound like mites, but that photo looks more like aphids. Bad guys (unless they are unmoving, parisitized aphid "mummies" as in the photo Night_Bloom posted). Sometimes, just knocking them off the plant with a stream of water from the hose is enough to discourage them, otherwise a little spray of insecticidal soap should do it. They have their favorite plants in my garden too!