Friday Beetle Blogging: Palo Verde Beetle

Derobrachus hovorei - Palo Verde Borer


Tucson, Arizona

Every June, hundreds of thousands of giant beetles emerge from beneath the Tucsonian soil. The enormous size of these beetles- up to several inches long- makes them among the most memorable of Tucson's insects. They cruise about clumsily in the evenings, flying at eye level as they disperse and look for mates.

Palo Verde beetles spend most of their lives as subterranean grubs feeding on the roots of Palo Verde trees. Adults emerge in early summer, usually ahead of the monsoon, and by August they are gone.

It is still a bit too early in June to see them, but in anticipation of this year's emergence I am posting photos I took in 2006.

photo details: Canon 100mm f2.8 macro lens on a Canon 20D

top photo: indirect strobe in a white box

bottom photo: natural light at dusk

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This beetle is now called Derobrachus hovorei. It was recently discovered that the name geminatus actually refers to a less common species we had been calling D. forreri.

Damn taxonomists ;-)


im no entomologist, but i have studied these beetle in my own backyard in east mesa for 15 years.there is only a little info on them as far as i can find. but i have found 1 VERY interesting observation. from the first day ( or usualy night ) that i see a p.v. bug it it approx. 2 weeks until our first monsoon storm. this has been true every year for at least the last decade that i have been tracking them.

today i noticed the formation of the monsoon clouds in the eastern sky, sneaking up on us from the south and east in mesa. i just saw my 1st p.v. bug last night in my pool while my kids were having a summer party. one of my accounts (im a bug man) noticed the bugs in their pool the other day.

so i would say our first monsoon storm should be approximately july4th. maybe i could get a job for fox news as a weather forecaster!.


chris h. in mesa

I have no palo verde trees, however I have the beetle in my house during late June and July. Does anyone know what I should do.


By john blackwell (not verified) on 28 Jun 2008 #permalink

I have a 9 month old puppy who is actually eating palo verde beetles and I know they bite. Any one know of any known problems related to ingestion?

what do they eat i have been catching them for ever but i cant any bug they like to eat i have tried june bugs, small lizards, but i dont know what to do

Warning: These bugs can bite! One flew onto the tennis court and I tried to push it to the side with my racket so it wouldn't be hurt. The bug bite through my string, which is pretty tough stuff.

By tennis player (not verified) on 15 Jul 2008 #permalink

Can't say I enjoy the presence of these bugs every year, and yet they do seem part of what makes the Sonoran Desert special.

Smart reply by Chris in Mesa about the approx 2-wk-prior-to-rains appearahce of these beautiful monster bugs. Thanks for the observation, and I'll do that myself from now on.

Also, I've been bitten: yes, they have a memorable bite, not anything that a little swipe of peroxide can't handle.

What form do they exist in underground? Are they involved now in mating and laying eggs? What does their immature form look like?


By Emma Hardesty (not verified) on 23 Jul 2008 #permalink

I find alot of these here in Los Lunas, NM. I've been observing one in my garage that had just layed eggs. Quite a spectacle watching it. I can tell you that the eggs appear to be about half the size of a grain of rice with the same appearence but they are very yellow.

i used to catch them when ia was a kid. I can tell you, if you need to handle one to grasp firmly behind their heads to avoid a nasty bite. one they get you they hold on.

fun to catch and watch.


I just found one of these beatles in my backyard... the thing terrified me, and I quickly went inside. I am starting a timer on monsoon season, but I can't be certain this is the first one of the year, it is however the first one I have seen in a quite bug filled year.

I found 4 of these beetles on my front porch last night, same day "scared" found them, I am highly curious about the monsoon timing, and I am as well going to start a monsoon timer assuming that 2 weeks will elapse or close to it before the first mega rains. This bug is really scary looking, but its so oafy and goofish in its movement I can't imagine how you could not like it! What a HUGE beetle, I am from Colorado, and have never seen something to the likes of a P.V. Beetle!

I am guessing 12 days until monsoon!

By Sighting in SO… (not verified) on 24 Jun 2009 #permalink

My wife and I saw one last night on our patio wall, after it rained here in Tucson. It was the biggest bug that either of us had ever seen! I ran in to get a camera to get a picture of it, but it crawled over the wall before I got back. We didn't know it was a Palo Verde until we searched on the internet tonight and found this site. Thanks for the tips, we are turning our lights off right now! It rained again today (26th) in Tucson and it's really humid, so maybe the monsoon is already here.

By Ultrashort (not verified) on 25 Jun 2009 #permalink

I have seen a lot more of these bugs, seems that they are coming out of their underground homes now. The recent sightings have not been as invasive as the first one, so I am not as terrified, I am soon to get a picture to post on here I love this website. Thanks to the OP for the info, and all the others here. It did rain today in Tucson (I live in Tucson) no monsoon but they might be upon us. My timer is on though until I see "big ole fat rain"

I finally got curious after a few years of seeing these critters during monsoon, so I googled them. They eat off of Palo Vede trees that are weak and dying and they do live under ground and are attracted to the light. I know it is not much info, however, these things scrare me to DEATH! I usually get 2-3 a week on my front screen b/c of the light. I literally freeze in fear and have my husband get rid of it before I get out of the car and go in the house. Ugh, so scary... Any ideas on over coming this fear? I won't be going outside after dark during monsoon... Crazy, I know.


Phoenix, AZ

By Freaked out! (not verified) on 26 Jun 2009 #permalink

I just found one tonight for the first time ever! My dogs had it in their mouth, we captured it because my kids wanted to see it. We will let it go tomorrow, but these things are amazing! This one is HUGE!!!

Hello, I'm 19 years old and live alone in a studio apartment, I seem to be having an infestation of these palo verde bugs. I just saw my second one and I am deathly afraid of bugs, so you can imagine my terror. I have the second one trapped in a glass and the first one i saw about a week ago i killed. I feel terrible because when i squashed it a bunch of eggs came out, but I cannot deal with the thought of waking up with one of these bugs in my bed. But I know they are basically harmless if you dont bother them, So I was wondering if theres anything I can do to keep them away.??

I have 2 cats and i would think they would stay away because of the smell but it doesnt appear to scare them at all. I saw the suggestion about the lights but i rarely use my porch light and I have no windows in this apartment beside the sliding glass door to the backyard.

Any suggestions or tips would be amazing thx

Hey I just caught one of these amazing beetles. I was thinking about keeping it as a pet. Its a full grown beetle, the length of an adults index finger and half the girth around. How cool! Looks like they only eat Palo Verde roots though, so I'll have to let it go soon if I can't find it a healthy subsitute. Monsoons must be on the way. These bugs emerge right before the monsoons hit. It rained last night, I definitly think that the D.H. Beetle was no coincidence. The rain is coming here soon. I live in Tempe AZ, and have always wondered what the heck these things are! They truely are clumsy, but thier pinchers which are around the size of a pencil eraser all together, look pretty scary, but thier intenna are so cool! My husband never likes the idea of me keeping bugs in the house, but what he doesn't know won't kill him. :) I'll probably have to let it go soon anyways. If you know of any way that they eat other things it would be very helpful.

You may want to take a can of raid for beetles, and spray just around your door frames, also bend down and look at the bottom of your front door. Can you see any light from the other side? Its really important to get a good door flap on the bottom of your door so that no scorpions or beetles, or saddle roaches sneak in. Raid helps though. So does taking a capful of bleach and dribbling it around the door frame on the bottom. DEFINITLY will keep away roaches. They can't stand the smell.

Looks like those clouds are brewing. I am seeing the Palo Verde Beetle more often now, almost 3-4 times a week. I live in Tucson and can see that the clouds are starting to move closer and closer ever so slightly every day. I keep my distance but really they have started to intrigue me.

By Monsoon Watcher (not verified) on 02 Jul 2009 #permalink

These things are tough! You can step on them with all your weight and it will only stun them. The best way I've found to exterminate them is by repeatedly smashing them with a brick, though it still only works about 3/4 of the time. It makes for a fun challenge though. I think my next attempt is going to be a flame thrower, maybe a lawnmower.

I'll have to try to keep my tree healthier so they won't come back next year.

Sorry, but I can't share the joy in finding one of these creatures on my patio last night! Have been in AZ for 21 years and this is the first one I have seen up close and personal. If I had this experience 20 years ago - I would not have stayed.

So - questions.....

Do these bugs make that horrid hot weather bug noise? At least one could brace themselves for an encounter!

Could this possibly be feeding off of a distressed cactus? Or, could it have caused my cactus to suddently become distressed?

Are they attracted by palm trees? I don't see any palo verde trees around me but my neighbors are loaded with palm trees - trunks are not trimmed.

For Sammy - I had a can of Terro Scorpion Killer2 (purchased due to a sudden influx of scorpions which I never had encountered until last summer). It has a nice little applicator attached (similar to the WD40 straw only it quickly flips up into position) so you can direct the spray without getting too close. It killed him. Of course, I sprayed him with so much it might have drowned him but he did eventually die - which was the goal, no matter what the cause.

Another tip, Sammy, keep a spray bottle of Lysol cleaner with bleach handy. It kills roaches almost instantly. And, try the folks at Bug & Weed Mart if you have serious problems.

By Bugged Out (not verified) on 06 Jul 2009 #permalink

The immature form is the white grub pictured. In early June I dug up an intermediate form. This was a beetle in the front part and a grub in the back half. It was still white and not black like the adult.

By William Scott (not verified) on 08 Jul 2009 #permalink

Some Observations:

I have lived in the Tucson area for 7 years now and have noted the following:

1. The first 'pioneers' of these beetles do seem to come out about 2 weeks before the first good rain of the monsoon season. This usually means mid-June.

2. The evening after the first ground soaking rain will trigger a mass exodus of the adults from their underground tunnels. These tunnels are vertical and go about 6 inches underground. They are about 1 inch in diameter which is the size of a quarter.

3. They will eat and kill a non-native cactus. I have seen my non-native ornamentals killed year after year by the larvae of these beetles.

4. The worst place to plant a non-native plant is under a tree.

5. The best place to plant a non-native plant is in the open.

6. I have taken to using a fine mesh cage around my ornamentals such that the adults can not fly or crawl thru it.

Does anyone know if these beetles have any predators? They are too big for the lizards and even the birds to eat. I doubt a snake would be interested in an insect.

By William Scott (not verified) on 08 Jul 2009 #permalink

I think the hot weather bug noise you're referring to is caused by cicadas. If it's an incredibly loud rattle, it's cicadas.

I've never heard PV beetles make any sound. And we get a ton in our backyard every year. Apparently, our backyard is the idea place for them to get it on.


I would recommend carry a can of bug spray the shoots 3-6 feet so you do not have to get close to them and chance them flying at you. I killed my first one last week. I went outside to move my trash can out to the street and when i came back, there was one about 2.5 inches cruising around my porch. I totally freaked out but kept a level head, ran inside and got the raid. I used half a can of raid of it and he was dead. I do not like to step on them b/c of the eggs and mess. YUCKY! So, I carry a can of bug srpay with me at all times.

Hope this helps...


By Freaked out! (not verified) on 09 Jul 2009 #permalink

That spray is axactly what I used as well with the little straw that comes out and shoot in a stream.

By Freaked out! (not verified) on 09 Jul 2009 #permalink

I live in Buckeye and found my first one! I'm originally from MI so seeing any bug this size real life was exciting. My hubby saw it on the patio trapped in a black widows web. We thought it was dead. I went out with the camera and started poking around to find out it was still alive. I freed it from the web and let it go over the wall. How amazing!

By Geckogirl (not verified) on 16 Jul 2009 #permalink

I work at a school in Phoenix. I noticed these bugs around our campus this summer as all of the kids are gone. They are in the classrooms and in the bathrooms. they are HUGE and very loud in the trees. I have to say, as an adult woman, I turn into a little squealy 5 year old becuase they are so big and creepy! They are all dying everywhere so I kind of feel bad for them but I didnt know that they could fly so that makes it even more scary! I am having an exterminator come out today to hopefully take care of them. I wish no death on any bug but good lord, do they have to be so big and scary??

By Mellissa R (not verified) on 21 Jul 2009 #permalink

I wish I could share the amazement with all of you! But, all I want to know is how to get rid of the damn things! Smashing them is not an option for me!


I called an exterminator and they said becuase they are flying bugs, they do not cover these types of bugs. I don't know if he meant that they just dont mess with flying bugs or if they don't have anything to kill them. He said then that their lifespan is almost up and that they should all be dying soon once they surface anyways. OK, so I didnt like that answer at all but I guess I have to figure our how to avoid them. Ugghhh, gives me the creepies just thinkin' about em!!!


By Mellissa R (not verified) on 23 Jul 2009 #permalink

I use a can of bug spray. I spray them until they are on their backs and then I put a small pot over them and they die. I hate smashing them too. I carry my spray everywhere!

By Freaked out! (not verified) on 23 Jul 2009 #permalink

I just found one of these in central phoenix home OMG! I am from flagstaff and am not familiar with this type of bug. I went to work after I took a picture of it asking is this going to hurt my lil boy!?? And thanks for your posts they were much help. I can share photo with if you would like... Also funny to see that it seems they are mostly to Tucson and here in phoenix I found one?!

They are freaky looking! I would love to see the picture of the one in the Central Phx home.

By Anonymous (not verified) on 23 Jul 2009 #permalink

Well, they must commute by air! N.L.V. NV. is one helluva walk!

They do commute by air! They look like little humming birds, or sparrows flying through the air. I can't wait until the monsoon season is over. I love the rain, but HATE the bugs. I have no "amazement" for these things either. When I see one, it must die. I spray it with bug spray and I carry the spray with me at all times.

By Freaked out! (not verified) on 24 Jul 2009 #permalink

I just found one of these bugs in Northern California. Can't figure out how/why it would be this far north?? By north I mean we are only 15 minutes from Oregon, right on the ocean.

We are building a lodgepole pine house and the bug was hanging out on one of my porch logs. Does anyone know if they always bore underground to get to the tree roots, or might they bore into my house logs as well? None of the wood for our house is touching the all sits on a concrete foundation at least 2 feet off the ground.

I also wonder if I should be looking for more of these bugs, or if it is just a fluke that this one is here?? Do they travel in packs?

Just stepped on and smashed TWO of these bugs!! I had no idea what they were because I was outside in the yard at night and I heard something drop from the sky. I could tell is was some kind of black bug but didnt know what. Once I stepped on it...ANOTHER ONE fell right there in the same place! eww these things are gross! Thank Goodness for Google because I had NO clue what these things were! Seems as if there in Surprise AZ also!! Happy hunting recommend a tough sneaker, these bugs are HUGE!


I live in Las Vegas and encountered one of these three nights ago while I was taking some pictures of the cicadas. This was about 2 AM. We saw one last year too in our front yard. And yes, that buzzing noise we all hear in this area and others are from the cicadas. People in Las Vegas think it's locusts...ha ha. Anyway, it was a big Derobrachus hovorei beetle! I measured it at over 5 inches long. They are one scary and huge beetle. It took every ounce of nerve, bravery I had to get close enough to measure it. And yep they bite!! Boy do they bite and hard--and pretty quick too :) I still have a mark on my finger.

Love your blog--really fantastic photos and information :)

I just discovered the existance of these bugs approx. 4 days ago when my cat brought one into the house and let it go... I thought it was a sewer roach until my dad informed me otherwise.

I was intrigued though to hear that they only come out in July and August and that my cat found one in October. We have sort of heated up-- could that be part of the reason?

Well I am in Barstow cali and found one of the P.V. in my garage last night, My brother let it loose in the street and tonight found eathier the same one or another one they are freaky looking. I have spent atlest a couple hrs looking up this beetle. It was a female I guess it hisses ( screams) I did take some pic's I will put some up here if I can tomorrow. It was freakin huge!!!!!!!!!!!!!!!!!!!!!!

I grew up playing with these beetles(I'm 60) but never got bite untill this weekend when I grabbed one and it bit me on the palm. It didn't break skin but the joints in my hand swelled up for 2 days. It hurt! Almost like a mild venom? anyone else ever get joint swelling?

By Jim Floyd (not verified) on 04 Aug 2010 #permalink