Friday 5: Recent Bug Photos (Briefly)

Due to a death in my family a few days ago, today’s Friday 5 is going to be short.  I’m out of town and don’t have access to my main hard drive, so it’s a little tough to do a good post anyway.  However, I have taken a ton of bug photos recently, largely as a way to stop thinking about sad things for a little while, and I have my cameras with me.  These are 5 of my recent favorites.

This beetle (the ten-lined June beetle, Polyphylla decemlineata) has been out in force in Flagstaff, AZ the last few nights.  Hundreds of them have come to the porch light each night.  They squeak when you pick them up too!  Pretty fun distraction.  This isn’t the most technically precise photo of the bunch I took, but I love the look of his (or her – don’t know why but I call all animals “he” until I know better) face:

ten-lined June beetle

Ten-lined June beetle, Polyphylla decemlineata

Okay, so you’ve seen several photos of palo verde beetles recently, but photographing them was a joy for me.  Hence, another Derobrachus hovorei:

palo verde beetle

Palo verde beetle, Derobrachus hovorei

A damselfly from Flagstaff, AZ.  It’s probably a plains forktail (Ischnura damula) or pacific forktail (I. cervula), but I honestly haven’t put much effort into IDing it yet.  Identifying a random damselfly hasn’t even come close to the top of my list of priorities lately, and I’m not great at IDing adult damselflies anyway:

Forktail damselfly, Ischnura sp.

This beetle (along with palo verde beetles) always makes me think of summer in Tucson, AZ.  This is a fig beetle, Cotinis mutabilis, aka my June bug:

fig beetle

Fig beetle, Cotinis mutabilis

Finally, I have no idea what this long-horned beetle is and haven’t even begun to try to ID it, but I thought he was just lovely.  And look at those long hairs on the abdomen!  He was sitting under the porch light at my house in Tucson earlier this week:

Longhorn beetle

Long-horned beetle

This may be my shortest Friday 5 yet, but it’s the best I can do.  Hope you enjoyed the pretty bugs!

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Unless otherwise stated, all text, images, and video are copyright © TheDragonflyWoman.com

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Palo Verde Beetles

It’s that time of year again!  Time for the palo verde beetles to descend on Tucson and fill the night sky with giant beetles flying around drunkenly looking for mates.  I already wrote a post about how much I love these beetles and promised to write more about their biology.  Today I am making good on that promise!

Meet the palo verde beetle (or palo verde root borer beetle), Derobrachus hovorei:

palo verde beetle top view

Palo verde beetle

I think these beetles are one of the best parts of living in the Sonoran Desert.  Each summer when the monsoons begin, these beetles start to appear.  They’re large, dark brown nocturnal beetles, 3 – 3.5 inches long.  Check out the long, luxurious antennae:

palo verde beetle antenna

Palo verde beetle antenna

Palo verde beetles belong to the beetle family Cerambycidae, the longhorn beetles.  You can see how the family got its common name!  Nearly all members of the group have these long antennae, including several important wood pest species (such as the Asian longhorn beetles).  The palo verde beetle is no exception.

I think the palo verde beetles look rather fierce.  Check out the spikes on the thorax:

palo verde beetle thorax

Palo verde beetle thorax

And the big pinching mouthparts (called mandibles):

palo verde beetle jaws

Palo verde beetle jaws

In spite of their size, their armor, and the powerful jaws, these beetles are largely harmless.  That’s not to say that they won’t flail about wildly and try to bite you if you pick them up, and they can deliver a strong, painful pinch if you’re not careful.  (That’s never stopped me from picking them up!)  Mostly though, the beetles use those impressive mandibles for fighting and/or mating.  I posted a photo of a male and a female palo verde beetle struggling with each other before they mated a while back and jaws were used extensively as the male subdued the female.  In fact, she lost a leg and both antennae in the struggle.  Those strong jaws are also used by males in battles with one another to win females.  The better fighter a male is, the more females he has a chance to mate with.

There’s one thing the jaws aren’t used for though: feeding.  Adult palo verde beetles don’t feed at all and rely on nutrient reserves they ingested as larvae to fuel their adult activities.  As result, their adult lifespans are pretty short, less than a month.  During that month, they fly around (not very well and in the dark – there’s nothing quite like seeing one of these flying toward your head at night!), fight, mate, and lay eggs.  That’s a lot to do for a large flying animal that doesn’t eat!

Once a male finds and mates with a female, the female will burrow into the soil at the base of trees and lay her eggs about a foot down.  When the eggs hatch, the larvae feed on the roots of the trees, focusing on the starches within the roots.  After 2-3 years of feeding and growing, the larvae are enormous and look like this:

palo verde beetle larva

Palo verde beetle larva! This one was over 3 inches long.

The larvae have strong and powerful mouthparts too, essential for cutting trees roots open so they can eat.  When they’ve grown large enough, they pupate underground.  The adult emerges when the monsoons arrive and dig their way up to the surface, leaving large round holes around the base of the tree where they grew up.  Then they go about the serious business of flying around in the dark (scaring a lot of people in the process), looking for mates, and starting the whole process all over again.

Palo verde beetles get their name from the palo verde tree, a gorgeous desert tree with green bark native to the Sonoran Desert.  If you dig up palo verde trees, you will supposedly nearly always find several palo verde beetle larvae happily munching away on the roots.  Because they are root borers and root borers are commonly associated with dead, dying, or unhealthy trees, palo verde beetles are often considered pests.  If you search the internet, you’ll find all sorts of crazy ideas for how to rid your yard of these “dangerous” beetles so that they don’t kill your trees.  It all a bit sensationalistic though!  Palo verde beetles DO eat roots of trees, but consider this: there are millions of palo verde trees in the Sonoran Desert and nearly all of them have several palo verde beetle larvae gnawing on their roots.  If the beetles are really destroying tress, wouldn’t there be fewer palo verde trees around?  Palo verde beetles can cause some damage to trees, especially non-native ornamentals, but usually only in trees that are already having problems.  The best defense against palo verde beetle damage is taking care of your trees!  If you keep young trees healthy by watering them regularly and fertilizing, they will usually be able to withstand palo verde beetle larvae eating their roots quite well.

While I completely understand why people might be scared of these lumbering, giant beetles – they are VERY large after all – I can’t help but love them!  I associate them with lazy, hot summers and the arrival of the much-needed rains.  They’re hilarious to watch flying around.  And they’re stunning!  As proof, I leave you with this last image:

Palo verde beetle side

Palo verde beetle, side view

Love ’em!

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Unless otherwise stated, all text, images, and video are copyright © TheDragonflyWoman.com

Palo Verde Beetles – An Appreciation

One of my earliest memories involves a giant insect.  If you’re one of the few people who’ve read my blog from the very beginning (and you, my friends, are amazing!), you already know about my unfortunate run-in with this beetle:

Palo verde beetle

Palo verde beetle (Derobrachus hovorei)

For those of you who haven’t read the story, it goes like this: Imagine a 4-year-old girl in a cute little sundress sitting on her backyard swing, the one her father created from a smooth board and some rope slung over a strong tree branch.  It’s dusk.  She’s happily swinging, maybe humming a little, when suddenly a monster falls out of the tree and lands on her shoulder.  It’s a 3 inch long, black beetle, one with massive jaws, spikes adorning its strong thorax, and sharp claws at the tips of its long legs.  It lands inches from her exposed neck.  The girl jumps off her swing and starts running around the yard, screaming her head off like any self-respecting 4-year-old girl does when a 3 inch long insect appears on her shoulder.  Eventually, one of her parents rushes into the yard to see what is going on, brushes the beetle from her skin, and takes her into the house to safety.

I have a very, very vivid memory of this incident, even though it happened so long ago.  The beetle did frighten me horribly when it fell onto my shoulder that night, but it was mostly from the shock, the beetle having magically appeared on my shoulder as if out of thin air.  For some reason, apart from this one moment of weakness (and let’s face it – ANYONE who has a large, 3 inch long peevish beetle fall onto their shoulder unexpectedly is going to be shocked for at least a moment), these beetles have fascinated for me as long as I can remember.

Palo verde beetle (Derobrachus hovorei)

Palo verde beetle (Derobrachus hovorei)

Palo verde beetles are gigantic and very scary to a lot of people who encounter them.  It’s wholly understandable that people might be a little squeamish of a 3 inch long, well armored beetle.  It probably doesn’t help that they’re also nocturnal and emerge from the shadows when you least expect them.  They’re so big that you can hear them walking before you see them, an audible harbinger of doom warning you before the beast appears.

But I love them still.  I can’t explain why exactly, but I do know that if you have a chance to watch these beetles they become vastly less intimidating.  Palo verde beetles are so large that they are very poor fliers.  They bumble around in the air, swooping and swerving this way and that.  They always look a little drunk when they fly.  As a child, I used to love watching them try to fly through our chain link fence, only to knock their heads or wings into one of the metal parts and fall to the ground, dazed and momentarily disoriented.  Often, they would fall on their backs and their legs would flail around in the air ridiculously as they tried to right themselves.  To this day, I enjoy watching these beetles moving around.  They smack into walls and cars and the sidewalk.  They trip over their own feet at times when they walk.  Even though they’re big and scary to look at, I love them in part because they’re hilarious to watch.  There’s something so comic about these hulks tripping all over their gangly bodies like teenagers who haven’t quite adjusted to their most recent growth spurt.

Palo verde beetle (Derobrachus hovorei)

Palo verde beetle (Derobrachus hovorei)

Palo verde beetles are inexorably tied to “home” in my mind as well.  I have hundreds of memories of these beetles from my early childhood and they eventually became a sort of symbol of my desert home for me.  I was very sad when I learned that Colorado didn’t have these beetles when we moved there.  Imagine a 9-year-old girl longing for a giant beetle!  But Arizona was always home to me, no matter how long we lived in another state.  When we came back to Arizona to visit my grandparents for the first time, about 7 or 8 years after we moved, I was absolutely thrilled that the very first insect I saw was a palo verde beetle, wandering along under the door to my grandparents’ guesthouse.  I don’t recall ever having picked one up as a child, so I didn’t realize they could bite until I watched the angry beetle clamp his jaws onto my grandfather’s hand as he scooped the bug up for me.  My poor, ailing grandfather cried out in pain because the beetle bit him.  I gained a new respect for these beetles that day.  But, I was still very happy when I moved back to Arizona and saw my first palo verde beetle.  I mistook her for a pack rat at first because she was so enormous.  I could barely believe it was possible for a beetle to be that big, but there she was, running along the wall of the apartment complex as I watched, the biggest insect I’ve ever seen.

Palo verde beetle (Derobrachus hovorei)

Palo verde beetle (Derobrachus hovorei)

The palo verde beetles are also a symbol of summer to me.  The summers in southern Arizona are rather miserable.  Temperatures of 110 degrees F are not uncommon and there is a long dry period of unrelenting sun and heat for a few months before the monsoons set in during the late summer.  The beetles start to come out during that hot time, when people just want to melt into their couches and never move again.  For me, they brighten an otherwise unpleasant time immeasurably.  I squeal with childish delight every year when I see my first.  Against my better judgement, I rush over to grab the beetle – carefully, by the abdomen directly behind the thorax.  As the beetle illustrates his displeasure at my interruption of his evening by thrashing around in a mad attempt to bite me or skewer my fingers with the spikes on his thorax, I carry him into the house as proudly as a hunter bringing home a 12 point buck.  I wave the giant beetle in front of  whoever happens to be in the house at the time and ramble on and on about how fabulous they are.  Then I snap a few photos and release him back into the yard, so he can continue flying drunkenly about the city in search of mates so that I can do it all over again the following year.

Palo verde beetle (Derobrachus hovorei)

Palo verde beetle (Derobrachus hovorei)

I really don’t know what it is about these beetles that I love so much.  They’re big.  They’re rather  ill-tempered and can have a nasty mean streak if you interfere with their business.  One of them frightened me as young child.  By all rights, I should hate these beetles.  But I don’t.  I find their presence near my home a cause for great joy.  I celebrate their return every year.  It makes me so happy to know that they’re out there, that I might find one crawling sluggishly around my front door one night as I run out to chuck a bag of trash into the can.  A whole day might turn around simply because I see one of these beetles.  A few months from now, I’ll be carrying surly beetles into my house to photograph them, to document their continued existence, and then let them go on their way again.  And it will make me happy, just like it always does.

I had intended for this post to focus on the natural history and lives of the palo verde beetles, but it has clearly turned into something else.  Someday I’ll share more information about their biology.  Today I wanted to share my appreciation for these magnificent animals.  Hope some of you will appreciate them with me!

Palo verde beetle (Derobrachus hovorei)

Palo verde beetle (Derobrachus hovorei)

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Unless otherwise stated, all text, images, and video are copyright © 2011 DragonflyWoman.wordpress.com

Wordless Wednesday: Beetle Battle

Last summer I found a male and a female palo verde beetle (Derobrachus hovorei) on the same night (hooray!) and decided to photograph them together:

palo verde beetle battle

Palo verde beetle (Derobrachus hovorei) battle of the sexes

In the flurry of motion that ensued moments after putting them together, during which time this photo was shot, the female (on the right) sadly lost both antennae and two entire legs to her overeager and highly abusive suitor.  This image was captured in the heat of the battle.

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Unless otherwise stated, all text, images, and video are copyright © 2011 DragonflyWoman.wordpress.com

All bugs are insects, but not all insects are bugs

I have always called insects bugs.  I know I’m using the wrong word most of the time since the word bug refers to a specific group of insects.  If I’m not talking about that one group, using the word bug instead of insect is technically incorrect.  If you’re around many entomologists , using the word bug to describe an insect that is not actually a bug is like scraping your fingernails down a chalkboard – highly annoying.  I don’t know. I’ve always found this attitude somewhat pretentious and counterproductive.  As an entomologist myself, I like to promote insect awareness and get people interested in what I do.   It’s hard to get people interested in what you do when they feel belittled because you corrected them for using a word they didn’t even know was wrong.  I use the word bug for all insects, even though I know I am wrong to use it most of the time (and yes, I have been corrected by other entomologists myself!), for several reasons:

1) It’s easier to say bug than insect.

2) I find people relate better to stories about bugs than stories about insects, especially when they know I’m an entomologist or if they are kids.

3) I happen to work with insects that are, in fact, bugs.  When you constantly use the word bug to describe your work, even in scientific papers, you get in the habit of using the word bug all the time.

Really, though, how many people who aren’t entomologists know the difference between an insect that is a bug and an insect that is not?  It’s a subtle distinction and most people don’t have any reason to learn the difference.  For those of you who don’t know what makes a bug a bug, allow me to enlighten you!

The insects are divided into about 25 smaller groups called orders.  All insects belonging to an order share certain traits, which is why they are grouped together in the first place.  A bug is an insect that belongs to the order Hemiptera.  Members of the order Hemiptera are also called true bugs, hence the word bug.  If you’re being technical, only insects that are true bugs should be called bugs and everything else should just be called an insect.  But how do you tell a true bug apart from other insects?  All true bugs share two main traits: hemielytra and piercing-sucking mouthparts.

The word hemielytra refers to the specialized top pair of wings (forewings) of the true bugs.  Most insects have 4 wings and true bugs are no exception.  Some insects, like beetles, have hardened forewings that protect the more fragile hindwings underneath.  These are called elytra.  Take a look at this palo verde beetle’s elytra:

palo verde beetle

A beetle. The arrow points to this beetle's elytra.

The true bugs have hemielytra, not elytra.  The forewings of bugs are only hard for part of their length instead of the entire length.  The upper part is thick and leathery and the lower part is membranous, about the same texture as the hind wings underneath.  Look at the forewings of this giant water bug and look for the differences in these wings compared to those of the beetle pictured above:

Lethocerus

Giant water bug. The arrow points to the hemielytra.

See the dark section of the wing toward the back end of the bug (to the right of the tip of the arrow)?  That’s the membranous part.  The rest of the wing is the thickened, leathery part and a completely different texture.  True bugs often have a sort of V-shape to their wings.  See the V just to the left of the tip of the arrow?  For the most part, if you see this V-shape in the wings of an insect, you’re looking at a true bug.  (Note: I’ll talk about that big, long piece sticking off the back of the giant water bug in a future post.)

The other trait that all true bugs have is piercing-sucking mouthparts.  Different insects have different types of mouthparts, but most people are familiar with insect chewing mouthparts.  This is what caterpillars, beetles, and grasshoppers have.  They use these mouthparts to grind their food up before swallowing it as the first step in digestion.  Look at the chewing mouthparts of the palo verde beetle:

palo verde beetle head

Palo verde beetle head. The arrow points to the chewing mouthparts.

Palo verde beetles have really big mouthparts that are easy to see.  These things can actually bite quite hard, even drawing blood if they get you in the right place!

In contrast, true bugs have piercing-sucking mouthparts.  Instead of putting food into their mouths and grinding it up the way beetles do (and humans too!), they inject digestive chemicals into whatever they want to eat using their mouthparts (hence the piercing part of “piercing-sucking mouthparts”).  These chemicals break the food down into a soupy mess which the bugs then suck into their mouths through their mouthparts (that’s the sucking part of “piercing-sucking mouthparts”).  It’s a lot like eating your food with a straw!  Check out the mouthparts on the giant water bug:

true bug bealk

Giant water bug mouthparts. The arrow points to the piercing-sucking mouthparts.

The piercing-sucking mouthparts of true bugs are often called beaks because they are long and pointy like a bird’s beak.  Can you see the similarity?  Unlike birds, bugs can fold their beaks down under their heads, which is how the beak of the giant water bug above is positioned.

An interesting aside: Bugs can have a really nasty bite.  That little straw-like mouthpart might not look that impressive, but remember how bugs eat: they inject digestive chemicals into their food.  If you handle one improperly or startle one, those same digestive chemicals can end up in your fingers!  They can’t do any lasting damage, but it can hurt a lot as it digests some of your muscle.  It’s usually a good idea to handle true bugs with care.

So now you know!  A bug is an insect that has hemielytra and piercing-sucking mouthparts.  The next time you want to get technical and use the word bug for an actual bug, think about whether the insect in question has that V-shape to its wings and a long beak folded down under its head.  If so, it’s a bug and you can use the word bug without fear or hesitation!  If not, you can still call it a bug.  The choice is yours after all.  Just expect any entomologists nearby who happen to overhear you to correct you.

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Text and images copyright © 2009 DragonflyWoman.wordpress.com