Kissing Bug or not?

It's time for the Kissing Bug post again: Yes, we have them in the Southwest US.

In the Soutwestern US, they are neither new nor uncommon. 
They may carry the microbe that causes Chagas desease (Trypanosoma cruzi) in fact, studies showed that  
about 40 % of the Kissing Bugs around Tucson are infected 
 with Trypanosoma cruzi. .But so far they are not known to transmit it to humans here in AZ. Behavioral differences from tropical species may play a role. 
Some possible cases in Texas were reported (there are different species of Kissing Bugs there, the same genus, Triatoma, plus some others.)

Female Triatoma rubida in Tucson, AZ

 Adult Kissing Bugs fly to lights at this time of the year, from the end of May to the beginning of July. They are NIGHT-ACTIVE. But I have found them sitting under our kitchen light in the morning, still there from their nightly visit. They are very flat and can get through narrow openings under doors.

Nymph of T. rubida, stilll flightless

I've found nymphs (flightless) indoors since January. The dogs may bring them in? We have packrat middens too close to the house and should get rid of those.  That's were most Kissing Bugs grow up.

Side view of the elongate head of a Kissing Bug (conenose) At rest, the sucking mouth parts are folded back. They stretch forward when in use. Photo by Eric Eaton (detail)

Taxonomically, Kissing bugs belong to the order Hemiptera, 
so they are True Bugs, not Beetles. One characteristic of that group are the piercing, sucking mouth parts.

Several other True Bugs are often mistaken for Kissing Bugs
Let's separate the Kissing Bugs, also called Conenoses, from similar True Bugs that are often mixed up with the real thing.

Eastern Boxelder Bugs Photo by Seth Ausubel

Some hints: if you find bugs on flowers, or anywhere in the sunshine, bugs in big aggregations, on leaves or fruit: Those are NOT Kissing Bugs. Several related species of these
Rhopalidae (Scentless Plant Bugs) and similar Lygaeidae (Seed Bugs) are very common in Arizona. They feed on leaves and milky, fresh seeds piercing them with their probosces and sucking the juice.

 Here are the Small and the Large Milkweed Bug. They are plant suckers and not interested in animal blood at all. Both are smaller than our common Kissing Bugs in AZ.

Some of our Leaf-footed Bugsdon't have actual 'leaves' on their legs

A number of Leaf-footed Bugs (Coreidae) is as large or larger than Kissing Bugs and shape and coloring may be similar. If you see flanges (leaves) along the hind legs, the separation is easy, but not all Coreids actually have those.  The large ones feed on fruit and cactus pads, often in aggregations, usually during the day 

Some Assassin Bugs found in Arizona may resemble Kissing Bugs

 Remember that  

Kissing Bugs are Assassin Bugs, but not all Assassin Bugs are Kissing Bugs! 

Most Assassin Bugs are predators of other arthropods. Many Assassins look similar to Kissing Bugs. They can be of similar size and also share a similar color scheme of red on black. If you look closely, their heads are not cone shaped like those of the Kissing Bugs.  Hint: if a predatory Assassin Bug bites you it hurts very much. 

If a kissing Bug bites you, it's completely painless and usually goes unnoticed.

Itching welts and inflammations may appear later. The strength of the reaction is dependent  on the immune reaction of the victim. Over time, after repeated exposure,  hypersensitivity can be developed and a person becomes allergic. These allergic reactions can be severe.  

Photo by Tony Palmer

 Here is Triatoma rubida, our most common Kissing Bug, feeding on a Mediterranean Gecko. The reptile made no effort to avoid the painless bite.  The bug injects an anesthetic and an anticoagulant.

 

1 Macrocephalus dorannae; 2 Lophoscutus sp.; 3 Phymata sp.; 4 Pseudozelurus arizonicus; 5 Narvesus carolinensis; 6 Oncocephalus geniculatus; 7 Reduvius sonoraensis; 8 Rhiginia cinctiventris; 9 Triatoma protracta; 10 Triatoma recurva; 11 Triatoma indictiva, 12 Triatoma rubida, 12a Triatoma rubida nymph

We have 3 or 4 species of Kissing Bugs here, all in the genus Triatoma,  In Tucson proper you'll see most likely Triatoma rubida, In Madera Canyon T. protracta is quite common, T recurva I have found at Clear Creek in Yavapai Co. All are night active and come to lights. 

My blog should help you to better identify the bugs you find. To learn more about Chagas disease and the status of vector infection in AZ, I suggest the paper 'Infection of Kissing Bugs with Trypanosoma cruzi, Tucson, Arizona, USA'  by Carolina Reisenman  et al. 

Assassin Bugs of Arizona

As a preparation for the BugGuide gathering 2013 in Arizona, I pulled BugGuide's data for Assassin Bugs in Arizona. I found that my own photos are the basis for many of the existing species pages. I also found that I had taken white background photos of all but one of the AZ species that are represented on BugGuide. The one missing was  Pseudozelurus arizonicus photographed by D.R. Swanny from a museum (UMMC) specimen. D.R. Swanny also did most of the identifications and I gave him many of my specimens, so I'm sure that he doesn't mind that I included his photo in the tableaux below.

1 Stenolemoides arizonensis; 2 Emesaya sp.; 3 Zelus tetracanthus ; 4 Zelus renardii; 5  Castolus ferox; 6  Apiomerus cazieri; 7 Apiomerus flaviventris; 8 Apiomerus sissipes; 9 Apiomerus longispinis, 10 Fitchia aptera; 11 Heza similis; 12 Pselliopus marmorosus ; 13 Pselliopus zebra; 14 Rasahus thoracicus; 15 Melanolestes picipes; 16 Rhynocoris ventralis; 17 Homalocoris erythrogaster; 18 Sinea rileyi; 19 Sinea diadema

1 Macrocephalus dorannae; 2 Lophoscutus sp.; 3 Phymata sp.; 4 Pseudozelurus arizonicus; 5 Narvesus carolinensis; 6 Oncocephalus geniculatus; 7 Reduvius sonoraensis; 8 Rhiginia cinctiventris; 9 Triatoma protracta; 10 Triatoma recurva; 11 Triatoma indictiva, 12 Triatoma rubida, 12a Triatoma rubida nymph

There is a lot of work in these tableaux. Since I composed similar collages of other Arizona insect families, I have learned several things: to always store my work as png files so I can go back and move the elements around. To keep the species names in the legend instead as part of the image file - it's easier to correct mistakes and to follow changes in taxonomy that are inevitable. Last, but not least, to post only a small watermarked version on the internet. My ladybug plate showed all intentions to go viral after it was posted on pintrest, turned up in an African language blog, and on several gardening web sites, but by then it had lost all connections to my name and copyright.

Prints of these and other insect plates are available. Please contact me at mbrummermann@comcast.net

Packrats in our Compost Bin and in Science

 In all biological questions, my husband usually refers to me. The latest was: "what do you want to do about the rat in the compost bin?"

In kitchen and yard, we religiously save all scraps of organic material to let them decompose into fertile soil in two upside down garbage bins that sit with their openings on the ground.

It works - industrious Turkestan Roaches seem to be doing a lot of the early break down, and that's no problem because the bins are far from the house in an old 4H-goat pen. The fence keeps out our Husky, Javelinas, Coyotes and Foxes, and rows of bricks around the bottom of both bins prevent most rodent intrusions. Somebody once chewed right through the plastic wall - so now there is a hardware cloth patch.

But for a couple of days there had been a packrat sitting in the cockaigne of lettuce leaves, cucumber seeds, carrot pieces, and onion peels. Gray and big eared, she wasn't shy at all - just glared at me from under the lid of the bin. I knew that my friend Ned Harris was looking for a packrat photo opportunity,  but I could tell that this background wasn't quite it.  So, a photo for myself (I'm much less critical than he) and then the release of the rat. First I tried to lift her by the tail like a white lab rat, but she desperately clung to the substrate and I could feel that the tail's loose sheet of skin would be sacrificed before I could dislodge the animal. So I just coaxed her onto a trowel, lifted her up to the rim of the bin and let her hop off . I wouldn't  try that with a wild Brown Rat (Rattus norvegicus). But this was a White-throated Packrat (Neotoma albigula), and I had noticed before that our resident females are rather calm-natured.  So now she can get back to her business of collecting Randy's cactus clippings to decorate her home. Notice those fences around single pots in the photo above? That's how we try to protect our favorites.

Photo by Doris Evans

All over the Americas, there are many species of packrats. Our backyard with its scattering of Creosote bushes and cacti is the ideal habitat for the local species Neotoma albigula, the White-throated Packrat, and not even our five dogs and two mostly indoor cats seem to be much of a deterrent.

We live in an uneasy truce with the rodents. As the name says: they collect stuff to pile on top of their nests. But the nest can be in the down-spouts of our rain gutter with lots of collectibles left on the living room window sill that happens to be part of the way to the roof. That rat had to be evicted twice.

Another one added parts of the start-plug cables of my car to its midden. I used to park in the shade of a large Ironwood Tree. As the rats prefer working in the dark of the night, I now park over special, photocell-activated lights that Randy has sunk into the driveway. So far no further electrical disasters to report.

Pack rats are also carriers of several transmittable diseases. Hanta Virus has been found in Pima County Neotoma populations, but since we are (hopefully) never exposed to a room full of dried, pulverized, airborne rat droppings that are the most likely source of infection, there seems to be no problem.

Kissing Bug, Triatoma rubida, adult and nymph

Pack rats middens are also the favorite breeding ground of Kissing Bugs. Every summer night we can find several of those, usually engorged with blood from our dogs,  around patio lights or my black light. Kissing Bugs are part of the Assassin Bug family Reduviidae. Adults usually appear from May to early July and disappear during the monsoon season. Immatures have been found crawling around even in winter. These bugs bite rats, dogs and people alike to drink their blood. They attack at night and use an anesthetic, so their bite goes unnoticed. If you don't get allergic (which can happen after repeated exposure) there seems to be no reaction to the bite itself, no itching or swelling. But Kissing Bugs can transfer the tropical flagellate protozoan Trypanosoma cruzi that causes Chagas disease. This parasite has been found in Arizona packrats. Luckily our local Kissing Bug species Triatoma rubida seem to abstain from behaviors that would transmit the parasite. (I will get back to Kissing Bugs in later blog).

Packrat populations may also attract rattlesnakes. Indeed, we had a big old Diamondback living in the entrance of a midden. I couldn't tell whether he shared it with the rats or whether he had already devoured his hosts. We were acquainted with him for years until he scared me several times too badly - by being nice, really: he just didn't rattle anymore when I was out there single-mindedly concentrating on my photography, and several times I found his big head less than a foot from my ankle or my dogs' paws. The midden in question was under a big old opuntia. I finally lost my nerve and we relocated the snake to the state land. It took less than one summer for the rats to destroy the cactus.

So there are plenty of reasons to dislike packrats. But I can't help finding them also entertaining and fascinating.

Pear Pads with Rodent damage                                                Javelina bites leave torn fibers behind

Low desert packrat species share their extremely arid and hot habitat, without access to fresh water, with a masters of desert survival, the Kangaroo Rat. But while K-rats can live on dry seeds thanks to the enormous concentration capacity of their kidneys,  packrats void copious urine.  Thus they are only able to maintain their water balance as long as they have access to their favorite high-water-content food, succulent plants like cacti and agave (Schmidt-Nielson and Schmidt-Nielson, 1952).

Middens are usually shaded by vegetation, but sometimes the rats bite of the cactus under which the nest

Their most special adaptation, which gives packrats their name and makes it possible for them to live in very hostile environments, is their ability to construct huge, insulating middens. Packrats seek rock crevices, caves or dense patches of vegetation as shelters, but they improve these by piling on sticks, pieces of cacti, bones, spent shells from guns, toys - just about anything portable that catches their eye. These piles can be conspicuous and over 2 m high in some species. Underneath this fortified den that protects from predators and buffers against temperature extremes is a burrow system with chambers serving to cache food (Packrats do not hibernate) and the small nest made from soft, shredded material.

 When we evicted the 'down-spout-rat' by turning on the water-hose I was surprised that it showed neither fear nor aggression even when cornered. Now I observed the same 'tame' behavior in our compost-bin guest. This character has probably evolved in packrats because the fortified den is a save haven for this animal that has no energy to spare for fight or flight. Packrats live under chronic energy stress due to their diet of low energy plant material (Cactus, Creosote, Juniper) much of which is also rather indigestible because it is loaded with defensive chemicals like terpenoids.  (McClure and Randolph, 1980).

Amberat, a treasure to science
So Packrats are extremely faithful to these middens that their survival depends on. Good den-sites are in short supply and the accumulation of material is costly, so generation after generation of the female line uses the same den, adding material and caching food. Over years, decades, centuries, even millennia, urine accumulated and dried in amber-like clumps under the nest - this substance is called amberat (Some starving miners around 1849 actually tried to eat the 'candy-like food'). 
Today, paleontologists and archaeologists are finding the Southwestern packrat middens a plethora of valuable information. Fossil plant pollen are imbedded in amber-like urine deposits and the whole den  is a collection of animal and plant records that reach far back into the Pleistocene.
As there are no pollen-preserving peat bogs in the Southwestern deserts, and pollen studies were limited to lake sediments in only a few locations, the study of packrat middens became one of the most important resources for the understanding of the changing biogeography of the Southwest from the Pleistocene to the present.

Literature: 
JL Betancourt, TR Van Devender, PS Martin (1990) Packrat Middens, the Last 40,000 Years of Biotic Change.  University of Arizona Press, Tucson
K Schmidt-Nielson,  B Schmidt-Nielson (1952) Water metabolism of desert animals , Physiological Review 32, 135-166
P A McClure, J C Randolph (1980) Relative allocation of energy to growth and development of homeothermy in Neotoma floridana and Sigmodon hispidus. Ecological Monographs 50, 199-219