Wednesday, October 27, 2010

Lubbers, our largest Grasshoppers

Even though grasshoppers and their growing nymphs can be found in Arizona at all times of the year, they really seem to dominate our insect fauna in late summer and autumn. Our local species hardly ever develop population densities that would induce them to turn into wandering bands of Locusts, but when you walk through grass land or brush a few of them seem to jump up under every step.

      Chihuahua Lubber                                    Horse Lubber                                    Plains Lubber
Phrynotettix tshivavensis                       Taeniopoda eques                             Brachystola magma

Because of their size, the heavy-built Lubbers or Romaleidae are especially conspicuous (Two immovable spines on the hind tibia separate them from Acrididae who have only one spine, but mostly they can be recognized by their large size and lumbering gate).
 So far, I have found the three species shown above in southeast Arizona. I am still hoping to find the Furnace Heat Lubber, Tytthotyle maculata, and the rare Spanistic Desert Grasshopper, Spaniacris deserticola, both in western Arizona.

The strange looking  Chihuahua Lubber is the rarest of the species that I found. It occurs in early summer in rocky or gravelly arid areas from the lower desert elevations up to the oak and juniper belt of the mountains.
 Chihuahua Lubber, Phrynotettix tshivavensis

Their compact shape, brownish color, and warty surface hide the flightless lubbers very well in that environment. It took me years to find my first one in Brown Canyon in the Baboquivari Mountains, but then, after having established a search image, I also found them in other places like Canelo Pass south of Sonoita and Florida Canyon in the Santa Ritas. Our Chihuahua Lubber is considered a distinctly different species from the Robust Toad Lubber, Phrynotettix robustus that is found in Texas.


The Plains Lubber has a wide, but patchy distribution. This year they seemed to be a banner year in southern Arizona, with big males basking in the sunshine wherever sunflowers or rabbit brush lined the road sides and even mated pairs slowly crossing the roads. 

 Plains Lubber Brachystola magma

Eggs are laid in the ground in pods of about 20. In a the USDA study the eggs needed two years of incubation and over-wintering before hatching. Field observations of population peaks in alternate years support the hypothesis of a two-year life cycle. 


 The nymphs hatch wingless and undergo five molts before they mature. The adults have only very small non-functional wings and their only means of dispersal is their lumbering walk and slow jumps. They feed voraciously on many different plants but seem to prefer the sunflower family. Only rarely do they venture into cotton fields and do some damage to the crops. Mainly phytopagous, they supplement their diet by scavenging and have been observed to kill  and eat smaller grasshoppers.



The Horse Lubber Taeniopoda eques is locally known as Mexican General. That's because of his bold aposematic coloration, over 3 in length and stately movements. In some years in October, when the lubbers cross the roads to Madera Canyon and Mount Hopkins by the hundreds they look like an army on the march.
 Horse Lubber Taeniopoda eques female
This female is roosting high in a mesquite tree before night fall. Most likely, this will allow her to catch the early sun shine to warm up and get active quickly in the cool desert morning. It's October!

Although many of the males have functional wings, they rarely fly. Instead, they use their wings in a defensive display when they are threatened. The flashing of the red hind wings is accompanied by clicks from the front wings and hissing. I addition, they may exude foul smelling froth from their thoracic spiracles (breathing openings).

Defensive pose Photo Katrina Weber

Judging from the numbers of Horse Lubbers that walk around openly and unencumbered by birds or other predators,  the strategy is working. However, many get run over by even the most respectful drivers. Any roadkill is immediately cannibalized by the survivors, often resulting in another series of traffic calamities.  Otherwise, they feed on the foliage of Mesquite and other brush and broad-leaf  weeds. 


Early instar nymphs tend to stay together in groups. I have found them in early to mid August and the adults as late as the end of October.












15 comments:

  1. Wow. The yellow on black of the Horse Lubber is really striking!

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  2. I don't think I've ever seen those horse lubbers - quite impressive.

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  3. p.s. I think the group is now accorded family status - thus, Romaleidae :)

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  4. You are right Ted, thanks for catching that! The book I was using is from 2004...

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  5. Very nice article on the natural history of the Romaleidae with very good photography. I have encountered two other species of lubbers in Arizona: the Furnace Heat Lubber, Tytthotyle maculata, and the Spanistic Desert Grasshopper, Spaniacris deserticola. The Spanistic Desert Grasshopper is Arizona's rarest lubber, found only in the desert south of Yuma.

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  6. Beautiful photos and great information, as usual. I've not see that Chihuahua Lubber here but will certainly look for it in the right time frame next year. The abundance of grasshoppers must be why the kestrels are still here.

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  7. Thanks birder, for the additions. I have tried to blend your info into the text above and I found that we actually have photos of both spp. from AZ on BugGuide (your photos, maybe?)so I linked to them.

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  8. My next-door-neighbor brought me two lubbers from New Mexico, which look quite a bit like the Plains Lubber. Very informative.

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  9. Hi Robyn,
    Plains Lubber is definitely in NM.

    When you get to the more coastal areas in CA, look for the Gray Dragon Lubber, Dracotettix monstrosus, your CA specialty. I'd love to have photos and specimen!

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  10. Well done! Hard not to love the lubbers :-) I remember the first time I saw the Horse Lubber. It was in September, 1989 on a rugged road into Portal. The lubbers were crossing the road in front of our vehicle. They'd raise their red hindwings as if to say "Stop! This is a 'hopper x-ing!"

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  11. Wow! Beautiful nature blog, Margarethe!

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  12. Hello, are the horse lubber poisinous to humans. The children are always catching insects and bugs. So I worry.
    Thank you.

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  13. Most grasshoppers are can be eaten, actually are eaten in many cultures. Horse Lubbers have obvious warning colors, so I assume they taste bad, at least. But what are your kids doing with the bugs that they catch, chew on them? Maybe it's time to teach them how beautiful and interesting insects are when they are alive and in one piece?

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  14. Ms. Brummermann,
    This article was quite helpful. I wasn't sure grasshoppers were prevelant in Arizona year-round. Could you tell me which one you might find in southeast Arizona in the month of May?

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  15. Sorry, Ida
    that's a question impossible to answer. In every given habitat, you'll find a plethora of grasshopper species, some nymphs, some already adults.

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