Thursday, April 19, 2012

Cutworms are beautiful

In fact, I am absolutely smitten with their velvety texture and beautiful, delicate patterns in soft earth tones highlighted with metallic accents.

 It didn't start that way. In early spring, when I turned rocks or dead wood around our house, instead of the interesting  tenebrionid beetles I was looking for I found fat, hairless brown caterpillars. They were everywhere, even under dry cow pies. They were so indistinct that I got no reaction when I posted one on Bugguide and it took Eric Eaton's blog on cutworms to make me realize what they were. I learned that they do not feed on dead wood, fungus or dry cow dung, they just hide under it during the day. At night they go out  to chomp off young plants at the base, hence the name.

Euxoa auxiliaris

This year, our winter rains made the desert annuals sprout, so lots of caterpillars had food to develop into adults. My first cutworm moth of the season  had crawled behind one of my paintings on display at an out-door art show. As it darted out (Dart is the other name mostly applied to the adult moths) my customer backed off in disgust. After the show, another moth, or maybe the same art loving creature, got itself loaded into my van, woke up at night during the drive home and fluttered into my face. At least it kept me from falling asleep on Interstate 10.

Heliolonche carolus and Schinia miniana

 Then Dave Wagner, author of several books on eastern moths, visited and got me to look more closely at some day active Owlets, very pretty and in the same family as the cutworms.

Striacosta albicosta,  Euxoa serricornis,   Abagrotis reedi, Anarta trifolii 

When it got warmer I began running black lights at night again.
I have two lights, one in our driveway and one at our neighbors' house across the street. Both places have sandy soil, lots of Creosote, Saguaros, Palo Verdes, Ironwood Trees and a few Mesquites. The annuals are mostly Fiddle Neck Amsinckia intermedia, Scorpion Weed Phacelia, Bajada Lupine Lupinus concinnus, Filaree Erodium cicutarium, Evening Prim rose Oenothera primiveris, a small mustard and a small very common Cryphantha species. This relatively limited number of food plants supports an amazingly divers population of cutworms.

Only the last one in this row is identified so far: Anarte mutata
Including the ones that still need identification I count at least 12 to 15 different morpho-species that appeared since the beginning of March. It seems that every night brings new ones. The two lights, about 400 yards apart, show surprisingly different results, maybe because one is closer to a (dry) wash.

Lacinipolia sp.
These pretty lichen-patterned ones for example only come to the light at our house. Most identifications are  by Maury J. Heiman. Thank you so much, Maury!

Cutworm or Dart moths form the subfamily Noctuinae in the huge family of the Noctuidae, the Owlet Moths.

From my own observations I'm pretty sure that cut worm moth populations here in the desert sharply increase in years with winter rains and resulting spring flower emergence. I can very well imagine how constant irrigation and spring seeding of crops offer ideal conditions for high Cutworm populations in agricultural settings. Under those conditions some species in this group can become economically important pests.


  1. Thanks Margarithe

    I enjoy when someone has a deeper appreciation about a subject matter or an element of nature like in this case 'Cutworms', which under the usual circumstances are demonized by most gardeners and industrial farming types. Yet if the industrial Agricultural practices weren't so disrespective of how nature actually worked and attempted for once to impliment holistic methods of avoiding the bad practices which created the opportunities which resulted in an out of balance population of various so-called pests, then just quite possibly they'd succeed at living with them instead of always trying to anilhilating them all into oblivion which takes everything else with them in the process.

    I enjoyed being reminded of the actual adult moth they came from. Sometimes you forget. I imagine these night roamers are also a part of the major diet of various bats which themselves have been demonized in the past.

    I've actually got a couple of ideas I'd love to play around with in many of the industrial agricultural areas of imperial valley. Wind breaks are an important mechanism to prevent those dry winds from desicating crops, but unfortunately various species of Tamarisks were brought in the accomplish this windbreaking task because of their amazing tough ability to withstand the extremes and grow where other plants won't. Many things were done in complete ignorance back then. Of course like the cutworms, the Tamarisk shouldn't be blamed for human incompetence and stupidty. They just do what they do.

    Yet did or has anyone considered the example of mesquite dunes or mounds that we find out in nature which would make the perfect replacement ? Of course not.

    But in this so-called modern times of enlightenment and the present understanding we have of how nature works, why haven't more holistic methods been devised ? If these so-called enlightened solutions extist anywhere, then they are extisting only on a small scale or in some tiny obscure Lab or field experiment and the findings shelved in favour of the conventional old school science based profiteering methods (Monsanto - Dupont) that have made these same entities power and wealth for well over a century and kept the right people in governmental positions of power that have assured their continual finacial success.

    I've got some plans and ideas and am about to finally put them into text, but I just need to get the time.

    Thanks again for your insect appreciation and sorry for the windy rant.


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