GHs use a wide variety of host plants. It's almost like listing host plants for a generalist moth and a neverending story. I am not opposed to listing additional host plants for the GH, but just pointing out that it will be an extensive compilation of host plants because the GH is not too specific.

The Dallas County Lep Society lists numerous hosts, as follows:

"EUPHORBIACEAE: Woolly Croton (Croton capitatus), Doveweed (Croton monanthogynus), FABACEAE: Southern Hog-Peanut (Amphicarpaea bracteata), False Indigo (Amorpha fruticosa), Ground Plum (Astragalus crassicarpus), Candlestick Tree (Senna alata), Tick-Clover (Desmodium spp.), Scarlet-Pea (Indigofera miniata), Round-Head Bush Clover (Lespedeza capitata), Hairy Bush-Clover (L. hirta), Texas Bluebonnet (Lupinus texensis), Alfalfa (Medicago sativa), White Sweet-Clover (Melilotus albus), Lima Bean (Phaseolus limensis), Garden Bean (P. vulgaris), Rattlebush (Sesbania drummondii), Multi-Bloom Tephrosia (Tephrosia onobrychoides), Rabbit-Clover (Trifolium arvense), Crimson Clover (T. incarnatum), White Clover (T. repens), Vetch (Vicia spp.) MALVACEAE: Okra (Abelmoschus esculentus), Rose-of-Sharon (Hibiscus syriacus), Cotton (Gossypium hirsutum), Tall Winecup (Callirhoe leiocarpa), Little Mallow (Malva parviflora), Common Mallow (M. neglecta), Running Mallow (M. rotundifolia), Alkali Sida (Malvella leprosa), Globe-Mallow (Sphaeralcea spp.), POLYGONACEAE: Wild Buckwheat (Eriogonum spp.), Willow Smart-weed (Polygonum lapathifolium), Dock (Rumex spp.), ROSACEAE: Parsley Hawthorn (Crataegus marshallii), POACEAE: Corn (Zea mays), VERBENACEAE: Lantana (Lantana spp.), ZYGOPHYLLACEAE: Soapbush (Guaiacum angustifolium)."

They don't include the one I find my GHs on, which is Hibiscus coccineus or Texas Star Hibiscus. So, as you can tell, the list will be almost endless, and can vary from region to region as well. On another note, and I don't know if you find this true of the GHs you have found on various hosts, but they always lay their eggs on the unopened flower buds of my hibiscus and you know they are there because they chew a hole in the bud and begin to consume the flower from the inside. Once the flower is opened up, you can easily (well, fairly easily) spot the tiny slug-like larvae. I find them quite fascinating.

Susan

Wow, reading on BFs and moths site it says:
Caterpillar hosts: Flowers and fruits from an almost endless variety of plants; most often from pea (Fabaceae) and mallow (Malvaceae) families including beans (Phaseolus), clovers (Trifolium), cotton (Gossypium), and mallow (Malva).
No wonder they are all around. I am looking for a pic of the caterpillar, wondering if the thing I've seen is it...

Here is a link that might be useful: BF and moths

Different species, but same subject. I'd like to note that GSTs commonly lay eggs im my lakewood jasmine/orange jessamine/murraya paniculata. However the babies will not live on it. Mostly will not eat it, although I have seen them eat a little. The first ones I brought in to rear were on the plant when I found them so I assumed it would work for them and it did not.
So I quit offering it but once I had a potted one in an enclosure and a couple of the bigger cats made their way to it, and died almost right away after eating some. Coincidence? I can't say for sure but that is my experience with this "host" plant.

Here is a link to cat images of GH.

Susan

Here is a link that might be useful: Gray Hairstreak Caterpillar

Oh that's a great page, thanks Susan!
kelly

Susan,
Yes, you do have a good point there. Currently, though, we don't have the Bean (Fabaceae) family as a whole listed as containing host plants for S. melinus - there's one species in it listed, but not the family name. I think it would be a good idea to at least list this family, even if it may not, as you point out, be worth it to list individual species.

About where they lay eggs, my experience has been similar. All of the eggs I have found (which, granted, is only three so far) have been laid in flower heads. However, the flowers might have been open one of the times - I don't remember for sure.

-Jmcat

Yes, jmcat, I will get those in the list soon. I think they will be the first additions in the FAQlist for 2009, so we didn't miss a whole year. We have had new additions every year since misssherry instigated it a few years ago.

Jmcat - I don't know how you spot those eggs! LOL! They must be almost microscopic IMHO. I have never seen the eggs, only evidence that they have hatched and the cats feeding on the flowers. That is exceptional!

Susan

At the time I snapped the picture of this cat on a Sweet Almond Bush (Aloysia virgata) I had no idea it was a Gray Hairstreak caterpillar until much later, even though there was an adult perched on a flower near by. It does seem that the variety of host plants it uses is just about endless!

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Gray Hairstreak on Coral vine. Thanks to the link above I'll be watching for pink cats on the flowers :-)
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Susan- Here's my secret:
1. First, find a female butterfly of this species flying around. 2. Follow said butterfly close enough to see it well without scaring it. 3. Wait until this butterfly lays an egg. 4. Pick the flowerhead containing the egg. 5. Repeat steps 1-4 as necessary.

Here are some Strymon melinus pictures from this past year (not all of the same individual). Their eggs look more blue-green (kind of a light aqua) than is shown in the first picture.

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-Jmcat

Fantastic photos, Jmcat!

Susan I was thinking the same thing! how small the eggs and cats must be!!
Jmcat - thanks for sharing those great pics.
kelly

I added the first two plants, but suggest holding off on the poppyflower as the small portion of the larval cycle involved and the uncertain plant ID make for a weaker case. Perhaps you could replicate the experiment next year.

Thanks for the FAQ input. The gray hairstreak is one of the few butterflies that appear most years in Portland, Oregon city yards.

Thank you both for the compliments! The eggs and young caterpillars are indeed small. Those are alfalfa flower buds in the picture of the egg, and the little bit of purple showing on the one bud might give you an idea of how big it is. The eggs are quite a beautiful color when you look at them; it's really too bad that this didn't come out in the picture.

Larry Gene- Yes, I was thinking you might want better confirmation on the poppymallow. If I have these butterflies again next year, I will try to remember to raise some on this plant. I will also try to remember to get some pictures of the plant for a better ID of it.

-Jmcat

Wow fantastic fotos, Jmcat! And, Rosalee, yours are great, too! That 3rd photo kind of took be back cuz the red stripe is reminiscent of a Red-banded Hairstreak, which I see frequently in my garden, too. But the GH also sometimes exhibits a thin broken red line as well. The RBH has a much wider, less broken, red stripe. I think I have a photo of a male GH, with the yellow body. I think it is the male that has this coloration - correct me if I am wrong.

For such tiny little butterflies, they are so interesting. I had to chuckle, Jmcat, when you suggested following them around. They are hard to keep an eye on because the flit so quickly from one place to another and are easily startled. I don't have such great eyesight, nor am I as agile as I used to be, so there is very little chance I will witness the egg-laying process, but I can certainly give it the old post-college try.

Susan

Loved your photos Jmcat. How in the world did you get them to open their wings long enough to snap a picture?

I googled Red-banded Hairstreak and was really supprised at what they eat. Are there any other butterfly larvae that eat leaf litter?

"Eggs are laid on the undersides of dead leaves on the ground beneath the host plants. Larvae are reported to feed on dead leaves and detritus in the leaf litter. (!!!)

"However, at least in the laboratory, they will also feed on living foliage and flowers. Reported host plants include wax myrtle (Myrica cerifera L.) sumacs (particularly winged sumac, Rhus copallinum L.), crotons and oaks. Early fourth instar larvae overwinter."

Another site also reported this diet:

"Caterpillar hosts: Fallen leaves of wax myrtle (Myrica cerifera), dwarf sumac (Rhus copallina), staghorn sumac (R. typhina), and several oaks."

http://www.butterfliesandmoths.org/species?l=1570

Here is a link that might be useful: Red-banded Hairstreak ...

Beautiful pics!!

Roselee- All of those pictures are of individuals that I raised. Since I raise them inside where it is somewhat cool, they are happy to open their wings and bask. In my first dorsal shot, the butterfly is outside sunning itself for a brief period before it flies away. In the second dorsal shot, a different (?) individual is inside. For this one, I actually could get it to open its wings by shining an LED flashlight on it, though I doubt it was actually getting much of any heat from the light. I would tend to interpret this to mean that this butterfly's basking response is triggered more by light than by heat, even though the heat is what the butterfly is interested in. This isn't directly related, but I think it is interesting.
-Jmcat

...so interesting in fact, that you should play around with it. Did you try interrupting the light beam repeatedly to see if the basking response repeats?

LEDs will put out a bit of heat, they are not perfectly efficient, but unless you can feel it with your hand covering the lens, the butterfly is not getting heated.

How far away from the butterfly was the flashlight held?

Butterfly basking experiments have been done using incandescent 150-watt bulbs, etc, but this was obviously heat input to the butterfly.

I wonder if a laser pointer would work as well. I don't know if you could damage a butterfly's eyes with a small laser, I would think the butterfly would be looking directly at the sun often during its daily routine. And butterflies can't blink.

Your assignment is to create the new field of butterfly optics.

This response was repeated a few times when I took the flashlight away and then brought the light back to the butterfly, and, as I recall, I could do this with other individuals of the same species. I vaguely recall trying this without success on a butterfly that had just been sunning in real sun, but I don't remember for sure whether or not this actually happened. This is the response I would expect from a butterfly that was at the correct temperature, though.

I cannot feel any warmth from the flashlight I was using, but I would like to use a thermometer to find out how much the light increases temperature.

I think the flashlight was about 3-5 inches away from the butterfly. This varied some, though, partially depending on whether I was taking a picture at the time. I may have had it as close as 2 inches when I shone the light on the butterfly to get it to open its wings in the first place.

There are a few things that would be interesting to do in conjunction with this to note the differences in results. One would be to expose a butterfly to light of the same brightness without heat (similar to what I was doing). Another would be to expose the butterfly to the same amount of heat without light, by a means such as infrared light or radiant heaters. To add to the first of these experiments, you could also experiment with different color temperatures of light.

Given the nature of light coming from a laser pointer, you would have to aim it at exactly the right part of the butterfly for it to work. If you could do it without harming the butterfly, though, this would open up the option of trying to find what part(s) of the butterfly sense light and then trigger the basking response. This is likely the eyes, but I don't know for sure. Other parts of the butterfly may also have to have some kind of signal coming in before the butterfly opens its wings to bask. Given that butterflies would seem to look in almost all directions at once, I would guess that you are right about them looking at the sun.

By butterfly optics, do you mean how and what butterflies see, or something else?

-Jmcat

By butterfly optics I meant studying how butterflies would react to artificial light sources in general, not having to do with sight.

All kinds of animals (and plants) respond to artificial light in a wide variety of ways: Dogs will chase light spots, humans may lessen seasonal depression if exposed to a bank of lights, alter their circadian rhythm, etc.

Would a laser pointer simply scare the butterfly off? Although we would only notice it if it impacted our field of vision, another species might be more sensitive on other body parts.

I thought it might be nice for photographers to have a reliable way to "pose" a butterfly, as LED penlights or lasers would be simple to have in the field.

OK, thanks for the clarification. In this field, I was just thinking about the fact that many species of butterfly are more likely to mate at certain times of day. So, if you found the angle of sunlight at the time when a species preferred to mate, could you influence butterflies to mate by putting a light on the butterflies at this angle? Also, am I correct in remembering that we don't really understand how butterflies navigate during migration? Given enough resources, you could at least test navigation off of the sun and magnetic fields. However, this would probably require a completely environmentally controlled enclosure that would likely have to be at least one hundred feet tall and several square miles in area. Inside, you would need lights across most or all of the ceiling that were moveable and highly directional. Then, you could simulate migration conditions (shorter days, lower angles of the sun) and see which direction butterflies flew to migrate. Then, you could basically change the direction of "solar south" by changing where the lights pointed, and compare where the butterflies flew under the new conditions. In addition, how do butterflies respond if they are in an enclosure where the light points up from the bottom, and the plants are upside-down on the roof? Of course, this leads to a question I have pondered and considered experimenting with for a few years: Which is stronger: phototropism or gravitropism? If you hang a plant upside down with a light below it, will the plant grow up or down, and how much does this vary by species? Another thing in this field that I have observed is phototropism in caterpillars. I have been able to consistently get Papilio polexenes (Black Swallowtail) larvae to move their body one direction or another (sideways, not forward or backward) toward a light source that is near them. They don't move their feet, but just rotate their body at the feet. This is most apparent in the fifth instar when the caterpillar is resting. I do not believe I have tried this with other species.

Laser pointers are fun with cats, also. I know a website someone linked to on this forum a while back (Raising Butterflies, on their Avoiding Diapause page) talks about using long periods of constant light to keep butterflies in various stages from going into diapause.

Whether a laser pointer would scare a butterfly or not would probably partially depend on how it was used and moved - sudden movements in front of a butterfly would probably scare it more than turning the laser on when it was already pointed at the butterfly.

You are right that it would be nice to be able to get a butterfly to open its wings simply by pointing a light at it. However, I doubt that a butterfly would open its wings for a light if it was already warmed up. This would be easy enough to test without fancy equipment, so, if I remember, I will try this next year.

-Jmcat

I don't think we should take this butterfly training too far, as there have been trained flea acts for many decades, and that would lessen the impact of responsive butterflies.

Butterfly training?

May I add another host plant? Porterweed ...

Here is a link that might be useful: {{gwi:553654}}