Post by evra on Feb 13, 2014 21:24:37 GMT -8
Since there's a sizable number of collectors interested in Hemileucas, especially on this board, I thought I'd share a collecting experience that is a little bit different. Tom's recent video on collecting Hemileuca maia was nice, but if you read a lot of books, the authors say that it is much easier to get most species as larvae. I tried collecting larvae for a long time without much success because you really need to hone a search image for them. I recently went out collecting Hemileuca electra clio larvae east of Phoenix, Arizona.
The habitat is classic upland Sonoran desert on rolling foothills. The geology of the area is mostly loose granite. There are lots of different plants with many kinds of cacti, making walking through it even more treacherous. You can go out to the spot in early October and see the male Hemileuca electra clio flying in the late morning, much like in Tom's video, but because of the terrain, you'd be lucky to net 1 out of every 50 you see. If you cannot get the adults though, you can still try to get immatures at different stages of their life cycle. Of the three stages: egg, larva and pupa, finding eggs or larvae are the easiest for Hemileucas. Hemileucas spin loose cocoons in leaf litter in the center of bushes (not necessarily the host plant) that are basically impossible to find. They lay eggs in masses around stems called egg rings, and for some species the egg rings are relatively easy to find in the winter, especially if the host plant is fully deciduous. Hemileuca electra clio egg rings are not super difficult to find, nor are they really easy. They are generally laid at the top of flower stalks on their host plant which is above the growth, making them somewhat searchable.
Here's what a hatched egg ring looks like:
The best way to get this species is to get the larvae and rear them at this time of the year. Their host plant is inland flattop buckwheat (Eriogonum fasciculatum var. poliofolium), a small bluish shrub that rarely grows above the knee. It primarily grows in the drainages on the sides of the foothills pictured. Interestingly there is another buckwheat: coastal flattop buckwheat (E. f. var. fasciculatum) growing along the roads, which was introduced from California. It is not a host plant for Hemileuca electra clio, even though it is a host for nominate Hemileuca electra electra in California. The point is that you have to know your plants. You could look on E. f. var. fasciculatum all day long and turn up nothing.
Like looking for everything else, the key is having a good search image of what you are looking for. Young Hemileuca larvae are black, usually until their third or fourth instar, at which point they take on a multi-color camouflage pattern. Young larvae are also gregarious, and generally like to cluster near the apex of stems, as opposed to the inside of the bush, which makes them easier to spot. Despite all this, they aren’t all that easy to spot even with a good search image, nor are they usually all that common. I would estimate that only one out of every 25 plants has any larvae at all. Additionally, they are only young and gregarious for about 2-3 weeks of the year, so you really have to time it just right.
If you are lucky enough to find a larval cluster, you then encounter another difficulty. They are sensitive to vibration, and if you wriggle the twigs in the bush, they instinctively drop off and down into the leaf litter in the center of the host plant, making them much more difficult to find. So I’ve found that it is a good practice to very carefully stick your left hand underneath the larval cluster without touching any of the twigs before trying to break off the stem the larvae are on with your right. That way if they fall, you can catch them in your left hand. And before you ask, yes Hemileucas have stinging spines, but not for the first two instars, so this is generally a safe maneuver.
Once you have your larvae in a container, the really difficult work begins: rearing them. Hemileucas are slow growing, disease prone, and frequently reject host plants for no apparent reason, making them one of the more difficult to rear Saturniid groups. I have a lot of respect for people with good Hemileuca collections who collected or reared them, because for most species in the genus, nothing about them is easy.
As I said, if you want to find the larvae, you really need to develop the search image through practice. Can you find the larvae in these images?
The habitat is classic upland Sonoran desert on rolling foothills. The geology of the area is mostly loose granite. There are lots of different plants with many kinds of cacti, making walking through it even more treacherous. You can go out to the spot in early October and see the male Hemileuca electra clio flying in the late morning, much like in Tom's video, but because of the terrain, you'd be lucky to net 1 out of every 50 you see. If you cannot get the adults though, you can still try to get immatures at different stages of their life cycle. Of the three stages: egg, larva and pupa, finding eggs or larvae are the easiest for Hemileucas. Hemileucas spin loose cocoons in leaf litter in the center of bushes (not necessarily the host plant) that are basically impossible to find. They lay eggs in masses around stems called egg rings, and for some species the egg rings are relatively easy to find in the winter, especially if the host plant is fully deciduous. Hemileuca electra clio egg rings are not super difficult to find, nor are they really easy. They are generally laid at the top of flower stalks on their host plant which is above the growth, making them somewhat searchable.
Here's what a hatched egg ring looks like:
The best way to get this species is to get the larvae and rear them at this time of the year. Their host plant is inland flattop buckwheat (Eriogonum fasciculatum var. poliofolium), a small bluish shrub that rarely grows above the knee. It primarily grows in the drainages on the sides of the foothills pictured. Interestingly there is another buckwheat: coastal flattop buckwheat (E. f. var. fasciculatum) growing along the roads, which was introduced from California. It is not a host plant for Hemileuca electra clio, even though it is a host for nominate Hemileuca electra electra in California. The point is that you have to know your plants. You could look on E. f. var. fasciculatum all day long and turn up nothing.
Like looking for everything else, the key is having a good search image of what you are looking for. Young Hemileuca larvae are black, usually until their third or fourth instar, at which point they take on a multi-color camouflage pattern. Young larvae are also gregarious, and generally like to cluster near the apex of stems, as opposed to the inside of the bush, which makes them easier to spot. Despite all this, they aren’t all that easy to spot even with a good search image, nor are they usually all that common. I would estimate that only one out of every 25 plants has any larvae at all. Additionally, they are only young and gregarious for about 2-3 weeks of the year, so you really have to time it just right.
If you are lucky enough to find a larval cluster, you then encounter another difficulty. They are sensitive to vibration, and if you wriggle the twigs in the bush, they instinctively drop off and down into the leaf litter in the center of the host plant, making them much more difficult to find. So I’ve found that it is a good practice to very carefully stick your left hand underneath the larval cluster without touching any of the twigs before trying to break off the stem the larvae are on with your right. That way if they fall, you can catch them in your left hand. And before you ask, yes Hemileucas have stinging spines, but not for the first two instars, so this is generally a safe maneuver.
Once you have your larvae in a container, the really difficult work begins: rearing them. Hemileucas are slow growing, disease prone, and frequently reject host plants for no apparent reason, making them one of the more difficult to rear Saturniid groups. I have a lot of respect for people with good Hemileuca collections who collected or reared them, because for most species in the genus, nothing about them is easy.
As I said, if you want to find the larvae, you really need to develop the search image through practice. Can you find the larvae in these images?
