Sunday, April 1, 2018

Globe Flash V2

Before getting into technical details, let me show three photos. All three are with the same camera and lens but were taken using different flashes:

The first uses a Sigma Ring Flash:

The second uses a Sony Twin Flash:

The third uses my latest DIY globe flash:

I chose ants because they move so fast they are really difficult to photograph without a flash you typically end up with a blurry mess. All three flashes do a reasonable job of stopping motion and at least making clear it is an ant. There is a real quality improvement from better diffusion though.

The Sigma flash always had a real problem with too little diffusion. Odd hot spots and dark spots really retract from the quality. It calls itself a ring flash, but due to lack of diffusion it is more of a twin flash with two fixed light sources.

The Sony flash was a solid flash, for $750 it better be! Still, even it ended up with some hot spots. I always wanted more diffusion when I worked with it.

The globe flash doesn't quite eliminate all specular reflections, some images still have hot spots when using it, but they are a much reduced level than the other two flashes. Typically they show up as a bright area rather than a totally over-exposed spot. Compared to any previous flash I have used this is great performance.

It isn't entirely a fair comparison since the photos are ordered chronologically and were taken a few months apart so I learned as I went. Also, the dedicated macro flashes give more control over shadows. Still, the DIY globe flash I am using is almost half the price of the Sigma flash, and and a quarter the price of the Sony flash.

The previous globe flash I used almost had this level of performance, but I found two somewhat annoying issues. Too little light got in meaning the flash took a long time to recharge and it had oddly shaped reflections on shiny surfaces. You can see the diffuser shaped reflections on the ants in the photo below:

So I upgraded from a 6" globe to an 8" globe. I chose 8" because that puts a subject at minimum focus distance right at the center of the light source. I obsessively keep subjects at minimum focus distance so I can add scale bars.

Going to an 8" globe created problems attaching the globe to the camera. The 8" globes do not come with smaller than 4" holes. That is larger than any cheap adapter I saw. So I had to purchase an acrylic disc to use to connect the step up ring to the globe.

The list of materials and tools for the project were:
First I used the dremel cut a hole in the acrylic disc matching the opening on the lens, then I cut off the flange attached to the globe and epoxied the step up ring, acrylic disc, and globe together. Once the epoxy dried I used the dremel to cut the globe into the shape I thought would work best:

As you can see the new flash diffuser is significantly larger than the old one. Just like last time, too little light makes it from the flash to the diffuser. This was easily solved by putting a paper towel above the two. In an attempt to ruggedize it, I covered the paper with packing tape.

If I used a 12" globe I could probably avoid the paper towel, and I will probably ultimately find a better way to trap the light than the paper towel. It does seem effective though.

This has been very successful. Unlike the old version I can fire off photos rapidly using this version. Also, while reflections aren't entirely gone, the smaller black area on the central hole and larger globe make the reflections less obviously the shape of my diffuser.

While the diffuser produces very good images, I have found some downsides:
  1. The shape makes it difficult to image insects in a tight space. 
  2. You look like a crazy person when you walk down the street carrying this camera. Honestly this is a problem with all macro flashes though.
  3. Diffusion could still be improved! This seems the best trade off of usefulness and image quality but I still often find myself wanting more diffusion. The only viable way I see to get more diffusion without making the system hopelessly bulky would be to use two small flashes, one on each side of the globe. 
  4. The paper towel is a pain to take on and off. Maybe a little aluminum foil hat for the flash? Maybe a white cloth with velcro?

This could be adapted to just about any macro lens. The only big change would be to use a different size step up ring to connect to whatever lens you want. I suspect it might even work on a superzoom camera with the on camera flash, but I have not tried.

Wednesday, March 21, 2018

Globe Flash

After my recent experiment with using a handheld flash for macro, I learned a few things. Most important of these things is that shadows are for artists. As someone who is mostly trying to take a whole bunch of high quality photos of insects in a hurry, shadows are not my friend. Ending up with a shadow covering an important part of an insect for identification is a real problem with that setup. Also it was bulky and a lot of work.

After some research on alternatives I ran into a clever flash which uses a globe shade off of a lamp as a diffuser. This made a whole lot of sense to me since the best diffusion comes from a sphere of light around the subject. I can't quite get there with a globe cut in pieces, but I can get a whole lot closer than with just about any alternative. The globe also reduces shadows since light is coming from a bunch of angles.

So I bought a six inch acrylic globe and went to work. 

There are a few challenging parts to making this setup work. First was cutting acrylic. This isn't necessary if you can find a hard plastic globe, but acrylic ones are much easier to find so I bought one of them. My first attempt  was with a hack saw. With sufficient patience this may work, I got tired of cutting though, rushed through, and cracked it. After that I tried cutting with a dremel tool. That seemed to work well.

The next problem is how do you attach the globe to the camera? My first thought was to order a 3D printed attachment to where the lens hood connects. This is probably the right answer, but I got lazy since this would require some real work. Eventually I realized a simpler solution is to buy an adapter ring from 62mm(the lens threads) to 77mm(the diameter of the globe). Then I epoxied the globe to the adapter:
 I am not quite sure how durable the epoxy/adapter connection will prove. If it does hold up though, this is a great solution for how to connect the globe.

After a bit of use, I realized  another problem. The shade blocks too much light! What ends up happening is that the background turns white because it is not shaded, and the area focused on is often too dark. Worse, the setup only works at minimum focus distance! Once the subject is further away, there is a big bright area which is not blocked by the globe, and a dark area which is.

A paper towel seemed to fix these problem, although using a 10 or 12 inch globe would probably be a better solution.

I have only used this setup two days, but so far results have been remarkable. To use an example everyone knows, here is a photo of a fruit fly. Extra diffusion from the wall, probably made it better than it otherwise would be but still it is impressive results from such a low cost flash:

This gets even more impressive when compared side by side with a photo using the same lens/camera and the Sony Twin Flash which was four times the price as this flash. The bright spots from reflection stand out much more with that setup:

Monday, February 26, 2018

Rancho La Habra Draft EIR Comments

 After a few boring months, we finally have a development in La Habra worth commenting to the city on. As usual, the a draft EIR was developed which fails to see the huge amount of harm to the residents of California which housing restrictions have caused.

Here are the comments I submitted:

The draft environmental impact report for the Rancho La Habra Specific Plan largely fails to see the big picture of the environmental impact from development of this housing. The project is blamed for a great many problems which are either not environmental problems, or will not actually be impacted by this project. A more reasonable analysis of the impact of this project would find that the actual lowest environmental impact of this project could be obtained by dramatically increasing the density of housing development, perhaps to the level of other recent projects along Beach Boulevard.

The environmental impact report blames the project for increasing population and states that this is a significant unavoidable impact. The project will do no such thing. The people who will live in the development are already born and there is no reason to think that the project will lead to increased birth rates in the future. The project will not increase the population. It will only increase the number of those people who live in La Habra. The significant environmental question is, would the environmental impact of this population be reduced or increased if these people move to La Habra? The answer is a very clear reduction. If this project is not constructed these people will find housing elsewhere. This housing will almost certainly have a higher environmental impact than this development due to the mild climate, minimal disturbance of wildlife habitat and central location of this project which will reduce environmental impacts when compared to exurban developments in the inland empire. 

Elsewhere the EIR repeatedly mentions increases in traffic as an unavoidable environmental problem. This is quite simply not an environmental problem. The environmental problem is cars, not traffic. If there is an environmental impact relating to transit which should be considered it is from the fact that this development will never support decent public transportation. Were the density to be tripled or quadrupled, it would plausibly be a high enough density urban area to support reasonable public transit service. As it is, the development is simply too low density to ever support good public transit. Unlike increased traffic from this project, this is a serious environmental impact. Also, the design could reduce driving by providing easier walking access to neighboring businesses, making these distances as short as practical and removing gates which are likely to reduce the number of people who walk. 

Again greenhouse gas emissions are over-stated because of a failure to understand what would happen were this development is not constructed. These people will live somewhere. The average resident will certainly be closer to their worksite if this development is constructed, reducing miles driven. The average resident will certainly be using less heating and cooling if this development is constructed, again reducing energy use and greenhouse gas emissions.

None of the evaluated alternatives properly account of the reduced environmental impacts which could be realized by increasing density. The amount of preserved habitat, viability of public transit, walkability, total greenhouse gas emissions, and even total revenue to the developer could all be improved by reducing the amount of land developed while increasing the total number of housing units installed. This is a dramatically superior option to all six alternatives considered in the draft EIR.

Friday, January 19, 2018

I am always tweaking my camera setup to try and squeeze the most out of it. My base setup of a Sony a6300 with a Sony FE 90mm Macro Lens is about as good as anything on the market. However flashes have always given me a lot more trouble.

First I got a Sigma Ring Flash. It did alright, but it unfortunately isn't really a ring flash. It is a twin flash which is built with no easy way to provide diffusion. That has lead to disappointing image quality compared to some other products on the market.

After six months of using the ring flash, I got a ridiculously good deal on to a Sony Twin Flash. This was a really solid macro flash. It suffered from a few problems though. It was pretty fussy, with lots of little pieces which always needed adjusting. It also it lacked high speed sync which made it almost useless for taking photos in full sun. Worst of all, it died in about six months. It was under warranty, but Sony refused to replace it and instead refunded it. Since I got such a good deal, buying another one with the money I got wasn't an option so I went back to the ring flash for another year.

After researching more, I decided that the way to go was a hand held flash. Something like what is done in this video. That is a far lower cost alternative than a dedicated macro flash. However it created some conundrums. How do you photograph at night when holding a flashlight? Also, I am usually dragging kids down trails so I often need two hands. So I decided to get a flash bracket which my flash usually goes to, but get a quick release to allow me to remove it and use it as a hand held flash.

The basic setup is:
Godox Ving V860IIS flash
X1T-S Wireless Flash Trigger
Straight Flash Bracket
Quick Release Plate.

I bought a packaged deal which included the first three items, but with a diffuser which is perhaps too small. Then I bought the larger diffuser because I wasn't sure what I wanted. Here is what the setup looks like:

This setup really does produce much better images than the sigma ring flash. Here are two very tiny Big-Headed Ants, one with the ring flash and the other with the Godox:

The lack of diffusion with the ring flash (top) leads to a lot more white spots on reflective surfaces. Also, the shadows are always coming to the far side of the camera. In a way this is good, the side you are looking at is illuminated. However, a more artistic type would probably complain about the inability to control the location of the shadows.

I am also trying this with a much larger 13"x8" diffuser. This diffuser is probably too large, but it does seem to give fantastic results so I may keep using it.

Using the larger diffuser seems to give fantastic results, but it messes up the center of mass of the camera rig so bad that it is unwieldy. Whether the slightly higher image quality is worth the fuss, I have yet to decide. I may get a medium sized diffuser in a few weeks.

This whole system is really an amazing deal. For under $300 you get a flash which can do TTL, High Speed Sync, and is radio controlled. It also can shoot thousands of macro shots on a single battery due to the Lithium ion battery. Unlike the similarly priced Sigma Ring Flash this flash is also useful for more than just macro as it is a typical speedlight.

Someone who wanted to reduce the cost could go with the Godox TT685S, it is basically the same flash just with AA batteries.

Someone trying to save cost and weight could go with the Godox TT350S. That flash reduces cost but at the cost of lower recycle times and lower maximum power.

Someone trying to save money could also go with a TTL flash cord. I don't actually recommend it though. The radio flash works amazingly well and the TTL cords seem over priced. There is a trick though with the transmitter, you need to turn it onto macro mode. This is done by holding down the test button while turning the transmitter on. If you forget to do this, it sometimes fails to fire unless it is more than 1 foot from the transmitter.

Someone wanting a bit higher quality flashes could use the Sony HVL-F45RM flash with the Sony Radio Control Wireless Commander. Again, I don't really recommend it. The setup costs three times as much for a slightly less powerful flash.

Friday, December 8, 2017

Aphids of Southern California

Looking back on the past few months it seems that I have done one of the more detailed and best documented searches for aphids which has been done in this area. It is nothing compared to Aphid Trek's 9,000 slide collection, but the more than fifty species I have found included species apparently never photographed, species apparently unreported in California, and even some which are almost certainly undescribed species.

After getting through so many, I thought it was time to put together one location where I can quickly reference all the aphids I have found in Southern California. I will add on to as I continue to find more. This should be able to serve as a quick reference for anyone trying to identify an aphid they found or looking to find more species.

Given the complexity of aphids I probably have a few incorrect identifications. Most have been confirmed by someone who knows more about aphids than I, but a few I have stubbornly held on to an identification which is not as certain as it should be.


Acyrthosiphon kondoi:
A common aphid on legumes. It can be separated from pea aphids by inspecting the antenna. The blue alfalfa antenna gradually darken to brown.

Host: I found it on a deervetch (Acmispon sp)

 Acyrthosiphon lactucae:

This is one of the most common aphids in California. However it is surprisingly difficult to find. When I first found it I had to stare at prickly lettuce plants for a good five minutes before I saw it. However once you start to watch for it among the flowers you will almost always find it.

Host: Prickly lettuce (Lactuca serriola) as well as cultivated lettuce


Aphis (asclepiadis?)
A difficult to identify aphid which I need to return to in an attempt to get a more certain ID.

Hosts: I found them on Red yucca (hesperaloe parviflora)

Aphis coreopsidis:

These aphids have distinctive antenna which are light at the base then dark, they also have a light head.

Hosts: A very common aphid on Bidens pilosa

Aphis craccivora:

A very common aphid on a wide variety of hosts. Unfortunately not very easily identified from photos due to the large number of black Aphis members.

 Hosts: I have mostly found these on the climbing milkweed (Funastrum cyanchoides) in my yard and on bur clover plants

Aphis (fabae?):

Very difficult to identify. I have never found one which is a solid ID for this species. However I included it since I found some aphids which are probably this species.

Hosts: The aphids I believe are this species were on nightshade and dock (Rumex) plants.

Aphis farinosa:
A rather generic looking green Aphis. On willows there are apparently not many similar aphids though making it reasonably easy to identify.

Hosts: Willows

Aphis gossypii:
One of the most common aphids in Southern California but not particularly easy to identify due to the number of similar Aphis species.

Hosts: I have found it on a huge variety of plants including star jasmine, roses, hibiscus, Bidens pilosa, and Triadica sebifera

Aphis (cytisorum?):
Another challenging to identify black Aphis

Hosts: I found it on Spanish broom(Spartium junceum).

Aphis nasturtii:
Yet another generic green aphid. The siphinculi is significantly lighter than melon aphids or spirea aphids.

Hosts: Primroses, thus far I have only found on Oenothera elata.

Aphis nerii:
This is probably the most commonly found aphids in Southern California. Find a milkweed plant, it almost certainly has loads of this aphid.

Hosts: I have found this only on Asclepias and Funastrum species although it can be found on a great many other plants.

Aphis pentstemonicola:
 Not particularly common but unusually easily identified from photos due to the large dark patches. 

Hosts: I found it on Penstemon grinnellii, although it is likely present on other Penstemons 

Aphis sambuci
Yet another generic Aphis. These seem to be distinctive due to how closely they pack on the stems of elderberries.

Hosts: I found these on blue elderberries, and docks (Rumex)

Aphis sedi:
These are so close to melon aphids that I am not certain I found them. However I have found aphids on a member of the stonecrop which look like melon aphids but have a dark cauda. 

Hosts: I only identified the host plant to the stonecrop family.

Aphis spiraecola:
 One of the most common aphids in Southern California, particularly in hotter months. It is present on a great many plants. On some hosts it is very difficult to separate from A. pomi but on many plants this is the

Hosts:  Seems like they are found on just about anything. Among other plants I have seen them on indian hawthorn. citrus, and Bidens pilosa.

Aphis Sp.
An aphid I found on docks and was never able to find a plausible species level ID for.

Hosts: Dock


Brachycaudus helichrysi:
I suspect that I have encountered this species much more as they just look to me like nymphs. Since nymphs are not typically identifiable I likely passed these by. When I found them they were with two Aphis species so I simply did not realize that there was a third species there.

Hosts: I found them on sunflowers, but they are likely to be present on many other plants.


Braggia deserticola
I only found this species because I noticed some ants among the flowers of a buckwheat plant. They hid well enough that I have probably walked past a great many.The really short siphunculi should separate them from other species in the genus.

Host: Buckwheat plants (Eriogonum)


Brevicoryne brassicae:

Cabbage aphids are one of the more reported aphids on iNaturalist due to how common and conspicuous they are.

Host: Mustards including wild black mustard and cultivated mustards such as cabbage, kale, and broccoli .


 Chaitophorus populicola:
One of the most common aphids on Poplar trees.  Easiest to identify from the winged alate form, but I never seem to find them.

Hosts: Poplar trees

 Chaitophorus sp 1:
 I found some aphids near Jenks Lake which don't seem to fit in any key. They must be an undescribed species.

Hosts: Willows

 Chaitophorus sp 2:
A batch of aphids I found in the Angeles National Forest but have not managed to identify to species.

Hosts: Willows

 Chaitophorus sp 3:
Another batch of aphids I found in the Angeles National Forest but have not managed to identify to species.

Hosts: Willows

 Chaitophorus sp 4:
Some aphids I found in Diamond Bar but have not managed to identify to species.

Hosts: Willows


Eulachnus (agilis?):

 This is a complicated genus which I need to do some research on. I only have found records of two species in the Eulachnus genus in California. If these are the two species I am finding than this one is E. agilis. Unfortunately it sounds like this genus is a mess, so confirming that will take some work:

Host: Pine trees

Eulachnus (rileyi?):

There is a very common species on pines in Southern California which sure looks like E. rileyi to me. However I have yet to be able to complete a key to identify one of these so given the complexity of the genus it may well be something else.

Host: Pine trees


 Essigella (californica?):
Like Eulachnus this is another genus of aphids on pines which I need to give some more thought to.

Hosts: Pine Trees


Eucarazzia elegans:
This is an oddball aphid which was relatively easily identified despite the fact I found it on a less than typical host.

Hosts: I found a group of them on a California Fuschia.


Greenidea (ficicola?):
The hairy siphinculi on this species makes it relatively easy tell from other aphids. I haven't done enough research to be certain there are not others in the genus, but as best I can tell this one is correct.
Hosts: Ficus trees


Hyperomyzus lactucae:
This is one of the most easily found aphids in Southern California. They are very common on sow thistle (Sonchus) plants which are a very common weed. The problem is that despite being common they are pretty difficult to tell from other members of the genus. In particular Hyperomyzus carduellinus is difficult to rule out. At the moment all the aphids in this genus I have investigated have been either inconclusive or Hyperomyzus lactucae though. So maybe that is the only species we have here.
Hosts: Sow thistles (Sonchus)


Hysteroneura setariae
Resembling yet another black Aphis, this is one of the more common aphids on grass. The pale sections on the antenna, tibae and cauda make this surprisingly easy to identify.

Hosts: A wide variety of grasses. I have found this most consistently on Bermuda Grass but it is not uncommon on other species such as Schismus


Illinoia liriodendri
Not a typical aphid of California but I found some on a Tulip Tree in a park.
Hosts Tulip tree (Liriodendron tulipifera)


 Macrosiphoniella ludovicianae
A difficult to identify inhabitant of Artemisia plants.

Hosts: I have found them on California mugwort(Artemisia douglasiana), they should be present on other members of the genus.


 Macrosiphum euphorbiae
If you search for Aphids in Southern California you quickly get tired of seeing yet another potato aphid. They inhabit a great many plants in huge numbers.

Hosts: I have found them on roses, prickly lettuce (lactuca serriola) sow thistles (sonchus), fleabanes (erigeron), orange bush monkeyflowers (mimulus aurantiacus), and white sage (Salvia apiana). Which pretty much means they eat anything.

Macrosiphum gaurae
A large aphid on primroses. Can be separated from M. euphorbiae by the additional dark on the siphinculi.

Hosts: I found it on Oenothera elata, it should be present on other primroses.
Macrosiphum rosae
One of the more common aphids, lots of look-alikes but I belive these can be identified due to the long dark siphunculi.

Hosts: Roses
Macrosiphum salviae
As far as I can tell I am the only one to have reported this aphid in California. The large dark patch on the back may be distinctive.

Hosts: Salvia greggii


 Metopolophium dirhodum
I will have to learn to pay attention to potato aphids on roses to make sure I don't confuse this one. They appear to typically be lighter colored than potato aphids.

Hosts: I have seen rose grain aphids on grasses. Presumably they also can be found on roses.


Mindarus Sp.
Relatively found on white fir plants because of the curling of newly grown in leaves they cause. They proved to be very difficult to get to species.

Hosts: I always found on white fir (Abies concolor)


Myzocallis punctata
One of the more brightly colored aphids. Supposedly there are some look-alikes but I haven't really researched the genus.

Hosts: Oaks

Myzocallis sp.
A drab aphid which proved incredibly difficult to get to species. I may try again once I finish some microscope upgrades.

Hosts: Oaks


Myzus persicae
Green peach aphids, another weedy aphid present on a wide variety of hosts.
Hosts: I most often find these on the leaves of mustard plants. I have also found on Vinca major.


Neophyllaphis (varicolor?)
Before doing this I failed entirely to grasp the transient nature of aphids. When I found this species in August they were ridiculously common. Then they disappeared within a few weeks of my seeing them and I have not seen them again.

Hosts: Afrocarpus falcatus. Although they must go somewhere when it isn't August...


Neosymydobius (paucisetosus?)
I came to the conclusion this is N. paucisetosus, or it seemed to key out correctly but any time a species is previousy unphotographed it is hard.

Hosts: Oaks


Neotoxoptera formosana 
Late the last few winters a plague of these descended on my onions. They seem to disappear by late spring.

Hosts: Onions and chives


Pterocomma Sp.
Now that I know a bit more about aphids I will have to track down this genus and try again to identify to species. Thus far I have failed to identify one though.

Hosts: Willows


Pleotrichophorus gnaphalodes
A hairy white aphid which I suspect is rather common and easily identified on California mugwort.
Hosts: California mugwort(Artemisia douglasiana)

Pleotrichophorus oestlundii
A well camouflaged species which can be found on Goldenbush plants.

Hosts: Ericameria


Pterocallis alni
A small aphid resembling a chaitophorous species. I found it in a park on an Alder tree. Thus far I have not been able to find it on Alder trees in wild areas.
Hosts: Alders


Rhopalosiphum (maidis?)
I found some grass aphids and completely failed to key them out. Looking at pictures of R. maidis it seems like they must be R. maidis though.

Hosts: I found it on a grass in the genus Phalaris, but it should be on many other types of grass.

(Rhopalosiphum nymphaeae?)
Often I find aphids after I get home. This aphid hiding on duckweed was one of them. A shame I didn't see it in the field or I would have got better photos.

Hosts: Duckweed

Rhopalosiphum padi
As far as I can tell this is one of the more common and easily identified of aphids on grass. The rust color around the siphunculi stands out a lot.

Hosts: Grasses and similar monocots. Hordeum murinum and Iris are two examples.


Sarucallis kahawaluokalani 
In the running for the hardest aphid name to say. Luckily it is about the easiest aphid to find and identify. Find a crape-myrtle tree. This isn't hard, you probably see a hundred trees a day as they are such commonly planted street trees. Look under a couple of leaves. There, you found it.
Hosts: Crape myrtle (Lagerstroemia indica)


Schizolachnus sp.
Did I mention pine aphids were hard?

Hosts: Pines


Sipha maydis 
A recent introduction to Southern California which is now one of the most common aphids on grasses.

Hosts: Grasses. I have found it on a couple grasses such as Hordeum murinum


Sitobion fragariae 
Another generic green aphid. Commonly found hiding among grass seeds.
Hosts: I have found on Hordeum murinum should be present on other grasses.


Stegophylla (essigi?)
This aphid can be commonly found on live oak trees by looking for either white fluff on the leaves or folded up leaves. I haven't been able to solidly confirm species, but it is probably S. essigi.

Hosts: Oaks


Tamalia Sp. 
These are what make the red galls on Manzanita plants. Almost all the Tamalia on iNaturalist are marked as Tamalia coweni. In parts of the state this might be accurate, but I suspect many are other members of the genus in many of those galls. If you find these, try to get a picture of the actual aphid, not just the gall.
Hosts: Manzanita


Therioaphis trifolii 
These have been present in my back yard for some time. They hide under clover leaves. Despite a lot of looking I have yet to see any on clover plants not in my yard.
Hosts: Clover


Tinocallis saltans
Surprise! Another aphid!

Hosts: Siberian elm, Ulmus pumila.

Tinocallis (ulmiparvifoliae?)
This is a common aphid in urban areas. It only has a winged form. I believe the bumps and markings on its head and thorax make it T. ulmiparvifoliae but I don't know the genus well.

Hosts: Elms. The type you usually find in parks in Southern California. 


Uroleucon ambrosiae
One of the red aphids that can be found on top of mule fat plants. Apparently there is some controversy as to whether this species actually inhabits plants other than ragweed, but it sure seemed to key out to this.

Hosts: Mule Fat

Uroleucon erigeronense
Looking suspiciously like potato aphids, these are supposed to be common on plants of the sunflower family.

Hosts: Telegraphweed (Heterotheca grandiflora)

Uroleucon picridis
Apparently both U. picridis and U. sonchi live on bristly ox tongue. Every time I find them though they seem to key out to U. picridis.

Hosts: Bristly ox tongue (Helminthotheca echioides)

Uroleucon sonchi 
There are supposed to be a great many Uroleucon species present on sow thistle. I often think I found a new one of them. Thus far every single one has been U. sonchi on closer examination.
Hosts: Sow thistles.

Uroleucon Sp. 
This species was very common northwest of Palm Springs on Brittlebush plants. At the time I was not up to the task of identifying it beyond genus but I will have to try again next spring. 

Hosts: Encelia farinosa


Wahlgreniella nervata
These have been on the tree in my front yard for a couple years now. They seem to come in waves where sometimes I can hardly find them and other times they are everywhere. Somewhat unusual in having two color forms.

Apparently species are poorly understood in this genus so the identification is somewhat tenuous.

Very common on Arbutus trees and can occasionally be found on roses.