Woolly Aphids

beetleman · Post by **beetleman** » Thu Oct 05, 2006 6:00 am

Found these aphids on a Mountain ash tree. This is the same tree ( in very rough shape) that has the lichen and the shelf mushrooms on it that I have posted before in the forums. From what I have read, eggs that have over wintered hatch as all females giving live birth to females. As autumn returns, a generation appears which includes both males and females. After mating, the females lay the fertilized eggs that overwinter and eventually hatch into wingless females in spring. I did see a few moving around but the next day I tried to touch them and they seemed to be dead. I moved them away and their were clusters of yellow eggs under their bodies. It is like they lay their eggs, cover them with their bodies, and than die. For the second picture I did a focus bracketing shot and combined the three images with Helicon focus for a little more DOF.

puzzledpaul · Post by **puzzledpaul** » Thu Oct 05, 2006 7:08 am

Interesting pics and scenario - makes me wonder where the males come from?

Top pic puts me in mind of a wedding reception for a couple of 'heavenly bodies' ... where a group of angels decide they want to dance and unclip their wings (dzus fasteners?) and thow them down on the ground ('cos they get in the way)

Or is that stretching things a bit ... ?

pp

Wim van Egmond · Post by **Wim van Egmond** » Thu Oct 05, 2006 7:41 am

Wow, that's weird!

Wim

rjlittlefield · Post by **rjlittlefield** » Thu Oct 05, 2006 3:37 pm

puzzledpaul wrote:Interesting pics and scenario - makes me wonder where the males come from?

Sex determination is different in aphids than in people. People use an XX/XY system: two X's makes a female, one X plus one Y makes a male. No male, no males ever again. But aphids use an XX/XO system: two X's makes a female, one X by itself makes a male. So, no sweat (for an aphid!) to make a male given just a female.

Google search on "male female sex determination" will get you a bunch of articles talking about the wonderful diversity of methods that Nature uses to get male and female. Quoting briefly from Wikipedia,

Most mammals, including humans, are genetically determined as such by the XY sex-determination system where males have an XY (as opposed to XX) sex chromosome. ... The ZW sex-determination system, where males have a ZZ (as opposed to ZW) sex chromosome may be found in birds and some insects and other organisms. Members of Hymenoptera, such as ants and bees, are determined by haplodiploidy, where most males are haploid and females and some sterile males are diploid. In some species of reptiles, including alligators, sex is determined by the temperature at which the egg is incubated. Other species, such as some snails, practice sex change: adults start out male, then become female. In tropical clown fish, the dominant individual in a group becomes female while the other ones are male. In some arthropods, sex is determined by infection. Bacteria of the genus Wolbachia alter their sex; some species consist entirely of ZZ individuals, with sex determined by the presence of Wolbachia.

So you see, just knowing about the birds and the bees isn't enough!

(That's what my parents always told me, anyway. It's nice to know they were right.

)

--Rik

Carl_Constantine · Post by **Carl_Constantine** » Thu Oct 05, 2006 3:46 pm

Well, I'm sure the women of the forum are glad it doesn't work that way for us humans. As a man, I'M GLAD it doesn't work that way!

ok, I'll shut up now before Sue or Teva come over and slap me with a 2x4.

Anyway, when I first saw this picture I thought it was some sort of flower growing on the tree, but then I actually read the description. Pretty interesting. I've not seen anything like that up here in the great north west. Good Shot Doug.

Ken Ramos · Post by **Ken Ramos** » Fri Oct 06, 2006 3:14 am

Great set of photographs Doug.

I'd be careful though, there was a guy on here about a year ago who took issues with woolly aphids.

MacroLuv · Post by **MacroLuv** » Fri Oct 06, 2006 4:07 am

Uhmmm.. Well, now I'm thinking.. am I altered by the bacteria? If all that is true, in any case, it seems like a males are females with a serious defect.

salden · Post by **salden** » Fri Oct 06, 2006 4:15 am

I think they are pretty. Nice image and they remind me of flowers too.

beetleman · Post by **beetleman** » Fri Oct 06, 2006 5:14 am

You know what you don`t see in this picture are Heads, legs, and bodies. There is one showing along the lower edge of the group that has a head and legs. When I first saw the aphids, I thought they were feathers and that a bird had struck the tree and left little spots of downy feathers stuck to the tree

Thank you all for commenting on my pictures