Juniperus chinensis - white dots
- Thread starter Krone
- Start date
Wires_Guy_wires
Imperial Masterpiece
Looks like scale aphids, I used neem oil to combat them in my junipers together with an insecticide. It seemed to work. But I found they need around 3 treatments per year in heavy infestations.
Wires_Guy_wires
Imperial Masterpiece
Steps:
1. Identify the pest with a magnifying glass or microscope and make sure it is what I think it is.
2. Put my bottle of neem oil in some warm water, shake every 2 minutes until it's mixed again.
3. Grab an old spray bottle, fill half with warm water.
4. Add 100mL (two or three teaspoons) of neem oil.
5. Add drops of regular dishwashing detergent and shake after every drop. Make sure the neem oil emulsifies. Then add water until the bottle is almost full.
6. Then add my oil-based insecticide (in my case a product called Promanal-R, which I checked for interactions with neem) per product instruction.
7. Let cool to room temperature.
8. Shake before use and use every week for 3 weeks in the evening.
Scale aphids usually die, but they don't drop off. A quick spray with the watering hose sure helps. Make sure you don't spray your plant out of the pot and avoid hitting the soil.
1. Identify the pest with a magnifying glass or microscope and make sure it is what I think it is.
2. Put my bottle of neem oil in some warm water, shake every 2 minutes until it's mixed again.
3. Grab an old spray bottle, fill half with warm water.
4. Add 100mL (two or three teaspoons) of neem oil.
5. Add drops of regular dishwashing detergent and shake after every drop. Make sure the neem oil emulsifies. Then add water until the bottle is almost full.
6. Then add my oil-based insecticide (in my case a product called Promanal-R, which I checked for interactions with neem) per product instruction.
7. Let cool to room temperature.
8. Shake before use and use every week for 3 weeks in the evening.
Scale aphids usually die, but they don't drop off. A quick spray with the watering hose sure helps. Make sure you don't spray your plant out of the pot and avoid hitting the soil.
Wires_Guy_wires
Imperial Masterpiece
I added a zero too many, it should be 10mL-50mL per liter of water. Otherwise you'll be using so much dishwashing detergent that it will damage the wax layer (cuticle) of the juniper. Junipers kind of need that layer to survive, that's why some people experience horrible failures with oil-based insecticides; either the cuticle dissolves in the oil and gravity does its job, or the emulsifier is present in such an excess that it dissolves the cuticle; after the first rain shower it just washes off. Detergent is made to do that, so it's better to use too little instead of too much.
If you can get a good insecticide meant for scale aphids, then I suggest you use that stuff instead. It's less of a hassle compared to making your own mixture. The Promanal-R that I use can even be used on its own, but most plants still need at least 3-4 treatments.
One thing to maybe keep in mind: I found all of my junipers to get this kind of scale, except for some Sabina junipers and one single chinensis juniper. The chinensis smells like it has been treated with lime sulphur, I've only had it for 6 months now, so I don't know how it's been treated before. But the smell is obviously lime sulphur. I know some people use heavily diluted lime sulphur as an insecticide. And honestly, it seems to work. I don't know what the ideal concentration would be, or what the best time for this treatment would be either. That might be something to look up.
If you can get a good insecticide meant for scale aphids, then I suggest you use that stuff instead. It's less of a hassle compared to making your own mixture. The Promanal-R that I use can even be used on its own, but most plants still need at least 3-4 treatments.
One thing to maybe keep in mind: I found all of my junipers to get this kind of scale, except for some Sabina junipers and one single chinensis juniper. The chinensis smells like it has been treated with lime sulphur, I've only had it for 6 months now, so I don't know how it's been treated before. But the smell is obviously lime sulphur. I know some people use heavily diluted lime sulphur as an insecticide. And honestly, it seems to work. I don't know what the ideal concentration would be, or what the best time for this treatment would be either. That might be something to look up.
parhamr
Omono
I manually kill juniper scale.
They’re easy enough (though I do have great eyesight) to find and squish by hand, with a toothpick, or chopstick. This requires only enough force to contact the insect and doesn’t damage the foliage.
They’re easy enough (though I do have great eyesight) to find and squish by hand, with a toothpick, or chopstick. This requires only enough force to contact the insect and doesn’t damage the foliage.
wireme
Masterpiece
Even with a microscope I sometimes find it difficult to differentiate between scale and resin flecks on my Junipers.
Do you ever question that yourself? It really should be easy with a scope I think yet sometimes I have a hard time being sure. I think if I can’t say for sure then it’s probably resin, the scale itself should have defining enough characteristics.
Wires_Guy_wires
Imperial Masterpiece
Wow, that's a good one! I have never found any resin specs on junipers. Their resin seems to dry up transparent over here, not like the white stuff we see on pines or spruce. Talking about those, they have some cool stuff running through their veins that gave me a lightbulb.
Resin specs have this awesome ability; they can become liquid again in most organic solvents, whereas insects do not. Put a few specs in cheap turpentine (is that white spirit in English?) and you'll know within minutes. Chitin usually doesn't degrade without the help of chitinase and I found that most insects do get more transparent in organic solvents (or in ethanol/methanol), but they don't dissolve. This might help distinguish and define certain characteristics.
Even though I use different microscopes 5 times a day, I still suck at the terminology.. So bear with me on this one ;-). When using a binocular microscope, viewing top down with light from below, most insects are hard to distinguish. I have this cheap Chinese USB-microscope that views from the top down, and lights from the top down as well. This one has proven to be pretty useful for determination, especially since I can use black plastic or black paper below the object. This really helps on finding almost transparent legs and antennae. These microscopes will cost you around 20 bucks on amazon or ebay. I do have to warn you: they suck for cell work and everything that's liquid because of those top-down lights, simply because you'll be viewing the reflection of the lens or the lights themselves. But for 'in the field' work and simple pest determination they are pretty useful.
wireme
Masterpiece
Wow, that's a good one! I have never found any resin specs on junipers. Their resin seems to dry up transparent over here, not like the white stuff we see on pines or spruce. Talking about those, they have some cool stuff running through their veins that gave me a lightbulb.
Resin specs have this awesome ability; they can become liquid again in most organic solvents, whereas insects do not. Put a few specs in cheap turpentine (is that white spirit in English?) and you'll know within minutes. Chitin usually doesn't degrade without the help of chitinase and I found that most insects do get more transparent in organic solvents (or in ethanol/methanol), but they don't dissolve. This might help distinguish and define certain characteristics.
Even though I use different microscopes 5 times a day, I still suck at the terminology.. So bear with me on this one ;-). When using a binocular microscope, viewing top down with light from below, most insects are hard to distinguish. I have this cheap Chinese USB-microscope that views from the top down, and lights from the top down as well. This one has proven to be pretty useful for determination, especially since I can use black plastic or black paper below the object. This really helps on finding almost transparent legs and antennae. These microscopes will cost you around 20 bucks on amazon or ebay. I do have to warn you: they suck for cell work and everything that's liquid because of those top-down lights, simply because you'll be viewing the reflection of the lens or the lights themselves. But for 'in the field' work and simple pest determination they are pretty useful.
That’s a great idea, the turpentine. Hopefully I have some in the garage somewhere. I’ll show you some of the white specs sometime, by the naked eye they certainly appear to be scale but I don’t think they are. If I can find the turps I’ll take a pic, check under the microscope and try dissolving them and get back to you
My microscope is old school but can light from top or bottom or both, never thought to lay black underneath. .
