Mealy bug friendly?

[Tina]

Astophytums, echeveria's and stapeliads always seem the most tasty for mealies in my collection.
I used proavdo a lot last year doing the whole collection but I still spotted some agiin, I'm going to try neem oil this year & maybe Malathion ( last resort)- with this do people spray or dip OR both ??

[IainS]

Hi Xannydoo!

Confidor is excellent (IRAC Insecticide Group Code 4A). If I have to apply anything serious, this would be my first choice. It is certainly used by cacti/succulent nursery professionals in hot countries such as South Africa but I have no experience of Australian commercial nurseries. As with any insecticide, don't overuse it because the nasty wee beasties can soon adapt and become resistant. Kemperin 200 EC is my second choice (IRAC Insecticide Group Code 3).

I worked in Australia with endangered wallabies for several years, so I'm familiar with your conditions. Pests breed quicker than quick in your hot country, compared to here in the UK. How long is enough time with regards to quarantine? Think "life cycle" of the unwanted beasties, rather than any narrow advice re. time. A "correct" answer would need to take into consideration time of year/season and speed of the life cycle. And if in doubt, be cautious. I'm also a professional nurseryman, but not cacti/succulents, and I've always been able to use hardly any insecticides in my business. But mealy bugs and other nasties are common in cacti/succulent collections so an initial precautionary treatment of new in-coming plants is advisable.

Learning better self-discipline may not be easy nor immediate, but it is cheaper than buying insecticides (and very environmentally friendly!). Good and bad habits usually last a life time, so unless you're near the end it's worth investing the effort to get better. Prevention better than cure, etc. If you know about the famous marshmallow test on young children, the consequences are felt for decades later as adults in differing ways. Bee prepared! (Sorry.)

[IainS]

Xannydoo: An extra thought. If you are having annual outbreaks, yet treating with Confidor, I wonder if the problem is actually repeated introductions, rather than a failure of the insecticide? In other words, are you adding new infected plants to your greenhouse each year?

And here's a link that's a popular introduction to the marshmallow experiment. It would be good to do a mealy bug equivalent.

https://www.youtube.com/watch?v=amsqeYO ... 5KJ0ytnANZ

[Ali Baba]

Although life cycle is important, think rather of your ability to spot very low level pest numbers. In practice pest numbers are quite high by the time I can spot them, even with a hand lens. So I keep new plants separate for a couple of seasons. It also depends on your host plants characteristics. Succulent monocots are good reservoirs of unseen colonisation for false spider mite particularly as they hide under the leaf bases, causing mysterious damage with no sign of external pests, until the colony size gets quite significant. For mealy bug removing all compost and dipping is most cost effective in the long run as there are no dry spots in the compost where mealies can escape, plus I reason you get maximum systemic uptake

[TS Hakansson]

I for one find that mealies suddenly appears on plants that i have had for maybe ten years and there are no others in the vicinity of the affected plant that have mealies ? Some years there are no mealies whatsoever, other times there might be ten-fifteen plants affected. Since there are relatively few (out of more than 2500) its no big deal to get rid of the blighters, but it means that you have to be on your toes all the time to be able to stop them before a major outbreak. Removing all the substrate and hosing them down with rainwater helps a long way, because i don´t like to use systemics...

[Tina]

At a convention this weekend someone said just soak your plant in water with detergent, you can only do this really in the summer but I suppose it might work as the detergent would permeabilise (?) the mealie exo skeleton.

[Peter]

Well Tina, I'm not dunking 3000 cacti in a bowl of Fairy Liquid. They probably mean spray them with soapy water but I can't recommend such a procedure as some plants will scar. Given what's involved we may as well use systemic, which, given the right one, works a treat.

[Terry S.]

In his original post, Brian said that he did not like spraying chemicals on his plants. However, what is Neem Oil but a mixture of chemicals which contains various triterpenes as its active ingredients. Because something is of natural origin, does not mean that it is "better" or "non-toxic". Taking a dose of a natural plant extract, hemlock, didn't do Socrates any good!

The amateur does not have many chemical controls still available for controlling mealy bug. Imidocloprid has been largely withdrawn because of its alleged effect on bees. The best bet at present would seem to be a product based on Deltamethrin and the latest reincarnation of Provado has this as its active ingredient.

The use of detergents was mentioned and these are surfactants which effectively suffocate insects. If you wish to use this approach then the best treatment is to spray with SB Plant Invigorator. This will kill most pests but does not effect eggs and is contact only. Therefore respraying at frequent intervals will be necessary to eliminate bug infestations.

[Xannydoo]

Thanks IanS , interesting watching the marshmallow test. As I'm nearer the end than the beginning I have an uphill battle to discipline myself!
So far Confidor is still available in Australia ,so I think the immediate soaking of new plants is sensible and as I have another glasshouse now I can quarantine for a season or so.
I too use a hand lens and mealy numbers are low , only on a couple of plants, but then I have to treat everything.
I did find a huge number two years ago on an epiphylum that was too big to move , and it has taken a while to completely get rid of them.The epiphylum unfortunately had to go on the bonfire!
In the last 12 months I have completely unpotted all new plants, which luckily made me aware of root mealies from some plants I bought at a national show. As I don't have any mealies anywhere else in the garden I must presume I am introducing them or not getting rid of all of them with my spraying regime.
So, self discipline it is, as it is much cheaper and healthier for us and the bees to reduce the use of chemicals.

[Brian]

Wilk, I use the neem oil three times a year. First dose should be any day, it seems to have worked in the past. I water it in, not spray it. If you spray it there is the danger of disfiguring the plants., for example echeveria .

Usually spring (now) then July and final dose September or October. I found a few mealies a couple of weeks ago and put the plants outside. Sorry for late reply, locked out because of problems logging in.

One or two baldy plants is okay, but I agree not as much fun as spiky and nasty plants!