dracaena with scale (i think)
 

I have a dracaena:
http://home.grandecom.net/~arborwork...2004_10_31.jpg

Which I think has scales:
http://home.grandecom.net/~arborwork...2004_10_31.jpg
http://home.grandecom.net/~arborwork...2004_10_31.jpg

First I ignored it, hoping it would go away.
When it got bad, I half-assedly scraped a bunch off with my thumbnail.
When it got bad again, I painstakingly scraped evey scale off every
leaf with my thumbnail outdoors and sprayed off the leaves with a
hose.
Now that some are back, I'm looking for a more reliable solution
before it gets bad again.

Google turned up a few ideas, from swabbing them off with a qtip
dipped in alcohol, to spraying with hort. oil, to discarding the plant
(absolutely a last resort for me.

Anyone have some encouraging words, preference for one of the above
remedies, or better ideas?

TIA,

Keith
For more info about the International Society of Arboriculture, please visit http://www.isa-arbor.com/home.asp.
For consumer info about tree care, visit http://www.treesaregood.com/

The hort oil should work. Insecticial soap and using a soft brush
should work too. Another method is to use a Q-tip and swab with
rubbing alcohol. For a more drastic cure, set the plant in a trash
bag, spray with malathion, and close up the bag for 2 days. Repeat
the procedure in 10 days. There are over 200 species of scale insect.
Females molt twice and remain on the host plant; the male molts twice,
pupates, then emerges as a winged-adult to find a female. Scale will
infest nearby plants, so it is best to isolate your dracaena (it may
be getting re-infected.) I had two parlor palms heavily infested
with scale, and finally got rid of them using a series of systemic
insecticide treatments.

Phisherman wrote:

The hort oil should work. Insecticial soap and using a soft brush
should work too. [...] For a more drastic cure, set the plant in a trash
bag, spray with malathion, and close up the bag for 2 days. Repeat
the procedure in 10 days. [...] I had two parlor palms heavily infested
with scale, and finally got rid of them using a series of systemic
insecticide treatments.

Agree with the above. In FL, we had several encounters with
scale on rare or otherwise desireable plants. The oil and/or
soap controlled minor infestations, but for heavy ones, I had
to resort to Orthene (a systemic), which seemed to me the
least frightening of a bunch of nasty chemicals.

Some synthetic insecticides can cause severe eye damage and
other problems if ingested or on contact. I followed label
instructions to the letter (gloves, long-sleeved clothing, eye
protection, washing all clothes separately after application)
and emerged unscathed. Saved some beautiful plants, too.


Mike Prager
Beaufort, NC (on the coast in zone 8a)
(Remove spam traps from email address to reply.)

Hi Keith,
First I'd like to say that your plant appears to be a yucca and not a dracaena. If the edges of the leaves are serrated and feel rough, then you have a yucca.
http://www.evergrowing.com/tips/yucca.htm

I don't use toxic chemicals like Malathion and don't recommend them. I would suggest that you use a horticultural oil. The timing of the application is important. From this site:
http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7408.html

"Spring/Summer Treatments. Dormant season applications of oils are not appropriate for scales on citrus or avocado because these trees do not enter a winter dormancy; oils are best applied to these trees in spring or summer. Horticultural oils can also be used in spring or summer against scale crawlers on deciduous plants. Treatment at this time requires more spray volume than a dormant treatment because foliage as well as bark must be thoroughly covered. Spring or summer applications must be carefully timed to reach crawlers, which are the most susceptible stage. Use traps made of double-sided sticky tape to determine when crawlers are hatching. Before crawlers begin to emerge in spring, tightly encircle several twigs or branches on the infested tree with transparent tape that is sticky on both sides (this tape is available at stationery stores). Change the tapes at regular intervals, about weekly, and examine the tapes with a hand lens to identify the crawlers. Once eggs begin hatching, scale crawlers get stuck on the tapes and appear as yellow or orange specks."

Newt

On Fri, 5 Nov 2004 22:08:44 +0000, Newt
wrote:

Hi Keith,
First I'd like to say that your plant appears to be a yucca and not a
dracaena. If the edges of the leaves are serrated and feel rough, then
you have a yucca.
http://tinyurl.com/66f3s
You may be right. The edges are quite sharp and I have the "paper
cuts" from my scale-scraping to prove it. I was basing my ID on the
growth habit and similarities to dracaenas I've seen.

I don't use toxic chemicals like Malathion and don't recommend them.
I'm with you. I'd sooner give up on the plant.
I would suggest that you use a horticultural oil. The timing of the
application is important. From this site:
http://tinyurl.com/3wgu9

"Spring/Summer Treatments. Dormant season applications of oils are not
appropriate for scales on citrus or avocado because these trees do not
enter a winter dormancy; oils are best applied to these trees in spring
or summer. Horticultural oils can also be used in spring or summer
against scale crawlers on deciduous plants. Treatment at this time
requires more spray volume than a dormant treatment because foliage as
well as bark must be thoroughly covered. Spring or summer applications
must be carefully timed to reach crawlers, which are the most
susceptible stage. Use traps made of double-sided sticky tape to
determine when crawlers are hatching. Before crawlers begin to emerge
in spring, tightly encircle several twigs or branches on the infested
tree with transparent tape that is sticky on both sides (this tape is
available at stationery stores). Change the tapes at regular intervals,
about weekly, and examine the tapes with a hand lens to identify the
crawlers. Once eggs begin hatching, scale crawlers get stuck on the
tapes and appear as yellow or orange specks."

Newt
Thanks for the info (and same to the earlier responses). I'll have to
drag this thing back outside some weekend soon, I guess, for a quick
shot, and I'll take a more thorough approach this spring.

k
For more info about the International Society of Arboriculture, please visit http://www.isa-arbor.com/home.asp.
For consumer info about tree care, visit http://www.treesaregood.com/

Keith,
You are very welcome! Good luck with your yucca!
Newt