There are some kind of teeny tiny white and black bugs all over my Colocasia 'Mojito' and 'Black Magic'. The insects are covering both sides of the leaves as well as the stems. I just sprayed them down thoroughly with Safer Insecticidal soap. Will Safer do it or will I have to go stronger? And is this going to be an ongoing battle all summer? I just bought these plants about 6 weeks ago so I have no experience.

What are these insects? They don't look like the aphids I have seen on roses and other plants. These were not yellow. They were smaller than regular aphids and they were white and black.

Thanks!
Carol

Here are some photos of the invaders.

Carol

Oh yeah. Those were aphids. I'm not sure if insecticidal soap is going to cut it. That is a heck of an infestation.

Aphids come in very many colors and even sizes. They can be creamy, green, orange, red, pink, black, and other colors. So color does not tell whether it is an aphid . . .

LariAnn

Does anyone have these Mojito or Black Magic? Is this going to be an ongoing battle all summer?

Thanks,
Carol

I grow quite a selection of elephant ears, including Black Magic, and I have never had aphids on them at all. I didn't even know they were attractive to them!

Dave, glad to know that you grow Black Magic and other EEs, too. I think they are increasing in popularity.

I found so few people with the same problem (aphids) on the internet that it must be uncommon. I don't know why they attacked mine, but you can see by the photos that it was definitely an onslaught. I think I have them whipped for the short run. Will have to keep my eyes open for the long run.

Carol

This site discusses Taro as a food crop including some "Pests and Diseases". Aphids, as well as spider mites are noted.
http://www.greenstone.org/gree...

Evan, thanks for the link. Much appreciated.

I was sad to read that these are also susceptible to root knot nematodes. I planted mine with tons of organics - aged manure, peat and bone meal - and I have read that organics are the enemy of root knot nematodes. Hopefully mine will be ok. They are planted in the ground, not in pots.

Do you grow taro? If so, what are your favorites? Very interesting to see that you live in the birthplace of Dr. Seuss. Is there a museum in your town?

Carol

Hi Carol,
Aside from what was labeled as the species, C. esculenta, I've got Mojito, Thai Giant and Black Coral and Bikini Tini which just arrived from Brent and Becky's. The Springfield MFA has a permanent collection of Dr. Seus work and some bronzes of his characters in the Quadrangle. The kids love them.

See if soaking the leaves in honey mixed with water could remove your aphids through creating a sticky coat of water on the outside, drowning the pests.

Better yet you can always order some ladybugs.

Hi Mangogirl ,

I had the same experience last year when I purchased two plants from the “Royal Hawaiian Colocasia Collection”. One a small “Hilo Bay” the other a very small "Blue Hawaii”. The Hilo Bay took off right away, but the Blue seemed to be struggling and never looked very happy like something was missing. It wasn’t too long before I noticed it was starting to acquire a growing numbers of aphids and when new foliage grew out it always looked damaged. It barely made it through the winter in protected quarters. I ended up taking it in the house because I was sure it would rot before it came out of dormancy if I didn’t. I fought the aphids on it last winter, while in the house, and now this spring outside. Time for drastic measures, Last week I pulled it out of the pot it had been in for the last 10 months washed about half of the dirt in the root ball off and placed it back in the same container adding a commercial acidic soil blend. Then I proceeded to soak it thoroughly. I really didn’t know if it would live through the trauma or not! Two days later it not only looked happier, it changed from a dark musky green color it had always been, to a real vibrant light green. I was shocked at the color change also, that there were no aphids that I could see on the plant what so ever. Now, I have noticed this year the ants are trying to “farm” some very large burnt blades on a couple Colocasia plants that were stressed during the time (a couple days) I was adjusting their new foggers to get the volume right. Based on these two observations, I conclude that when plants are stressed that insects somehow must zero in on the plant’s weakened condition for a quick meal. I’m quite sure if I could ask LariAnn (PLEASE) to comment on my observations I will learn more on the subject, do insects in fact “feel” a stressed plant is in trouble?. I have many other Colocasia and Alocasias and have only seen this one time before (on a Black Magic) that was thoroughly stressed out and declining rapidly just before the first frost last year. After dormancy it started growing quickly without the aphid problem. I hope this may have helped you in some way with your problem solving process, Good Luck!

Birdmanmar,
You are on the right track - stressed plants do give off a "signal" that attracts pests. In fact, one way to find out if your plants are in trouble is if they begin to be infested with pests. A few pests are normal (but unacceptable to us gardeners) but excessive numbers are a sign that something is amiss with your plant. I also note that you mentioned switching your soil mix to an acidic blend. That is significant because I have found that many aroids prefer an acidic blend/fertilization, particularly Alocasias and Anthuriums. In fact, I had some Anthuriums that were barely hanging on until I started giving them Miracle Gro acid blend (for azaleas and rhododendrons). Some of the finickiest Alocasias are finicky in part because they don't get the acidic mix and fert they really need. So they rot instead.

IMHO, when a plant begins to succumb to pest infestation, it is nature's method of taking the plant out of an unsuitable niche. If a niche is suitable, the plant thrives and pests cannot overtake it, but if the niche is unsuitable, the plant will be "forced out" of the niche to make way for a more suitable plant. So if we want to keep a plant "in captivity", we have to make the niche as suitable to it as possible, which means paying more attention to things like soil pH as well as soil medium composition, watering, light, temperature, nutrition and aeration. Growing plants in containers and gardens is growing them outside of the natural balance so we must be responsible for providing the proper balance, or nature will do it for us, even if it means we lose the plant!

LariAnn
Aroidia Research

Carol, I would just keep treating with the soapy water spray every few days, and also hose the plants off to wash off any aphids between soap treatments. My Blue Hawaii had a few aphids when it was very small, but soaping and washing cured the issue just fine. IF you persist you can win. A stronger chemical is not going to kill the aphids any faster or better. Dead is dead. Just be sure the soap gets down in the leaf axils etc.

Try mulching around the root zones of your plants with melaleuca mulch, too. It has aromatic oils that insects dislike, and I always find that after I put down fresh Florimulch, the insects are much fewer for weeks afterwards.

Best thing for spider mites or aphids is AVID miticide by SynGen. Expensive but extrmely effective.
I lost my patience and money getting rid of mites on my very very large Black Magic. Tried
all kinds of insecticide labeled for mite, nothing, they seemed to thrive on the stuff.
One application with AVID and it was like a theromuclear attack, gone, zip, nada left of the Mites.
AVID will not harm plants specifically Black Magic which is very tender foliage.

I have Nancy's Revenge, Mojito, Pink China, Black Magic, Hydrax, alocasia Nile High and Esculenta and
about 50 Caladiums.

None have ever shown any aphids or Spider Mites on them. Let them beware my new Nuclear arsenal
will wipe them out. This stuff is incledible [a bit expensive] but well worth it.

An additional note about spraying pesticides - avoid spraying in the heat of the day. It is best to spray in earlly morning or early evening so as to avoid phytotoxicity due to excessive heat on the leaf surface.

LariAnn