Bug questions

Are there some hoyas that are more prone to bugs, ie mealies, spider mites, etc. than other hoyas? I've had a couple Iris Maries over the few years I've collected - lost all to spider mites! Now, my current Iris Marie (that bloomed!) has spider mites - so did chlorantha and cembra. I've already put them in a closed baggy after spraying them with neem. But it got me thinking about whether some hoyas are more prone to bugs than others. The cembra and Iris Marie are the "bush" hoyas...is that a connection? Or is it the conditions - ie more/less humidity, more/less heat, more/less water, etc. Anybody have any thoughts on this? Also, how can you tell when the plant is spider mite free? Mine have been baggied up for a few days - still have that spotted discoloring from the spider mites - are the mites still there, will the discoloring go away? Thanks for your thoughts!

Karen

Karen...the discoloration will not go away because it is the chlorophyll sucked out of the leaf. Generally, I find, the thin leafed hoyas like H. cembra are more prone to mites and whiteflies. Others, like H. naumanii and H. magnifica are faves of the mealie bugs...the furry leafed ones get mealies easily. Yes...bugs like certain conditions. The spider mites need to be sprayed every 5-7 days, generally 3 times to get the eggs which they have laid. One application won't do it. Using neem you are trying to suffocate them...they aren't being poisoned...so continual application is needed. Good air circulation will bother the mites/whiteflies and so will spraying water under the leaves....they hate it and are reluctant to colonize.

I get anal and spray about every 4 days....and then spray alot of water on them inbetween. Use the finest spray you can get...like a fine mist so you can get the best coverage!!!!

HTH,
Carol

Karen, I'm sorry to hear about your beautiful iris marie's. I hope you will be able to save this one. If you cut off those leaves will new ones grow in their place?

Carol: Thanks for all of the good information you are always giving us on these beautiful plants. I will be watching for mealie bugs on my H. magnifica that I got in the Spring DL order. It is doing really, really well, growing like crazy and I think I saw a peduncle on it this morning. We have so much humidity and I have had a problem in the past on other plants with mealies. I will definitely keep a close watch on the magnifica. I have a good sized compacta from a trade here on DG and she told me it tends to get mealies too.

I've never had a problem with spider mites on any plants but I spray everything with the hose every couple of days so that might keep those pests away, I'm not sure.

What is the Bayer Advanced Tree & Shrub stuff good for? I have heard some folks talk about using it on hoyas as well as other plants.

The Hoya I have noticed or heard are prone to spider mites are:

lanceolata
l.ssp. bella
linearis
engleriana
dickasoniana
'Iris Marie'
odorata
cummingiana
densifolia
golamcoana
sp. Tanna Island 2
chlorantha

Probably others. They do seem to usually be thin-leaved, but sometimes bella can have fat little leaves. I wonder what the actual mechanism is that makes them susceptible?
There are some new Bayer products that work on spider mites, one that I have used on Brugsmansias is a spray, a three in one that kills mites, insects and fungi. The common one, BATSS (Bayer advance tree and shrub systemic) that contains only imidacloprid, doesn't kill mites and actually can make mites worse, as the chemical has been reported to somehow make them more fertile. So don't use BATSS alone for mites.

Spider Mites are actually not spiders....so the key word here is MITES and there are lots of different kinds....

Off to fertilize the back gardens!!! Bob is off to spray all the citrus for aphids which are carrying a virus which is killing them....we have lost 4 big trees!!!!! The bugs here are very healthy!!!!! It doesn't go past citrus, which is lucky!!!

The only one on Mark's list that I have is cummingiana. I will watch it closely! I love my little one that I got in a trade a year or so ago. It is slow growing for me but seems to be very healthy. I was outside earlier and thought I would check each and every one for pests/critters! I have a large basket of H. brevialata that had some webbing on it. I sure hope it isn't mites but it could very well be. I sprayed it hard with the hose, let it dry and then gave it a good spray with Safer Insecticidal Soap. I have isolated it from all the other plants and will be watching it closely. I have had problems with mealy bugs on different plants before but rarely mites (except an infestation of cyclamen mites on some Gesneriad plants inside the house a year or so ago.) I hate using chemicals but sometimes we just have to!

Carol, Sorry to hear about your loss of 4 large Citrus trees! Here in Florida there has been a problem with Citrus Canker for a number of years. I remember about 6 or 7 years ago where the Florida Dept. of Agriculture was inspecting every tree in every yard because of that disease doing so much damage to the State's Citrus Crops. My mom had a neighbor at the time and they removed every citrus tree in her yard because they found the canker in one or two trees. If they find no canker they tag the tree but any sign of the disease and the trees are removed and destroyed. They are afraid of it getting out of control and destroying the citrus business in the state.

is that the same as citrus scab? We have it....makes the citrus look nasty but doesn't affect the flavor.... The Tristeza virus is nasty. NO cure...slow death!!!

I haven't heard of citrus scab but maybe they are related? Citrus canker is a bacterial disease: http://www.doacs.state.fl.us/pi/canker/faqs.html

Ah...read your information....thanks. No the scab and the canker are different....the scab is a mite...

If it's not one thing, it's another!!!! We are being invaded by so many alien pests the nurseries are having a rough time of it....trying to keep up with the state's requirements. Hawaii pays more attention to what goes oUT than what comes in....so in order to ship out we have to comply with rules and regulations actually set by California. It is more touble than it is worth....