Pest/Pathogen ID--Cyr. chailluana rust on leaves

[DBoro9]

Hi I have a Cry. chailluana that was kept with a cattleya that exhibited brown-rusty leaf damage. The infection/infestation seems to stunt leaf growth, eventually causing the leaves to dry and fall off. I separated the catt. and treated it with Physan which seemed to resolve the issue.

However, my Cry. chailluana is now exhibiting the same symptoms. I've been treating it with Physan but it is not improving. Can someone assist me w/ 1) identifying the pest/pathogen and 2) providing treatment recommendations. See photos.

I appreciate any insights.

[estación seca]

That looks like it could be damage from spider mites, tiny 8-legged beasties. Take a tissue and run it along the undersides of the leaves. Squashed mites leave brown or reddish streaks on the tissue. Mites are outside in your landscape so you cannot get rid of them. They prefer warm and dry conditions, with low humidity. They are a constant threat to orchids in homes.

Physan won't help. Mites can be controlled by regularly spraying plants with plain water, and keeping relative humidity over 60%. I spray all my plants with plain water every 1-2 weeks. Attacks with large populations can be knocked down by spraying with 70% alcohol (rubbing alcohol) or insecticidal soap. There are miticides. but they are quite toxic as well as quite expensive. I wouldn't use them in a home. The other treatments are almost always adequate to control them.

[alecStewart1]

Originally Posted by estación seca

That looks like it could be damage from spider mites, tiny 8-legged beasties. Take a tissue and run it along the undersides of the leaves. Squashed mites leave brown or reddish streaks on the tissue. Mites are outside in your landscape so you cannot get rid of them. They prefer warm and dry conditions, with low humidity. They are a constant threat to orchids in homes.

Physan won't help. Mites can be controlled by regularly spraying plants with plain water, and keeping relative humidity over 60%. I spray all my plants with plain water every 1-2 weeks. Attacks with large populations can be knocked down by spraying with 70% alcohol (rubbing alcohol) or insecticidal soap. There are miticides. but they are quite toxic as well as quite expensive. I wouldn't use them in a home. The other treatments are almost always adequate to control them.

A lot of people on the FlyTrapCare Forums swear by Captain Jack's Insecticidal Super Soap for spider mites and some other pests. It's $10 in the US, so a decently cheap option.