Unhealthy rivularis

[Philly J]

I need to preface this by saying I brought this guy to my office from a big box store when it was, no joke, -36F with the wind.  The car was previously warm and ready.  Backed up to the sliding doors, 7 foot fronds double bagged from top to bottom, but when it had to spend the few seconds outside in that -36, some wind got through several seams in the bag and hit many leaves.  I immediately got its temperature back to tropical but dry in my car for the short trip to its new home.  Have cared for it religiously since then with non stop LED, 8 gallon soaks into its 4 gallon bucket every other day with distilled water only, and am humidifying and misting it.  Here is what is happening, and spreading:  is it shock from where the sub zero wind hit the leaves for a split second, or is it fungal or bacterial?  I don’t see a single spider mite or any mealy bugs. The dark green parts are completely desiccated.

[Philly J]

Was affecting several fronds so all of the leaves on each were given a trim.  Nothing else changing in the care.  I am wondering about some root rot though, every time I do a leach it has that sewer smell.  Still in Costa nursery container with pretty decent mulch type stuff for good drainage, so I haven’t investigated for any black roots yet.

[Ben in Norcal]

Looks like it is totally infested with scale to me.

[Philly J]

1 hour ago, Ben in Norcal said:

Looks like it is totally infested with scale to me.

Isn’t scale like raised bumps that can be scrapped off?  The brown spots are places where it looks like an insect sucked out the juices, like indents in the leaf not a raised bump.  But no evidence at all of insects.  I rub the leaf between my finger and can feel the tiny dents.

[Ben in Norcal]

22 minutes ago, Philly J said:

Isn’t scale like raised bumps that can be scrapped off?  The brown spots are places where it looks like an insect sucked out the juices, like indents in the leaf not a raised bump.  But no evidence at all of insects.  I rub the leaf between my finger and can feel the tiny dents.

Tough to tell w/o being there in person, but sure looks like scale to me.

[chad2468emr]

This doesn’t look like scale to me personally since those are recessed bumps and not raised, and I’d imagine if it were cold damage that it’d just look burnt. 

Have you checked for thrips? They scrape and suck plant material out of the leaflets and the recessed spots make me feel they could be the culprit. If you’ve never seen thrips in person before, make sure to note that googling them makes them appear much larger than they are. They are almost hard to see. Tiny little black or brown elongated insects that almost look like little flecks of metal or graphite. I’m talking SMALL. Make sure not to confuse them with the ramenta that grows on the underside of the leaflets in the crease but those are silvery and hairy and significantly larger on rivularis, so they’re pretty easy to distinguish vs on a kentia or renda. 

[Philly J]

6 hours ago, chad2468emr said:

This doesn’t look like scale to me personally since those are recessed bumps and not raised, and I’d imagine if it were cold damage that it’d just look burnt. 

Have you checked for thrips? They scrape and suck plant material out of the leaflets and the recessed spots make me feel they could be the culprit. If you’ve never seen thrips in person before, make sure to note that googling them makes them appear much larger than they are. They are almost hard to see. Tiny little black or brown elongated insects that almost look like little flecks of metal or graphite. I’m talking SMALL. Make sure not to confuse them with the ramenta that grows on the underside of the leaflets in the crease but those are silvery and hairy and significantly larger on rivularis, so they’re pretty easy to distinguish vs on a kentia or renda. 

Wow fantastic advice I will bookmark this for sure!

luckily I still had the receipt and showed that out of the two I bought one is great and the other is getting worse every day so they let me exchange.  Thoroughly inspected the new one and am crossing my fingers.....

[Palmfarmer]

fill a spray bottle with water and soap wash it down gently with a rag or your hands and rinse away the soap. If you can try and put the plant outside a bit in the day if the climate allows for it, and increase the humidity where you have your plant

[Philly J]

5 hours ago, Palmfarmer said:

fill a spray bottle with water and soap wash it down gently with a rag or your hands and rinse away the soap. If you can try and put the plant outside a bit in the day if the climate allows for it, and increase the humidity where you have your plant

Humidity was at 80% and the ultra fast desiccation of the leaves continued at an astounding pace.  I would lose 6 giant leaves in a 24 hour period.  As soon as the recessed bumps showed up on a leaf that leaf had 2 days tops and it would shrivel to dark green dust.

 

I can’t go outside it’s -36F/-45C.  But it doesn’t matter they let me swap that diseased one for a new one today.  It looks so far so good like it’s same size brother who was purchased with the diseased one.

Edited February 17, 2021 by Philly J

[Philly J]

Update the new one is as healthy as my other.  Whatever it was with the one I returned I still have no idea but it was like a disease that was spreading to like 20 new leaves daily.  Never seen anything like it, especially since there was no visible culprit, even under magnification.