Guy Posted August 16, 2020 Report Share Posted August 16, 2020 My Sarracenia are all developing black spots. They've got considerably worse in the last week or so. Looking through here it seems thrips are most usually suggested as the reason. If so, then I'm happy to spray with Provado. But what else could it be, please? Thanks. Guy Quote Link to comment Share on other sites More sharing options...
RobH Posted August 16, 2020 Report Share Posted August 16, 2020 Could it be fungal spots from being too hot and humid and little air circulation with the current weather? Just a guess. If you have any plants outside, are they suffering with the same spots? Rob Quote Link to comment Share on other sites More sharing options...
Guy Posted August 16, 2020 Author Report Share Posted August 16, 2020 Thanks. The outside plants are not showing any signs of these black spots. Until about a month ago I had a fan going in the greenhouse 24 hours a day. When the weather warmed up I left the door open all the time, with the two roof windows opening and closing automatically. I thought that would give enough air circulation, but perhaps not. So I've turned the fan back on now. What should I do about the infected plants? Just leave them, or cut the pitchers off. Hopefully I won't have to throw them all away, there's quite a lot there! Guy Quote Link to comment Share on other sites More sharing options...
Gaz Posted August 16, 2020 Report Share Posted August 16, 2020 Looking at the lid in the foreground in the first pic it does seem there is mould present, backing up Rob's theory. Air flow is always an issue for me in the greenhouse, I've kept cacti for years and always lose more during Summer heatwaves than I do in the Winter. Now I'm back to CP's and found it was my VFTs suffering during the recent hot weather. I have 2 fans going 24/7, side vents, door and 3 roof vents all open. On top of all that, at this time of year, I take out some of the windows and hang netting over the space to keep birds out, at night I use 2mm perspex sheets to temporarily cover the window space. When Autumn comes I put 5mm perspex sheets back instead of the original glass (easier to handle). Whether it be cacti or CPs, although our plants may come from hotter climates than we have in the UK, they generally have good air circulation in habitat which we struggle to provide in our greenhouses. Some of your pitchers, particularly in the first pic, look like they're gonners and may need removing. I couldn't comment on a fungicide as I've never had to use one on CPs, I'm sure someone with that experience will chime in. Could you temporarily move these plants outside till they recover and you sort out the GH airflow issues? Quote Link to comment Share on other sites More sharing options...
Greg Seed Posted August 16, 2020 Report Share Posted August 16, 2020 I would say it looks like thrips droppings. I had exactly those black spots on a new plant last year. When I spotted more appearing, I thoroughly inspected the plant and found one or two adults. Once they were gone, the black spots stopped appearing. I would remove the damage, isolate the plants and spray with provado. Is it possible to stop bees etc getting to the plants and eating the provado-flavoured nectar? Quote Link to comment Share on other sites More sharing options...
Guy Posted August 18, 2020 Author Report Share Posted August 18, 2020 Thanks for the replies. So, it might be thrips or a fungus. I'll cut off one of the affected leaves and have a good look for thrips. Guy Quote Link to comment Share on other sites More sharing options...
Guy Posted August 22, 2020 Author Report Share Posted August 22, 2020 Finally got round to having a close look at the affected pitchers. There is no sign of Thrips and even the worst affected pitchers are still green on the inside. This is only affecting the Sarracenia, everything else is OK and now I've turned the fan back on, it's stopped spreading. Suggests to me it's a fungal infection. Would it be best to cut off all the infected pitchers , or should I leave things as they are now the infection has stopped spreading? Guy Quote Link to comment Share on other sites More sharing options...
Alexis Posted August 22, 2020 Report Share Posted August 22, 2020 I've never seen anything like that through lack of air flow. I'd just spray them with BugClear and see what happens. Quote Link to comment Share on other sites More sharing options...
RobH Posted August 22, 2020 Report Share Posted August 22, 2020 Cut off any dead pitchers and the upper part of pitchers which are dead/infected but I would suggest leaving any pitcher which is greenish even if it has the spots on it since you say they no longer appear to be spreading. Rob Quote Link to comment Share on other sites More sharing options...
Guy Posted August 23, 2020 Author Report Share Posted August 23, 2020 Job done, but what a massacre! Loads of leaves to cut off and most of the Sarracenia are looking really sad. The S.purpurea showed absolutely no sign of the problem, but others; S.tygo, S.minor (1 pot only), S.purple haze and an unnamed pot have disappeared completely. I just hope whatever is below the surface is strong enough to grow back. Doubt it somehow. Some ferns had taken up residence in the pots, they were all affected as well. Plus there were several empty snail shells. Any of these bits of information suggest what the problem is? Guy Quote Link to comment Share on other sites More sharing options...
Greg Seed Posted August 23, 2020 Report Share Posted August 23, 2020 I'm still 99% sure it's thrips. Tar-like black spots and a scratched-off appearance of the leaf on the outside only (insects can't climb on the inside of the tube - not a problem for fungus) are exactly what i look for if I'm worried about thrips. Quote Link to comment Share on other sites More sharing options...
Guy Posted August 23, 2020 Author Report Share Posted August 23, 2020 In that case I'll also spray with Provado. I couldn't see any Thrips when I cut the leaves off, but a bug spray will give double protection. None of the other plants; VFTs, Drosera, Pinguicula, Cephalotus, or the S.purpurea, S, psitticina have been affected. Do Thrips usually affect these plants? Guy Quote Link to comment Share on other sites More sharing options...
Greg Seed Posted August 23, 2020 Report Share Posted August 23, 2020 They're difficult to spot at the best of times. They are good at hiding - they like to nestle under the lip, for example - and it doesn't take many of them to do lots of damage. Keep an eye on the plants which have very little or no damage - that's where i would expect to see them. I've not heard of them attacking any of those other genera. Quote Link to comment Share on other sites More sharing options...
Greg Seed Posted August 23, 2020 Report Share Posted August 23, 2020 A quick google search brought this up: https://carnivorousplantresource.com/thrip-damaged-pitcher-plant/ Quote Link to comment Share on other sites More sharing options...
Guy Posted August 23, 2020 Author Report Share Posted August 23, 2020 Thanks Greg, you are absolutely right. Thrips. The link you gave shows exactly the same damage as on my plants. I went out to the dustbin where I'd put the leaves I'd cut off and very quickly found a couple of Thrips wandering about. Perhaps putting the leaves in a completely dark place encouraged them to come out. As soon as the light hit them they whizzed off and, to my eyes, just disappeared! The plants have been sprayed with Provado now. Hopefully that'll stop it getting any worse. Will I need to spray again? Interesting they don't attack other species and, clearly, not all Sarracenia species. The purps and psitticina are definitely clear. Thanks again. Guy Quote Link to comment Share on other sites More sharing options...
Greg Seed Posted August 23, 2020 Report Share Posted August 23, 2020 Glad you've nailed down the problem! You'll probably need to reapply the provado. Just follow the instructions and you'll be fine. All these little sods have preferences. I have lots of different plants which are susceptible to spider mite but i rarely find them on anything other than my Alocasias. Kids don't eat carrots when there is cake on the table! I noticed in your photos that the damage is largely restricted to the green parts of the plants. My guess is that they don't like the anthocyanins in the purps and psitts. Quote Link to comment Share on other sites More sharing options...
Guy Posted August 23, 2020 Author Report Share Posted August 23, 2020 (edited) 1 hour ago, Greg Seed said: I noticed in your photos that the damage is largely restricted to the green parts of the plants. My guess is that they don't like the anthocyanins in the purps and psitts. Interesting thought. And you're right. The pitchers which had red tops had no Thrip damage on the red bits at all. Just the green bits. Hadn't thought about that until you pointed it out. Guy Edited August 23, 2020 by Guy Quote Link to comment Share on other sites More sharing options...
Gaz Posted August 23, 2020 Report Share Posted August 23, 2020 5 hours ago, Guy said: In that case I'll also spray with Provado. I couldn't see any Thrips when I cut the leaves off, but a bug spray will give double protection. None of the other plants; VFTs, Drosera, Pinguicula, Cephalotus, or the S.purpurea, S, psitticina have been affected. Do Thrips usually affect these plants? Guy Good to hear you got to the bottom of it. I've seen thrips on VFTs and Pings this season, only in small numbers fortunately but ended up with deformed traps and damaged grow point. Sprayed with Bug Clear Ultra 2 and monitoring with magnifying glass, so far only seen dead ones since. I can't say with any certainty that the BCU2 didn't set the Ping development back a bit as well but now recovering. Quote Link to comment Share on other sites More sharing options...
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