Thrips/Scales or....

[Rokosauros]

Recently, I had four nepenthes down with pests. Poor stenophylla and hamata x platy had mites while truncata x (ventri x aristo) got downed with a huge mealybug attack (the whole rootball was literally covered with white fuzzy guys ). Now, I've got N. truncata x spectabilis EP making me anxious with these funny leaves:-

Newest leaf.

Overall plant, didn't trim off the dead pitchers yet.

AS you can see on the underside of the leaves, they're numerous red spots and some of them leave a mark on the top side of the leaf. What worries me are those scar-like 'cuts' at the lamina of the leaf. You have to look closely. I've been applying Malathion systemic insecticide to my plants (including this guy) following recommended dosage which would be 3 times with a 10 days gap between each spray. Today was the 3rd and final spray, but having looked at my truncata x spectabilis, conditions do not seem to be improving, if any, it's getting worse. I've isolated the plant from my shadehouse and right now, the only other thing I can think of doing is to get a different systemic insecticide to rid the pests since they'd probably be resistant to Malathion already.

One of the reason why I never pay much attention to this guy is because red spots are common for N. truncata and bicalcarata for us grower here. My truncata and bicalcarata went through the same problem before (though less red spots and it didn't have that strange 'cut' on the lamina of the leaf) and they eventually cured. Only recently have I noticed that my truncata x spectabilis had not pitchered 3 times in a row, new tendrils are too thin and short and leaves seemed slightly smaller.

So my main question is:-What is the plant suffering from? How can I cure it besides systemic insecticide? I do believe thrips or scale is the crux of the matter here, but I am not sure as I've never had thrips or scale attack before. Thanks for any help!

 

[Not a Number]

It looks to me that there are brownish lumps or blisters associated with the "scars" on the mid-rib which suggest scale insects. If you can detach these blisters easily with a thumbnail or tip of a knife you should be able to see the adult insect either remaining on the plant or on the underside of the scale shell. A contact insecticide like Malathion is most effective against the immature "crawler" stage of the insect as these insecticides do not easily penetrate the waxy scale. As in comedy, timing is everything and you want to apply the control during the crawler stage. You just have to monitor the plant with the aid of a magnifier and see when the crawlers are present. One site suggests sealing an infested leaf in a clear plastic bag to do the monitoring.

Using a systemic insecticide gets incorporated into the plant and eventually ingested by the insect.

Be sure to wash your hands after handling an infested plant as you can transfer the insects or eggs to other plants.

 

[riceman]

Those ellyptical lesions on the midrib looks like fungal spots but can't be sure from the pictures. Are the lesions sunken in the middle ?

 

[Rokosauros]

Riceman-Definitely not fungus. Prior to the insecticide, I applied fungicide on the plant, didn't seem to do anything at all. And yes, the lesions are sunken in the middle.

Not A Number-I think you may be right about scales...

AT least, most of the shell like lumps have either fallen off or disappeared! Most probably scale. Thanks for the advice, guys!

 

[vraev]

Can u post a closer pic of that brown things on the midrib of the leaf? Those look like soft scale...but need a better pic to be sure.