Avoiding caterpillar damage to seedlings

Since yesterday, I have BIG FAT caterpillar damage to one of my ‘Sweet Chariot’ hips, as well as to some nearby chili seedlings. I have destroyed three fat caterpillars since this morning.

Inches away from these attacked plants are the Viru rose seedlings, which are ok. I am worried the Viru seedlings are going to be next on the caterpillar menu. Clearly, there is a mass larval hatching going in this part of the garden, starting yesterday.

I normally don’t EVER spray/dust any of my plants in my garden, but it would be silly of me to ignore this present caterpillar attack, as the Viru seedlings are too important to allow nature to do as it pleases.

Should I spray/dust these rose seedlings, or is the risk of burning/death too great? They receive morning/midday sun which is HOT, and the weather lately has unfortunately switched over to hot summer conditions since last week :0(


You could dust them with Sevin. It won’t hurt seedlings.


The closest dusting product I have to what you recommend is a Rotenone-based dust (branded as “Derris Dust”)… It is not anticholinegic in action, but damages electron transport mechanisms in the insects…(scary I know)…

Some insecticidal dusts have been banned here due to some concern they are contributing to some environmental collateral damage (eg. such as to bees and other “desirable” insects).

I am guessing the Rotenone based dust should be ok for rose seedlings?!

Yes, Rotenone should be fine. It will have to be reapplied over time. Don’t fret, Mammalian toxicity is low.

Thanks for the advice Robert. I’ll use it then. I feel better in this case, there is no point me pussy footin about when the warnings are there, staring me in the face.


If you got a photo of these menace I would be interested in seeing what you have down there.

If those are actually caterpillars, they would have had to be feeding for a week or so to be big and fat. So the outbreak was actually a while ago. If they are lepidopterans (larvae of moths or butterflies), they would be sensitive to Bacillus thuringiensis (BT) an organic farming acceptable treatment, that is quite harmless to animals. I don’t know what is available in Australia in that category, brand names vary. But you have lots of BT (genetically engineered )cotton I beleive. That has just one gene for the specific insect toxin from the bacteria.

BT doesn’t kill instantly. The insects just go off their feed and wander round for a while as they starve to death. So it might not save hips under heavy attack, or all the leaves.

If the prickles aren’t too many or too sharp, the old fashioned finger and thumb method works very well. And is as cheap as your time- depends on your hourly rate.

I will take a picture if I can.

There are loads of moths, but very few butterflies around here.

The local butterfly population has diminished drastically as far as comparisons go from what I see now, to what numbers I used to see as a young boy around here, over 30 years ago. How time flies!

Here is one of the caterpillars I was talking about…it just fell off a chili seedling as I was watering it.

I’m getting the Rotenone dust in an hour or so.

And while I’m in the mood to show off the local garden insect predators, here is a locust I just discovered laying eggs on on my night blooming cactus plant. It is so gross! I would hate to think the sort of damage something like this can inflict on rose seedlings, if it liked the taste of them!

Thanks George for amusing me. I really like the picture of the locust it is very comical looking. You even made my wife laugh. I like taking pictures of insects and plant diseases. I got two whole photo albums full of them. One of these days when I finally get a digital camera I think I will have a blog of them and botanical terms in pictures along with some seedling pictures.

You’re welcome Adam.

Spinosad is an organic bacterial which is effective on a wide variety of insects, caterpillars, leaf eating worms (SAWFLY!), tomato horn worms, etc., as well as thrips. Monterrey Chemical and Greenlight both make it but only Greenlight uses a manufacturing method which allows it to carry the OMRI label and be sold as “organic”. It can be used on everything from turf, ornamentals and edibles with only a four hour re entry. It has low toxicity to beneficials, too. And, unlike BT which it replaces, it has no foul odor. It mostly smells like a mild, mint scented school paste.

I’d imagine it would take care of your caterpillars quickly. It did wonders at the beach on Saw Fly larvae which decimated roses thirteen months of the year.

Kim that product sounds great. I’ll have to ask around about whether it is available locally.

Or you can Google it to see where you can buy it on line, too. Monterrey is an OK product, it is just more expensive here and doesn’t carry the Organic Materials Review Institute label because of how it’s manufactured. I’m not sure what the manufacturing difference is, but there you have it.

Yes Spinosad is available here, but it runs into the $400+ mark for a one litre product…So I’m gonna stick to the dust…too bad!

The Rotenone dust is quite water repellant. The dust that has fallen onto the germinating medium is clumping when I water it, and not washing away.

I wonder whether this dust that has fallen also kills snails/slugs. If so, I can do away with the slug baits and substitute the dust as an all purpose thing…(I hate slug baits because the local rats devour them and wreck the seedlings in the process).

Robert N-R, I just wanted to let you know that the Rotenone dusting has worked just fine with no seedling damage. Thanks for the timely advice.

It’s a botanical. Thank Mother Nature. :wink:

true enough