Canna damage

Canna damage
Originally uploaded by sassycrafter

The other day, I noticed a lot of damage on this canna. I figured I'd better take a look at the plant and see what was going on. After a brief scouting session, I found a hungry larger canna leaf roller that was treating my beloved canna like his own personal all-you-can-eat buffet. This was definitely not cool in my book, since this was the Canna 'Intrigue' that I paid good money for on my trip to Plant Delights Nursery.

If you live in Florida and don't know about canna leaf rollers, then it's time you learned. Most of the people I work with here at UF/IFAS would probably agree that leaf rollers are the most troublesome canna pests in our state. In fact, all of the damage that I found on my plant seemed to be the result of a single critter. Sure, it took me a few days between when I noticed the problem and when I checked it out. But still -- that's a lot of damage for just one caterpillar.

Larger canna leaf roller (UF/IFAS)

The lesser canna leaf roller can be a little harder to discover. These caterpillars are much smaller and typically roll themselves up in the edge of a leaf, where they then feed only on the top layer of the leaf.

Lesser canna leaf roller (UF/IFAS)

So if you have cannas in your yard, be sure to scout for pests often. It's a snap to make your own scouting kit, and it's much easier to get a problem under control if you find it early. You can hand pick the pests if there's just a few of them, or treat the plant with a biorational insecticide like Bt (Bacillus thuringiensis) that kills the caterpillars without harming beneficial insects.

Needless to say, that leaf roller won't be bothering my plants again.

Sick crinum update -- mites!

Sick crinum update (normal photo)
Originally uploaded by sassycrafter

Here's what my crinum is looking like these days. A few of the leaves have fallen off since the last shot. I talked with a few people about the office about its decline and Tom suggested it could be spider mites.

Bingo! I had seen some webs on the plant but had assumed they were from beneficial spiders. When I looked more closely, sure enough, there were spider mites on the undersides of the leaves. Apparently they were sucking the plant dry.

It was too late that night to take chemical measures, so I blasted the plant with the hose, which is often a good first line of defense against insects. Then later I treated the plant with a pyrethrin-based insecticide. I would have preferred an oil-soap spray, but I happened to have the other product handy.

I'll reinspect in a few days and see if the mites have disappeared. If not, I'll need to treat them again.

Caterpillars

Southern armyworm caterpillar on my tomato plant
Originally uploaded by sassycrafter

I found a big brown caterpillar on my tomato plant today and went trolling on the Internet to find out what it was. Apparently, it's a southern armyworm (Spodoptera edidania).

I've actually seen a lot of small caterpillars skeletonizing the leaves of my tomato. Apparently, they're the younger larval instars of this guy. Most caterpillars go through several larval instar stages, which can make it difficult for folks like me to definitively identify them. This guy's darker coloration suggests that he (or she) is a later instar stage.

Speaking of identifying caterpillars, it looks like I misidentified this caterpillar. It's actually a tobacco hornworm (Manduca sexta) and not a tomato hornworm (Manduca quinquemaculata). Tomato hornworms have eight white V-shaped markings on their side while tobacco hornworms have seven diagonal white lines.

Scout early and often

Tomato hornworm caterpillar on my tomato plant
Originally uploaded by sassycrafter

I've been checking my tomato plants almost daily to see how they're progressing (lots of baby tomatoes!) and also to check for signs of diseases and pests. This week I found my first tomato hornworm caterpiillar.

Well, to be truthful, I found the frass first. Frass, you ask? Well, it's just a fancy word for caterpillar poop. It's usually easy to spot because it's dark and stands out strongly against the leaves, unlike the caterpillars themselves which tend to blend in. For a close-up of the frass, click here.

I scoured the tomato bushes and found four young caterpillars and quickly introduced them to the bottom of my shoe. This is the first line of defense (pick and squash) if you're using integrated pest management. My next step was going to be treating the plants with Bacillus thuringiensis, a microbial insecticide, but I was unable to purchase it at my local big box store during last night's late shopping trip. Darn those big box stores.

My tomatoes have shown other signs of pest damage, namely leaf miners, but I haven't treated them because leaf miners usually don't cause major problems. Tomato hornworms, on the other hand, have voracious appetities. No way I'm leaving those buggers on my prized tomatoes.

Update 6/21/08: it looks like I misidentified this caterpillar. It's actually a tobacco hornworm (Manduca sexta) and not a tomato hornworm (Manduca quinquemaculata). Tomato hornworms have eight white V-shaped markings on their side while tobacco hornworms have seven diagonal white lines.