Insects

[Dr Sardonicus]

The butterflies I am accustomed to see starting in late Spring were nearly absent locally this year until well into July. There was a steady dribble of some of the common smaller butterflies, but, apart from a few sightings early on, the larger butterfly species just weren't around.

There was one exception to this, however. Thanks to the Common Milkweed (Asclepias syriaca) I planted by my front steps last year, and which grew at least seven feet tall and spread by underground runners this year, I had many visits by Monarch butterflies (Danaus plexippus). Female monarchs laid eggs on the leaves, and the caterpillars came out at dusk to feed. (There had been a few Monarch caterpillars last year, but last year there were only a couple of stalks, and they weren't very tall.) This year the Milkweed also bloomed, and Monarchs fed at the flowers, which are very fragrant.

The other large butterflies finally showed up starting around mid-July, and the Monarchs kept coming. And kept laying eggs. I saw female Monarchs landing on the Milkweed I'd transplanted to my back yard from "starts" that had spread too far in my front yard. Those plants won't bloom until next year, so I knew the butterflies weren't feeding.

As the summer wore on, the Monarchs began feeding more on my other flowers. And today (September 5) one of these, feeding on some Zinnias, caught my eye. First, I noticed it was a female, a bit more brown than orange in the range of color variations, and was a bit the worse for wear. Its wings were a bit frayed around the edges.

Then, I noticed a discolored spot on the outside of its L hind wing. Approaching slowly from behind allowed me to get a close look. And what to my wondering eyes should appear, but a round white plastic tag! The printing on it identified it as part of the Monarch Watch tagging program.

The fall migration of Monarch butterflies is underway!

[richs]

Congrats on the milkweed success! We have milkweed we planted this year but it got infested with aphids. I bought a container of 1500 ladybugs for US$10 and put them on the milkweed where they ate most of the aphids. Unfortunately the ladybugs flew away after two days and the aphids came back. We keep hammering the aphids with water blasts to contain them, but no Monarch eggs, although we've seen a few Monarchs. Our parsley in the herb pot gets eaten down to the stems nightly, snails maybe?

[kladner]

Originally Posted by richs

..... Our parsley in the herb pot gets eaten down to the stems nightly, snails maybe?

Snails a possibility, but there are also parsley-specific caterpillars. They are black and green banded. The ones I get mostly seem to leave bare stems. Check daily. They can get over an inch, but look for tiny black things on the leaves. Larger ones can be on stems under the leaves. They are not exclusively nocturnal, though they may keep eating 'round the clock.

[Dr Sardonicus]

Yes, the Black Swallowtail Papilio polyxenes is a likely suspect:

Other Common Names
Eastern Black Swallowtail
Parsely Swallowtail
Dill Worm, Parsley Worm, Celery Worm
Carrot Worm, Fennel Worm

Explanation of Names
Papilio polyxenes Fabricius, 1775
The common names for the caterpillars vary because they can be found on many important cultivated plants in the Carrot Family. Pick the host plant, add the word "worm", and you have another common name that has probably been used and published somewhere.

This page has a number of good images of the caterpillars; click on an image to enlarge.

Like most swallowtail caterpillars, they have a "bison-shouldered" appearance, and have a pair of "horns" that are normally retracted, but which will protrude and emit a bad smell if the caterpillar is disturbed. (Many swallowtail caterpillars have large eye spots on the "shoulder hump," but these do not.)

As to the aphids: My milkweed got heavily infested with dark aphids this year. They went to the tender young growth at the ends. I didn't want to use insecticidal soap for fear of harming the Monarch caterpillars so I picked off the ends -- aphids, "farmer" ants, and all. This controlled the problem, and in later days I saw ladybugs munching their way through the aphids. BTW I remember wondering as a kid what those black-and-orange things were that looked like little 6-legged lizards. They're ladybug larvae! And they chow down on aphids even faster than the adults.

Last year my milkweed got hit by swarms of horrible bright-orange aphids, a type I'd never seen before. I looked them up and found they were Oleander aphids, Aphis nerii. They think they're better than ordinary aphids because they're imported. When feeding on milkweed they accumulate the plant's toxins, and this prevents ladybug and lacewing larvae that eat them from maturing. One control method I read was to dab them with a swab soaked in rubbing alcohol. Rubbing alcohol has been in short supply because of COVID-19, so I feel fortunate that I haven't been bothered with these appalling pests so far this year. I have seen them in the area, though.

[kladner]

I should have gotten pictures to share. Those are the ones. Since I haven't grown anything in that group but parsley for a long time, I didn't know they afflict other garden plants. I had not known that so many common vegetables and herbs are Carrot Family., either. Thanks!

[richs]

Whatever is eating the flat-leafed parsley doesn't touch the curly-leafed variety.

And the aphids are white. I have two videos of the ladybugs chowing down.

[kladner]

Originally Posted by richs

Whatever is eating the flat-leafed parsley doesn't touch the curly-leafed variety.

And the aphids are white. I have two videos of the ladybugs chowing down.

That's weird. I only have the curly variety, which was getting eaten until I wised up and started frequent caterpillar searches.

[Dr Sardonicus]

Originally Posted by richs

Whatever is eating the flat-leafed parsley doesn't touch the curly-leafed variety.

And the aphids are white. I have two videos of the ladybugs chowing down.

I don't know how big your herb pot is. If it's large enough, you can try to eliminate any slugs or snails by burying a shallow container so its top is level with the soil's surface, then filling it with beer. The snails will crawl in and die a happy death. The presence of slugs is often indicated by slime trails.

I'm not sure how to account for the preferential damage to one type of parsley. One possibility is (assuming the problem is caterpillars) the adult insect was better able to lay eggs on the flat leaves than the curly leaves. It could also be pure happenstance -- I don't know how many parsley plants you've got, or how they are situated.

Besides Black Swallowtails, another type of caterpillar that might be responsible is cutworms. They are the larvae of moths that are often light brown and maybe an inch long. A typical variety is "miller moths" that can become a nuisance in houses when they're flying through an area. Cutworms will bite small enough stems off at the ground. They generally feed at night. By day, they hide under leaf litter, or, (if they're in a potted plant and the pot is in a saucer), they might crawl under the pot and be hiding in the saucer. One Spring many years ago, my older sister complained that the plants she was starting from seeds were disappearing! She had them growing in vermiculite, in those rectangles of little square plastic "pots," which were sitting in flats. I went to investigate when she was out. I lifted a container out of the flat, and saw -- cutworms! I removed them and left them in a small container of rubbing alcohol with a note to the effect "I think I found your problem" and where to look for any I might have missed. The seedlings stopped disappearing.

White aphids, huh? Oh, joy, another kind of aphid. The only aphids I'm familiar with that truly look white are wooly aphids, and I don't think you've got those. Some pale-green aphids leave white skin husks when they molt.

In any case, mixing a little bit of soap (or an even smaller amount of dishwashing liquid) with water in a spray bottle makes an effective insecticide. The soapy water clogs the breathing tubes on their abdomens, and they drown. There will, however, likely be survivors. And an established population of aphids reproduces by "parthenogenesis" -- they breed like bacteria, and their numbers explode.

[kladner]

On the home-brew spray: I don't remember the proportions, but my mom also added a bit of isopropyl alcohol. This was supposed to take on some kinds of waxy or waxy-fuzzy insect exteriors. Clearly, one doesn't want to go overboard on alky or detergent. I think Mama used drops of something like Ivory Liquid in a substantial amount of water. Again, this is decades old vague memories. There would certainly be recipes on the web. My current insect battles involve " pick off and squish" tactics. I've not found any for a day or two, and the weather is cooler. So maybe the swallowtail laying season is over.
EDIT: I'll have to watch the forecasts and see if I need to bring the basil plants inside. Parsley doesn't care until it gets really cold. Basil may droop in the low40s F, and recovery is doubtful.

[xilman]

Originally Posted by Dr Sardonicus

I don't know how big your herb pot is. If it's large enough, you can try to eliminate any slugs or snails by burying a shallow container so its top is level with the soil's surface, then filling it with beer. The snails will crawl in and die a happy death. The presence of slugs is often indicated by slime trails.

We save coffee grounds in our household to use as a mulch around the stems of snail and slug food. An annulus 1cm thick out to a distance of, say, 4cm away from the stems is applied to the top of the soil.

Works pretty well for us but YMMV.

[Dr Sardonicus]

Originally Posted by xilman

We save coffee grounds in our household to use as a mulch around the stems of snail and slug food. An annulus 1cm thick out to a distance of, say, 4cm away from the stems is applied to the top of the soil.

Works pretty well for us but YMMV.

I will pass this on. It's been many years since I gave up my two mugs of morning coffee because my stomach started complaining. I still enjoy an occasional cup of good coffee as a treat, though.

It would be bad if slugs or snails actually liked coffee. Instead of being sluggish or moving at a snail's pace, it would be, "look at that escargot-go-go!"