Early spring is a great time to be investigating signs of insects on plants, because with all the leaves being fresh, there is a good chance of finding the insects themselves, perhaps even catching them in the act of leaving the signs in question. I spent the past week or so in Ohio, and on one walk in the woods I started paying attention to the leaves of Ohio buckeyes (Aesculus glabra).
Right away I noticed some tiny holes in the leaf blades, which I imagine were made by some kind of flea beetle (Chrysomelidae: Alticini), but I never got around to photographing or investigating those because I got distracted by the subtler feeding sign left by lace bugs (Tingidae) sucking the leaf juices from below.
It didn’t take long to find some of these buckeye lace bugs (Corythucha aesculi) hiding on the leaf undersides.
My attention then turned to some leaves that were conspicuously drooping and wilting.
Close examination revealed that each one had a tiny hole at the point where the petiole began to droop.
A couple of days later, I revisited these drooping leaves, and this time found the tiny holes covered by extruded frass.
I brushed away one of these frass accumulations, and immediately a little caterpillar face appeared, putting a new fecal pellet in place.
Splitting the petiole open, I got a better view of the caterpillar. It was evidently working its way toward the tip of the leaf, presumably finding less physical and chemical resistance from the plant in the wilted portion.
Since I’ve been on the road with limited internet access, I haven’t had a chance to try and figure out what kind of moth this caterpillar will turn into. This may a well-documented life history; possibly the answer is even in my book, but for the moment it’s a mystery to me.
Charley
Thanks for posting about the buckeye caterpillar mystery. Here in Jefferson County, Iowa nearly every buckeye tree I see has many of these droopy leaves. And sure enough there is a hole on the petiole of the leaf. Was hoping you know what they are by now so I do not have to try to rear them 🙂
Anxious to here what you have found.
Moni Hayne
Hi Moni– I strongly suspect this is the work of Proteoteras aesculana, which is known as the “maple shoot borer” but clearly was originally found on buckeye given its Latin name. I’m not sure if any of the larvae I collected are going to make it (leaves getting moldy), but I will post an update if they do.
So do you want me to collect some of the leaves to try to rear? If so how do you recommend I handle them for best success?
Thanks for the feedback
Moni
That would be great… I’m not sure what to suggest, exactly. The goal is to keep the leaves from drying out while also keeping them free from mold. The mold in my vials is concentrated around the piles of frass, so removing all the frass periodically would probably be a good idea. Just putting the leaves in a vial or a ziploc bag should be sufficient to retain moisture.
OK, will gather some and see what I can do. Would assume if I keep them outside in a protected area that would be best for getting them to develop under the most normal temperature conditions?
Thanks help with ideas for rearing.
Keeping them inside is fine. Temperature is only an issue when you want an insect to experience winter.
Ok…good to know!
Well, went out to get the leaves this morning and was quite surprised at how few were left!
I dutifully collected any suspicious leaves or petioles and put it in a bag. Pouring the contents out on the counter to separate a few things that were different…like some mines (thought of you) on the buckeye leaves to photograph.
As an entomologist, I was amazed at all the critters that crawled out of the leaves!! …flea beetles, spiders, Psocids, and tons of caterpillars that I thought were the tufted thyatirid -Pseudothyatira cymatophoroides but are not…probably a dagger moth…so now to go thru Wagner’s book and see if I can figure it out. Perhaps faster to post to BG!! Perhaps should try rear a few of them too since I seem to have various stages?
Did find a few of the leaves like yours, so will see what I can rear?!?
Sounds great! Can you post photos of the leaf mines to BugGuide? I don’t think we have any buckeye mines yet. Off the top of my head, I think there’s a Stigmella and a Cameraria… this seems early for any kind of mine, so I’m curious what it is.
Charley
I have photos of 3 of the leaves with mines…they look a bit different. Do you want them entered separately? Do you want them resized to BG preferred sizing? Or left larger pixels? Have not torn any apart to see what was in them…want you to see them first.
Here is the first submission of the mines…decided one leaf per BG page was best…had to resize as it would not take the full photos. http://bugguide.net/node/view/920526
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