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| Life on a spicebush leaf -Tonya Smith |
I borrowed these photographs from Tonya Smith MN who has recently become addicted to macro photography. Recovery is seldom possible so I am using this blog as a warning to others who might be spared. She found this on a spicebush leaf and sent it in to
Bugguide on September 5th as a Bug Track. On the 10th, she had this reply.
"This is a row of eggs inserted under the leaf epidermis. The little
lid-like appendage at the top of each one suggests Heteroptera, and my
first guess is Miridae (plant bugs), but I don't have any experience
with their eggs, so it would be great if you could collect the leaf and
see what pops out. Great photos!"… Charley Eiseman, 10 September, 2019 - 5:49am
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| Closeup with "lid-like appendage on top" - Tonya Smith |
There are several lessons to be learned here. First, there is a community of fellow "macrophiles" out there who are willing to give a helping hand, although some like me can be wrong at times.
Charley Eiseman, quoted above, is the guru and has helped me out several times and is generous with his expertise. After years of assisting me in my gall addiction, he has ventured into life "in a leaf."
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| Leaf miner on Verbesina virginica - REK |
While chasing chasing tiny critters on leaves I frequently see these scars. They may occur on the upper or lower surface, sometimes on both. I had always assumed that they were caused by something browsing the epithelium but it turns out to be something much more interesting.
A leaf miner is any one of numerous species of insects in which the larval stage lives in, and eats, the leaf tissue of plants. The vast majority of leaf-mining
insects are moths (Lepidoptera), sawflies (Symphyta, close relatives of
wasps), and flies (Diptera), though some beetles also exhibit this
behavior. Wikipedia
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| Leaf miner tunnels with trails of frass - REK |
Note that it says "lives in." These tiny larvae mine in between the upper and lower surface epithelium, frequently leaving little tiny strings of dark frass (insect poop). Eventually they emerge, leaving through a small exit hole which you may see under magnification.
If you want to pursue leaf miners beyond the Wikipedia reference, Charley has just published
Leafminers of North America. It is 1857 pages long (plus a 54-page table of contents, 20-page
glossary, and 68-page bibliography), illustrated with thousands of color
photographs. To prevent injury to the UPS delivery drivers it is only available as an ebook but it is a great reference.
"Abandon all hope, ye who enter there" for I have sampled the incredible deep dive into my copy and it is hard to emerge.
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He and Noah Charney wrote Tracks & Sign of Insects and Other Invertebrates which is an indispensable book for those who wander through nature wondering "what made that?" be it a gall, egg case, pupae, exuviae or an engraving left by an insect.
