Which insect has these eggs?

Which insect has these eggs?

We had Charley Eisman as our speaker in 2015…  This Saturday, The Connecticut Botanical Society Meeting Features Charley as their speaker of the Spring Meeting:

Spring Meeting 2017

March 25th, 2017CT Forest & Parks Association headquarters
16 Meriden Rd. (Route 66), Rockfall, CT 06481

Native Plants as Insect Habitat

Charley Eiseman

Each native plant species has a suite of host-specific insects that depend on it for food.  Even allowing a single “weed” to grow in your garden can significantly increase its habitat value, and choosing to plant native trees, shrubs, and wildflowers will cause your yard to teem with life.  Using a number of common New England plants as examples, Charley will introduce us to some of these insects, their natural history, and signs of their presence to look for on their host plants.  His close-up photos will provide an unusual perspective on the tiny animals going about their lives right under our noses.
Charley Eiseman is a freelance naturalist, conducting plant and wildlife surveys for nonprofits, state agencies, and universities throughout New England. He has also co-taught an “Ecology Through Animal Tracking” course since 2004. He holds an MS from the University of Vermont’s Field Naturalist Program and a BS in Wildlife and Fisheries Conservation and Management from the University of Massachusetts. Charley is the lead author of the award-winning field guide, Tracks & Sign of Insects and Other Invertebrates (Stackpole Books, 2010) and is currently writing a book on leaf-mining insects. His insect-themed blog “BugTracks” can be found at http://charleyeiseman.com.


The Connecticut Forest and Park Association building is on the north side of Route 66, 2.8 miles west of the Route 9 intersection in Middletown and 4 miles east of the I-91 intersection in Meriden.


9:45 AM – Light Refreshments and Used Natural History Book Sale
10:30 AM – Announcements and raffle of Bees:  An Identification and Native Plant Forage Guide by Heather Holm
11:00 AM – Guest Lecture
12 noon – Potluck lunch

Join us on Wednesday, October 28th, 2015 as Charley Eiseman speaks to the Hardy Plant Society of New England Connecticut Chapter about “Native Plants as Insect Habitat: Signs of Insect Use & Insect Facts”. Discover why native plants are important insect habitat, what suite of insects use which specific plants, and the natural history of this long term beneficial relationship. Charley will shows close-up photos of insects as he highlights specific plants they use as habitat while discussing the different types of signs insects leave on our plants.


One of Charley’s blog postings is being shared here:

Ragweed Residents

This is the time of year that everybody is ragging on ragweed (Ambrosia spp.)—at least, everyone who realizes that it is the pollen of this plant, and not goldenrod, that is responsible for their summer allergies. At times like this, when some may feel like ridding the world of ragweed entirely, it’s good to remember that every native plant has a whole community of insects that depend on it.

Last August I noticed some striking little fruit flies (Tephritidae) hanging out on the ragweed in my yard:

IMG_6148 IMG_6150 IMG_6152 IMG_7257

These flies are Euaresta bella, whose only known host is common ragweed (Ambrosia artemisiifolia). The females lay eggs in female flowers and the larvae develop in the fruits, where they overwinter, pupating in the spring. The females in the last two photos above are on male flowers, which produce the dreaded pollen and presumably are not suitable oviposition sites.

Another species that feeds only on common ragweed is the leaf beetle Ophraella communa (Chrysomelidae). It lays clusters of yellow eggs on the foliage (these empty eggshells aren’t quite as yellow)…


…which produce hairy larvae that feed on the leaves.


Ophraella species are unusual among beetles in that they pupate in cocoons on their host plants (most beetles do not spin cocoons, and/or pupate in a cell hidden from view).


The adults are stripey and likewise feed on ragweed foliage.


Here’s an aphid that was sucking away on a ragweed stem in my yard last summer. It’s probably a Macrosiphoniella species, or possibly Uroleucon, according to Natalie Hernandez. Not being sure what it is, I can’t comment on its host specificity.

IMG_6173 And then, of course, there are the leafminers. I count 30 North American species that are known or suspected to mine leaves of various ragweeds. Not all of these are specific to these hosts, but Astrotischeria ambrosiaeella (Tischeriidae) is an example of one that is. As far as I know it doesn’t occur in New England, but Julia and I found the distinctive mines on giant ragweed (Ambrosia trifida) at a rest area along I-70 in Missouri.


In the middle of the brown mined area is a green “nidus,” a silken retreat in which the larva ultimately pupates. The related species Astrotischeria heliopsisella, which mines leaves of sunflowers as well as ragweeds, eats the leaf tissue above the nidus so that it appears white instead of green. One of the mines in the above photo produced this adult moth:


The other mine produced this parasitoid:


The only chalcid parasitoid recorded from Astrotischeria heliopsisella is Pnigalio maculipes (Eulophidae). I think the one I reared is probably a Pnigalio, but probably not P. maculipes, since it doesn’t have the spotted legs that give that species its name. The genus Pnigalio needs revision anyway; the last set I gave Christer Hansson (reared from this eriocraniid) consisted of two species that couldn’t be identified using existing keys. Anyway, the point is, lots of bugs eat ragweed.


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