Currently viewing the category: "Inchworms"
What's That Bug? does not endorse extermination

Subject: Help Identify
Location: Talbott, Tn 37877 in a 80 year old cedar tree
July 20, 2016 5:04 pm
My daughter recently found this little guy hanging from what appeared to be a spider web but upon further examination could have been its own silk. I have been told that it could be a chameleon worm but I can’t find any info to back it up. Can you help identify please? I would like to know incase my daughter finds another one I can tell her to either stay away or its safe to touch. Thanks in advance!
Bryan Hux
6th Grade Science
Jefferson Middle School
Jefferson City Tn
Signature: Bryan Hux

Unknown Spanworm

Juniper Twig Geometer

Dear Bryan,
Though we have not had any success with a species identification, we can tell you this is an Inchworm or Spanworm in the family Geometridae, and it poses no threat to humans as it is neither venomous nor poisonous.  We wish we could be certain that the cedar upon which it was found was also the host plant as we couldn’t find any similar looking Spanworms associated with cedar.  Perhaps one of our readers will have more success at a species identification than we have had searching BugGuide and other sites. 

Karl finds the ID
Hi Daniel and Bryan:
It looks like a Juniper-twig Geometer caterpillar (Patalene olyzonaria). Despite the name, the principal food for the caterpillars is given as cedars of all varieties. Regards, Karl

Thanks so much Karl.  We like our name “Diamondback Spanworm” since the BugGuide description is:  “Larva: body brownish or grayish with dark angular lines dorsally and laterally, creating a diamond-shaped pattern; whitish patches below angular lines in subdorsal area; pair of black dorsal warts on ninth abdominal segment; head brown and gray with dark brown herringbone pattern on lobes.”

What's That Bug? does not endorse extermination

Subject: Colorado Caterpillar
Location: 11 mile Canyon outside of Lake George, Colorado
June 23, 2016 8:10 am
Hey Bugman!
I have no idea what kind of caterpillar this is! Or what kind of moth/butterfly it will become. I tried all of my bug books and online resources.
This little guy was found in 11 mile Canyon in Colorado.
Thank you!
Signature: Frankie

Barberry Geometer

Colorful Inchworm:  Meris alticola perhaps

Dear Frankie,
Because of the reduced number of prolegs, your caterpillar is easily identified as an Inchworm or Spanworm in the family Geometridae, though its colorful markings make it unusual in that family, most of whose members have caterpillars that are green or brown and effectively mimic twigs.  At first we thought we had correctly identified your Inchworm as a Barberry Looper or Barberry Geometer,
Coryphista meadii, based on this BugGuide image, but we remembered identifying a similar Inchworm in the past and we could not find one in our archives.  We searched our archives for “colorful Inchworm” and we found this posting of Meris paradoxa that looks possible as well, but the species is only reported from Southern Arizona according to BugGuide.  The related and similar looking Meris alticola is also pictured on BugGuide, and it is reported on BugGuide from Colorado, so of the three, our money is on Meris alticola

What's That Bug? does not endorse extermination

Subject: Caterpillar/Inchworm Michigan
Location: Redford, Michigan
May 31, 2016 6:40 am
Dear Bugman,
This little caterpillar fell on my arm, while I was sitting under a Black Walnut Tree in southeastern Michigan on 5/28/2016. He was quite small, maybe inch long and a quarter inch wide.
Thank you for the service you provide.
Signature: Kristin

Filament Bearer

Filament Bearer

Dear Kristin,
This Inchworm is one of the Filament Bearers in the genus
Nematocampa, an identification that can be verified on BugGuide.

What's That Bug? does not endorse extermination

Subject: Caterpillar id
Location: Big Lake, Minnesota
May 30, 2016 3:29 am
Good morning. My sister has caterpillars in her semi woodland garden in Big Lake Minnesota that are literally dropping from the trees (pine and ornamentals) on the margin of the woodland. They seem to be most active now – mid May. It is her first summer there so cannot say whether this is unusual.
Signature: Lorna

Ed. Note:  We had an offline exchange with Lorna since the image attached to the original email was a Black Arches Caterpillar from our site.  We finally received the correct image.

Oops. I don’t know how that happened – I am sorry. Here it is:

Inchworms dropping from trees

Cankerworm dropping from trees

Dear Lorna,
The general term Cankerworm is used to describe several species of Inchworms or Spanworms that feed in trees and drop to the ground.  According to Virginia Green Lawn Care:  “The term ‘canker worm’ is used, not to describe a single caterpillar, but a group of inchworms that cause damage to many different ornamental and fruit trees. … These leaf eating insects are not only a nuisance; they can cause great damage or even destroy a grown tree over a period of time. You may have run into one dangling from a silk thread as you walked under a tree. It is a battle between canker worms and the trees you love and have planted and nurtured.  When heavy populations are present, they can completely defoliate a tree in just a few weeks. This is when you need to step in.”  The individual in the new image you attached looks like the Linden Looper,
Erannis tiliaria, a species that according to BugGuide feeds on:  “Deciduous trees, including apple, ash, beech, birch, elm, maple, oak, poplar, Prunus and Ribes.”

What's That Bug? does not endorse extermination

Subject: Caterpillars unknown?
Location: Florida central
May 8, 2016 8:52 pm
I’d love to find out what kind of beautiful butterfly or moth this is 😁 I have looked all over hope you can help!
Signature: Sure

Filament Bearer

Filament Bearer

This Inchworm or Spanworm in the family Geometridae is commonly called a Filament Bearer or Horned Spanworm, Nematocampa resistaria, because of the unusual protrusions on its body.  Your individual has much more exaggerated markings than most of the individuals pictured on BugGuide.  According to BugGuide, the caterpillar is:  “Strange! Eversible tentacles extend from the dorsal surface of A2 and A3. In the first photo (below, left) they are in the ‘relaxed’ condition; when the caterpillar is alarmed these tentacles can be extended to 2x their resting length. These same structures probably occur in other species in the genus; but otherwise I believe they may be unique.”

What's That Bug? does not endorse extermination

Subject: Ugliest caterpillar
Location: Southeast Michigan
July 17, 2015 8:38 am
I found this in someone’s garden while i was working. What type of moth or butteffly might it be? I have never seen anything like it before.
Signature: – ruth the gardener

Spanworm

Spanworm

Dear Ruth the gardener,
This is an Inchworm or Spanworm in the family Geometridae, and larvae can often be very difficult to identify to the species level.  One of the most noticeable features on your Spanworm is the red color of the spiracles or breathing openings on the side.  We thought that might lead us to an identification, but alas, it did not.  Knowing the plant the Spanworm was feeding upon might help.  Though we can make out a leaf on the right, we cannot tell the identity of the plant.  If you can supply us with the plant, we might have better luck.

What's That Bug? does not endorse extermination