You are here:

Entomology (Study of Bugs)/mystery egg mass/larva - update


I found another egg mass of the same sort on the same Spicebush. The larvae hatched in 2 days, and this time I put in my standard fall-back food when I don't know a larva's host plant - dandelion. It's being worked over pretty well.

ANSWER: Dear Joyce - I hope that this time, the cats may mature to a stage where identification will be possible. If you can find tender leaves from other nearby trees/shrubs, you might try offering those as well. Please let me know what happens.

---------- FOLLOW-UP ----------

6 days after hatching, the little guys (lgs) have gone thru several dandelion leaf chunks, left lots of tiny frass dots, but don't seem any bigger. I'm still using a magnifying glass.
A friend who also raises lots of lgs used to call them 'cats' as you do. Then one night she had a dream that she had tiny felines in her tubs and jars!

ANSWER: Thanks for the update, Joyce - keep your fingers crossed and watch your dreams!
Awaiting further news,

---------- FOLLOW-UP ----------

mystery larvae
mystery larvae  
24 days after hatching, these lgs are still very uninteresting. Maybe sawfly larvae? Not lepidopteria. About .5 inches now and have turned greenish instead of black/brown. I couldn't find any dandelion (!)in our yard, so tried clearweed briefly. No good. Back to dandelion now. The tree they were on has no other soft-leaved plants nearby except grass and various lawn weeds. Maybe I'll try juniper which is the only thing other plant near.

Dear Joyce - They look more like cats than sawfly larvae to me, but you can tell for sure by looking at their underside. Sawfly larvae have prolegs on the second abdominal segment and caterpillars always lack prolegs on that segment. Also, caterpillars never have more than five pairs of prolegs whereas sawfly larvae have at least six pair.
Eagerly awaiting updates,

Entomology (Study of Bugs)

All Answers

Answers by Expert:

Ask Experts


Ed Saugstad


Will accept most questions in general entomology, including those related to medical entomology, taxonomy, ecology, arthropod surveillance, and pest management. If you are requesting a 'mystery bug' identification, PLEASE either attach an image to your question, or post an image on a web page (such as Flickr) so that I can look at it, as verbal descriptions frequently are insufficient for a definitive identification.


21 years in the U.S. Army as a medical entomologist; duties varied from surveillance of pest populations (including mosquitoes, cockroaches, ticks, and stored products pests) to conducting research on mosquito-virus ecological relationships and mosquito faunal studies. Ten years as a civilian analyst for the Department of Defense, primarily on distribution of vector-borne diseases worldwide. Limited experience on surveillance of agricultural insects in North Dakota and Indiana.

Entomological Society of America, West Virginia Entomological Society, Society for Vector Ecology, National Speleological Society, West Virginia Association for Cave Studies.

American Journal of Public Health, Contributions of the American Entomological Institute, Japanese Journal of Sanitary Zoology, Journal of Economic Entomology, Mosquito News, and Mosquito Systematics.

B.S. in entomology from North Dakota State University in 1963, M.S. in entomology from Purdue University in 1967.

©2017 All rights reserved.