Mantis Ootheca

Subject: My neighbor found this on her fence.
Location: 45° 30′ 34″N 122° 30′ 28″W
April 4, 2016 10:40 am
Im trying to identify a “cacoon like” structure on my neighbors fence i currently have only a picture go by. I would say a moth cacoon off first glance but the striations throw me off a bit. Please help me in figuring if this needs to be gotten rid of or left alone.
Signature: Jeff Homsley

Mantis Ootheca
Mantis Ootheca

Dear Jeff,
This mantis ootheca will hatch several hundred beneficial predators.

Thank you sooo much…thats incredible

Update:  April 6, 2016
Though we originally responded to this request, we did not create a posting.  Since posting our own images of a California Mantis hatchling and the ootheca from which it emerged, we decided to turn this submission into a bit of a public service message for home gardeners.  It is frequently necessary to prune plants in the garden, but it is always a good idea to look closely to see if there are any beneficial critters, possibly in the form of immobile eggs or pupae, in the trimmings.  We make it a habit to toss branches into the green bin, but to leave the lid open in the event that anything needs to escape.  Just last summer, while trimming the guajes, we found two California Mantids, so we relocated them elsewhere in the garden.  We encountered more Mantids last year than any other year, and we credit that to becoming more aware while cleaning up the yard.  About a month ago, we removed a broken branch from the butterfly bush and found three California Mantis oothecae, so we tied them securely to other plants, and we have now been rewarded with a sighting of a hatchling Mantis.  The ootheca in this image looks to be a native species in the genus
Stagmomantis.  According to the 4H pdf, the California Mantis is reported from Oregon.  Though we are in favor of organic gardening, we like to caution our readers about the potential problems of purchasing commercially available Mantis oothecae from dealers as those are generally not native, and introducing non-native predators can have a negative effect on native species.  Non-native Mantids are larger and more aggressive than our native species, and we suspect our natives are being eaten by Chinese and European Mantids.

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