This is a message from the Museumpests List. To post to this list send it as an email to [email protected] To unsubscribe please look at the footer of this email. ----------------------------------------------------------- Hi Betsy, The creatures are bristle millipedes. I've sorted quite a few over the past 35 years from litter samples. Here's some info modified from Wikipedia and other sources: Polyxenus is a genus of millipede in the order Polyxenida, containing at least 30 valid species as of 2012. The class is Diplopoda. Polyxenus fasciculatus is a species of millipede about 2 millimeters (0.079 in) long which is notable for its use of detachable bristles which entangle predators such as ants, spiders, pseudoscorpions, and centipedes. The tail bristles have grappling hooks at the tip which lock on to the setae of an ant, and barbs along their length which cause them to interlink. You can see on the ventral side that there are more than 3 pairs of legs so not an adult or larval insect. The tuft of tail bristles are analogous to those on certain dermestid larvae (these are the hastisetae, the spear-headed setaet) such as found on members of commonly encountered species of Trogoderma and Anthrenus. The body setae of Thylodrias contractus (odd beetle) are a bit enlarged toward the tip, but also flattened and rounded and have no spear-heads. Molting by the insect larvae and molting by the millipede replaces the specialized hair tufts that are lost when defending itself. Tom Eisner from Cornell University reported on the anti-predator behavior back in 1996. BTW, new world tarantulas (Theraphosid spiders) have urticating hairs that are flicked off by the spider when it is bothered by a predator or pet keeper. This is not good if these impact your eyes. There are 4-7 different types of these hairs and the spider also replaces these by molting. This is very useful for the spiders since many will live 20-30 years, so there are female post adult molts in these spider species and the anti-predator structures are replaced. Males normally don't live long after maturing at around 7-10 years, although I've kept some in good health and one or 2 males did have post-adult molts only to lose their pedipalps since these went with the shed skin. If you know about spider reproduction, these secondary sexual characters are what move the sperm from the male (via a sperm web) to the female (via courtship and mating). His age is against him anyway and will soon die. The female because it molts actually replaces the structures (spermathecae in her abdomen, connected to ovaries) and in effect becomes a virgin since the old spermathecae may have been filled with sperm from previous matings. Lou
Louis N. Sorkin, B.C.E. Entomologist, Arachnologist Division of Invertebrate Zoology American Museum of Natural History Central Park West at 79th Street New York, New York 10024-5192 [email protected]<mailto:[email protected]> 212-769-5613 voice 212-769-5277 fax The New York Entomological Society, Inc. www.nyentsoc.org<http://www.nyentsoc.org/> [email protected]<mailto:[email protected]> From: [email protected] [mailto:[email protected]] On Behalf Of Betsy Bruemmer Sent: Monday, March 10, 2014 6:48 PM To: [email protected] Subject: [pestlist] beetle or millipede? This is a message from the Museumpests List. To post to this list send it as an email to [email protected]<mailto:[email protected]> To unsubscribe please look at the footer of this email. ----------------------------------------------------------- We had a recent invasion of small pests that I am having difficulty identifying. I thought they were carpet beetle larvae but an entomologist on bugguide.net has suggested bristle millipede. They were found crawling all over a white wall in a textile storage room, following a water leak through the exterior wall. We have in the past found old dried up dermestid casings on some of our textiles but we don't know if the textiles came in that way or if the evidence is due to recent activity. It's a huge collection that is just now being properly catalogued. There is surprisingly small amount of damage to the textiles overall so it seems more likely to me that these larvae came in through the leaky building envelope. The images for both these pests are quite similar, however, millipedes are not usually mentioned as museum pests and we have not seen adult millipedes to date but we did find one carpet beetle last year. Thanks for your help. BETSY bruemmer collections manager MOHAI Resource Center 5933 6th Avenue South Seattle, WA 98108 P: 206.324.1126 Ext. 122 | F: 206.780.1533 [email protected]<mailto:[email protected]> www.mohai.org<http://www.mohai.org> [cid:[email protected]] Explore the people and events that made this city and changed the world, at the new Bezos Center for Innovation, now open at MOHAI! ---------------------------------------------------------------------- To send an email to the list, send your msg to [email protected]<mailto:[email protected]> To unsubscribe from this list send an email to [email protected]<mailto:[email protected]> and in the subject put: "unsubscribe" - no quotes please. You are receiving the Pestlist emails in standard mode. To change to the DIGEST mode send an email to [email protected]<mailto:[email protected]> with this command in the body: set mode digest pestlist Any problems email [email protected]<mailto:[email protected]> or [email protected]<mailto:[email protected]> ---------------------------------------------------------------------- To send an email to the list, send your msg to [email protected] To unsubscribe from this list send an email to [email protected] and in the subject put: "unsubscribe" - no quotes please. You are receiving the Pestlist emails in standard mode. To change to the DIGEST mode send an email to [email protected] with this command in the body: set mode digest pestlist Any problems email [email protected] or [email protected]
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