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Southern Black Widow (Latrodectus mactans)
Photo#34659
Copyright © 2005
Christopher C Wirth
Guide Plate for the Southern Black Widow -
Latrodectus mactans
The female is on the left and the male is on the right.
Is the size comparison accurate?
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Contributed by
Christopher C Wirth
on 15 October, 2005 - 3:49pm
Last updated 11 September, 2018 - 12:06pm
On adult females the only red
On adult females the only red is on the hourglass. They have those red dots while they are maturing.
…
Levi F. C. Smith
, 10 January, 2024 - 3:23pm
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identification of L. mactans
This is a very good article but it still presents somewhat conflicting information about the identification of L. mactans.
The article says:
"The adult female black widow spider has a glossy jet black color all over, including body and legs. The only red marks are the bright red hourglass mark on the underside of the abdomen, and a red spot just behind and above the spinnerets."
But this diagram shows read marks on the dorsal side of the abdomen. I have seen some pictures where these marks are very distinctive. Do the marks disappear as the spider ages? Is this just a variation between individuals? Does L. mactans almost always have at least one read dot above the spinnerets?
…
davefoc
, 13 September, 2008 - 1:46pm
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Gut feeling
that the male is a bit smaller. I was amazed how small he was when I found one the other day. I thought it must be an immature male, but was ID's as mature.
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Lynette Elliott
, 15 October, 2005 - 5:28pm
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Male Black Widow
I will make the male a bit smaller. Thanks for your help!
…
Christopher C Wirth
, 15 October, 2005 - 6:35pm
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