Entomology (Study of Bugs)/Spider id
QUESTION: What type of spider is this? Is it dangerous? Is it native to southern Indiana? It looks like a red backed spider, but I thought they only lived in Australia. This is the second one we have seen this month. The red on its abdomen continues from the top in a stripe all the way to the belly side. We also say male that looked much smaller with yellow and red guarding the egg sac. Please identify for me. Thank you.
ANSWER: Hi Cris
This is a Black Widow (Lactrodectus mactans) and you described a male widow also. They are not usually found in Southern Indiana but can occur there. The red hourglass associated with Widows can vary. The Australian widows are called Red backs. As you probably know a black widow bite can cause harm. If this spider is in your house or near where children could confront it you should destroy it and the egg sac. Otherwise just leave it alone.
This is a nice photo by the way and the first time someone has sent me a widow photo from Indiana
---------- FOLLOW-UP ----------
QUESTION: Even with this coloration on the back? Though widows had either spots or the hour glass. This solid stripe made me think red back.
You took two views of this spider,one with a single spot and another with the stripe. Some L. mactans have three spots that are separate.
I admit it looks like the Australian widow but unless this spider and the male hitched a ride on a plane or if some fool collected them and brought them here,which is highly unlikely, I have to assume this a color variation on L. mactans.
Considering the remote possibility that is an import you can contact the top spider guy in Ohio at the Ohio State University Dr. Richard Bradley and send him the photos. Contact him at
Dr Richard Bradley
Department of Ecology
Acarology rm 1380f
Columbus Ohio 43212
If you contact him let me know what he says