Skip to content

After writing my post on Wednesday about seed bugs, I sent it down to the Great Bug Guru and Swell Guy, Carl Olson, at the University of Arizona. Carl was nice enough to straighten me out on the scientific name of the bug in the photo. He also let me know that there is similar bug that he has been hearing a lot about here in Phoenix.

Here is a photo of the bug he's been getting calls about, Neacoryphus lateralis.

Neacoryphus laterali

Carl was also nice enough to send me a photo of the small milkweed bug, Lygaeus kalmaii. This is the species that may also occur on milkweeds, and also has a white spot (actually a pair of white spots), on the back of its wing.

Small milkweed bug:

small milkweed bug

This morning it was a bit difficult to find a bug for bug of the week. Can you guess why from this picture?


Woo, woo, it is raining here. Rain is a novel event, and all the insects apparently have sought shelter. I knew where to look, however, to find an insect that would be still out. There is always something happening on the desert milkweed, and this morning was no exception. Here is our bug this week, captured quickly before it started to rain again.

milkweed bug

The bright red bug shown is commonly called a seed bug (Oncopeltus sanguiniolentus). It may resemble the boxelder bug found in other parts of the country, but it lacks the black bars on the red section (top) of its wings.This species has one white dot in the black part (bottom) of its wings. Another species that has the black bars in the red, but has two white dots in the black is the small milkweed bug, Lygaeus kalmii. (See photo in newer post). To paraphrase Dr. Seuss, "what a very lot of bugs there are!"

It is amazing that there are so many insects feeding on the desert milkweed. The sap of milkweeds contains both rubbery latex and poisons. Insects like queen and monarch caterpillars, yellow oleander aphids and these milkweed bugs have ways to deal with it. In this case the bugs avoid the latex-carrying channels with their straw-like mouthparts.

If there aren’t any milkweeds available, these versatile bugs also feed on the seeds of various plants.

This morning when I was talking on the phone with my sister outside, I noticed a spider wrapping up a fly it had caught in its web. I recognized it immediately as a cellar spider, Family Pholcidae, because of its slender body, long legs and the tangled shape of its web. It also has dark markings on the underside of its body.

The larger cellar spiders common around homes in the Southwest have been introduced from Europe. This one looks like the marbled cellar spider, Holocnemus pluchei, because of the marbled white and pinkish-red pattern on its abdomen.


We have a community of cellar spiders that live on the outside of one of the windows where we watch our bird feeder. When the feeder is quiet, we watch the spiders instead.

Have you ever watched a spider?