Growing With Science Blog

Category: Bug of the Week (Page 100 of 219)

Bug of the Week: Leaf or Flea Beetles

April 16, 2014 / / 2 Comments

What is eating the nasturtium flowers this week?

nasturtium-what-is-eating

I noticed some holes were developing in the flower petals on Saturday.

flea-beetle-222

A few of the flowers were covered with leaf or flea beetles. They are small, shiny black beetles with enlarged back legs.

flea-beetle-okay

The beetles seemed to have arrived from nowhere. When I went to check them again today, they were all gone. I wasn’t too concerned anyway because the nasturtiums had already produced a lot of seeds and they are getting to the end of their season. In a few weeks the heat will cause the plants to collapse and I’ll pull them out.

These might be the same kind of beetles that are commonly found feeding on Mexican evening primroses here. I know there are some flowering in the neighborhood.
I’ll have to check them.

Bug of the Week: Crab Spider Camouflage

April 9, 2014 / / 0 Comments

We haven’t had a spider lately for Bug of the Week.

crab-spider-face

How about a crab spider waiting for a meal?

crab-spider-on-purple-100

Crab spiders are known for using camouflage. In fact, adult female crab spiders have been shown to be able to change color to match the color of the flower they are sitting on.

So, why isn’t this crab spider purple, or sitting on a white or yellow flower? Isn’t being white going to wreck its chances of catching prey?

As this article from Wired points out, color matching does not necessarily help the spider to catch prey. One reason may be because bees can see ultraviolet light. Some spiders may reflect ultraviolet light, so even though the crab spiders look like they are matching the flower to our eyes, to the bees they stand out against their background.

This video suggests that standing out against the background may attract prey rather than dissuade it (it also shows crab spiders hunting).

Why would bees be attracted? The video does not explain this, but flowers have patches of ultraviolet that serve as beacons to the nectar. These patches are contrasting, and are thought to act like “signposts” directing the bees to the good stuff. Crab spiders may be trying to change the signs to direct flies and bees to themselves instead.

Now we are back to the question, why do female crab spiders change colors to match the flowers as we see them? Do you have any ideas?

Bug of the Week: Parasitoid Wasp

April 2, 2014 / / 1 Comment

Hey, what is that insect on the sunflower leaf?

good-parasitoid-wasp-perspective

The one amongst all those aphids.

parasitoid-wasp-closer

Look at those stripy back legs!

parasitic-wasp-222

This is a parasitic wasp, or more technically a parasitoid wasp. Parasitoid wasps lay their eggs in other insects. The wasp larvae feed and complete their life cycle inside their host.

I think this wasp is rather large to have completed its development within an aphid, don’t you? It is more likely to use something larger, such as caterpillars, as hosts.

After a bit of research I found out it is Diplazon laetatorius, a parasite of hover flies. Why is it hanging around aphids?

The larvae of hover or flower flies feed on aphids (see this previous post). So, this parasitoid of hover flies is sitting in the food of its host. Talk about sly!

Have you ever seen parasitoid wasps on plants?

« Older posts Newer posts »

© 2026 Growing With Science Blog

Theme by Anders Noren — Up ↑