assassin bug | Roads End Naturalist

Pay attention to what gets your attention.

~Gina Mollicone-Long

First, the answers to yesterdays Attention to Detail post… I’m sure many of you already knew the answers, but, just in case, here is what each of the images in yesterday’s post depicted:

Sensitive Fern – the spore-containing capsules are round in this species.
Foamflower – looking down at the spike of flowers of one of my springtime favorites.
Silk highway left on a cherry tree trunk as a few hundred Eastern Tent Caterpillars venture out in search of feeding sites. They leave a trail of silk with chemical cues for others to follow to the best feeding areas.
A twisted dried tendril from last year’s Muscadine Grape tangle on the fence.
Looking down on some Flame Azalea buds about ready to burst into flower.
Close up of a Dandelion puffball (seed head).
A gathering of Eastern Tent Caterpillars on a Wild Cherry tree trunk.
The tiny yellow flowers of Golden Alexander.
The tip of a single flower on a Red Buckeye flower stalk.
Larvae in a Spotted Salamander egg mass the day before they hatched.
Cross Vine tendrils.
An unopened flower bud of Dwarf Crested Iris.

Today was a truly beautiful day so I spent most of it outside doing some chores and just admiring the wildflowers. Surprisingly, not many photographs taken, so I am sharing something from a couple of days ago that I saw again this afternoon.

Nymph of a Pale Green Assassin Bug on a hickory bud (click photo to enlarge)

I spotted this little bug as I was walking past a hickory sapling. It seems I can’t walk by a leaf bud this time of year without pausing to glance to enjoy their amazing shapes and fullness as they prepare to burst. This one had a special treat, a tiny nymph of what I assumed was an assassin bug of some sort. I looked online and discovered it is most likely the nymph of a Pale Green Assassin Bug, Zelus luridus. Adults are a little over a half an inch long and prey on a variety of insects using that long beak to pierce them and suck out their fluids. But this group of assassins has a rather unique weapon in their bag of tricks – they secrete a viscous fluid from their front legs (and maybe also their second pair of legs), which helps secure their prey when they grab it. You can see a lot of pollen grains stuck to the legs (and other parts) of the nymph in the photo below.

Pale green assassin bug on hickory bud close up

Close up view showing the stalked hairs on the legs

I’m thinking this is not such a bad idea in these times of infrequent trips to the grocery store (our version of the assassin bug hunt). If you drop a cookie crumb it just sticks to your arm so you can retrieve it.

There is no better designer than nature.

~Alexander McQueen

While out in the yard looking at the tent caterpillars the other day, Melissa turned around and saw an interesting pattern on the trunk of a small tree. The pattern and details of the egg tops told us it was the egg mass of a Wheelbug, Arilus cristatus. Wheelbugs (and many other members of this family of insects known as assassin bugs) typically lay a patch of eggs covered with a resinous substance that hardens as it dries. This is a fairly large egg mass, measuring about 2 inches from top to bottom. If you are bored inside today, perhaps you can guess how many eggs are here, and then count them…you may be surprised.

Egg mass of a Wheelbug attached to a small tree (click photos to enlarge)

A closer view shows the typical fringe-like border around each egg top. I’m not sure what the function is, but I am guessing it could be to increase surface area for oxygen absorption.

Close-up of the egg mass shows the fringe along the top of each egg.

A side view shows the eggs are somewhat bottle-shaped and tightly stacked together. One reference described the eggs as looking like “brown bottles with fancy stoppers”.

Side view of eggs…the tiny dots are pollen grains.

These should hatch sometime later this spring and a horde of tiny reddish-orange and black (at first) robotic insects will be unleashed. I am guessing they may prey on one another as well, so their numbers will be greatly reduced before they reach adulthood in late summer (there is one generation per year). Once they are at that stage (over an inch long), they are formidable predators of many types of insects from caterpillars to bees. They are important predators of some pest species like the introduced and invasive Brown Marmorated Stink Bug, and some hairy caterpillars (like tent caterpillars) that are avoided by many birds. With their distinctive gear-like crest and large size, they are fascinating to observe, but handle them cautiously (or better yet, not at all), as they can inflict a painful bite with that long, needle-like beak.

An adult Wheelbug with its namesake armament and strong, piercing-sucking mouth part.

By the way, I counted 184 eggs in this group.

Roads End Naturalist

Educating myself and others about the natural world as I wander and ponder at road's end.

Tag Archives: assassin bug

Pale Green

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