Wasps, yellow jackets...

[Longroof]

I've got some wasp looking bugs around most of my bamboo, in different areas of the yard. They are mostly black, with yellow stripes, thin bodied. I'll post a picture when I catch one. I haven't been able to find a nest or anything, but they do congregate on the underside of the leaves...

I'm wondering if these themselves are a problem of if they are simply feeding on something else that is the problem. (Mites, or something..) I don't know.

I have had a number of new culms end up dying at about the 4 foot level. It's like someone just pinched the tip. It turns brown, rots and dries up and then the culm doesn't get any taller. This has happenend to at least 4 new culms and I know it's not just physical damage.

Any ideas or suggestions? Is this a candidate for the oil/detergent spray? Or just bug killer?

[Mark Meckes]

I don't know about the wasps unless you can see a prey that it's after.

Regarding the aborting culms ...
Are there some shoots that have successfully made it?

Because bamboo has a limited season each year that it produces shoots, it often grows more shoots than what can successfully survive, kinda like an insurance policy, in case some get damaged.
Also they may not all develop if it didn't store up enough nutrients through it's roots prior to the shooting season, or due to certain environmental conditions, like lack of rain or too much shade.

A bug that can affect emerging shoots is the Bamboo Mealybug - Palmicultor lumpurensis (http://www.bamboocraft.net/bamboo/showgallery.php?cat=535)

Mark

[Longroof]

I haven't seen any evidence of the mealy bug, but will look closer.

As for the shoots, they are small stands of bamboo and I haven't had a lot of growth lately, so losing the tops of both new culms kinda hurts. These are the first new culms in about a year.

I'll get some pictures of the tops and the bugs tonight if I think about it...

[Longroof]

Here are some pictures of the wasp things I've got all over...

[Mark Meckes]

Is this the wasp?

Excerpt from the Audubon Society Field Guide to North American Insects and Spiders - 1980 edition

TIPHIID WASPS Family Tiphiidae

Five-banded Tiphiid Wasp - Myzinum quinquecinctum

Description
1 1/8 - 1 3/8" (30-35mm)
Black, streaked on head ... thorax with yellow
Antennae black, Legs yellow,
Wings dusky brown, translucent

Habitat: Medows, fields, lawns.

Range: Throughout the US and Canada except in the West.

Food: Adults drink nectar.
Larvae is parasite of May beetle larvae.

Life Cycle: Female lays eggs on May beetle larvae in soil, depositing one egg on each host.
Wasp larvae penetrate hosts, feed first on nonessential tissues, later eat essential organs, killing host.
Pupae overwinter in soil. Adults emerge in early summer.
There is one generation per year.

Because this wasp preys on beetles, it is considered to be highly beneficial.
It in turn is parasitized by velvet ants.

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The photo of the wasp in the above book looked like yours and showed 6 yellow markings on the thorax, and a yellow tip, so I guess someone has a reason for calling it a Five-banded Tiphiid Wasp

(Tiphiid ... How is this pronounced?
... similar to the sound made spitting out watermelon pips? ;)

... hmmm ...
Adult Five-banded Tiphiid Wasp likes to drink nectar ...

Could they be attracted to the pungent aroma caused by anaerobic fermentation of the moisture and nutrient rich decomposing shoots?

Mark