I Spy with my Little Eye... Tons of Robber Flies!

Robber Fly
Photo Credit: Bart Drees

I was overwhelmed today as I took a walk in the sun and the number of robber flies buzzing around!  You'll probably notice them too, if you spend a little time outside this spring and through the summer.

I'm seeing a grey colored robber fly at the moment (pictured to the left), but later on, as it gets warmer, I'll start to see the bumble bee mimics.

Robber flies are beneficial insects, acting as predators and eating all sorts of insects out of the sky.  But, they aren't picky about what they eat.  They are known to eat up honey bees and camp outside their hives to catch them as they fly past.  The bumble bee mimics will also eat up bumble bees.

You can tell a robber fly from other insects it resembles by looking at the eyes.  Flies have huge eyes that are almost triangular in shape and can almost touch at the top of the head.  The shape of fly eyes are a giveaway for their identification. Robber flies also look like they have mustaches with fuzzy faces and generally fuzzy bodies as well.

Robber fly
Photo Credit: Bart Drees

Last summer, I had a robber fly that sat on a fig tree, next to a blooming shrub that was always overwhelmed with bumble bees.  Every time I walked past that fig tree, that darn robber fly had a bumble bee in it's grasp.  I let this go on for a week or so before I had to put an end to it and smoosh the robber fly.  I like my predator insects, but I love my pollinators more!

My prediction for why robber flies are so active at the moment is because their food source (other flying insects) are out and about right now and the feeding is good!

This Caterpillar Says DON'T TOUCH ME!

It is a good general rule of thumb to avoid caterpillars with hairs or barbs coming from their body.  There is a good chance they are stinging caterpillars.

Eastern Buck Moth Caterpillar
Photo: Molly Keck

This guy, an Eastern Buck Moth Caterpillar (Hemileuca maia)
has been found all over the San Antonio area this spring and it would be wise to avoid it.  They are stinging caterpillars and everyone reacts differently, so don't touch!

I had the misfortune of getting one on my pants the other day and accidentally bringing it inside.  When I rested my hand on my leg, I encountered the hairs/barbs and it didn't feel good!  Itched and left an uncomfortable feeling on my thumb for a couple hours.

These caterpillars will turn into interesting looking moths, called Eastern Buck Moths.  What amazes me, is that the caterpillar (immature form) is so much larger than the moth (adult form)!

There isn't much you can do about managing these caterpillars until they all pupate and go away, so for now, just don't touch!  You are more likely to encounter them as they leave their host plant in search of a spot to pupate, which is currently happening.  They aren't aggressive and won't come after you, but they can drop from trees.

Weekly Gardening Webinar Series

Horticulturist David Rodriguez and Entomologist Molly Keck are joining forces to provide a weekly plants and bugs webinar series.  Join us to learn about your landscape and the insects that could wreak havoc on it!

Every Tuesday and Wednesday in April @ 1-2pm Central Time

To join, CLICK HERE at the time and date of the presentation.

Turfgrass Basics

April 14 – It’s More Than Just Mowing! – David Rodriguez

April 15 – Bugs That Hurt the Lawn – Molly Keck

What’s Happening in Your Veggie Garden

April 21 – The Plants – David Rodriguez

April 22 - The Pests – Molly Keck

Growing Citrus on Your Patio and Landscape

April 28 – An Easy and Fun Way to Grow Vitamin C – David Rodriguez

April 29 – The Pests that Reduce That Vitamin C – Molly Keck

Native Pollinator and Pollinator Planting Webinar Series

Spring is sprung and the bees and butterflies are getting busy! 

If you have an interest in the pollinators in your landscape, we hope you can join us for a Webinar Series on Native Pollinators and Planting for Pollinators!  Hosted by Texas A&M AgriLIfe Extension Entomologist, Molly Keck and Horticulturist, David Rodriguez. 

Learn what pollinators are common in your landscape and how you can encourage them on Wednesday at 1pm.  Then learn what you can plant to produce nectar 12 months out of the year, Thursday at 1pm!

1pm Central Time
Wednesday, April 8 – Native PollinatorsMolly Keck, Entomologist with Texas A&M AgriLife Extension in Bexar County

Thursday, April 9 – 12 Months of Nectar Producing PlantsDavid Rodriguez, Horticulturist with Texas A&M AgriLife Extension in Bexar County

Did you miss the webinar live?  You can watch it on our YouTube Channel HERE!