Category Archives: biocontrol

War on Aphids

When most people see aphids on their plants they immediately seek help on how to eliminate them often grabbing a bottle of soapy water or some other recommended concoction. Me? I get positively giddy with delight.

You see, aphids are on one of the low rungs on the web of life partner’s ladder. They serve as a feast for others, growing a variety of pollinators and ultimately reptiles, amphibians and birds. Where there are aphids, critters on the next link in the food chain are sure to follow.

I’ve written before how aphids are much like butterflies in that they flock to particular host plants. You can often identify the species by using the aphid host database although you might only narrow things down to genus.

Honey, this looks like a great spot to raise our young. Look at all the aphids! (Dioprosopa clavata)

This week I got giddy…VERY giddy. I spotted some aphids on the Bidens alba, my all-time favorite Florida native plant. You would be hard-pressed to find any aphid damage on the B. alba…it grows quickly and any chewing or sucking damage is quickly covered by new leaf growth. More importantly, what followed my spotting of the aphids was a parade of critters and the benefits abound.

Adult Ladybugs and syrphid fly larva work side by side to clean up the aphids

Cornell reports:

“Although the impact of any one species of natural enemy may be minor, the combined impact of predators, parasitoids, and insect pathogens can be considerable.”

So, what infantrymen were on my Bidens battlefield?

Larva of a native spotless lady bug was on the job
Larva of Tribe Scymnini (Dusky Lady Beetle) was scouring stems
and you ocan see was having great success

Lady beetles. “A single lady beetle may eat as many as 5,000 aphids in its lifetime.”

Even the exotic ladybugs were showing up.
And this pupa shows that future generations are possible

Hover [syrphid] flies. “A single syrphid larva can consume hundreds of aphids in a month.”

eggs of Syrphid Fly (Dioprosopa clavata) were layed
and the larva began to grow
and grow
and GROW

 

The pupa forms and the next generation is secure
As the empty cocoon shows

Not to be outdone, the airmen showed up:

Long legged flies. As adults, Longlegged Flies (Dolichopodidae family) are predaceous on small insects such as aphids. And with their metallic colors they’re pretty too!

Long legged flies land to eat
They are small by easily spotted with their bright metallic coloring
Some of them downright bright and shiny

In my research I learned about a new-to-me aphid web of life partner. The Braconid wasp. While cropping photos I noticed an insect I was not familiar with. Turns out it was an “aphid mummy”. Braconid wasps in the subfamily Aphidiinae are parasitoids and oviposit their eggs in aphids. What I was seeing was an aphid that had been parasitized. Soon a tiny beneficial wasp will emerge.

This aphid was parasitized by a beneficial Braconid wasp from which offspring should soon emerge

 

This is a new syrphid fly player in the war for me. Ocyptamus cylindricus species group

The waste aphids produce is known as [honeydew]. I found the following of interest:

 Adult hover [syrphid] flies require honeydew or nectar and pollen to ensure reproduction, whereas larvae usually require aphid feeding to complete their development (Schneider 1969). However, there are exceptions: in the absence of aphids, larvae of some species can subsist and complete development on diets made up solely of plant materials such as pollen (e.g., Melanostoma and Allograpta obliqua [Schneider 1969] and To x o m e r u s [Mesograpta sp.] [Cole and Schlinger 1969])

One of the Toxomerus sp. of Syrphid Flies. The honeydew may be what attracts them

So, if you remove aphids from your plants you may defeat attracting future generations of beneficials. Given, I would treat aphids on a houseplant by wiping them off since natural predators won’t have ready access to perform pest control indoors and thus the plant would suffer. On the other hand, its seems that aphids on your outdoor plants can benefit your garden by attracting those wonderful pollinators, predators and parasitoids especially those whose larvae use aphids as hosts.

Spined soldier bugs (Podisus maculiventris) are predators who probably are lying in wait for those that feed on the aphids….or perhaps may nosh on an aphid or two themselves

Don’t spray the aphids and then buy commercial ladybugs in an attempt to keep them in check. Likely, you’ll only to have them fly off. If you already removed the aphids or discouraged them in any way, adult ladybugs will go to lay their eggs where there is an ample supply of the host for their young…like my house. 😉

Looks like the dusky lady beetle larva did a good job of cleaning up the aphids

While other branches of the Bidens had signs of aphids from time to time, the branch in the original photo was scoured clean within a day. Give natural control a chance to develop and hopefully you will see the circle of life perform beautifully at your place too.

Tip: Group different genera of plants native to your area using the “right plant, right place” theory and avoid monocultures. That way your garden will attract a mix of native insects and predators and never look overly chewed since it will have balance just like Mother Nature intended.

Select resources:

ENTFACT-105: Ladybugs by Ric Bessin, Extension Entomologist, University of Kentucky College of Agriculture

Hoffmann, M.P. and Frodsham, A.C. (1993) Natural Enemies of Vegetable Insect Pests. Cooperative Extension, Cornell University, Ithaca, NY. 63 pp. (Anthony Shelton, editor). Accessed August 27, 2017, from http://www.biocontrol.entomology.cornell.edu/

Aphids on the World’s Plants: an online identification and information guide.

 

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When Garden Drivel Meets World Research

In 2009 when I began writing about my garden encounters I felt good that I was getting the word out about the importance of native plants in the scheme of things. At that time I had no idea just how important they are since I was clueless about how each creature performs a vital role in the rungs on the food chain and often are dependent on a single plant as a host. It was a hobby I embraced as I found I liked learning about creatures’ interaction with plants and I also love to spin a yarn as anyone who knows me could attest.

With each new encounter I became more aware of the circle of life and that even aphids can be important in the scheme of things. Killing one creature that we may not hold in awe ultimately will result in less food for someone higher up. I threw away my soapy water bottle in which I dropped leaf-eating beetles. I stopped picking off the bagworm “cocoons” that I was told were so bad for my plants. I started the practice of “live and let live”. A chewed plant is not something to frown about …it is something to rejoice. It just might help grow a baby bird in the making.

I have a few blogs that I write. Back in January 2016 I received a comment on one of my “Central Florida Critter of the Day” posts from an arachnologist in Switzerland.

Dr. Martin Nyffeler, Senior Lecturer in Zoology at the University of Basel was requesting the use of my photo and encounter of a Regal Jumping Spider who had a treefrog in his clutches. Dr. Nyffeler has studied and published many research papers on spiders. Things I find fascinating…like spiders eating various critters including fish and bats. He was in the process of putting together a research paper on spiders eating vertebrates and my treefroggy encounter qualified.

I was thrilled that someone internationally known for spider research was interested in my little rendezvous with nature. I knew that my encounter was not a normal, run-of-the-mill occurrence, but I didn’t realize that it might just be rare.

Regal Jumping Spider (Phidippus regius) with invasive cuban treefrog

So, my encounter was included in Dr. Nyffeler’s research paper “A vertebrate-eating jumping spider (Araneae: Salticidae) from Florida, USA”. This week it was published in the Journal of Arachnology, 45(2):238-241 put out by American Arachnological Society. It was one of 8 Florida encounters included in his paper so I’m feeling pretty darn special. *My* spider is picture “D”. I’m also feeling pretty darn good that my mindless drivel may actually have a useful purpose.

In my retirement hobby I feel like I’ve made some extraordinary strides. From writing the newsletter for the local Native Plant Society Chapter to blogging about weekly encounters in my garden, to an interview for the statewide Guide for Real Florida Gardeners (2013 issue) published by Florida Association of Native Nurseries, to a 2013 spread in the nationally published Humane Society Magazine All Animals, and in 2017 The Humane Gardener book by Nancy Lawson. Now I’ve gone International. What’s next…a movie? I can see it now “Lizards on a Car”. HA!

Hot Diggity Wasps

This tale was originally published by Loret T. Setters on October 13, 2013 at the defunct national blog nativeplantwildlifegarden[dot]com. Click the date to view reader comments and find working links to other stories.

Great Golden Digger Wasp
Great Golden Digger Wasp

I was taking my routine morning walk and headed back toward the pond.  As I approached the one spot where I have a good view of the turtles and fish, I heard a loud buzzing.  Something large, VERY large circled away from me, but quickly came back and landed on the ground.

Dragging her prey behind her
Dragging her prey behind her

How fun that it was to watch a Great Golden Digger Wasp (Sphex ichneumoneus) bringing a katydid to provision her nest in order to lay her eggs. The prey may have been a grasshopper, but, at any rate,  it was some sort of Orthoptera, an insect order that also includes crickets in addition to the other two.  Let’s just say jumping things.
diggerwaspHopperA-e1381674039473

This prey will serve as the food for the larvae that hatches and will grow into future Sphex wasps. Momma Wasp stings the prey to paralyze it with toxins.  She then flies, as this one did or if her prey is too big or heavy drags it to the nest.  This prey was much larger than the wasp itself but it still managed to fly it in.  Makes you wonder if katydids are hollow.

Very neat entryway
Very neat entryway

Prior to the capturing process, a nest is painstaking dug in a sunny location with Momma carefully digging out grains of sand or dirt, carrying it to the entrance between her arms and then flipping it underneath her body and between her legs.  Sounds like the digging method my Irish setter uses.  I’m betting it is a long process since I read that they create several tunnels off this main deep entrance.

She just left her prize unattended. Brave wasp with all the other visitors in my habitats
She just left her prize unattended. Brave wasp with all the other visitors in my habitats

These wasps have a fascinating provisioning behavior.  I was surprised to see her crawl into the nest leaving her jumping friend lying at the entrance.  Of course since it was paralyzed it didn’t have the ability to escape on its own.  Good for me as I was able to get a photograph or two, but I thought it odd that she would leave it exposed where another critter (looking up to the sky…no, not me) might come along and scoop it up as a ready-made meal.  Apparently this does happen, with birds being the likely suspects.

Research reveals that if the prey is moved further away (mean researchers they are) when Momma comes out, she will drag the prey back close to the entrance and once again pop in to check the nest prior to bringing the prey inside.  She will do this numerous times (REALLY mean researchers they were) despite the fact that it is the same exact prey that she initially caught.

The only thing I can think of is that she is so wary that something might infiltrate her house, even in the short time it takes to bring the prey back a few inches that she feels the need to double check that all is in order. Rather paranoid if you ask me, but hey, I’m not in the wasp business, so what do I know.  Heck, many humans have neurotic behavior (think checking two or three times to see if the windows are locked).  If Momma wasp wants to be super-careful with her nursery seems like she should be nominated for a mother of the year award rather than cast in the light of needing therapy.

Great Golden Digger Wasps are Pollinators too!
Great Golden Digger Wasps are Pollinators too!

Adults take nectar and aren’t at all aggressive.  All these years, the fear of wasps is turning out to be wasted anxiety.

Since the only prey of the Great Golden Digger Wasp are what one might consider pest species, and since it pollinates, it is definitely high on the beneficial list.

Spider Wasps provision nests with…you guessed it….spiders!
Spider Wasps provision nests with…you guessed it….spiders!

Another prey-dragging wasp is in the Pompilidae  Family: the Spider Wasp. A while back I observed what I believe to be a Blue-Black Spider Wasp (Anoplius spp.), Wolf Spider in tow.  A very BIG spider; much larger than the wasp itself.  All these wasp-types must work out.
She seems unconcerned with the large size. Must work out to build muscles
She seems unconcerned with the large size. Must work out to build muscles

This tenacious flying insect walking along the ground with its prize also fascinated me.  Now that I think about it, I’ve seen more spider wasps crawling around the ground looking like they are on a mission, than I have seen flying around the flowers.  Yet another wasp that has a set behavior in life.

The spider is likely a Wolf Spider
The spider is likely a Wolf Spider

Wasps are important players in the garden with their pest control and pollination duties, so don’t grab the bug spray out of fear.  Let them be to do their jobs and sit back to enjoy the show.

The baby wasps will be well fed with this big fella
The baby wasps will be well fed with this big fella