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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5 thoughts on “War on Aphids”

  1. A most wonderful post Loret. You are most definitely a citizen-scientist. Such careful observer and documentation. Of course I knew if lady bugs, and leave aphids alone, but all the other creatures were a revelation..Well done! Thank You 😊

    Liked by 1 person

    1. Amazing how the digital camera with macro settings has added to our knowledge. I was all set to finalize this article going through my photos when the aphid mummies appeared in frame. A little more research was needed and once again I learned something new about our natural world. Thanks for your kind words and support. It’s a great hobby that I highly recommend 🙂

      Like

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