Thursday, September 3, 2009

Tachinid flies, aerial hornworm marauders (Now, with video goodness!)

Na na na NA NUM! (to the melody of Ride of the Valkyries)

Na na na nah NUM!
A couple days ago I came upon this incredible sight in the garden:

Though I'm still an amateur at recognizing beneficial insects, the only fly of use I could recall in my head was the Tachnid fly and after the great pics and footage I confirmed it on the web. (pardons for the weird angle... I don't tend to use my video feature on camera often, so I forgot about the angle).

The tenacity of the fly in the video incredible, to take on such a large, flex-y caterpillar, reminds a person of David and Goliath, or more precisely as this is so far from human relationships, of a great sci-fi action scene flick. If I had the abilities or patience to add little human people running around or hanging onto the leaves this would make this video truly superb :)

Tachinid flies parasitize quite a few common pests such as this hornworm here. This tachinid fly is either directly laying eggs upon the hornworm or is laying live larvae (I know, the phrase" laying larva" is odd enough) onto the caterpillar body, and the larvae will burrow into the host body to FEED before exiting the host to pupate, thus killing the host. Other species of tachinid flies will simply lay their eggs on leaves so their host can eat them and the larvae will hatch inside. (remind me to not eat tomato leaves)

It is my understanding too that a host organism infected by tachnid fly larva are also weakened and do not feed as much, so I left the hornworm alone to serve as a vessel for the cult of Tachinidae and allow their brood to burst forth and populate my garden universe thereafter. (Too sensational?)

The temptation is often great to squish bugs in the garden or unrecognizable eggs, but as I have taken to heart from my readings from the Rodale Institute (, most bugs are good to innocuous, so let them be! (unless you have a serious infestation going on, break out the neem oil)

I'm actually a little surprised to find that I have tachinid flies as the adults feed on little tiny flowers and as my dill, parsley and cilantro bloomed and were then voraciously eaten by the swallowtail caterpillars I didn't think I have enough flowerage to attract them.

Speaking of which, some good flowers to plant to attract and keep the tachinid flies in your garden include:

•Anthemis tinctoria (Golden marguerite)
•Eriogonum fasciculatum (CA Buckwheat)
•Melissa officinalis (Lemon balm)
•Mentha pulegium (Pennyroyal)
•Petroselinum crispum (Parsley)
•Phacelia tanacetifolia (Phacelia)
•Tanacetum vulgare (Tansy)
•Thymus serpyllum coccineus (Crimson thyme)
(Many thanks to for the info)

Last but not least, I leave you with another video!