This is a special page on Winthemia manducae tachinid flies. Tachinids are a family of flies that use other insects to complete their life cycles. This means that large caterpillars can be the host for one to two dozen fly larvae. In this case, a Manduca sexta moth larva (tobacco hornworm/carolina sphinx) becomes an unwilling host to Winthemia manducae¹ flies. To quote the source: "(This fly) is often seen near last stage hornworm larvae. Eggs of this species hatch, and the maggots bore into the hornworm. The hornworm is killed while in the soil during the pupal stage, before it can transform into an adult and initiate a new generation."¹

Here is the story in pictures that took 209 days to play out.

Class: Insecta, Order: Lepidoptera, Family: Sphingidae, Subfamily: Sphinginae

Manduca sexta

Day 1. Tobacco Hornworm, wandering stage just prior to pupation. No sign of being parasitized by one or more tachinid flies.

Swan/Sunrise, Tucson, AZ

10/27/2002

Class: Insecta, Order: Lepidoptera, Family: Sphingidae, Subfamily: Sphinginae

Manduca sexta

Day 7: Tobacco Hornworm pupa, apparently in diapause (suspended development) to wait-out the coming winter. Everything is proceeding normally with no indication of parasitization.

Swan/Sunrise, Tucson, AZ

11/02/2002

Class: Insecta, Order: Lepidoptera, Family: Sphingidae, Subfamily: Sphinginae

Manduca sexta

Day 191: Tobacco Hornworm pupa transforms into 19 fat little maggots. I was expecting this darn moth to hatch any day now for the past few months, then one day when checking in on it, I noticed that it looked a bit strange. On closer look I saw that it was starting to crack open, and then it became clear what had been happening.

Swan/Sunrise, Tucson, AZ

05/06/2003

Class: Insecta, Order: Diptera, Family: Tachinidae

Winthemia manducae¹

Day 209, Hatching Day #2: Newly emerged fly from the second batch (10 in first, 9 in second) with wings still folded up.

Swan/Sunrise, Tucson, AZ

05/24/2003

Class: Insecta, Order: Diptera, Family: Tachinidae

Winthemia manducae¹

Day 209. Newly emerged flies ready to fly for the first time.

Swan/Sunrise, Tucson, AZ

05/24/2003

Class: Insecta, Order: Diptera, Family: Tachinidae

Winthemia spp.

Female tachinid fly

Patagonia, Santa Cruz Co., AZ

10/20/2002

Class: Insecta, Order: Diptera, Family: Tachinidae

Winthemia spp.

Tachinid fly, female, following a White-lined Sphinx (Hyles lineata) color variant hornworm.

Patagonia, Santa Cruz Co., AZ

10/20/2002

Class: Insecta, Order: Diptera, Family: Tachinidae

Winthemia spp.

Female tachinid fly pressing ovipositor onto side of a White-lined Sphinx caterpillar to lay an egg.

Patagonia, Santa Cruz Co., AZ

10/20/2002