Fly pupa?

McClung Dale adverweb at adver-net.com
Sat May 14 10:34:14 EDT 2011


Chris,

They are Tachinid fly pupa. They have been feeding on the pupae you received for the exhibit. The fly is a parasitoid   which always kills its host as opposed to a parasite which may not kill its host. The pupae will die. You may notice some silk threads hanging down the maggot used to drop to the "ground" in order to pupate outside its host.

My experience with Tachinid flies is limited to the subfamily Danainae, Danaus plexippus in particular, and the species is Lespesia archippivora. This species has been employed as a biological control. However, this fly  species is considered a generalist and the number of insects known to be parasitized by L. archippivora comprises 25 species of Lepidoptera and one Hymenoptera. 

Generally, in commercial rearing operations, Tachinid flies are not a problem as the larva are shielded from infestation unless one enters in accidentally, but most breeders know them, they look like a house fly but slightly larger, and kill them on sight. It is more a problem with wild collected larva that are exposed to the flies.

The fly only introduces 1-4 young to the host larva in order to insure there is enough food for the larva to mature before causing death to the host.

There is a lot of information on the web. Just google the scientific and common names.

Dale McClung



On May 13, 2011, at 8:51 PM, chris kline wrote:

> 
>  I work at franklin Park Conservatory in Columbus, Ohio and we are currently having our butterfly exhibit.  Something that the butterfly specialist found, and that I found on one occasion last year as the bfly spec' is what looks like mouse droppings in the bottom of the emergence cage.  The cage has latching doors so that it would be impossible for an actual rodent to get inside, but what was found looks all the world like rodent droppings.  Under a hand lens you can see ridges circling the object.  The object is dark brown, a little more than a quarter inch long and about half as wide, rounded at both ends.
>  
> My theory, and feel free to shoot it down, is that a fly or another insect lays an egg on the chrysalis, the larva eats the inside of the chrysalis, emerges, and falls to the ground, or in this case the bottom of the cage, to pupate.
>  
> Does anyone have experience with this sort of phenomena?
>  
> chris
>  
> 
> Chris Kline 
> Sugar Grove, Ohio
> Follow my 2011 Big Butterfly Year on Facebook at Butterfly Rider or at http://butterflyrider.blogspot.com/
>  



 
 ------------------------------------------------------------ 

   For subscription and related information about LEPS-L visit:

   http://www.peabody.yale.edu/other/lepsl 
 


More information about the Leps-l mailing list