Hunt for fly infested dogwood fruits
Hello fellow nature lovers!
I am a first year PhD student at the University of Notre Dame working in Dr. Feder's lab; for my research I am traveling around the US collecting dogwood fruits to rear out the flies that infest their fruits.
I am an Evolutionary Biologist interested in plant-insect interactions. My PhD research will focus on the population genetic structure of the fly species belonging to the Rhagoletis tabellaria species complex. Two of the four fly species infest dogwoods that are widely distributed across North America. To better understand how species form and become specialized to specific host plants, I will be collecting flies from all of the dogwood species they infest throughout their geographic ranges.
This brings me to the purpose of this journal post - I am requesting the help of the iNaturalist community to help me identify potential sites I can collect ripe dogwood fruits from.
Below are the fly species I am trying to collect and their associated host plants
(1) Rhagoletis tabellaria infests Cornus sericea/red osier dogwood
(2) Rhagoletis electromorpha infests Cornus racemosa/gray dogwood, Cornus foemina (stricta)/swamp dogwood and Cornus drummondii/roughleaf dogwood
Because we do not know much about fly infestation rates, I am ideally trying to collect 2,000-4,000 fruits from each plant species at each site. Flies are most likely to infest ripe fruit that are a bit soft (easier for their ovipositor to deposit eggs). I have not seen an infested fruit yet first hand because this is my first field season - I will post example pictures once I have some, but I've been told that infested fruits can usually be identified by:
(1) Their appearance (two-toned, looks a little off/sickly colored)
(2) Lightly squeezing the fruit (the maggot will eat the inside of the fruit, so it will have a hollowed out feel, sort of like a balloon)
(3) Opening up some fruits to look for larvae
If anyone is interested in collecting samples for me and mailing them to me I can arrange for FedEx overnight shipments, especially if you have a site with confirmed infestation.
If you are curious about trying to rear the maggots yourself we basically just put the fruits in a tray and monitor them daily for emerging larvae. Larvae are then collected, stored in moist vermiculite at room temperature for 10 days, then placed in a refrigerator to simulate over wintering conditions. After several month, the pupae are removed from the refrigerator to room temperature and monitored for adult eclosion.
I greatly appreciate everyone who has taken the time to read this! I look forward to hearing from the iNaturalist community :D
In hopes of finding potential sites and starting a dialogue with the iNaturalist community I am tagging the leading iNaturalist dogwood observers, and thanks @sambiology for telling me about this Journal feature!
C. sericea: @wdvanhem , @tsn ,@ajwright ,@charlie ,@graysquirrel ,@gwynethgovers ,@rick_williams ,@seanblaney ,@tanybo ,@csledge
C. drummondii: @sambiology ,@txlorax ,@connlindajo ,@lanechaffin ,@suz ,@foresterbabberney ,@ckneuppe ,@aguilita ,@itmndeborah ,@lisa281
C. racemosa: @wdvanhem ,@gwynethgovers ,@owenclarkin ,@seanblaney ,@rcurtis ,@sanguinaria33 ,@aaroncarlson ,@charlie ,@elfaulkner ,@reuvenm
C. foemina (stricta): @marykeim ,@mfeaver ,@edwinbridges ,@ericpo1 ,@jayhorn ,@alexdelapaz ,@vita-sativum ,@anewman ,@j_albright ,@janetwright
Thanks everyone!
Amanda Driscoe
