Watching species evolve, one after another

apple maggot (Rhagoletis pomonella) by Joseph Berger, Bugwood.org

The apple maggot (Rhagoletis pomonella), a fruit fly native to the U.S., is curious, as apples are not native to the U.S. Before the apple maggot started feeding on the apple in the 1850s, they would feed on native hawthorns and their life cycle was tied to the life cycle of the hawthorn.  Interestingly, there are wasp parasitoids which will infest larval apple maggot,s and so their life cycle is also tied into the same time frame.  As some of the apple maggots have displayed a preference for the apple trees over the hawthorns, very slowly, their life cycle has shifted to match the fruiting cycle of the apples.  Scientists have been watching the apple maggot and have seen how the feeding and mating habits have changed in the apple tree feeders, thus splitting the apple maggots into two different species based on their apple or hawthorn preferences.  As the life cycle of the maggots is changing, the parasitoid wasps are also splitting based on their hosts' preferences.  This supports the "sequential speciation" evolutionary process, stating that adaption and speciation doesn't occur independently and is more of a cascade of new species that arise as new niche opportunities are introduced.

apple maggot (Rhagoletis pomonella) by Whitney Cranshaw, Bugwood.org

Source Article: Caught in the act: New wasp species emerging
Apple Maggot Images: Rhagoletis pomonella

Give us your common dandelion seeds!!!

Some of you remember our recent call for oak caterpillars.  We have another researcher who wants your unwanted critters...Dandelions!

John Cardina at The Ohio State University needs your dandelion (Taraxacum officinale) seeds.  He's looking at their genes to find out how much diversity is in the population and determine if they mainly with themselves or if they cross with other dandelions.  To do this, he needs dandelion seeds from all over the country AND he needs to know where the seeds came from!

 Here’s how to collect dandelion seeds:

1. Select 4 healthy dandelion plants from different parts of your yard or field.  They could also be from different parts of your life – one on the way to work, one in the park, one in the flowerbed next to the grocery store, etc.  In other words, not four plants right together (but if that’s all you can get, that’s fine too).
2. Pick one flower head (puff-ball) per plant.  He needs the seeds (achenes) – with or without fluff (pappus) - from one individual flower head per plant
3. Pluck the seeds (the entire puff-ball), and put them into a coin envelope or folded paper. Please keep the four puff-balls separate (different envelopes or in separate folds of paper).
4. Label each one with information on where and when you found each one.  GPS coordinates are preferred but zip code, street address, road intersection, or other reference will work.  The date is collected on is all we need for the when.
5. Send the seeds to John at:
        John Cardina
        OSU/OARDC
        1680 Madison Ave.
        Wooster, OH  44691

As an added bonus, We'll be working with John to post the occurrence data into EDDMapS.  Right now our data on dandelion is pretty sparse.

Give us your Oak Caterpillars!!!

Researchers at the University of Georgia are initiating a regional-level study on oak caterpillar outbreaks in the southeastern U.S.  Our project objectives are to better understand the ecology and distribution of caterpillars feeding on oak trees in early spring, and to provide guidance on management of caterpillars. 

 

For the purpose of this project, we are requesting all folks who have seen caterpillars in large numbers on oak trees on their properties to send us samples.  Specific instructions for collection are as follows:

1. Collect as many caterpillars from oak trees as possible.  Caterpillars are nocturnal, and can be collected using tweezers directly from the tree.  Bands of cloth can be placed on the tree trunk to stop the caterpillars from climbing the trees and to collect many insects at the same time. 
2. We prefer >10 caterpillars per tree, but we will take up to 250.  Place caterpillars in a small plastic container or a bag, and freeze them.  Similarly, collect 4-5 leaves from each oak tree, and freeze them separately in a plastic bag.  Collect from as many trees as possible from your property. 
3. Number caterpillar and oak leaf bags from each tree individually.  So, plastic bags labeled Tree 1 will have caterpillars and leaves collected from that tree, bags labeled Tree 2 will have caterpillars and leaves collected from that tree, etc.
4. Put all samples together in a small box, and include information about location and date of collection.  Location information should include county and if possible full address so that we can estimate latitude and longitude.  This information will be kept strictly confidential.
5. You can drop the caterpillars and oak leaves at the local extension office, and send us an email about it.  Or, you can ship the frozen caterpillars and oak leaves (1-day shipping) to the address as follows:

Evelyn Carr
Warnell School of Forestry and Natural Resources
180 Green Street
University of Georgia
Athens, GA 30602

If you are unable to do either of these things, then please contact us to pick up samples.  The samples need to be either alive or frozen so that we could extract DNA from them to determine caterpillar species.  Any assistance with learning more about our native caterpillars will be greatly appreciated!  Thank you for your participation in the project.