Extra Credit

Ah Extra Credit- I'm sure some of you are thinking does she REALLY need extra credit? Well, in my opinion, YES!!! I really do.

So one of our extra credit "assignments" is to find two videos (one bad & one good) based on a crop that we have looked at (corn, wheat, soybean, alfalfa, sunflowers, and sorghum) on http://www.you-tube.com/. Then we are to explain why we liked or disliked each video. We can only do two crops since each crop is worth 5 points and there is a maximum of 10 extra credit points.

So first up: CORN


In my opinion this is a good video. Two men (Darren & Brian Hefty) have a television show (Ag PhD) where they talk about several aspects of farming. I looked at a few of the shows videos before I found this one. In this episode they discuss tips for when to use fungicides in corn. I appreciate the fact that they talk about how important weather is when determining if using a fungicide is justified. However, I think the video could be improved with better photography (its a bit grainy) and if they discussed the diseases and signs of the disease in more detail.



In my opinion this is a BAD, BAD, BAD video for many reasons. If you don't want to watch the video I understand its 10 minutes LONG - yes I watched the entire video. It seems to be what occurs in this farmers life when he's harvesting corn; he harvests corn, loads corn, unloads corn, drives through town (NOTE- they have nice bus stops), and repeat (several times). In addition, there are no words or text so unless you are a farmer or know a lot about farming- you have NO IDEA what's going on. No I'm not a farmer so I'm guessing as to what he's doing. However, the music is great (sounds a bit like Enimga) so I enjoyed listening to that while being bored by the video. However, I think this could become a good video with editing (lots of editing). In addition, add some text or voice overs for what's going on (for example- the farmer could introduce the video by saying "Hi I'm [insert name here] and I'm going to show you a typical day when I'm harvesting corn."). Now, I understand that this video was done in some other country (likely a slavic country given the text at the end of the video {credits?}) but I'm sure that not everyone in this persons country knows what he's doing and there are translator software packages out there. For those of you with young ones- I'm curious as to if your children liked the video (lots of cool machinery) so if you could give me some feedback on that aspect I would appreciate it.



I admit that this video was just for fun. I was looking for corn videos and ran across this one and despite the fact that its not educational it is visually & musically enjoyable. Think of this as a reward for sitting through the above 10 minute video- a well deserved reward!



Next up: SOYBEANS

I found another good video on insects. However, this video is VERY long (16 minutes). They do use text to break up the video and provide information such as economic thresholds. In addition they have music in "text breaks". However, I think this video could be improved by cutting the video in half in essence making two videos (one for Japanese Beetle and one for Soybean Aphid). In addition, I think that Dr. Cullen could discuss natural enemies of these two pests in order to provide a more complete picture of these soybean insect pests.



So I thought I would see if I could find a better harvesting video. I watched several and they are all similar to the 10 minute corn video. However, this one while still bad for all the non-informative reasons mentioned above is MUCH BETTER than the corn video. So please note that this one is shorter (much shorter- less repetition) and the song kicks ASS (yes, it's more metal so be forewarned before going down this road). If there are any farmers out there that are interested in making a video of your harvest, please, please, please tell us less farm machinery oriented people what you are doing so we can learn. Thanks! (Note- I did talk to one of my friends about these harvesting videos and he agrees with me that there should be some detail about what the farmer/grower is doing)



And to end on a high note: I found dancing slugs (that's right I said dancing slugs)! Enjoy!!

How on earth do Dectes survive the winter?

This week we had ANOTHER indoor lab. I'm sorry, I would have rather gone out in the sprinkles (if you could call them that) and looked at anything (dirt, soybean lodged plants from Dectes larvae, jack-o-lanterns, heck even pre-Halloween Christmas decorations). My brain really didn't want to be inside and thinking!

Images from extension.missouri.edu

Dectes larva (left); Dectes adult (right)

So, this weeks assignment was to look at if Dectes texanus (Dectes stem borer) are cold tolerant or cold intolerant (avoid cold). Dectes is a stem borer in soybean; its “original” host is sunflower but in Kansas it is typically found in soybeans (weird, right? another one of entomology's conundrums). For more information on Dectes: http://www.ca.uky.edu/entomology/entfacts/ef149.asp


Cold tolerant insects have “defenses” that keep them alive after they have been frozen at the supercooling point. These defenses include the use of ice nucleating proteins, production of cyroprotectants, and restriction or tolerance of intracellular freezing.

Cold intolerant insects, also, have defenses against cold but often die when they are frozen at the supercooling point. These defenses include migration, hibernation, avoidance, and removal of ice nucleating materials from gut.

For more detail on insect winter survival strategies: http://en.wikipedia.org/wiki/Insect_winter_ecology

We used a “frosty” (seriously that's what they are called) to lower the temperature of 10 thermoconductors with Dectes larvae on them and wrapped in gauze to -15 degrees C and look at survival. Unfortunately, only two of these showed the curve that our teacher is looking for but he reassured us that he has done this several times and that all of the Dectes died. So how do they survive the winter in Kansas?

We then looked at reasons why/how Dectes larvae (overwintering life-stage) would be able to survive in the winter, in Kansas in the two plants (sunflower & soybean). The class came up with several hypotheses:


Tunnel humidity caused by frass cap at end of stem
Stem Size
Chamber Size (width)
Snow and/or soil as insulation against cold
Dectes size (more pith in sunflowers so larger in sunflowers than in soybeans)

The class decided to test chamber size by selecting three representatives from each crop (sunflower and soybeans) with a similar amount of soil around the roots, place the thermocoupler electrodes into the stem to a depth where the Dectes larva would overwinter (so under the soil), and run the experiment until it plateaus out so where there is no more change. So the idea is to see if there is a difference between the two crops. I would say that the hypothesis is that it takes longer for the wider chambers (sunflowers) to reach the supercooling point (-15 degrees C).

For further information on how this experiment was done please look at the teachers class blog: http://ipdmanhattan.blogspot.com/

The below graph is the result of "our" experiment. Each line is a mean of the three plants; xsun is the sunflower, xsoy the soybean, and the control is a measure of the external temperature of the plants (the termocouplers were attached to the outside of the plants).


The first thing to note about this graph is that the control rapidly drops in temperature whereas the plants have a slow descent into the colder temperatures. This indicates that the plants provide some protection for the Dectes larvae overwintering in these plants. The second key point is that the plants plataue above the supercooling point of -15 degrees C which further strengths the thought that the plants are providing protection for the overwintering larvae. The third point is that the sunflowers have a "gentler" slope than the soybeans which may provide more time for overwintering larvae to "adjust" to the colder temperatures. The final point is that soybeans and sunflowers plateau at the same time which indicates that at that point there is no advantage over one plant or the other for the survival of the overwintering larvae which as mentioned earlier is above the supercooling point.

My initial thought about this study was that we might need another control which represented stems without a ball of dirt around them. Now that I've looked at the data I'm undecided about another control (it could help and it shouldn't hurt the data). Setting that aside- I think this data tells us quite a bit and indicates that perhaps just being in the plant keeps the Dectes alive during the winter. However, I think a more important question (given the above data) is why the shift from the original host plant (sunflowers) to soybeans?

Experience rating:

Interesting even though we didn't get to "play" outside. Now that I've looked at the data I have more questions than I did during the class devoted to this lab.

Lab 4: The JOY of estimating soybean damage

This weeks lab assignment was to look at two different ways of estimating plant damage in soybeans. Unfortunately, this did not mean that we were allowed out into the field but the “field” was brought to us.

We used two different types of qualitative methods:
The first one was to look at soybean plants and determine the types of damage to the plants and try to determine what type of insect caused that damage.

The early planted soybeans had already gone through senescence. So they were brown and dead looking. It was difficult to determine what kinds of damage the plant had sustained. It appeared like it had some root loss but this could have been caused by being ripped out of the ground. However, “real” root loss is caused by various grubs (beetle larvae). I would say that its too late to sample these plants again especially since its so difficult to see the damage.

On the other hand, the late planted soybeans were green and yellow and it was easier to find potential insect pest damage. Some of the leaves had “window paining” damage which is usually caused by caterpillars. There was chewing damage in the middle of the leafs which is indicative of bean leaf beetle feeding. Chewing damage in the leaf margins indicates the presence of grasshoppers and caterpillars.

Some of the soybean pods had round damage which indicates more caterpillar feeding. I think that the late planted plants coudl be sampled again and could benefit from a sampling of the pests that are in the field.

The second estimation method involved estimating soybean leaf damage. Sixty leafs were obtained from the KSU Ashland Research Farm and were placed in plastic sandwich bags. Each student was asked to estimate the percent of damage on the leaf and write it down in a grid. My leaf estimates ranges from 1-96%, the mean was 26.1, and the standard error was 25.4. The standard error is quite high but in this case where we are estimating damage it is quite possible that there would be that much variation in the estimates of leaf damage. The teacher and his students used a scanner and image analysis software to determine the actual leaf damage estimate. The then compared the students estimates to the actual leaf damage estimate.

The teacher posted the above graphs with the equations and R2 values at the below link if you are interested in the r2 values and linear equations.

http://ipdmanhattan.blogspot.com/2009_10_01_archive.html

The class r2 values range from 0.8447 to 0.6798. The r2 values indicate the fit between the observed (our estimates) and the model (the scanner). R2 values run from 0-1, where 1 indicates a "perfect" fit. So our estimates are fairly good to medium in range.

http://en.wikipedia.org/wiki/Coefficient_of_determination link for more information on r2 values

I did not "win" the prize for having the best r2 value but my r2 of 0.7801 was good enough for second place so I can't complain. Additionally, this indicates that my mean and standard error were very good and there was that much variation.

Experience rating:

So-so, I would rather have been outside and not in a lab but I did learn that my leaf estimation is decent.

On a non-lab related note. One of my friends heard the below song and suggested that I listen because "its me." I agree, and it does have one of my favorite insects in the title so if you like music and can handle metal then check it out. The video is not theirs but is done by a fan and he/she includes dragonfly slides so it is "educational" to a small degree.

Note that I FINALLY figured out how to embed videos into the blog!!!!!

This week we also turned in another bug byte so to see mine click on the below link:

http://ent612.wetpaint.com/page/convergent+ladybeetle