Locusts will be affected by temperature

Investigate A Factor affecting the breathing rate of a Locust

Research

I plan to see how temperature affects the locust since I know the facilities are available for testing. I’ve chosen temperature because it is widely know that temperature affects a lot of things especially Biological beings.

I think that the Locust would be affected by temperature since the enzymes within all living life forms are affected by temperature. Since the species of locust we are using is ‘Schistocera Gregaria’, The Desert species, it means they will be used to higher temperatures than the rest of the locust family (Grasshoppers etc.) In all enzymes there are boundaries which no creature can go since the bonding within the enzymes will not be able to stand the temperature. Enzymes are proteins; Enzymes are segmented into three groups which have different structures and bonding associated with the group:

Primary structure- a single Protein strand containing only: peptide bonds.
Secondary structure- is like primary but contains a single protein chain folded with Hydrogen bonding along the folds.
Tertiary structure- a single protein strand containing: Peptide bonds, Hydrogen bonds, disulphide bridges which is a covalent bond so makes it stronger.
Quaternary structure- two or more protein chains bonded together with all the bonds of Tertiary structures: Peptide bonds, Hydrogen bonds, disulphide bridges

The Idea of surface area to volume ratio is important now because the insect has evolved to a multi-cellular creature it means no longer is the Surface area adequate to allow enough chemicals to be exchanged with the environment to keep it alive. So Insects have a specialist respiratory system that has evolved from the simple diffusion of the single cellular ancestors. The system includes a simple method of changing the air pressure within the abdominal by the Contraction and Relaxation of the abdominal muscles, to allow the flow of air into and out of the Insects abdominal. There are tubes (Bronchioles) along the side of the insects abdominal clearly visible with the naked eye, which is the passageway into the centre of the insect. These create a larger surface area that means the Insect can exchange gasses with the environment Easily. Also the Bronchioles are moist to assist diffusion since the Gasses are dissolvable in water easily so the chemicals then just travel through the liquid and the membrane, which is very thin.

First of all I need a Locust and A Boiling tube to with hold the locust. I’d count the number of times the abdominal contracts and relaxes (Ventilation rate). Possibly if it were too fast I’d film the experiment (with the camera pointing at the Insect where there was no possibilities of disturbance like someone walking in front of the camera.) and play it back in slow motion to count the times accurately.

Variables:

Me- Since I’m counting the times I have to be precise and not make mistakes although it may be easy depending upon the speed of the inhalations

Locust- The species is a very important factor since there are different types of Locust one, which migrates, can’t be exposed to too much cold, whereas the desert Locust can be exposed to extreme variation as to temperature. The amount the Locust has had to eat could affect the experiment because if the stomach is empty there’s more chance it won’t survive or the results will be anomalous. The temperature and light it’s kept at could also affect the readings because insects relate to these for there seasons to allow mass breeding. If it is mating season for the Locust then its more likely to be very lively and then in season the Male/Female Variation level at which they can stand may alter. Although the movement will be suppressed by the test tube the locust would still be more alert so the insect equivalent of adrenalin would be produced in larger amounts. I could beat this problem of movement and alertness by maybe making the insect unconscious with a small amount of gaseous aesthetic. This would also help keep the breathing rate steady, because it’s not awake the breathing will only be controlled be the autonomic part of the brain and stop all conscious movement.

Humidity- will affect the concentration gradients because the air will be full of water

Air Pressure- will affect the diffusion rate of the oxygen because of the partial pressures being changed. With the temperature changing it will obviously change the pressure within the boiling tube and may change the breathing rate

Carbon Dioxide Concentration- This would affect the diffusion rate of the locust because they have on a very simple form of Ventilation. As the temperature increased along with the breathing the Locust would be surrounded by CO2 that would change the gradients around and within the ...

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Humidity- will affect the concentration gradients because the air will be full of water

To cope with these I can;

Me- Make sure I’m alert and awake in the morning of the Experiment with no possibility of distractions (Hunger, So have a good Breakfast)

Locust- I could beat this problem of movement and alertness by maybe making the insect unconscious with a small amount of gaseous aesthetic. This would also help keep the breathing rate steady, because it’s not awake the breathing will only be controlled be the autonomic part of the brain and stop all conscious movement But the chemicals for this would need to be very precise and the school does not have the facilities. I also don’t have an adequate knowledge of Locusts to do it without placing it in danger.

Humidity- If I placed Calcium Chloride in the tube. Although the Desert species of locust do live in a humid area.

Carbon Dioxide Concentration- to keep this steady I’d place a small quantity of Potassium Hydroxide in the tube to Absorb the CO2, and keep the concentrations steady

I think with enzymes being affected by temperature, which the locust needs. The locust itself should be affected by temperature. My research shows that the locusts optimum temperatures is 35’c-40’c and the temperature in the country of origin ranges from –3 - 55’C (two extremes of summer and winter) although the locust is cold blooded and has to regulate it’s own temperature. Regulated by burying in sand, entering the sun, hiding behind a leaf or like when they roost they all enter the tips of trees to warm them up with the morning sun, between 10-50.

Plan:

What I need to know is the way temperature affects the breathing of a locust. So I will need to manipulate the Temperature and Measure it’s breathing. To do this I will need to some how keep the insect still and make sure I can see the body moving. I need to control temperature of the locust.

I have decided to keep the experiment simple to reduce the risks involved and also increase the productivity. To keep the Locust controlled I will have to keep it within a Boling tube with a plug with a hole in the top. The control of temperature can be achieved by using a water bath to hold the Locust. The locust will be suspended in the jar by a clamp. The bath shall only heat the air around the locust and since air is an insulator I’ll need to allow a few minutes to heat the air and the Locust to acclimatise to the localised environment. A Bunsen burner will heat the water; with a thermometer in the water I can regulate the temperature. To allow the Bunsen under the beaker of water I’ll also need a Tripod, which will need a benchmat. I’ll also need paper & pen etc to record the results and any implementations.

I shall Regulate the temperature from 10-45’c because I know the temperature inside the boiling tube will be about 6-8’c less than the actual water temperature since water is an insulator, while the low temperatures will be warmer so the true exposure will be a lot less than it seems. I would like to measure temperature within the Boling tube but the thermometer will cause discomfort to the locust.

I’m fully aware that working with a living organism, any sign of distress or worrying signs of extreme discomfort, then I will terminate the experiment. The risk assessment of this experiment on the locust, I felt was not of a high risk because the locust can withstand this temperature range in the wild but these had been bred specially at a pet shop and not exposed to extremes previously. Then every individual locust is unique and will have a separate threshold to temperature. So if I happened to pick the locust with a virus or just in a state of unusualness then the experiments results will be incorrect for the locust as a species.

Does not show The Clamp or Bunsen burner or Magnifying glass

Implementing

Apparatus:

Tripod Mat (Heatproof) Bunsen burner

Jar (1100ml) Gauze Kettle

Boling tube Rubber Bung (with hole) Locust

Thermometer Clamp *2 Stop watch

All the Apparatus was checked to make sure there were no faults, cracks or defects. The apparatus was set up as in the plan and the locust was placed into the Boiling tube, gently, with ease and consideration. A spare empty test tube was used to check the set up before the locust was entered, to make sure of the apparatus.

I then checked the locust itself to see if there were any signs that could affect the experiment like Missing ligaments or pregnancy. I found it was a female but there were no signs of pregnancy and the age was too young.

I started the experiment with the locust at 19’c for a test run. The locust was then found to be climbing up the boiling tube walls, trying to escape. This meant the locusts abdominal was distorted by the water level, there was no way I could stop diffraction so I decided to collect a larger jar which held 1100ml of water which meant I could submerge the boiling tube further and the abdominal wouldn’t be distorted. I also found that it was easier on my neck since the jar held the locust higher up, which previously there was more chance that I’d look away and distort the results because of an aching neck. The size of this jar meant that the time it took to heat up would be too long. So a more efficient way would be to have a boiled kettle and then top up with cold water. In my plan I wanted to start at 10’c then work my way up but I decided it would be more efficient to star at 45’c and work down because of the heat loss to the environment. Then once I got to room temperature which at the time was quite hot at 25’c because of the Bunsen’s in the class, I’d cool it down with the ice and let it warm up back to room temperature.

The visibility was still very poor so a magnifying glass was found to allow the locust to be seen, larger and more clearly.

The measurements were made as accurately as the apparatus could allow, obviously I would more trust and prefer to use a correctly working digital thermometer which would record the temperature for me at a very precise accuracy to within 0.01’c. But the facilities were not available. These results were correct to within 1’c and the counting on my behalf was as accurate as possible. The results on pg5 were contained in a hand drawn table with the Time (seconds), No. Of Inhalations, Temp (‘c) and also I wrote if there were any extra movement that would affect the temp.

When I started the experiment the locust was fine, I examined it and sound it was a female, the experiment started at 45’c and was allowed to warm the atmosphere in the boiling tube for two minutes. The readings were taken but as I got to the last reading the locust seemed to become discomforted moving a lot then not moving. I was worried so I stopped the experiment immediately. I once again examined the locust and I left it alone for five minutes to revive itself. The locust seemed fine. I left it a further five minutes to make sure, and I was then confident it was not harmed. So I continued the experiment.

Results

The results were accurate and all retakes were also. The final taking of the first experiment was not done I decided not to re-administer the locust to the extreme temperature ‘just in case’ of any mishaps. So to get a fifth reading I just took the average of the other four

The graph starts at 10’c, which is at 33.2 breaths/min, and the graph only rises 0.8 to 34 which shows the Locust is still inactive at this temperature. As the temperature increases to 25’c the graph show a very distinct rise of 18 breaths per 60s. After that the graph rises slowly to 35’c where it was 53 Breaths per 60s that would be the Optimum temperature for the locust but straight after the graph falls back to 51.6 breaths/60s which I feel means that the locust would be dyeing. The Locust was fine and survived the experiment since I started the Experiment at 45’c the locust went on to complete the rest of the results. So I think that the result of 35’c would be anomalous because the graph falls afterwards. A hand drawn graph is supplied at the back.

The readings I took could not be translated into a rate graph, I think our teacher did give us some hints to this but as usual I was slow to catch on.

Analysis

I think my experiment went how I would like it with no mistakes but I feel I tried to keep my experiments too simple. I should of Acted upon all my thought of variable and made the experiment measure a factor which could be displayed within a rate graph. Like Using a miniature respirometer that could measure the volume of Gas Taken in by the locust and a more precise conclusion could have been formed. My limitations were empathised by my inability to ask for the requirements of my experiment. I might have been able to acquire most of the thing I needed but will never know. The theory I’d discovered was very useful and did help me a lot but in deciding my experiment and also coming to a conclusion.

If I had the chance to repeat the experiment I’d use a respirometer experiment with an empty boiling tube as a control and with all the chemicals I’d decide on in my research. I’d also test more than one Locust to see if there were Male/Female divides other differences like between young and old. With this I would test more than one locust of each group (Young/Old/Male/Female) to gain a better average that could be applied to the whole species. I think a bit more thought before I’d decided what the final test would be. Had I not been experimenting on a living organism I’d have more confidence to doing the experiment and to allow a better margin on all aspects.

Conclusion

The graph shows a distinct curve where the optimum temperature is. The curve exists because the insect is changing the rate of breathing to suit the atmosphere. The locust is very good at changing itself to suit the needs of the location its at, usually the locust will use other methods to keep a steady temperature and the locust would not actually be exposed to such high temperatures because it moves toward/away from the heat supply. The graph is a visible curve that levels off after 25’c. The dependant variable increases increasingly then steadies, which is the trend seen throughout the group, whatever the way they done the experiment. I feel this is a good way to compare my results and there was a good trend that backs up the fact of my experiments being correct and usable for a conclusion.

I think that at 30’c – 40’c the graph had actually levelled off and that the real optimum temperature for this locust was 25’c the following few results were not varied enough to let me come to the conclusion that they were still moving. I would like to find out as to how far the line would extend before it started to decline but I would not risk the locust’s life. The research I done I’d found to be incorrect. Although they don’t state what the locust is like, because they do increase their temperature when breeding.

Hypothesis

I predict that the Locust will be affected by temperature since:

Firstly diffusion will be affected- The rate at which the chemicals defuse into the body fluid will increase since temperature affects the movement of particles so the insect will need to take fewer breaths to gain the needed quantity of chemicals.

Enzymes will be affected- All enzymes within the locus will be affected by the temperature since the bonding and movement of them is. The Enzymes will have an optimum temperature of the locust, which is dictated by the Enzymes according to where they are most suited. So temperature change will mean the enzymes may not work to their full capacity or may denature if the temperature exceeds the optimum.

The locust’s body cannot regulate it temperature by itself so the locust either has to move to warm up or go into shade to cool down. So if this happens in the wild, surely the temperature is important to the locust and if it weren’t vital the locust wouldn’t bother try to regulate it. If the locust has to regulate it, it does not mean it will affect the breathing rate but may affect another function. I feel since the breathing will be used to obtain vital gasses, and the air around the locust will be at the temperature, so will be changing its movement according to the temperature, then the locust will have to change its breathing to keep a steady amount of gas exchanges. The enzymes will use these gases or a constituent of them and if these are affected then once again the locust will have to change the breathing to allow the correct quantity. So I would expect a curve in the graph extending up then levelling off ant decreasing. But my experiment will not let it decrease because the locust would be dyeing.

Daniel Rose Pg.3b