Entomology Lab Report Paper
In this experiment, the effectiveness of biological control is tested using lady beetles and aphids. Lady beetles are predacious coelenterate that feed primarily on aphids (order hemisphere). Aphids feed on a plethora of plants including peach, plum, and apricot. Aphids are also vectors of plant disease. Eight replicates were conducted. In each replicate a lady beetle is places in a Petri dish with aphids; 3 lady beetles are placed in a dish with aphids; and insecticide was used against the aphids. Materials & Methods In order to conduct the experiment a total of twenty four Petri dishes were used.
Three Petri dishes were used for each replicate. Five aphids were placed in each Petri dish. The first Petri dish of a given replicate contained one lady beetle; the second Petri dish contained three lady beetles; and the third contained a solution of soapy water that functioned as an insecticide. In each Petri dish, a pepper leaf was placed to stimulate living conditions for the aphids. After observing each Petri dish for ten minutes, the results were recorded and the number of aphids killed during this period were noted. The experiment was replicated seven more times giving a total of eight replicates.
Discussion The objective of this experiment is to prove that biological control is a more cost-effective way of managing pests. The hypothesis of this experiment was that if biological control is a more cost effective-way of managing pest then the benefit of using biological control (by using price as a standard) will outweigh the benefits of using soapy water as a pesticide to kill aphids; Based on our we results we accepted the hypothesis. Using information from table 1 , we can see an average of 0. 74 aphids were killed per lady beetle during treatment 1 .
For treatment 2 an average of 0. 8 aphids were killed per lady beetle. Since treatment 3 did not contain the use of lady beetles I had to estimate the equivalent number of lady beetles used had biological control been used in treatment 3 instead. To do this I took the average number of aphids killed in treatment 3 (average of 4. 125 aphids killed) and divided it by x, where x represents the number of lady beetles placed in the Petri dish. I averaged the two ratios of aphids killed per lady bug obtained from treatments one and two; the result was an average of 0. 825 aphids killed per lady beetle. By setting this averaged ratio equal to the ratio of aphids killed per lady beetle in treatment 3; found that x was equal to approximately 6. 043 lady beetles. To determine the cost effectiveness of each treatment I multiplied the number of aphids survived by their estimated cost damage ($ . 07 per aphid) and compared the cost to the use of lady beetles ($. 023 per lady beetle) and pesticide ($ 0. 30 per plant). Using this data it can be seen that $. 2982 worth of damage would occur in treatment 1, $. 1875 worth of damage would occur in treatment 2, and $. 06125 worth of damage would occur in treatment 3. The estimated total cost per treatment would be $. 023 for treatment 1, $. 069 for treatment 2, and $0. 30 for treatment 3. Treatment 3 is by far the most expensive but also the most effective. If we used the extrapolated number of lady beetles (6. 043 lady beetles) found in my calculations for treatment 3 and apply the estimated cost associated with this number, we find that the average cost of treatment 3 is $0. 13.
This value is far cheaper than the cost of using pesticide ($0. 30 per plant) while maintaining the same amount of plant damage. Thus, we can clearly see that if enough lady titles are used during biological control it is a much more cost effective than using soapy water as a pesticide. It should be noted that a source of error was the pesticide used. The results do not conclusively determine if biological control is more cost effective than all pesticides since there are many potent and cost effective pesticides available.
The results only apply if it is assumed that the pesticide is soapy water. Regardless, the results are very relevant to the agriculture industry because it provides sufficient information that biological control against a pesticide (soapy water) is more cost effective. This data can help the agriculture industry save hundreds of millions of dollars. Abstract Pest control is a prevailing issue in the agriculture industry. Methods to control pests include biological control and pesticides.
In biological control another organism is used to control a pest species. In this experiment we determined which method is more cost effective when it comes to pest control. To conduct this experiment fifteen aphids are placed in a Petri dish (five aphids per dish). In the first dish one lady beetle is placed in, three lady beetles in the second, and solution of soapy water in the third. The average number of aphids killed per treatment was: 0. 74 aphids for treatment 1; 1. 875 aphids for treatment 2, and 4. 25 aphids for treatment 3. By analyzing data obtained from my results I found that the average cost of using biological control was significantly less than the average cost of using pesticides. In treatment 3, assuming that property damage is identical; if biological control was used it would cost an average of $0. 13 per plant and if pesticide was used it would cost an average of $0. 30 per plant. The exults showed that biological control was a more cost effective way of controlling pest species than pesticide.
References Griffith, G. J. K. 2007. Efficacy and economics of shelter habitats for conservation. Biological Control: in press. DOI:10. 101 6/j. Obstruction. 2007. 09. 002 Core, J. And Myers, J. 2000. Direct and indirect ecological effects of biological control. Trends in Ecology & Evolution. 15, 4, 137-139. Johnson, M. 2000. Nature and Scope of Biological Control. Biological Control of Pests EN LOLL 3/26/201 1 Cost effectiveness of biological control and pesticides for pest management