Biol2050 Week 4 Lab PanTrap Species Abundance

Pan Trap Experiment Location: York University Dansby grasslands and woodlot, conducted on September 28th at 2:30pm on a moderately humid and moist day with a temperature of about 19 degrees celsius. Wind speeds estimated at around 10km/h. The dansby grasslands provide a suitable environment because they allow the experimenters to observe a variety of insect species in condensed sections of high grass surrounded by an abundance of plant life. The dansby woodlot of York university provides large canopy cover and many different tree species, which provides a diversity of insect species which reside just above and around the placed pan traps. We used two different types of environments to assess the abundance of flying insects in each area. Conducted with Ameena Mohammed, Hinal Patel, Keerthana Ledchumykanthan, Taylor Kerekes. The method we used to capture the insect species for examination was the pan trap method. The pan trap method is effective in establishing an estimation of the diversity of flying insects because of the variation of colours of the pan traps used, of which our bowls were blue, yellow, and white. This variance in colours allows for a variety of insects, including pollinators who are attracted to different colours, to be captured. The pan trap involves a shallow coloured plastic bowl filled halfway with soap and water, which is effective in attracting and capturing the flying insects because when they fly into the soapy water they are unable to escape. MetaData: Bowl Colour: we had a variety of 3 different colour bowls to attract different flying insects that have different preferences in colour attraction. The bowls were placed around a large tree in the middle of the grasslands because we believed this large tree attracted an abundance of flying insects We placed the bowls separately in 5m gaps from each other, starting with one colour, then a second coloured bowl, then a third coloured bowl and then continued to follow that pattern in a circle around the large tree. Our bowls went from yellow to white to blue, and our decision to space them relatively far apart was to span as large an area as possible with this technique. In the woodlot we alternated to a line pattern because the structure of the woodlot meant that a line formation made the bowls the most accessible, and also to ensure that we were placing the bowls on flat land. Our bowls were very shallow so to ensure the experiment was not altered by the absence of soapy water from spilling, we had to certify the bowls were placed on very flat land. Number of insects: We believed we would have more significant data for our number of insects but this variable had relatively low numbers for what we expected. We simply took the pan traps and emptied the bowls into a sieve, in which we are able to count the number of insects. Species Abundance: Much like the number of insects our species abundance was relatively low for what we expected. We hypothesized that with each bowl we would have many different insects from many different species. What we found was that species abundance was almost always in line with number of insects, meaning that in each bowl when we found multiple insects they were usually of the same species. It is possible that this was an effect of the species’ preference to specific colours and that coloured bowl seemed to attract all insects of the same species. Species abundance was observed by filtering the soapy water through the sieve and examining each of the individual insects and assessing which insects had all similar features along with the assistance of a taxonomic key if necessary.盘诱捕实验（Pan Trap Experiment）地点：约克大学丹斯比草原与林地，实验于9月28日下午2:30开展，当日湿度适中、空气湿润，气温约19摄氏度，风速约10公里/小时。 丹斯比草原为实验提供了适宜生境：该区域高草连片、植被繁茂，便于研究者在集中样地内观测多种昆虫类群。约克大学丹斯比林地拥有茂密林冠层与多样乔木种类，可为放置于其中及周边的盘诱捕器（pan trap）提供丰富的昆虫栖息类群。本实验选取两类生境以评估各区域飞虫丰度，实验由Ameena Mohammed、Hinal Patel、Keerthana Ledchumykanthan与Taylor Kerekes共同完成。 本次实验采用盘诱捕法（pan trap method）采集昆虫样本以开展后续检测。盘诱捕法可有效估算飞虫类群多样性，其原理在于利用不同颜色的诱捕碗：本实验所用诱捕碗分别为蓝色、黄色与白色。颜色梯度设置可吸引包括对特定颜色有偏好的传粉昆虫在内的多种昆虫。盘诱捕器由半注有肥皂水的浅色彩色塑料碗构成：飞虫接触肥皂水后将无法挣脱，从而实现诱捕效果。 元数据（MetaData）： 诱捕碗颜色：我们设置了3种颜色的诱捕碗，以吸引对颜色偏好各异的飞虫。草原区域的诱捕碗围绕中央的一棵大树布设——我们推测该大树可吸引大量飞虫。诱捕碗之间间隔5米布设，按黄→白→蓝的颜色顺序循环排列，围绕大树形成圆形阵列。采用较大间距布设的目的是最大化覆盖实验样地范围。 林地区域的诱捕碗则采用直线阵列布设：因林地生境结构限制，直线排布可保证诱捕碗的布设可达性，同时确保诱捕碗放置于平整地面。由于诱捕碗较浅，为避免肥皂水溢出导致实验变量改变，我们严格确认所有诱捕碗均放置于平整地面。 昆虫数量：原计划可获取更具统计学意义的昆虫数量数据，但实际捕获量低于预期。实验过程中，我们将诱捕碗内的样本全部倒入筛网（sieve），进而完成昆虫个体计数。 类群丰度：与昆虫数量结果一致，类群丰度同样低于预期。我们最初假设每个诱捕碗内可捕获多个物种的昆虫，但实际观测发现，单碗内的昆虫大多为同一物种，且类群丰度与昆虫数量基本呈正相关。推测该现象可能源于昆虫对特定颜色的偏好：单一颜色的诱捕碗仅会吸引对应偏好的同种昆虫。类群丰度的观测流程为：将肥皂水通过筛网过滤，逐一检视捕获的昆虫个体，通过形态特征进行类群鉴定，必要时借助分类检索表（taxonomic key）辅助确认。