When I visited my sister in Pennsylvania in June of 2021, they took me to Delaware Canal State Park for a walk. Huge trees growing along the canal provide good shade which is hardly seen in Southern California. I really enjoy the peaceful walk there. We hardly see people there. You don’t hear loud noises from the car, people or radio but nature. The most intriguing thing to me was listening to the high-pitched sound coming from the Cicada. It reminds me of my home country, Taiwan. I don’t know how many of cicadas were there. I was surprised to see countless of them along the path. Periodical cicadas are native to eastern North America. There are 17-year lifecycle ones and 13-year lifecycle ones. The ones that we saw are 17-year lifecycle Pharaoh Cicada (Magicicada septendecim). The majority of the life of Magicicada septendecim is spent in an underground or subterranean habitat. After the Pharaoh Cicada mates, the female cicada pierces the tender bark of the branch with its well-developed, serrated ovipositor, and then lays eggs inside. She will lay about 10 eggs at a time and about 25 times. The total number of eggs can be laid about 250. The nymphs feed on the sap of the tree until the eggs fall to the ground, which can cause serious damage to small trees. Once in contact with the soil, the nymphs make holes in the ground (usually 18 inches or 2 feet deep) and when they find the roots, they start chewing. Its population is huge, with dense cicada caves often appearing on the ground, with 370,000 cicadas per square meter. After the 17th spring, they will appear again. Cicada pupae will begin to burrow in April, and at this time, you will first see some small holes on the edge of fresh soil. But they will not come out of their holes to look for food until the soil temperature reaches 18 degrees Celsius. They will climb up the nearest vertical object, such as trees, shrubs, telephone poles, and even dandelion stems, and shed their outer skin. After a few hours, their wings will harden and so will their bodies.
2021 年 6 月，當我去賓州拜訪我妹妹時，他們帶我去了德拉瓦運河州立公園散步。沿著運河生長的大樹提供了在南加州幾乎看不到的大樹蔭。我真的很喜歡在那裡清靜的散步。在那裡看不到什麼人，也聽不到汽車、人或收音機發出的吵雜聲，只聽得到大自然的聲音。對我來說最有趣的事情是聽蟬發出的高音。這讓我想起了我的家鄉台灣。我不知道那裡有多少蟬。我很驚訝沿路看到屬不清的它們。週期蟬原產於北美東部。有17年生命週期的和13年生命週期的。我們看到的是17年生命週期的法老蟬。十七年蟬的大部分生命都在地下或地下棲息地度過。十七年蟬交配後，雌蟬將尾部發達的、有鋸齒的產卵器刺入樹枝嫩皮，隨即將卵產在裏面，一次產卵約10粒，產卵約25次，合計可產卵250粒。在卵掉到地上以前，蟬蛹一直以樹的汁液為食，這樣一來，小樹就會受到嚴重損壞。一旦接觸到土壤，蟬蛹就會在地上打洞 (通常 18 英寸或 2 英尺深)，找到樹根後，就會開始咀嚼。它的種羣數量龐大，地面常出現密密麻麻的蟬穴洞，每平方有 37 萬隻蟬。第17個春天過去後，它們會再次出現。蟬蛹會於4月份開始打洞，而這時，你會首先在新鮮泥土的邊緣看到一些小洞。但在土壤温度未達到18攝氏度以前，它們不會從洞中出來尋找食物。它們會爬上距離最近的垂直的物體，如樹、灌木、電線杆，甚至蒲公英的莖，蜕去它們的外皮。幾個小時後，它們的翅膀會變硬，軀體也會變硬。
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Notes 筆記
- Pharaoh cicada or the 17-year locust is a periodic cicada native to Canada and the United States. It is also the largest and most northern species of periodical cicada with a 17-year lifecycle.
- The insect’s eyes and wing veins are reddish and its dorsal thorax is black. It is distinguished by broad orange stripes on its abdomen and a unique, high-pitched song said to resemble someone calling “weeeee-whoa” or “Pharaoh”.
- Because of similarities between M. septendecim and the two closely related 13-year species M. neotredecim and M. tredecim, the three species are often described together as “decim periodical cicadas.”
- Their median life cycle from egg to natural adult death is around seventeen years. However, their life cycle can range between thirteen and twenty-one years.
- The majority of the life of Magicicada septendecim is spent in an underground or subterranean habitat. The area in which a periodical cicada brood is located must contain a large population of deciduous trees, on whose roots the cicadas feed during the underground nymph stages. The trees are also necessary for the molt into adulthood, choruses, and egg-laying. After the Pharaoh Cicada mates, the female cicada pierces the tender bark of the branch with its well-developed, serrated ovipositor, and then lays eggs inside. She will lay about 10 eggs at a time and about 25 times. The total number of eggs can be laid about 250. Its population is huge, with dense cicada caves often appearing on the ground, with 370,000 cicadas per square meter.
- 十七年蟬是原產於加拿大和美國的周期蟬，也是最大和生存地點最北的周期蟬，生命週期為 17 年。
- 昆蟲的眼睛和翅脈是紅色的，它的背胸是黑色的。它的特點是腹部有寬闊的橙色條紋，還會發出獨特的、高亢的歌聲，據說類似於有人叫“哇哦”或“法老”。
- 由於 M. septendecim 與兩個密切相關的 13 年生物種 M. neotredecim 和 M. tredecim 之間的相似性，這三個物種通常被一起描述為“十進制週期蟬”。
- 它們從卵到成年自然死亡的平均生命週期約為 17 年，故名。然而它們的生命週期可能在十三到二十一年之間。
- 十七年蟬的大部分生命都在地下或地下棲息地度過。週期性蟬巢所在的區域必須有很多落葉喬木，在地下幼蟲階段，蟬以其根為食。樹木也是它們由蛻皮到成年、合唱和產卵所必需的。十七年蟬交配後，雌蟬將尾部發達的、有鋸齒的產卵器刺入樹枝嫩皮，隨即將卵產在裏面，一次產卵約10粒，產卵約25次，合計可產卵250粒。它的種羣數量龐大，地面常出現密密麻麻的蟬穴洞，每平方有 37 萬隻蟬。
Insects Posts 昆蟲的帖子
References 參考資料
- Wikipedia: Magicicada septendecim
- Penn State Extension: Periodical Cicada
- 百度百科: 十七年蟬
- 維基百科: 十七年蟬