1
there is a ladybug on/in [place]
there is 后接可数名词单数，表示“某处有……”。
There is a ladybug on the windowsill.
窗台上有一只瓢虫。
瓢虫
先理解核心含义，再看它在真实句子里的用法。
瓢虫
ladybug
There is a ladybug on the windowsill.
窗台上有一只瓢虫。
瓢虫
small round bright-colored and spotted beetle that usually feeds on aphids and other insect pests
A bright red ladybug landed on the leaf.
一只鲜红色的瓢虫落在叶子上。
Ladybugs eat aphids, so farmers like them.
瓢虫吃蚜虫，所以农民喜欢它们。
I found a ladybug on my windowsill this morning.
今天早上我在窗台上发现一只瓢虫。
there is 后接可数名词单数，表示“某处有……”。
There is a ladybug on the windowsill.
窗台上有一只瓢虫。
feed on 表示“以……为食”，主语是单数时用 feeds。
A ladybug feeds on aphids and other insect pests.
瓢虫以蚜虫和其他害虫为食。
with 短语作后置定语，修饰 ladybug，说明其斑纹或颜色等特征。
I found a ladybug with black spots in the garden.
我在花园里发现了一只带黑点的瓢虫。
Not this
I saw ladybug in the garden.
Use this
I saw a ladybug in the garden.
ladybug 是可数名词，单数形式前需要冠词 a/an 或 the；这里第一次提到，应用 a ladybug。
Not this
There are many ladybug on the leaf.
Use this
There are many ladybugs on the leaf.
ladybug 的复数形式是 ladybugs，在 many 等数量词后必须用复数，且搭配复数谓语。
Focus on the distinctions below. Other candidates are kept compact until a reliable usage note is available.
红色瓢虫
A red ladybug landed on the windowsill.
一只红色瓢虫落在窗台上。
七星瓢虫
The seven-spotted ladybug is common in gardens.
七星瓢虫在花园里很常见。
异色瓢虫
Asian ladybugs often gather in large numbers in autumn.
异色瓢虫常在秋天大量聚集。
瓢虫幼虫
The ladybug larva feeds on aphids before becoming an adult.
瓢虫幼虫在变为成虫前以蚜虫为食。
幸运瓢虫
She believes that seeing a lucky ladybug brings good fortune.
她相信看到幸运瓢虫会带来好运。
瓢虫，瓢虫，飞回家去吧；你的房子着火了，你的孩子也都不见了。
When a ladybug landed on her sleeve, the little girl chanted the old rhyme, "Ladybug, ladybug, fly away home."
一只瓢虫落在她的袖子上时，小女孩念起了那首古老的童谣：“瓢虫，瓢虫，飞回家去吧。”
《爱生气的瓢虫》
Eric Carle's picture book The Grouchy Ladybug follows an ill-tempered ladybug as it learns a lesson about kindness.
艾瑞·卡尔的绘本《爱生气的瓢虫》讲了一只坏脾气的瓢虫学会友善相待的故事。
Use ladybug naturally, then get feedback on meaning, tone, grammar, and phrasing.
Revisit a common error or keep this word in your review list.
lady（女士）+bug（虫）：瓢虫红黑斑点像穿礼服的小姐。
语域：neutral 常见场景：日常交谈、儿童科普、一般文章 ladybug 是表示瓢虫的日常中性词，通常用于日常对话和一般科普语境，比较常见于通俗表达，正式程度不高也不低。
所有以 /ʌɡ/ 结尾的词都与 ladybug 的最后一个音节 /bʌɡ/ 押韵，如 bug、mug、tug、rug、plug、hug。注意拼写相似的 ladybird（英式）读作 /ˈleɪdibɜːrd/，并不押韵。
Dictionary facts from ECDICT, WIKTIONARY.