卵 Egg卵是昆蟲生命的開始，雌螢與雄螢交配後，會去到特定的地方產卵：水生植物、蘚類植物的莖葉之間、較潮濕隱蔽的樹皮裂縫、石縫、土縫等位置、或者枯枝落葉和泥土底下，因不同品種而異；產卵數目由幾十粒到過百粒不等；卵的大小也差別很大，直徑0.5mm - 2.0 mm 不等 (體積相差64倍); 因不同品種而異。螢火蟲的卵也會發光，相信也是警戒訊息。卵期一般由幾天到30天左右，以卵期越冬的，可長達幾個月。凹眼螢產卵後會捲曲身體包圍產下的卵，並全身發出最多33點光。
Egg is the beginning of insect life. After mating, depends on different species, female fireflies would lay eggs at specific place, such as between leaves of aquatic plants or mosses, wet and sheltered bark cracks, rock crevices, soil cracks, or beneath litter and soil. Number of eggs laid by one female ranges from tens to hundreds. Egg size variation across different species is great, egg diameter ranges from 0.5mm - 2.0mm (64 times in volume). Firefly eggs glow, also a warning signal. Egg stage lasts for few days to 30 days, for over-wintering cases, the egg stage lasts for several months. Rhagophathalmus would curl up its body around the eggs and emit up to 33 light spots from its body.
幼蟲 Larva幼蟲是攝取食物和成長的階段，唯一的工作就是不斷尋找食物及避開捕食者。所有昆蟲都是外骨骼的，外骨骼不能生長，需要每隔一段時間把舊殼脫掉，換上較大的新殼，這過程叫脫皮。脫皮後除了身體增大，外貌也改變。由卵孵出的稱為一齡幼蟲，第一次脫皮後變成二齡幼蟲，如此類推；化蛹前的階段稱為終齡幼蟲，一般是4至7個齡不等，因品種及食物充足程度而異。已知幼蟲都是夜行性，捕食夜行性的蝸牛、蛞蝓 、蚯蚓、馬陸，以至其他昆蟲。 幼螢用毒液癱瘓獵物，並分泌消化液進行體外消化，同時吸食已消化的食物，取食時間比較長， 往往通宵取食。本港大部份的熠螢亞科成員的幼蟲皆未被發現。
Larva is the feeding and glowing stage, the only task is searching for food and preventing attacks by predators. All insects bear exoskeleton, exoskeleton does not grow, to accommodate enlarging body, the old exoskeleton must be shed and replaced by a larger exoskeleton. This process is called moulting. After each moulting, body size increases, external appearance also changes. The larva hatches from the egg is called 1st instar larva, after moulting, it becomes 2nd instar larva, and so on. The last stage before pupation is called final instar larva. Depends on different species and food availability, there are usually 4-7 instars. All the known larvae are nocturnal, predate on nocturnal snails, slugs, earthworms, millipedes, or other insects. Larva excretes venom to paralyse the prey, and digestive juice to undergo external digestion. Digested food is absorbed simultaneously. Time for feeding is much longer, commonly overnight. Larva of most members of the Luciolinae in Hong Kong are not known yet.
蛹 Pupa蛹是成長的最後階段，終齡幼蟲會找尋適當地方準備化蛹， 有些品種會鑽入泥中造個蛹室、有些品種會用泥土在地面築成土繭、有些品種只簡單地鑽到土縫中或在枯枝落葉堆底下化蛹。終齡幼蟲先進入前蛹期，這個階段，外殼底下正發生重大變化，幼蟲原有的一些器官開始消失，同時開始發展成蟲專有的器官。數天後正式化蛹，原來的外殼裂開並脫掉，形成蛹。螢火蟲的蛹跟我們較認識的蝴蝶蛹不同，蝴蝶蛹體壁堅硬，附肢和翅緊貼在蛹體上不能活動，稱為被蛹；而螢火蟲蛹跟大部份甲蟲蛹一樣，附肢和翅不貼附在身體上，可自由活動，扁螢的蛹甚至可以爬行一段頗長的距離，這稱為離蛹。已知的螢火蟲的蛹基本上都能發光。香港螢火蟲的蛹期大概十天左右，就會羽化為成蟲。
Pupa is the last stage of growth and development. Final instar larva finds a suitable place for pupation, some species make underground soil chamber, some species build mud coccoon around the body, some species simply go into soil cracks or beneath litter to pupate. Mature final instar larva changes to pre-pupa first. Organs belonging to larval stage disappear and adult specific organs start to develop. After a few days, the exoskeleton cracks and sheds. Pupa is formed. Firefly pupa is very different from butterfly pupa which is well known to us. Butterfly pupa has appendages and wings firmly attached to the pupa body and is immobile. This is called obtect pupa. Like most other beetles, fireflies have exarate pupa. Appendages are free. Pupa of Lamprigera spp. can even walk for a long distance. Generally, all known pupae glow. For Hong Kong fireflies, pupa stage lasts for around 10 days before emerge as an adult.
成蟲 Adult成蟲是生命中的最後階段，不會生長，唯一功能就是交配產卵，成蟲特有兩雙翅主要是避敵、有效覓偶和有效散播後代。 大部份品種的成蟲口器退化，只能吸取水份，只有極少數品種會能進食其他螢火蟲。成蟲壽命通常短速，只有幾天到十多二十天，少數缺翅雌螢可生存幾個星期到幾個月不等。作為生態系統中的一員，螢火蟲也是一些獵食者的對象，其中在野外最常見的是誤墮蜘蛛網，成為蜘蛛的獵物;蜘蛛網上的螢火蟲，被吃掉之前，還會一直放光。
Adult is the last stage of an insect's life. It does not grow. The only function of adult is mating and laying eggs. Wings are specific to adults. They are mainly for efficiently escaping from enemies, searching for mates and dispersing offsprings. Most species have their adult mouthparts degenerated, could only absorb water. Only few species would feed on other fireflies. Adult life is usually short, varying from a few days to about 10 to 20 days. Some wingless female adults could survive several weeks to months. Being a member of the ecosystem, fireflies are also preys of some predators. Fireflies being caught on spider web is most commonly seen in the wild. The fireflies being caught on spider web would keep emitting light until eaten by the spider.
成熟蛹 Mature Pupa
剛羽化的成蟲 Newly emerged adult
四隻螢火蟲被困蜘蛛網 4 fireflies caught by a spider web