Having fun with kanji again. Here are all Japanese characters with the insect (虫) radical, occurring in Aozora Bunko works, sorted by frequency. Aozora Bunko is a large electronic library of Japanese public domain literary works, including many literary classics with expired copyrights. It contains close to 100 milion words. I downloaded and processed the whole thing, extracted the relevant kanji and computed the frequencies.

In the table below, Count is the total number of occurences, Frequency is relative frequency within the characters sharing the same radical. The Readings and Meanings are taken from KANJIDIC.

Compared to the previous experiment with fish characters, there are much more jōyō characters: 虫, 蛇, 蜂, 蚊, 融, 蛮, 蜜, 虹, 蚕, 螢. Note, however, that 蛮 (honey) and 虹 (rainbow) have been added to jōyō only in 2010. I actually think even after the 2010 update jōyō isn’t a very useful guideline for learners (if for anyone). I have marked the jōyō characters in red. Compared to fish characters, there almost aren’t any kokuji characters, this time it’s just 蛯 えび for shrimp. Most often shrimp is written as 海老 (if kanji is used).

Note that characters just containing 虫 as a component, not radical, are not included (such as 触). Tip: If you just want a list of all Chinese and Japanese characters with a certain radical try this (technical note: limited to Unicode BMP).

About funny two-character beasties

There are two spider characters of just about the same frequency. They are actually used together as 蜘蛛 to spell くも, spider. This is a practice borrowed from Chinese used for spelling a less common two-syllable word phonetically with two characters sharing the same radical, but unfortunatelly it has nothing to do with the corresponding Japanese words and their sounds. All the words below seem to follow this pattern (native kun’yomi readings given in hiragana, Chinese on’yomi in katakana):

• spider 蜘蛛 くも
• bat 蝙蝠 こうもり
• dragonfly 蜻蛉 とんぼ
• earthworm 蚯蚓 みみず
• cricket 蟋蟀 こおろぎ
• lizard 蜥蜴 とかげ
• “meandering” 蜿蜒 エンエン (not a bug, used this way: 河は平野を蜿蜒と流れている “The river meanders across the plain.”)
• mantis 蟷螂 or 螳螂 かまり or トウロウ
• centipede 蜈蚣 むかで (百足 seems to be a more common kanji spelling of the same word)
• slug 蛞蝓 なめくじ
• toad 蟾蜍 ひきがえる or センジョ (the former reading denoting a Japanese toad, the latter a different Chinese species)
• grasshopper 螽蟖 きりぎりす (note that 蟖 hasn’t been part of the JIS standard for a long time, which may have contributed to the 螽斯 spelling being common, 螽蟖 is actually being written as ※［＃「虫＋斯」、第3水準1-91-65］ in Aozora Bunko for this reason)
• mayfly 蜉蝣 かげろう or フユウ (also figurative meaning: ephemera)
• hornworm 螟蛉 メイレイ (only Chinese reading, also figurative meaning: adopted child)
• house centipede 蚰蜒 げじ (the second character is more often seen as part of 蜿蜒 “meandering” above)
• tadpole 蝌蚪 カト (according to most dictionaries, this one has only a Chinese reading, as the more common word for a tadpole has its own characters 御玉杓子, read おたまじゃくし; for the curious: look up this: 蝌蚪文字)
• butterfly
  • 蝶 チョウ (1768 occurrences), which doesn’t follow the two character-pattern, is the most common word for butterfly, but there are also these two:
  • 蝶々 + 蝶蝶 チョウチョウ (372 + 9 occurrences)
  • 胡蝶 + 蝴蝶 コチョウ (116 + 34 occurrences)

Most of these words have an on’yomi (Chinese reading), as you would expect for borrowings from Chinese. I have mostly omitted them if there is a common Japanese reading.

Update: Emma Uhl told me about mayfly 蜉蝣, which escaped my attention. Thank you! Apparently 蜉蝣 is used a lot for fancy band and song names. I also added house centipede 蚰蜒, and more info on butterfly words including 蝴蝶.

Note that scorpion さそり is written either as 蠍 or 蝎, not with two characters, while snail かたつむり (蝸牛) and short-neck clam あさり (浅蜊) are usually written with two characters, but they do not follow this pattern.

The frequency table

Character	Count	Frequency	Readings	English meaning
虫	11443	14.406 %	チュウ キ むし (nanori: む)	insect, bug, temper
蛇	7371	9.280 %	ジャ ダ イ ヤ へび (nanori: あぶ み)	snake, serpent, hard drinker
蝶	3915	4.929 %	チョウ	butterfly
蜂	3417	4.302 %	ホウ はち (nanori: ほ)	bee, wasp, hornet
蝋	3245	4.085 %	ロウ みつろう ろうそく (nanori: あじ)	wax
蚊	3065	3.859 %	ブン か	mosquito
蛙	2845	3.582 %	ア ワ かえる かわず	frog
融	2299	2.894 %	ユウ と.ける と.かす (nanori: あきら)	dissolve, melt
蠅	2273	2.862 %	ヨウ はえ はい	fly
蛮	2239	2.819 %	バン えびす	barbarian
蜀	2050	2.581 %	ショク ゾク いもむし	green caterpillar, Szechwan
蜜	2047	2.577 %	ミツ ビツ	honey, nectar, molasses
蜘	1900	2.392 %	チ くも	spider
蛛	1884	2.372 %	チュ シュ	spider
蟹	1806	2.274 %	カイ かに	crab
蟻	1762	2.218 %	ギ あり	ant
螺	1527	1.922 %	ラ にし にな	small, edible, helical fresh-water mollusk
蝉	1463	1.842 %	セン ゼン せみ	cicada
虹	1421	1.789 %	コウ にじ	rainbow
蝦	1341	1.688 %	カ ゲ えび (nanori: えみ)	shrimp, prawn, lobster
蝠	1021	1.285 %	フク	bat
蝙	1020	1.284 %	ヘン こうもり	bat
蟲	971	1.222 %	チュウ キ むし	insect, bug, temper
蟇	958	1.206 %	バ マ ひき	toad
蚕	806	1.015 %	サン テン かいこ こ	silkworm
蜻	651	0.820 %	セイ	dragonfly
螢	638	0.803 %	ケイ ほたる	firefly
蛉	630	0.793 %	レイ	dragonfly, moon moth
蛍	616	0.776 %	ケイ ほたる	lightning-bug, firefly
蝕	579	0.729 %	ショク むしば.む	eclipse, occultation, be defective
蛸	522	0.657 %	ソウ ショウ たこ	octopus
虱	518	0.652 %	シツ しらみ	lice, vermin
蛾	479	0.603 %	ギ ガ ひむし	moth
蠢	459	0.578 %	シュン うご.めく	wriggle
蚤	435	0.548 %	ソウ のみ はやい	flea
蠣	427	0.538 %	レイ かき	oyster
蝮	395	0.497 %	フク まむし	viper, adder, asp
蟠	384	0.483 %	ハン わだかま.る わらじむし	coiled up
蚓	347	0.437 %	ズ イン みみず	earthworm
蚯	344	0.433 %	キュウ みみず	earthworm
蛋	339	0.427 %	タン	barbarian, egg
蛤	336	0.423 %	コウ はまぐり	clam
蟀	335	0.422 %	シュツ	cricket, grasshopper
蟋	315	0.397 %	シツ	cricket, grasshopper
蜥	309	0.389 %	シャク セキ とかげ	a lizard
蜴	306	0.385 %	エキ	lizard
蛭	305	0.384 %	シツ チツ ひる (nanori: えび)	leech
蛆	272	0.342 %	ソ ショ うじ	worm, grub, maggot
蟒	252	0.317 %	ボウ モウ うわばみ おろち	boa constrictor, python
蝸	249	0.313 %	カ かたつむり	snail
虻	248	0.312 %	ボウ あぶ	gadfly, horsefly
蜿	243	0.306 %	エン ワン	meandering
蜒	239	0.301 %	エン タン	meandering, serpentine
蝿	223	0.281 %	ヨウ はえ はい	fly
蟄	220	0.277 %	チツ チュウ ちっ.する かく.れる	hibernation of insects
蝗	215	0.271 %	コウ いなご ばった	locust
蠱	211	0.266 %	コ ヤ まじ まじこ.る	rice worm, lead astray
蠻	205	0.258 %	バン えびす	barbarian
蜃	199	0.251 %	シン	clam
螫	177	0.223 %	セキ カク さ.す	bee sting
蜩	172	0.217 %	チョウ ひぐらし せみ	clear-toned cicada
蟆	152	0.191 %	バ マ ひき	toad
蜆	145	0.183 %	ケン しじみ	fresh-water clam
螂	133	0.167 %	ロウ	mantis
蟷	121	0.152 %	トウ	mantis
蠶	120	0.151 %	サン テン かいこ こ	silkworms
蝎	110	0.138 %	カツ さそり すくもむし	scorpion
蜈	110	0.138 %	ゴ	centipede
蚣	109	0.137 %	コウ ショウ	centipede, grasshopper
蠍	102	0.128 %	カツ さそり	scorpion
蛟	94	0.118 %	コウ キョウ みずち	dragon
蝟	88	0.111 %	イ はりねずみ	hedgehog
蜚	85	0.107 %	ヒ あぶらむし	beetle, cockroach
蝓	77	0.097 %	ユ	slug, snail
蛞	77	0.097 %	カツ	kind of slug
蟾	75	0.094 %	セン	toad
蜍	67	0.084 %	ショ	toad
蜑	65	0.082 %	タン あま	egg
蠕	56	0.071 %	ゼン ダ ネン ジュ ニュ うごめ.く	crawling of a worm
蛹	54	0.068 %	ヨウ さなぎ	chrysalis, pupa
螽	53	0.067 %	シュウ いなご	grasshopper
蚋	50	0.063 %	ゼイ ネイ ゼツ ネチ ぶゆ ぶよ ぶと か	gnat, sand fly
蝴	46	0.058 %	コ	butterfly
螻	45	0.057 %	ロウ ル けら	mole cricket
蜊	43	0.054 %	リ あさり	a kind of bivalve
蠑	41	0.052 %	エイ	newt, turban shell
蝨	38	0.048 %	シツ しらみ	lice, vermin
蜷	33	0.042 %	ケン にな	an edible river snail
蜉	33	0.042 %	フ	kind of ant, may fly
蛄	33	0.042 %	コ	mole cricket, cicada
蠹	32	0.040 %	ト きくいむし	moth, insects which eat into clot
蝣	32	0.040 %	ユウ	mayfly
蠧	31	0.039 %	ト きくいむし	worm-eaten
蛔	26	0.033 %	カイ ユウ かいちゅう はらのむし	intestinal worms
蠡	23	0.029 %	レイ ライ リ ラ にな ひさご	worm-eaten, conch
蛻	22	0.028 %	ゼイ セイ タイ もぬ.ける ぬけがら	insect moulting
蠖	17	0.021 %	ワク カク	inchworm, geometer
螟	11	0.014 %	メイ ミョウ ずいむし	injurious parasite
蚫	11	0.014 %	ホウ あわび	abalone, dried fish, surname
蠎	9	0.011 %	ボウ モウ うわばみ おろち	python, boa constrictor
螯	9	0.011 %	ゴウ はさみ	claws
蚰	9	0.011 %	ユウ	millipede
螳	8	0.010 %	トウ	mantis
蝌	7	0.009 %	カ	tadpole
蛩	7	0.009 %	キョウ こおろぎ	cricket
蚪	7	0.009 %	ト	tadpole
蚌	7	0.009 %	ボウ ホウ ビョウ はまぐり どぶが.い	clam
蝪	5	0.006 %	エキ	lizard
蛬	4	0.005 %	キョウ ころぎ きりぎりす	cricket
蛎	4	0.005 %	レイ かき	oyster
蚶	4	0.005 %	カン	ark shell
蚩	4	0.005 %	シ	fool, make a fool of
蟶	2	0.003 %	テイ まて	razor clam
蟯	1	0.001 %	ギョウ ジョウ	intestinal worm
蛯	1	0.001 %	えび うば	shrimp (kokuji)