第三章 昆虫的胚后发育
Postembryonic development
?孵化
?生长与脱皮
?变态
第一节 孵化 Hatching,Eclosion
? 幼虫从卵中破壳而出的过程。
? To escape from the eggs,a larva must break the
various membranes which surround it,These
include the chorion,vitelline membrane,
? 破壳方式
– 化学物质
– 破卵器 eggburster
– 上颚 mandible
第二节 生长与脱皮
Growth and moulting (ecdysis)
? Insect growth is discontinuous,
because the rigid cuticle limits
expansion,
? Size increase is by moulting
(ecdysis),
– The formation of new cuticle of
greater surface area and shelding
of the old cuticle,(由激素控
制 ——蜕皮激素 Ecdysone)。
– 蜕 Exuvia
– 不同种脱皮次数不同，同种脱
皮次数一般相同。一般脱皮
2—20次
? 龄期 stadium (stadia),The period between moults相邻两次
脱皮之间的时间。
? 虫龄 instar,The growth stage,or the form between two
successive moults.相邻两次脱皮之间的阶段。
– first instar larva一龄幼虫,second instar larva二龄幼虫 ??????
– last instar larva末龄幼虫（ full-grown larva老熟幼虫）
? Insect development involve two
components of growth,
– Moult increment蜕皮期生长
? It is the increment in size occurring between one star
and the next,
– Intermoult period increment龄期生长
? It is the increment in a stadium or instar duration,
第三节 变态 Metamorphosis
? Metamorphosis,The relatively abrupt change in body form
between the end of immature development and the onset of
the imaginal (adult) phase,
? 胚后发育过程中，昆虫从幼期状态转变为成虫状态的
现象 。
– 5 patterns of development,
? 一、增节变态
Anamorphosis
– A metamorphosis in
which the immature
stages have fewer
abdominal segments
than the adult.原尾目腹
部体节数由 9变为 12节
– 是系统演化中多足纲遗
留下来的特征。
? 二、表变态 Epimorphosis
– In Collembola,Diplura,
Archeognatha and Thysanura,
which as adults remain wingless,
the degree of change from
juvenile to adult is slight and is
manifest primarily in increased
body size and development of
functional genitalia,
? 弹尾目、双尾目、石炳目、缨尾
目
? 幼虫基本具备了成虫的特点
? 除了个体增大、触角及尾须节数
增多、性器官继续成熟以外，性
成熟后仍继续脱皮。
? 三、原变态 Prometamorphosis
– Nymphs of mayflies have 12-45 aquatic instars,
and wings are visible in older nymphs,Between
the nymph stage and adult stage there is a
subimago, 蜉蝣幼虫到成虫期之间有一个很
短的, 亚成虫期, 。
– The subimago is fully winged,flying or
crawling,
? 四、不全变态
Incomplete
Metamorphosis
? 一生只经历三个虫期：
egg-juvenile-adult stage
? 幼虫均为寡足型，具明
显的翅芽；成虫期不再
脱皮
? 半变态类 Hemimetabola、
渐变态类 paurometabola
或外翅部 Exopterygota。
? （一） 半变态
Hemimetaboly
– The naiads of
dragonflies and
stoneflies are
somewhat not
resemble the
adults,
? 蜻蜓目 Odonata
(dragonfly )
? 襀翅目
Plecoptera
(stonefly)
? （二） 渐变态 paurometaboly
– Orthoptera直翅目,Phasmatodea竹节虫目,Mantodea螳螂目、
Blattaria 蜚蠊目,Isoptera等翅目,Hemiptera半翅目
– 特例 ——过渐变态 hyperpaurometamorphosis
? 蓟马、粉虱、雄蚧从幼虫期转变为成虫前，有一个类似
蛹期的不食不动阶段
五、全变态 Holometamorphosis
（ Complete Metamorphosis）
? complete metamorphosis（ holometabola）,
egg—larva—pupa--adult,
– 此类昆虫被称作 全变态类 holometabola
? 特例
– 复变态 hypermetamorphosis (heteromorphosis)
? There is an apparent additional larval (pseudopupa
or pre-pupal) stage when the larva changes its form
radically as a result of altered feeding circumstances.
某些幼虫营寄生生活的昆虫，幼虫末期变为 拟蛹
pseudopupa，然后变为蛹。
– 芫菁（幼虫肉食性，成虫植食性）
– 寄生性蜂类等
第四节 幼虫期 juvenile(larval) stage
? 特点：取食量大，体积急
剧增大
? Dyar,s law
– Mathematically expressed,
the law states x/y=constant
? X=size in a given instar
? Y=size in previous instar
– 生物学意义：积累营养，
为发育为性成熟的成虫创
造条件。
幼虫类型 larval or nymphal types
? 不全变态类 Hemimetabola
? Immature individuals of aquatic hemimetabolous insects
(Odonata,etc), naiads,稚虫 naiads
? Immature terrestrial insects with hemimetabolous
development are called nymphs,若虫 nymphs
? 全变态类 holometabola
– All immature holometablous
insects are called larvae,
– 1,原足型 protopod larvae
? Eggs hatched at the forepart of
protopod period of embryonic
development and larvae legs are
simple and undeveloped,
? 腹足与胸足均不发达
? 膜翅目寄生蜂
? 2,多足型 polypod (eruciform) larvae
– Eggs hatched at the polypod period of embryonic
development..卵在胚胎发育的多足期孵化
– The Lepidopteran caterpillars are the commonest example of
polypod larvae,with short thoracic legs and abdominal
prolegs,头明显，体圆柱形，有腹足，又叫蠋型幼虫。
– Such larvae are mostly phytophagous.一般为植食性
– 鳞翅目、长翅目、膜翅目的叶蜂等
? 3,寡足型 Oligopod larvae
– Oligopod larvae lack abdominal prolegs but have
functional thoracic legs and frequently prognathous
mouthparts,
– Coleoptera,Trichoptera,some of Neuroptera
– 具有发达的胸足但无腹足。
– （ 1） 蛃型幼虫 campodeiform larvae
? （ 2） 蛴螬型幼虫 scarabaeiform larvae
– 身体肥胖,C形，头部发达，如金龟子幼虫
? 4,无足型 Apodous
larvae
– 双翅目、膜翅目的细腰
亚目、蚤目以及象甲等
的幼虫附肢完全消失。
– （ 1） 全头型无足幼虫
Eucephalous larvae
? 全头型幼虫头部骨化，头
部附肢正常，包括双翅目
（孑孓）、蚤目、膜翅目
的细腰亚目等
Mosquito larvae
– （ 2） 半头型无足幼虫 Hemicephalous larvae
? In hemicephalous larvae,the head and its appendages
are reduced and partially retracted into the thorax.半头
型无足幼虫头部部分退化，后端缩入胸部，如双翅
目的大蚊及一些寄生性膜翅目幼虫。
– （ 3） 无头型无足幼虫 Acephalous larvae
? In acephalous larvae,no sign of the head and the its
appendages can be seen apart from a pair of sclerotized
hook.无头型无足幼虫头部非常退化，全部缩入胸
部，仅外露口钩，例如蝇蛆。
蝇蛆
第四节 蛹期 The Pupal Stage
? 蛹 Pupa
– The evolution of a pupa; stage in the life
history has made holometabolous development
possible,
– The pupa is a nonfeeding,generally quiescent
instar which serves as a mold in which adult
features can be formed,全变态昆虫由幼虫到
成虫之间须经历的一个静止虫态 —蛹期。
? 前蛹期 (prepupa or pseudopupa),过渐变态类蛹
期之前有一个不食不动的时期
? 一、蛹的类型 Pupal types
– 强颚蛹 decticous pupa(脉、
长、毛翅目 )
? 无颚蛹 adecticous pupa（鞘、
双、膜翅目）
蝴蝶的蛹
– 离蛹 exarate pupa（裸蛹）,
– 被蛹 obtect pupa,
– 围蛹 coarctate pupa：又称 伪
蛹 puparium。
A pupa of a mosquito
龙
虱
的
蛹
二、蛹的保护物
? An immobile pupa is
vulnerable to attack by
predators or parasites
and to server changes in
climatic conditions,
particularly as the pupal
stadium may last for a
considerable time,
? To obtain protection
against such adversities
the pupa of many
species is enclosed
within a cocoon or
subterranean cell
constructed by the
previous larval instar,
Postembryonic development
?孵化
?生长与脱皮
?变态
第一节 孵化 Hatching,Eclosion
? 幼虫从卵中破壳而出的过程。
? To escape from the eggs,a larva must break the
various membranes which surround it,These
include the chorion,vitelline membrane,
? 破壳方式
– 化学物质
– 破卵器 eggburster
– 上颚 mandible
第二节 生长与脱皮
Growth and moulting (ecdysis)
? Insect growth is discontinuous,
because the rigid cuticle limits
expansion,
? Size increase is by moulting
(ecdysis),
– The formation of new cuticle of
greater surface area and shelding
of the old cuticle,(由激素控
制 ——蜕皮激素 Ecdysone)。
– 蜕 Exuvia
– 不同种脱皮次数不同，同种脱
皮次数一般相同。一般脱皮
2—20次
? 龄期 stadium (stadia),The period between moults相邻两次
脱皮之间的时间。
? 虫龄 instar,The growth stage,or the form between two
successive moults.相邻两次脱皮之间的阶段。
– first instar larva一龄幼虫,second instar larva二龄幼虫 ??????
– last instar larva末龄幼虫（ full-grown larva老熟幼虫）
? Insect development involve two
components of growth,
– Moult increment蜕皮期生长
? It is the increment in size occurring between one star
and the next,
– Intermoult period increment龄期生长
? It is the increment in a stadium or instar duration,
第三节 变态 Metamorphosis
? Metamorphosis,The relatively abrupt change in body form
between the end of immature development and the onset of
the imaginal (adult) phase,
? 胚后发育过程中，昆虫从幼期状态转变为成虫状态的
现象 。
– 5 patterns of development,
? 一、增节变态
Anamorphosis
– A metamorphosis in
which the immature
stages have fewer
abdominal segments
than the adult.原尾目腹
部体节数由 9变为 12节
– 是系统演化中多足纲遗
留下来的特征。
? 二、表变态 Epimorphosis
– In Collembola,Diplura,
Archeognatha and Thysanura,
which as adults remain wingless,
the degree of change from
juvenile to adult is slight and is
manifest primarily in increased
body size and development of
functional genitalia,
? 弹尾目、双尾目、石炳目、缨尾
目
? 幼虫基本具备了成虫的特点
? 除了个体增大、触角及尾须节数
增多、性器官继续成熟以外，性
成熟后仍继续脱皮。
? 三、原变态 Prometamorphosis
– Nymphs of mayflies have 12-45 aquatic instars,
and wings are visible in older nymphs,Between
the nymph stage and adult stage there is a
subimago, 蜉蝣幼虫到成虫期之间有一个很
短的, 亚成虫期, 。
– The subimago is fully winged,flying or
crawling,
? 四、不全变态
Incomplete
Metamorphosis
? 一生只经历三个虫期：
egg-juvenile-adult stage
? 幼虫均为寡足型，具明
显的翅芽；成虫期不再
脱皮
? 半变态类 Hemimetabola、
渐变态类 paurometabola
或外翅部 Exopterygota。
? （一） 半变态
Hemimetaboly
– The naiads of
dragonflies and
stoneflies are
somewhat not
resemble the
adults,
? 蜻蜓目 Odonata
(dragonfly )
? 襀翅目
Plecoptera
(stonefly)
? （二） 渐变态 paurometaboly
– Orthoptera直翅目,Phasmatodea竹节虫目,Mantodea螳螂目、
Blattaria 蜚蠊目,Isoptera等翅目,Hemiptera半翅目
– 特例 ——过渐变态 hyperpaurometamorphosis
? 蓟马、粉虱、雄蚧从幼虫期转变为成虫前，有一个类似
蛹期的不食不动阶段
五、全变态 Holometamorphosis
（ Complete Metamorphosis）
? complete metamorphosis（ holometabola）,
egg—larva—pupa--adult,
– 此类昆虫被称作 全变态类 holometabola
? 特例
– 复变态 hypermetamorphosis (heteromorphosis)
? There is an apparent additional larval (pseudopupa
or pre-pupal) stage when the larva changes its form
radically as a result of altered feeding circumstances.
某些幼虫营寄生生活的昆虫，幼虫末期变为 拟蛹
pseudopupa，然后变为蛹。
– 芫菁（幼虫肉食性，成虫植食性）
– 寄生性蜂类等
第四节 幼虫期 juvenile(larval) stage
? 特点：取食量大，体积急
剧增大
? Dyar,s law
– Mathematically expressed,
the law states x/y=constant
? X=size in a given instar
? Y=size in previous instar
– 生物学意义：积累营养，
为发育为性成熟的成虫创
造条件。
幼虫类型 larval or nymphal types
? 不全变态类 Hemimetabola
? Immature individuals of aquatic hemimetabolous insects
(Odonata,etc), naiads,稚虫 naiads
? Immature terrestrial insects with hemimetabolous
development are called nymphs,若虫 nymphs
? 全变态类 holometabola
– All immature holometablous
insects are called larvae,
– 1,原足型 protopod larvae
? Eggs hatched at the forepart of
protopod period of embryonic
development and larvae legs are
simple and undeveloped,
? 腹足与胸足均不发达
? 膜翅目寄生蜂
? 2,多足型 polypod (eruciform) larvae
– Eggs hatched at the polypod period of embryonic
development..卵在胚胎发育的多足期孵化
– The Lepidopteran caterpillars are the commonest example of
polypod larvae,with short thoracic legs and abdominal
prolegs,头明显，体圆柱形，有腹足，又叫蠋型幼虫。
– Such larvae are mostly phytophagous.一般为植食性
– 鳞翅目、长翅目、膜翅目的叶蜂等
? 3,寡足型 Oligopod larvae
– Oligopod larvae lack abdominal prolegs but have
functional thoracic legs and frequently prognathous
mouthparts,
– Coleoptera,Trichoptera,some of Neuroptera
– 具有发达的胸足但无腹足。
– （ 1） 蛃型幼虫 campodeiform larvae
? （ 2） 蛴螬型幼虫 scarabaeiform larvae
– 身体肥胖,C形，头部发达，如金龟子幼虫
? 4,无足型 Apodous
larvae
– 双翅目、膜翅目的细腰
亚目、蚤目以及象甲等
的幼虫附肢完全消失。
– （ 1） 全头型无足幼虫
Eucephalous larvae
? 全头型幼虫头部骨化，头
部附肢正常，包括双翅目
（孑孓）、蚤目、膜翅目
的细腰亚目等
Mosquito larvae
– （ 2） 半头型无足幼虫 Hemicephalous larvae
? In hemicephalous larvae,the head and its appendages
are reduced and partially retracted into the thorax.半头
型无足幼虫头部部分退化，后端缩入胸部，如双翅
目的大蚊及一些寄生性膜翅目幼虫。
– （ 3） 无头型无足幼虫 Acephalous larvae
? In acephalous larvae,no sign of the head and the its
appendages can be seen apart from a pair of sclerotized
hook.无头型无足幼虫头部非常退化，全部缩入胸
部，仅外露口钩，例如蝇蛆。
蝇蛆
第四节 蛹期 The Pupal Stage
? 蛹 Pupa
– The evolution of a pupa; stage in the life
history has made holometabolous development
possible,
– The pupa is a nonfeeding,generally quiescent
instar which serves as a mold in which adult
features can be formed,全变态昆虫由幼虫到
成虫之间须经历的一个静止虫态 —蛹期。
? 前蛹期 (prepupa or pseudopupa),过渐变态类蛹
期之前有一个不食不动的时期
? 一、蛹的类型 Pupal types
– 强颚蛹 decticous pupa(脉、
长、毛翅目 )
? 无颚蛹 adecticous pupa（鞘、
双、膜翅目）
蝴蝶的蛹
– 离蛹 exarate pupa（裸蛹）,
– 被蛹 obtect pupa,
– 围蛹 coarctate pupa：又称 伪
蛹 puparium。
A pupa of a mosquito
龙
虱
的
蛹
二、蛹的保护物
? An immobile pupa is
vulnerable to attack by
predators or parasites
and to server changes in
climatic conditions,
particularly as the pupal
stadium may last for a
considerable time,
? To obtain protection
against such adversities
the pupa of many
species is enclosed
within a cocoon or
subterranean cell
constructed by the
previous larval instar,
