1. Juvenile growth trajectories evolve via the interplay of selective pressures on age and size at maturity, and developmental constraints. In insects, the moulting cycle is a major constraint on larval growth trajectories.
2. Surface area to volume ratio of a larva decreases during growth, so renewal of certain surfaces by moulting is likely needed for the maintenance of physiological efficiency. A null hypothesis of isometry, implied by Dyar's Rule, would mean that the relative measures of growth remain constant across moults and instars.
3. We studied ontogenetic changes and allometry in instar‐specific characteristics of larval growth in 30 lepidopteran species in a phylogenetic comparative framework.
4. Relative instar‐specific mass increments (RMI) typically, but not invariably, decreased across instars. Ontogenetic change in RMIs varied among families with little within‐family variation. End‐of‐instar growth deceleration (GD) became stronger with increasing body size across instars. Across‐instar change in GD was conserved across taxa. Ontogenetic allometry was generally non‐isometric in both RMI and GD.
5. Results indicate that detailed studies on multiple species are needed for generalizations concerning growth trajectory evolution. Developmental and physiological mechanisms affecting growth trajectory evolution show different degrees of evolutionary conservatism, which must be incorporated into models of age and size at maturation.

中文翻译：

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鳞翅目幼虫生长的比较分析显示了幼龄水平的限制

1. 少年的生长轨迹是通过对成熟年龄和大小的选择性压力以及发展限制的相互作用而发展的。在昆虫中，换羽周期是幼虫生长轨迹的主要限制。
2. 幼虫的表面积与体积之比在生长过程中会降低，因此可能需要通过换毛来更新某些表面，以维持生理效率。代尔定律所暗示的等轴测零假设将意味着成年和成年期相对生长指标保持不变。
3. 我们在系统发育比较框架中研究了30种鳞翅目物种的幼虫生长的成因变化和异速生长。
4. 相对于幼龄的相对质量增量（RMI）通常但并非总是减少。RMIs的个体遗传学变化在家庭中变化不大，家庭内部变化很小。随着龄期个体的体型增加，龄末期生长减缓（GD）变得更强。在整个分类单元中，GD的整个龄期变化均得以保留。在RMI和GD中，个体遗传异体通常是非等距的。
5. 结果表明，需要对多种物种进行详细的研究才能得出有关生长轨迹演变的概括。影响生长轨迹进化的发育和生理机制显示出不同程度的进化保守性，必须在成熟时将其纳入年龄和大小模型。