Seed quality is an important bottom-up factor driving life-history traits of seed beetles (Chrysomelidae: Bruchinae). However, information on how seed traits change spatiotemporally and affect herbivores' survival is incipient in Neotropics. We evaluated how the spatio-temporal variation in seed weight, hardness, size, and water content of Mimosa setosa var. paludosa (Fabaceae: Mimosoideae) affects the occurrence and body-size pattern of the seed beetle, Acanthoscelides quadridentatus (Schaeffer, 1907), in Brazilian Cerrado. We collected 400 fruits from four populations of M. setosa var. paludosa in Cerrado roadsides from Goiás and Minas Gerais states and then we assessed in laboratory seed traits along with the weight and body size of A. quadridentatus. Additionally, we collected a total of 76 fruits (immature plus mature) in beginning and end of the fruiting phase and counted the frequencies of unhatched and hatched eggs of the seed beetle to evaluate the effect of seed hardening on beetle posture. We found greater seed damage in the population with softer, smaller and lighter seeds. Larger and heavier seeds were harder than smaller and lighter seeds; and male and female reared from larger and heavier seeds were respectively 15 and 25% larger than that reared from smaller and lighter seeds. We also found that weight and body size of A. quadridentatus were positively correlated with seed length, weight and water content. Unhatched eggs were found only in beginning of fruiting phase when seeds were immature and softer, suggesting the occurrence of a window of time in which females lay their eggs before seed hardening to facilitate the entry of first instar larvae. These results highlight that larger and heavier seeds are most protected against herbivory, but individuals of A. quadridentatus that overcome plant hardness can grow larger in size. We suggest that seed traits change across a spatio-temporal scale and affect life-history traits of A. quadridentatus.

种子质量是驱动甲虫生活史特征的重要的自下而上因素（Chrysomelidae：Bruchinae）。然而，新热带地区关于种子性状如何随时间变化并影响草食动物生存的信息尚处于起步阶段。我们评估了含羞草种子重量，硬度，大小和水分含量的时空变化。paludosa（Fabaceae：Mimosoideae）影响巴西甲虫种子甲虫Acanthoscelides quadridentatus（Schaeffer，1907）的发生和体型。我们从四个种群的M. setosa var收集了400个水果。帕卢多萨在来自Goiás和Minas Gerais州的Cerrado路边，然后我们对实验室种子的性状，以及A. quadridentatus的体重和体型进行了评估。此外，我们在结果阶段的开始和结束时总共收集了76种水果（未成熟和成熟），并计算了种子甲虫的未孵化和孵化卵的频率，以评估种子硬化对甲虫姿势的影响。我们发现，种子中的种子更柔软，更小，更轻，对种子的伤害更大。较大和较重的种子比较小和较轻的种子更硬。从较大和较重种子繁殖的雄性和雌性分别比从较小和较轻种子繁殖的雄性和雌性分别大15％和25％。我们还发现四肢拟南芥的体重和体型与种子长度，重量和水分含量呈正相关。未孵化的卵仅在结实期开始时才被发现，此时种子不成熟且较软，这表明出现了一段时间窗口，雌性在种子变硬前产卵以利于第一龄幼虫的进入。这些结果表明，较大和较重的种子对草食性最有保护作用，但是克服植物硬度的四线拟南芥个体可以长大。我们建议种子性状在整个时空范围内变化，并影响四倍体拟南芥的生活史特征。