Crop colonisation, feeding, and reproduction by the predatory beetle, Hippodamia convergens, as indicated by stable carbon isotope analysis
Crop colonisation, feeding, and reproduction by the predatory beetle, Hippodamia convergens, as indicated by stable carbon isotope analysis
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DOI：
10.1111/j.0307-6946.2004.00585.x
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发表时间：
2004-04-01
影响因子：
2.2
通讯作者：
Winemiller, KO
中科院分区：
文献类型：
--
作者：
Prasifka, JR;Heinz, KM;Winemiller, KO
1.加强农业系统天敌种群的栖息地管理可能有助于调节作物害虫的水平，但很少有研究涉及迁入有益昆虫的行为。在互补性的实验室和野外研究中，使用稳定的碳同位素来检查瓢虫对短暂的农业栖息地的定居行为。在实验室条件下，在其食物供应从以C-4-为基础的分别以谷物高粱或棉花生产的蚜虫为基础的饲料转变为以C-3为基础的饲料后，聚合型麦长管虫的碳同位素比率(Delta(13)C)发生了变化。成虫的最终同位素比率更接近于以C-3为基础的新饮食，其中Delta(13)C的大部分变化发生在饮食转变后的3天内。棉田采集的瓢虫成虫的碳同位素比值表明，在附近许多高粱成熟衰老之前，籽粒高粱一直是聚合草的持续来源。在没有捕食棉蚜的情况下，甲虫种群的碳同位素比值不随时间变化，几乎没有检测到聚合型棉蚜产卵。这表明甲虫对棉花来源的非蚜虫资源的取食很少。在棉蚜存在的情况下，甲虫的同位素比值向棉花的碳同位素比值下降，表明成虫在棉花中取食。因此，所生产的蛋团的碳同位素比率在C-3值范围内。结果表明，一些捕食者物种可能被保留在没有大量猎物种群的栖息地，这是控制农业系统害虫的关键品质。
1. Habitat management to enhance natural enemy populations in agricultural systems may help regulate levels of crop pests, but little research addresses the behaviour of immigrating beneficial insects.2. Stable carbon isotopes were used in complementary laboratory and field studies to examine colonisation behaviour of an ephemeral agricultural habitat by the lady beetle, Hippodamia convergens Guerin-Meneville.3. Under laboratory conditions, H. convergens carbon isotope ratios, delta(13)C, changed after its food supply was shifted from a C-4- to a C-3-based diet of aphids produced on grain sorghum or cotton respectively. Final isotope ratios of adult H. convergens were closer to that of the new C-3-based diet, with most change in delta(13)C occurring within 3 days after the diet shift.4. The carbon isotope ratios of lady beetle adults collected in cotton fields suggested that grain sorghum was a continuous source for H. convergens until many nearby sorghum fields matured and senesced.5. When cotton aphid (Aphis gossypii Glover) prey were absent, carbon isotope ratios of beetle populations did not change over time and virtually no egg production by H. convergens was detected. This indicates that beetles were feeding little on non-aphid resources originating in cotton.6. With cotton aphids present, beetle isotope ratios decreased towards the carbon isotope ratio of cotton, indicating adult feeding in cotton. As a result, egg masses produced had carbon isotope ratios in the C-3 range of values.7. The results suggest that some predator species may be retained in habitats without large prey populations, a quality essential in controlling pests in agricultural systems.