Nutrition versus defense: Why Myzus persicae (green peach aphid) prefers and performs better on young leaves of cabbage

Abstract

Plant leaves of different ages differ in nutrients and toxic metabolites and thus exhibit various resistance levels against insect herbivores. However, little is known about the influence of leaf ontogeny on plant resistance to phloem-feeding insects. In this study, we found that the green peach aphid, Myzus persicae, preferred to settle on young cabbage leaves compared with mature or old leaves, although young leaves contained the highest concentration of glucosinolates. Furthermore, aphids feeding on young leaves had higher levels of glucosinolates in their body, but aphids performed better on young leaves in terms of body weight and population growth. Phloem sap of young leaves had higher amino acid:sugar molar ratio than mature leaves, and aphids feeding on young leaves showed two times longer phloem feeding time and five times more honeydew excretion than on other leaves. These results indicate that aphids acquired the highest amount of nutrients and defensive metabolites when feeding on young cabbage leaves that are strong natural plant sinks. Accordingly, we propose that aphids generally prefer to obtain more nutrition rather than avoiding host plant defense, and total amount of nutrition that aphids could obtain is significantly influenced by leaf ontogeny or source-sink status of feeding sites.

Disturbance and competition drive diversity effects in cabbage–aphid–onion systems with intra-specific genetic variation

“…These results strongly suggest that aphids have nuanced 'personalities' sensu Schuett et al (2011), with large display of plasticity depending on the embedding environment (Tremmel & Müller, 2013). A possible expression of these aphid personalities may be found in the differential performance on different cabbages that can be driven by the variance in sulphur and glucosinolate production between savoy and red cabbages (Cao et al, 2018). Kanvil et al (2014) showed a similar analogy with pea aphid biotypes reared on various Medicago truncatula genotypes; and this also receives support from our previous experiment with a group of pea aphid clones (Khudr et al, 2017b) showing a large array of contextual performance and behaviour on different cultivars of Vicia faba.…”

“…Furthermore, differential age-dependent and line-dependent content of amino acids, sulphur and defensive metabolites (e.g., glucosinolates) may exist between conspecifics (Castro et al ., 2004; Bellostas et al ., 2007) along with distinct leaf morphology (blistered in savoy cabbage but smooth in red cabbage). With a simpler leaf surface/texture, red cabbage phloem is more reachable by aphid stylets than that of savoy; leaf ontogeny also can pose a degree of ecological challenge to aphids as older leaves are less penetrable than younger ones hence the latter are more preferable to colonize (Vickers, 2012; Cao et al ., 2018). Comprehensive information, however, on cultivar by genotype adverse effects of anthocyanins and glucosinolates on aphid performance is thus far lacking ( nota bene ).…”

“…The onion line used in this study is a recognized resistant variety. Together with the two cabbage lines, these are the products of intensive selective breeding and they are common cultivars because they show uniformity, stability, productivity, cold tolerance and resistance to pests (Fang et al, 2005;Cartea et al, 2010; CABI Plantwise Knowledge Bank, 2019). However, the cabbages have intrinsic differences that may stem from genetic differences (Verkerk et al, 2010).…”

“…We could, therefore, speculate that any advantage arising from competition between aphids to the benefit of their shared host plant Disturbance and competition drive diversity effects in cabbage-aphid-onion systems can be utilizable in pest. Since young leaves are more vulnerable to aphids, which prefers to feed on them (Cao et al, 2018), compared with older leaves, the earlier aphid competition occurs, the better. Given the exponential rate of aphid reproduction, this could delay catastrophic consequences in agricultural settings.…”

Respon Populasi Kutu Daun Persik Terhadap Pemberian Beberapa Jenis Ekstrak Kulit Jeruk pada Cabai

“…Kutu daun persik dalam penelitian ini banyak ditemukan pada permukaan bawah daun dan pada daun muda, terutama pada pucuk tanaman. Adanya kutu daun persik pada daun muda menyebabkan ekskresi embun jelaga (Cao et al 2018). Menurut Macedo et al (2003) Berdasarkan hasil analisis yang ditunjukkan pada Tabel 5 menunjukkan dapat diketahui bahwa aplikasi ekstrak kulit jeruk bali dan kulit jeruk manis tidak berpengaruh nyata terhadap jumlah daun.…”