Topic
Aphid
About: Aphid is a research topic. Over the lifetime, 11380 publications have been published within this topic receiving 229721 citations. The topic is also known as: Aphidoidea & plant lice.
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TL;DR: Clear intraspecific variation in B. brassicae susceptibility among B. oleracea cultivars under glasshouse and field conditions that can be partly explained by certain differences in induced transcriptional changes is shown.
Abstract: Intraspecific variation in resistance or susceptibility to herbivorous insects has been widely studied through bioassays. However, few studies have combined this with a full transcriptomic analysis. Here, we take such an approach to study the interaction between the aphid Brevicoryne brassicae and four white cabbage (Brassica oleracea var. capitata) cultivars. Both under glasshouse and field conditions, two of the cultivars clearly supported a faster aphid population development than the other two, indicating that aphid population development was largely independent of the environmental conditions. Genome-wide transcriptomic analysis using 70-mer oligonucleotide microarrays based on the Arabidopsis thaliana genome showed that only a small number of genes were differentially regulated, and that this regulation was highly cultivar specific. The temporal pattern in the expression behaviour of two B. brassicae-responsive genes in all four cultivars together with targeted studies employing A. thaliana knockout mutants revealed a possible role for a trypsin-and-protease inhibitor in defence against B. brassicae. Conversely, a xyloglucan endotransglucosylase seemed to have no effect on aphid performance. Overall, this study shows clear intraspecific variation in B. brassicae susceptibility among B. oleracea cultivars under glasshouse and field conditions that can be partly explained by certain differences in induced transcriptional changes.
76 citations
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TL;DR: Results indicate very high prospects for using the essential oil obtained from F. vulgare in the development of environmentally safe botanical insecticides designed for plant protection against aphids.
Abstract: Aphids are an important agricultural pest that not only damage plants by suction, but can also transmit a number of economically important plant viruses. Protection against aphids is based on the use of synthetic insecticides. However, these products can be dangerous for non-target organisms. Therefore, it is important to develop new, environmentally safe plant protection methods. In this study, we have tested an essential oil (EO) obtained from Foeniculum vulgare for the mortality of Myzus persicae, an important polyphagous pest, its natural predator Harmonia axyridis, and Eisenia fetida as a representative of soil organisms. The EO, with its major compounds trans-anethole (67.9%) and fenchone (25.5%), was found to provide excellent efficacy against M. persicae (LC50 = 0.6 and LC90 = 2.4 mL L−1) while not causing any significant mortality of the tested non-target organisms. On the contrary, application of an insecticide based on the active substance alpha-cypermethrin not only caused mortality in the aphids, but also had a fatal negative effect on both the non-target organisms we tested, resulting in their high mortality. Our results indicate very high prospects for using the essential oil from F. vulgare in the development of environmentally safe botanical insecticides designed for plant protection against aphids.
76 citations
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TL;DR: This study highlighted the considerable role of symbionts in host–parasite co‐evolutionary dynamics by using an experimental evolution procedure in which parasitoids were exposed either to highly resistant aphids harbouring the symbiont or to low innate resistant hosts free of H. defensa.
Abstract: Insects harbour a wild diversity of symbionts that can spread and persist within populations by providing benefits to their host. The pea aphid Acyrthosiphon pisum maintains a facultative symbiosis with the bacterium Hamiltonella defensa, which provides enhanced resistance against the aphid parasitoid Aphidius ervi. Although the mechanisms associated with this symbiotic-mediated protection have been investigated thoroughly, little is known about its evolutionary effects on parasitoid populations. We used an experimental evolution procedure in which parasitoids were exposed either to highly resistant aphids harbouring the symbiont or to low innate resistant hosts free of H. defensa. Parasitoids exposed to H. defensa gained virulence over time, reaching the same parasitism rate as those exposed to low aphid innate resistance only. A fitness reduction was associated with this adaptation as the size of parasitoids exposed to H. defensa decreased through generations. This study highlighted the considerable role of symbionts in host-parasite co-evolutionary dynamics.
76 citations
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TL;DR: Exposure to δ-endotoxin of Bacillus thuringiensis tenebrionis has no statistically significant effect on survival, aphid consumption, development, or reproduction in beetles.
Abstract: We exposed larval and adult Hippodamia convergens (Guerin-Meneville), convergent lady beetle, to Myzus persicae (Sulzer), green peach aphid, reared on potatoes expressing δ-endotoxin of Bacillus thuringiensis tenebrionis . Because the toxin may be ingested by the aphid, the beetle may in turn be exposed to the toxin. However, we measured no statistically significant effect on survival, aphid consumption, development, or reproduction in beetles.
76 citations
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01 Feb 1975
TL;DR: The more polyphagous predators, the chrysopidae and Hemiptera, become important in the control of the aphids only when the dominant coccinellids are inactive because of diapause or when lack of aphids for reproduction prompts the beetles to leave the fields.
Abstract: Alfalfa fields in two climatically different regions were sampled for aphids and their
natural enemies throughout 3 years (1957-1959). The fields were under an integrated
control program and therefore received minimum amounts of insecticides. The four imported
parasites of the spotted alfalfa aphid and the pea aphid were not yet important in
the study area, so predators were mainly responsible for the high degree of naturally
occurring biological control. By pooling the data of entire regions, it was possible
to follow changes in populations of these mobile predators more accurately than is
possible from surveys of single fields because short-distance migration resulting
from harvesting practices as well as uneven distribution could be neglected.
Coccinellids and hemerobiids, two oligophagous groups, were closely linked in a density-dependent
fashion to the aphid populations. This is a good indication that these predators (especially
the lady beetles) are able to control the aphids. The more polyphagous predators,
the chrysopidae and Hemiptera, become important in the control of the aphids only
when the dominant coccinellids are inactive because of diapause or when lack of aphids
for reproduction prompts the beetles to leave the fields. When aphid development exceeds
the lady beetles’ momentary capacity for increase, however, syrphids are able to take
a large toll. Furthermore, several species having similar biologies were found to
replace each other throughout the year. Finally, the phenologies of the species could
be explained by their biologies (diapause, temperature thresholds, ovipostional behavior).
76 citations