scholarly journals A clonally reproducing generalist aphid pest colonises diverse host plants by rapid transcriptional plasticity of duplicated gene clusters

2016 ◽  
Author(s):  
Thomas C Mathers ◽  
Yazhou Chen ◽  
Gemy Kaithakottil ◽  
Fabrice Legeai ◽  
Sam T Mugford ◽  
...  

BackgroundThe prevailing paradigm of host-parasite evolution is that arms races lead to increasing specialisation via genetic adaptation. Insect herbivores are no exception, and the majority have evolved to colonise a small number of closely related host species. Remarkably, the green peach aphid,Myzus persicae, colonises plant species across 40 families and singleM. persicaeclonal lineages can colonise distantly related plants. This remarkable ability makesM. persicaea highly destructive pest of many important crop species.ResultsTo investigate the exceptional phenotypic plasticity ofM. persicae, we sequenced theM. persicaegenome and assessed how one clonal lineage responds to host plant species of different families. We show that genetically identical individuals are able to colonise distantly related host species through the differential regulation of genes belonging to aphid-expanded gene families. Multigene clusters collectively up-regulate in single aphids within two days upon host switch. Furthermore, we demonstrate the functional significance of this rapid transcriptional change using RNA interference (RNAi)-mediated knock-down of genes belonging to the cathepsin B gene family. Knock-down of cathepsin B genes reduced aphid fitness, but only on the host that induced up-regulation of these genes.ConclusionsPrevious research has focused on the role of genetic adaptation of parasites to their hosts. Here we show that the generalist aphid pestM. persicaeis able to colonise diverse host plant species in the absence of genetic specialisation. This is achieved through rapid transcriptional plasticity of genes that have duplicated during aphid evolution.

2020 ◽  
Vol 8 (1) ◽  
pp. 66-73
Author(s):  
Julio M. Grandez-Rios ◽  
Carlos G. H. Pizango ◽  
Walter S. de Araújo

Background: The term ‘super host’ plant is often used in the literature surrounding plant-galling interactions, but the different contexts in which the term is used generates doubt and confusion due to the absence of a systematic definition of the term’s meaning. Objective: In this study, we used 60 well-defined plant-galling assemblages to propose a systematic definition of super-host plants at the local and regional level. In addition, we investigated factors that explain the number of galling species per host plant at different geographic scales. Methods: Plant-galling assemblages were compiled from an extensive literature review on insect gall inventories carried out in Brazil. Results: We found 888 host plant species belonging to 94 families and 340 genera hosting 2,376 insect gall morphotypes. At a local scale, 33.2% of host plant species harbored one insect gall morphotype and 12.2% hosted two gall morphotypes, making up 45.4% of the host plant species in each locality. At the regional scale, 51.5% of host plant species harbored one insect gall morphotype, and 17.9% of host plant species hosted two gall morphotypes, corresponding to 69.4% of all host plant species. Based on the average number of galling species per plant species, we classified the plant species into: 1) Host species; 2) Multi-host species and 3) Super-host species. The super-host plant species that showed the greatest richness of gall morphotypes at the local level were Baccharis reticularia and Adenocalymma neoflavidu. Furthermore, we found a positive relationship between plant life-form architectural complexity and the number of galling species at the local level. At the regional scale, we registered five super-host species (Guapira opposita, Protium heptaphyllum, Copaifera langsdorffii, Myrcia splendens, and Byrsonima sericea) which hosted 21 or more insect gall morphotypes. The number of galling species per host plant species at the regional scale was influenced positively by geographic distribution rank and number of biomes in which each species of the plant occurs. Conclusion: The present study stands out as the first of its kind to provide a systematic standardization for the super-host plants and to investigate factors influencing these species.


2017 ◽  
Vol 38 (01) ◽  
pp. 71-76
Author(s):  
Bishnu Prasad Bhandari ◽  
Zhiqiang Cheng

AbstractThe lobate lac scale,Paratachardina pseudolobataKondo & Gullan, is a recent insect invader to Hawaii that was first found in October 2012 on Oahu, Hawaii. It infests young branches of woody plants (usually less than 2 cm in diameter), forming a mass that appears as a dark crust, resulting in an unhealthy appearance, defoliation of leaves, and death of some plant species. This insect has infested many native and non-native plant species on Oahu, and the number of infested plant species is increasing. Our recent survey results, reported in this article, revealed 28 new host plant species in addition to 83 host species that we had reported previously, making 111 host plant species in Oahu's urban landscape. Efficacy and longevity of preventive treatment using the systemic insecticides imidacloprid and emamectin benzoate, delivered through trunk injection, against lobate lac scale on Chinese banyan,Ficus microcarpa, and curative treatment using imidacloprid on weeping banyan,Ficus benjamina, were evaluated. Forty-five Chinese banyans and 10 weeping banyans were included in this study. Our findings suggest that imidacloprid delivered via trunk injection is effective in preventing lobate lac scale infestation for at least 22 months post-treatment, and also in reducing lobate lac scale infestation curatively for at least 20 months post-treatment. This study provides an update on lobate lac scale's host species in Hawaii's urban landscape, and an effective preventive and curative management strategy against this pest.


Author(s):  
Marcin W. Zielonka ◽  
Tom W. Pope ◽  
Simon R. Leather

Abstract The carnation tortrix moth, Cacoecimorpha pronubana (Hübner, [1799]) (Lepidoptera: Tortricidae), is one of the most economically important insect species affecting the horticultural industry in the UK. The larvae consume foliage, flowers or fruits, and/or rolls leaves together with silken threads, negatively affecting the growth and/or aesthetics of the crop. In order to understand the polyphagous behaviour of this species within an ornamental crop habitat, we hypothesized that different host plant species affect its life history traits differently. This study investigated the effects of the host plant species on larval and pupal durations and sizes, and fecundity (the number of eggs and the number and size of egg clutches). At 20°C, 60% RH and a 16L:8D photoperiod larvae developed 10, 14, 20 and 36 days faster when reared on Christmas berry, Photinia (Rosaceae), than on cherry laurel, Prunus laurocerasus (Rosaceae), New Zealand broadleaf, Griselinia littoralis (Griseliniaceae), Mexican orange, Choisya ternata (Rutaceae), and firethorn, Pyracantha angustifolia (Rosaceae), respectively. Female pupae were 23.8 mg heavier than male pupae, and pupal weight was significantly correlated with the duration of larval development. The lowest and the highest mean numbers of eggs were produced by females reared on Pyracantha (41) and Photinia (202), respectively. Clutch size differed significantly among moths reared on different host plants, although the total number of eggs did not differ. This study showed that different ornamental host plants affect the development of C. pronubana differently. Improved understanding of the influence of host plant on the moth's life history parameters measured here will help in determining the economic impact that this species may have within the ornamental plant production environment, and may be used in developing more accurate crop protection methodologies within integrated pest management of this insect.


2020 ◽  
Vol 168 (12) ◽  
pp. 900-910
Author(s):  
Eduardo G. Virla ◽  
María B. Aguirre ◽  
Guido A. Van Nieuwenhove ◽  
Erica B. Luft Albarracin ◽  
Guillermo A. Logarzo

2008 ◽  
Vol 140 (2) ◽  
pp. 192-202 ◽  
Author(s):  
Gaylord A. Desurmont ◽  
Paul A. Weston

AbstractExperiments were conducted under laboratory conditions to determine the influence of the relative sizes of predator and prey, temperature, presence of refugia, size of the search area, and host-plant species on the predation performance of Podisus maculiventris (Say) nymphs against viburnum leaf beetle, Pyrrhalta viburni (Paykull), a new landscape pest in North America that feeds on the foliage of species of Viburnum L. (Caprifoliaceae). Predator handling time was positively correlated with body mass of the prey for all instars of P. maculiventris, but the rate of increase of handling time relative to prey mass decreased as predator age increased. Temperature was positively correlated with predation rates, but the presence of refugia did not have an impact on predation. The influence of host-plant species and size of the search area was tested on southern arrowwood (Viburnum dentatum L.) and American cranberrybush (Viburnum opulus L. var. americanum Aiton). There was a significant interaction between plant species and size of the search area, the species effect becoming significant as leaf surface area increased. In the case of southern arrowwood a negative correlation between size of the search area and predation rate was also detected. The identification of these factors adds valuable knowledge for using P. maculiventris as a biological-control agent against P. viburni.


2004 ◽  
Vol 164 (2) ◽  
pp. 337-346 ◽  
Author(s):  
Claudia G. León-Ramírez ◽  
José Luis Cabrera-Ponce ◽  
Alfredo D. Martínez-Espinoza ◽  
Luis Herrera-Estrella ◽  
Lucila Méndez ◽  
...  

2019 ◽  
Author(s):  
Ivan Andreevich Kerchev

Stridulatory signals are involved in conspecific interactions between bark beetles (Coleoptera: Curculionidae, Scolytinae). In this study, we compared the qualitative profiles of acoustic signals in three species from the genus Polygraphus Er. Sympatry can be periodically observed in two of them – P. proximus and P. subopacus. Sporadically they occur on the same plants. P. nigrielytris colonize distinctly different host plant species; however, on the island of Sakhalin it inhabits the same biotopes. The purpose of the study is to identify species-specific parameters and the extent of differences in stridulatory signals of these species. Airborne signals produced during the contact of males of the same species were experimentally recorded. Among tested parameters of stridulatory signals, as the most species-specific were noted: chirp duration, interchirp interval, number of tooth-strikes per chirp, and intertooth-strike interval.


Sign in / Sign up

Export Citation Format

Share Document