251 research outputs found
The parasitoids of the African white rice borer, Maliarpha separatella Ragonot (Lepidoptera: Pyralidae)
A key is provided for the recognition of the hymenopterous parasitoids of the African white rice borer, Maliarpha separatella Ragonot, a pest of rice in Africa and Madagascar. Five species are described as new: Braconidae: Chelonus maudae Huddleston, Rhacanotus carinafus Polaszek; Ichneumonidae: Prisfomerus bullis Fitton, Prisfomerus caris Fitton, Venturia jordanae Fitton. The following synonyms are proposed: Goniozus indicus Muesebeck, G. natalensis Gordh and G. procerae Risbec are synonymized with Goniozus indicus Ashmead. Phanerotorna major Brues is synonymized with Phanerotoma saussurei Kohl. Lectotypes are designated for Goniozus procerae Risbec, Rhaconotus scirpophagae Wilkinson and Garouella ovicida Risbec. The known distributions, biologies and alternative hosts of each parasitoid are provided, and their use as biological control agents or components of integrated pest management programmes are discusse
Description of a new species of Orseolia (Diptera: Cecidomyiidae) from Paspalum in West Africa, with notes on its parasitoids, ecology and relevance to natural biological control of the African rice gall midge, O. oryzivora
Field sampling of grasses growing in and near rice fields at 12 sites in Nigeria during April/May 1994 recorded the presence of galls on Paspalum scrobiculatumat densities of up to 10.9 galls per m2. These galls were induced by Orseolia bonzii Harris, sp. n., which is described. This species is morphologically close to, but distinct from, the African rice gall midge, Orseolia oryzivora Harris & Gagné, with which it has been confused in earlier studies of that pest species. In host-transfer experiments O. bonzii did not transfer to rice, Oryza sativa. Six hymenopterous parasitoids were reared from galls of O. bonzii and the most abundant of these were Platygaster diplosisae Risbec, Aprostocetus nr. procerae (Risbec) and Neanastatusnr. cinctiventris Girault. Host-transfer experiments with the Platygasterand Aprostocetus species from O. bonzii on Paspalum indicated that the Platygaster may not transfer onto O. oryzivora on rice whereas the Aprostocetus does. The overlap between the parasitoid faunas of the two species of Orseolia is potentially useful as it may be possible to enhance the natural biological control of O. oryzivora by manipulating parasitoid populations on Paspalu
Biodiversity into your hands - A call for a virtual global natural history 'metacollection'
10.1186/1742-9994-10-55Frontiers in Zoology101
Novel molecular approach to define pest species status and tritrophic interactions from historical Bemisia specimens
Museum specimens represent valuable genomic resources for understanding host-endosymbiont/parasitoid evolutionary relationships, resolving species complexes and nomenclatural problems. However, museum collections suffer DNA degradation, making them challenging for molecular-based studies. Here, the mitogenomes of a single 1912 Sri Lankan Bemisia emiliae cotype puparium, and of a 1942 Japanese Bemisia puparium are characterised using a Next-Generation Sequencing approach. Whiteflies are small sap-sucking insects including B. tabaci pest species complex. Bemisia emiliae’s draft mitogenome showed a high degree of homology with published B. tabaci mitogenomes, and exhibited 98–100% partial mitochondrial DNA Cytochrome Oxidase I (mtCOI) gene identity with the B. tabaci species known as Asia II-7. The partial mtCOI gene of the Japanese specimen shared 99% sequence identity with the Bemisia ‘JpL’ genetic group. Metagenomic analysis identified bacterial sequences in both Bemisia specimens, while hymenopteran sequences were also identified in the Japanese Bemisia puparium, including complete mtCOI and rRNA genes, and various partial mtDNA genes. At 88–90% mtCOI sequence identity to Aphelinidae wasps, we concluded that the 1942 Bemisia nymph was parasitized by an Eretmocerus parasitoid wasp. Our approach enables the characterisation of genomes and associated metagenomic communities of museum specimens using 1.5 ng gDNA, and to infer historical tritrophic relationships in Bemisia whiteflies.© The Author(s) 2017. This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.
The attached file is the published pdf
Prospects for plant defence activators and biocontrol in IPM - Concepts and lessons learnt so far
There is an urgent need to develop new interventions to manage pests because evolution of pesticide resistance and changes in legislation are limiting conventional control options for farmers. We investigated β-aminobutyric acid (BABA), jasmonic acid (JA) and fructose as possible plant defence activators against grey mould disease, . Botrytis cinerea, and root knot nematode, . Meloidogyne incognita. We also tested . Trichogramma achaeae parasitoid wasps and an antifeedant plant extract for biocontrol of the invasive tomato leafminer, . Tuta absoluta. BABA and JA enhanced resistance of tomato plants to . B. cinerea but neither treatment provided complete protection and the efficacy of treatment varied over time with BABA being more durable than JA. Efficacy was partly dependent on tomato cultivar, with some cultivars responding better to BABA treatment than others. Furthermore, treatment of tomato with BABA, JA and fructose led to partial suppression of . M. incognita egg mass development. Biocontrol agent, . T. achaeae, performance against . T. absoluta could be enhanced by adjusting the rearing conditions. Both attack rate and longevity were improved by rearing the parasitoids on . T. absoluta rather than on other insects. Finally, . Ajuga chamaepitys extract was shown to have significant antifeedant activity against . T. absoluta. Our findings suggest that there are potential new solutions for protection of crops but they are more complicated to deploy, more variable and require more biological knowledge than conventional pesticides. In isolation, they may not provide the same level of protection as pesticides but are likely to be more potent when deployed in combination in IPM strategies
Roger Blackman 1941-2022 an appreciation
Dr Roger Laurence Blackman (Fig. 1) passed away on 17 March 2022, after more than 50 years dedicated to
advances in aphid science. There can be very few scientists studying any aspect of aphids whose papers have not
cited the works of Roger Blackman. To his name, we add that of Victor Eastop (1924–2012), for the two of them
formed an inspirational, complementary and indefatigable pair at London’s Natural History Museum. Together they
were responsible for, amongst many other seminal works, the three testaments of the aphidologists’ bible: Aphids
on the World’s Crops, Aphids on the World’s Trees and Aphids on the World’s Herbaceous Plants and Shrubs, now
brought together and regularly updated by Roger until very recently in the online version, Aphids on the World’s
Plants (www.aphidsonworldsplants.info). Victor was an out-and-out taxonomist, absolutely amongst the best the
world has known, whilst being very familiar with most aspects of aphidology. Roger’s contributions were broader as we shall see
Telenomus nizwaensis (Hymenoptera : Scelionidae), an important egg parasitoid of the pomegranate butterfly Deudorix livia Klug (Lepidoptera: Lycaenidae) in Oman
The pomegranate butterfly Deudorix (= Virachola) livia is the major pest of pomegranate, a crop of economic importance, in Oman. A species of parasitoid wasp in the hymenopteran family Scelionidae is responsible for high levels of mortality of its eggs. This wasp is described herein as Telenomus nizwaensis Polaszek sp. n., based on morphology and DNA sequence data. T. nizwaensis is currently known only from D. livia, which is also a pest of economic importance on other crops in North Africa, the Arabian Peninsula, and the Mediterranean. We summarise current knowledge of T. nizwaensis life-history and its potential to provide biological pest control.Peer reviewe
How to escape from insect egg parasitoids: a review of potential factors explaining parasitoid absence across the Insecta
The egg is the first life stage directly exposed to the environment in oviparous animals, including many vertebrates and most arthropods. Eggs are vulnerable and prone to mortality risks. In arthropods, one of the most common egg mortality factors is attack from parasitoids. Yet, parasitoids that attack the egg stage are absent in more than half of all insect (sub)orders. In this review, we explore possible causes explaining why eggs of some insect taxa are not parasitized. Many insect (sub)orders that are not attacked by egg parasitoids lack herbivorous species, with some notable exceptions. Factors we consider to have led to escape from egg parasitism are parental egg care, rapid egg development, small egg size, hiding eggs, by e.g. placing them into the soil, applying egg coatings or having thick chorions preventing egg penetration, eusociality, and egg cannibalism. A quantitative network analysis of host–parasitoid associations shows that the five most-speciose genera of egg parasitoids display patterns of specificity with respect to certain insect orders, especially Lepidoptera and Hemiptera, largely including herbivorous species that deposit their eggs on plants. Finally, we discuss the many counteradaptations that particularly herbivorous species have developed to lower the risk of attack by egg parasitoids.Copyright © 2020 The Author(s) Published by the Royal Society. All rights reserved. The linked file is the published version of the article.NHM Repositor
Effect of Different Constant Temperatures on Life History and Life Table Parameters of Trichogramma euproctidis (Hymenoptera: Trichogrammatidae)
Abstract: Temperature has a profound effect on performance and behavior of egg parasitoids. Egg parasitoids are a well-known alternative for the control of lepidopterous pests. Selected life history parameters of Trichogramma euproctidis (Girault) (Hymenoptera: Trichogrammatidae), an established egg parasitoid species in Khuzestan- Southwest Iran, were appraised at eight constant temperatures (22.5, 25, 27.5, 30, 32.5, 35, 37.5, and 40°C) using Ephestia kuehniella Zeller (Lepidoptera: Pyralidae) eggs as the host. We found significant effects of temperature on the number of parasitized eggs, development time, sex ratio, progeny’s longevity, and fecundity. T. euproctidis developed on E. kuehniella eggs at all temperatures tested, but performed best at 32.5°C. At this temperature, they parasitized the most eggs, produced the most female progeny, and had high rates of survival. Our findings revealed that temperature significantly affected the longevity of female progeny and fecundity of T. euproctidis. A life table analysis confirmed that temperature resulted in optimal effects on T. euproctidis life history. Net reproductive rate (R0) of T. euproctidis was different among the temperatures tested. The intrinsic rate of increase (r) was positively correlated with temperature from 22.5 to 32.5°C and then decreased from 35 to 40°C. Generation time (T) and doubling time (DT) decreased as temperature increased from 22.5 to 37.5°C and then increased at 40°C. These data suggest that this strain of T. euproctidis is adapted to high temperatures and harsh environmental conditions and has the potential to be used in integrated management programs in Southwest Iran.Copyright © The Author(s) 2022. Published by Oxford University Press on behalf of Entomological Society of America. This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial License (https://creativecommons.org/ licenses/by-nc/4.0/), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited. For commercial re-use, please contact [email protected] Repositor
RefConcile – automated online reconciliation of bibliographic references
Comprehensive bibliographies often rely on community contributions. In such a setting, de-duplication is mandatory for the bibliography to be useful. Ideally, it works online, i.e., during the addition of new references, so the bibliography remains duplicate-free at all times. While de-duplication is well researched, generic approaches do not achieve the result quality required for automated reconciliation. To overcome this problem, we propose a new duplicate detection and reconciliation technique called RefConcile. Aimed specifically at bibliographic references, it uses dedicated blocking and matching techniques tailored to this type of data. Our evaluation based on a large real-world collection of bibliographic references shows that RefConcile scales well, and that it detects and reconciles duplicates highly accurately
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