Chalcidoidea (Hymenoptera) is extremely diverse with an estimated 500 000 species. We present the first phylogenetic analysis of the superfamily based on both morphological and molecular data. A web-based, systematics workbench mx was used to score 945 character states illustrated by 648 figures for 233 morphological characters for a total of 66 645 observations for 300 taxa. The matrix covers 22 chalcidoid families recognized herein and includes 268 genera within 78 of 83 subfamilies. Morphological data were analysed alone and in combination with molecular data from ribosomal 18S (2105 bp) and 28S D2-D5 expansion regions (1812 bp). Analyses were analysed alone and in combined datasets using implied-weights parsimony and likelihood. Proposed changes in higher classification resulting from the analyses include: (i) recognition of Eriaporidae, revised status; (ii) recognition of Cynipencyrtidae, revised status; (iii) recognition of Azotidae, revised status; (iv) inclusion of Sycophaginae in Agaonidae, revised status; (v) reclassification of Aphelinidae to include Aphelininae, Calesinae, Coccophaginae, Eretmocerinae and Eriaphytinae; (vi) inclusion of Cratominae and Panstenoninae within Pteromalinae (Pteromalidae), new synonymy; (vii) inclusion of Epichrysomallinae in Pteromalidae, revised status. At a higher level, Chalcidoidea was monophyletic, with Mymaridae the sister group of Rotoitidae plus the remaining Chalcidoidea. A eulophid lineage was recovered that included Aphelinidae, Azotidae, Eulophidae, Signiphoridae, Tetracampidae and Trichogrammatidae. Eucharitidae and Perilampidae were monophyletic if Eutrichosomatinae (Pteromalidae) was included, and Eupelmidae was monophyletic if Oodera (Pteromalidae: Cleonyminae) was included. Likelihood recovered a clade of Eupelmidae + (Tanaostigmatidae + (Cynipencyrtus + Encyrtidae). Support for other lineages and their impact on the classification of Chalcidoidea is discussed. Several life-history traits are mapped onto the new phylogeny.© The Willi Hennig Society 2013. Without question, Chalcidoidea is one of the most megadiverse groups of insects. Their morphological diversity is staggering (Fig. 1). They range in size from such veritable giants as females of Leptofoenus (Pteromalidae), which exceed 20 mm, to the minute and morphologically bizarre male of Dicopomorpha echmepterygis (Mymaridae), the smallest known specimen of which is 0.13 mm long. Males of D. echmepterygis have lost eyes, ocelli, mouthparts, antennal flagellum, wings, tarsi except for a highly modified arolium, and virtually any other feature that places them as parasitic wasps (Fig. 1a). Other bizarrities include male fig wasps, which can be reduced to turtle-like fighting machines that bear no resemblance to their corresponding females and are hardly recognizable as chalcidoids, or the grotesquely enlarged scutellum (Fig. 1h) of Galearia latreillei (Eucharitidae) and the dart-shaped ovipositor sheaths (Fig. 1j) of Cameronella (Pteromalidae). Convergent morphology is also rampant, and enlarged...
▪ Abstract Cereals (maize, sorghum, millet, rice) are extremely important crops grown in Africa for human consumption. Of the various insect pests attacking cereal crops in Africa, lepidopteran stem borers are by far the most injurious. All 21 economically important stem borers of cultivated grasses in Africa are indigenous except Chilo partellus, which invaded the continent from India, and C. sacchariphagus, which has recently been found in sugarcane in Mozambique. C. partellus is competitively displacing indigenous stem borers in East and southern Africa. A parasitoid, Cotesia flavipes, was introduced from Pakistan for biological control of C. partellus and caused a 32–55% decrease in stem borer densities. This article is an attempt to summarize the status of knowledge about economically important cereal stem borers in Africa with emphasis on their distribution, pest status and yield losses, diapause, natural enemies, cultural control, host plant resistance, and biological control. Special attention is given to Busseola fusca and C. partellus, the most important pests of maize and grain sorghum.
While many studies have demonstrated that organic farms support greater levels of biodiversity, it is not known whether this translates into better provision of ecosystem services. Here we use a food-web approach to analyse the community structure and function at the whole-farm scale. Quantitative food webs from 10 replicate pairs of organic and conventional farms showed that organic farms have significantly more species at three trophic levels (plant, herbivore and parasitoid) and significantly different network structure. Herbivores on organic farms were attacked by more parasitoid species on organic farms than on conventional farms. However, differences in network structure did not translate into differences in robustness to simulated species loss and we found no difference in percentage parasitism (natural pest control) across a variety of host species. Furthermore, a manipulative field experiment demonstrated that the higher species richness of parasitoids on the organic farms did not increase mortality of a novel herbivore used to bioassay ecosystem service. The explanation for these differences is likely to include inherent differences in management strategies and landscape structure between the two farming systems.
Field trials in Kenya demonstrated that the forage grass, Sorghum vulgare sudanense (Sudan grass) attracted greater oviposition by stemborers than cultivated maize, resulting in significant increase in maize yield. On the other hand, the non-host forage plant, Melinis minutiflora (molasses grass), when inter-cropped with maize, repelled gravid stemborer females from ovipositing on maize, resulting in significant reduction in stemborer infestation. Using these trap-and repellent gramineous plants, a novel pest management approach based on a 'push-pull' or stimulo-deterrent diversionary strategy is being developed where stemborers are repelled from the food crop and are simultaneously attracted to a discard or trap crop. The plant composition and permanence of habitat surrounding maize fields also influence the abundance of natural enemies that invade agroecosy stems once a pest population is present. It may be advantageous to promote the growth of native Gramineae and other wild plants which minimise, or even suppress, population growth of pests during noncropping seasons, but still provide a suitable habitat for natural enemies.Resume-Des essais de terrain au Kenya ont prouve que l'herbe fourragere, Sorghum vulgare sudanense (herbe du Soudan) attirait plus de foreurs de tiges pour la ponte que le mai's cultive, entrainant une augmentation significative de la recolte de mai's. D'autre part, la plante fourragere non-hote, Melinis minutiflora (herbe melasse), une fois en culture mixte avec le mai's, empechait des foreurs de tiges femelles gravides de pondre sur le mai's, ce qui reduisait significativement l'infestation du mai's par les foreurs de tiges. I/utilisation de ces plantes graminees pieges et repulsives, une approche nouvelle du controle des ravageurs basee sur une strategie diversionniste de 'pousse-tire' ou de 'stimulation-deterrence' est en train d'etre developee la ou les foreurs de tiges sont repousses loin des cultures de consommation et sont simultanement attires vers une plante rebut ou piege. La composition botanique et la permanence de l'habitat entourant les champs de mai's influencent aussi 1'abondance des ennemis naturels qui envahissent des agroecosystemes des qu'une population de ravageurs est presente. II serait avantageux de promouvoir la croissance des graminees indigenes et d'autres plantes sauvages qui minimisent ou meme inhibent la croissance des populations des ravageurs durant les saisons de jachere, tout en assurant un habitat favorable pour les ennemis naturels.
A key is provided for the recognition of previously described Encarsia species which are known to attack the tobacco whitefly, Bemisia tabaci (Gennadius). 28 nominal species are included, of which type material has been examined for 22. Eight new synonymies are proposed: Encarsia aleyrodis (Mercet) and E. partenopea Masi are both synonymized with E. inaron (Walker); E. bemisiae (Ishii) is synonymized with E. transvena (Timberlake); £. citri (Ishii) is synonymized with E. strenua (Silvestri), E. angelica Howard and E. deserti Rivnay & Gerling are both synonymized with E. luteola Howard; E. perspicuipennis (Girault) is synonymized with E. auaintancei (Howard); £. tabacivora Viggiani is synonymized with E. pergandiella Howard. E. hispida De Santis is removed from synonymy with E. meritoria Gahan. A lectotype is designated for E. porteri (Mercet). The known distributions and alternative hosts of Encarsia species attacking B. tabaci are provided as well as references to biology and notes on their use in biological control.
The fall armyworm, Spodoptera frugiperda, a moth originating from tropical and subtropical America, has recently become a serious pest of cereals in sub-Saharan Africa. Biological control offers an economically and environmentally safer alternative to synthetic insecticides that are being used for the management of this pest. Consequently, various biological control options are being considered, including the introduction of Telenomus remus, the main egg parasitoid of S. frugiperda in the Americas, where it is already used in augmentative biological control programmes. During surveys in South, West, and East Africa, parasitized egg masses of S. frugiperda were collected, and the emerged parasitoids were identified through morphological observations and molecular analyses as T. remus. The presence of T. remus in Africa in at least five countries provides a great opportunity to develop augmentative biological control methods and register the parasitoid against S. frugiperda. Surveys should be carried out throughout Africa to assess the present distribution of T. remus on the continent, and the parasitoid could be re-distributed in the regions where it is absent, following national and international regulations. Classical biological control should focus on the importation of larval parasitoids from the Americas.
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