Since the 1960s, there has been very little diversification of oil palm (Elaeis guineensis) seed production, with mainly Deli × La Mé and Deli × Congo type crosses. The Deli origin, which was introduced from Africa into Indonesia in 1848, is unavoidable in breeding. In order to understand the complementarity between the Africa and "Asia" origins, and to diversify the genetic base of oil palm production, the structure of the genetic resources involved in the history of oil palm breeding in relation to African germplasm including subspontaneous populations needs to be understood. In this study, 318 individuals from 26 origins and eight countries were analysed with 14 microsatellite loci. Descriptive and Bayesian analyses of oil palm genetic diversity (Principal Coordinates Analysis, Neighbour-Joining Tree and Structure software) revealed two original groups which reflected the discontinuity of African species at the Dahomey Gap, West Africa (Group I) on the one hand, and "Benin-Nigeria-Cameroon-Congo-Angola" (Group II) on the other hand. The Deli group (Group III), derived from group II, is the result of artificial selection (mass selection). The genetic structuring revealed showed the positive contribution of the within-population mass selection practiced in the Deli population, and explains the success of Deli × La Mé and Deli × Congo crosses. A selection strategy is proposed, based on the yet-to-beexploited complementarity that exists between the two African genetic groups and on within-group improvement. We suggest (Deli × Group II) × Group I crosses, so that group II benefits from the quality of the Deli origin.
The stem-galling tephritid fly Cecidochares connexa (Macquart) was investigated as a potential biocontrol agent against the weed Chromolaena odorata (L) King & Robinson in Indonesia. Adults were tested in choice and no-choice tests, on 55 non-target plant species in 17 families. No oviposition was recorded on 53 of the species, while oviposition but no larval development was recorded on two. Field releases commenced in 1995 and establishment was immediate. The gall fly is now widely established in most Indonesian provinces, where gall parasitism and predation is generally low.
Monoecious and dioecious forms of the submerged aquatic plant hydrilla, Hydrilla verticillata (Linn. f.) Royle (Hydrocharitaceae) are invasive weeds in the US. Surveys for biological control agents of hydrilla throughout its native range have been conducted since the 1970s. Surveys between 1996 and 2013 focused on China, Southeast Asia and Australia, with 425 collections of hydrilla made in seven countries. Most of the herbivores collected were typical of previous surveys and included three main feeding guilds and taxonomic groups: stem-boring Bagous weevils, leaf-mining Ephydridae flies and defoliating Crambidae moths. Preliminary testing of prioritized agents collected from 1996 to 2013 did not reveal candidates for use as biological control agents with those tested being polyphagous. Further surveys are currently in China and South Korea, where hydrilla forms/genotypes exist that match those found in the US.
Cacoxenus indagator vit dans les nids linéaires de différentes abeilles maçonnes et en particulier d'Osmia cornuta que nous avons étudié. Son cycle est en parfaite coïncidence avec celui de son hôte. Le comportement des larves montre qu'elles préparent, avant la nymphose, l'orifice de sortie des adultes. Ce diptère, observ é depuis 1861 (G IRAUD) sur divers Apoïdes du genre Osmia (O. emarginata LEP., O. ventralis Pz, O. rufa L., O. cornuta LATR. O. coerulescens L.) et du genre Chalicodoma, a été surtout étudié par J ULLIARD (1947, 1948), mais le
Sparganobasis subcruciata Marshall merupakan jenis kumbang moncong di Papua dan Indonesia Timur yang mulai dilaporkan menimbulkan kerusakan pada tanaman kelapa sawit di Boven Digoel. Tujuan penelitian ini adalah untuk mengetahui gejala serangan S. subcruciata dan tingkat serangannya di salah satu perkebunan kelapa sawit di Boven Digoel, Papua. Penelitian dilakukan dengan mengamati karakteristik gejala tanaman terserang dan tingkat kerusakan yang ditimbulkan. Hasil pengamatan menunjukkan bahwa stadia yang menyerang adalah larva yang menggerek batang tanaman terutama pada bagian bawah sehingga membentuk gejala mirip dengan gejala penyakit Ganoderma, yakni kemunculan daun tombak lebih dari tiga, pelepah tua menggantung, mengering hingga tanaman tumbang. Hama ini telah mengakibatkan kematian tanaman kelapa sawit tua hampir di semua blok yang dikunjungi sehingga dapat dikategorikan sebagai hama utama pada perkebunan kelapa sawit di Papua dan berpotensi menjadi hama utama di Indonesia Bagian Timur. Deteksi dini sangat sulit dilakukan. Pengendalian dengan pemutusan siklus hidup hama kumbang menggunakan feromon perlu dikembangkan.
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