The Sudanese citrus industry is mainly based on oldline cultivars of grapefruit, sweet orange and willow leaf mandarin, grafted almost exclusively on sour orange. Infection with graft-transmissible agents, viroids in particular, may have deleterious effects on the productivity of these citrus species and, more importantly, limits the choice of rootstocks should sour orange be replaced by altern...

The brown citrus aphid, Toxoptera citricida (Kirkaldy), is an important pest of Florida citriculture because it causes feeding damage to citrus and vectors citrus tristeza virus. Parasitoids recovered from brown citrus aphids in Florida include Lysiphlebus testaceipes (Cresson), Lipolexis scutellaris Mackauer, and Aphelinus gossypii Timberlake. Monitoring the levels of parasitism caused byeach ...

Six Alabama Satsuma mandarin orchards (four conventionally sprayed and two unsprayed) were surveyed during 2005 and 2006 to determine the population dynamics of arthropod pests and their natural enemies. Twenty-eight arthropod pest species were encountered; the major foliage pests were citrus whitefly, Dialeurodes citri (Ashmead); purple scale, Lepidosaphes beckii (Newman); Glover scale, L. glo...

Citrus sinensis is a perennial woody species, for which genetic approaches to the study of reproductive development are not readily amenable. Here, the usefulness of the CitEST Expressed Sequence Tag (EST) database is demonstrated as a reliable new resource for identifying novel genes exclusively related to Citrus reproductive biology. We performed the analysis of an EST dataset of the CitEST P...

The convergent lady beetle, Hippodamia convergens Guérin-Méneville (Coleoptera: Coccinellidae), is an important predator of soft-bodied insect pests in many regions of the United States, but generally uncommon in Florida citrus. Certain citrus producers in Florida recently initiated releases of commercially available H. convergens from California against the Asian citrus psyllid Diaphorina citr...

The mosquito repellent activity of phytochemical extracts from Peels of five citrus fruit species, Citrus sinensis, Citrus limonum,Citrus aurantifolia, Citrus reticulata and Citrus vitis, was investigated. The volatile phytochemical extracts were obtained from processed air-dried and powdered citrus fruit peels by Soxchlet extraction using Diethyl Ether as solvent. Five different concentrations...

We studied species diversity and genetic variation among populations of Brevipalpus mites from four species of citrus host plants. We sampled mites on orange, lime, grapefruit and mandarin trees from orchards at six localities distributed in the five most important citrus producing states in Mexico. Genetic variation among citrus host plants and localities were assessed by analysis of nucleotid...

This study analyzes the structure and composition of ant communities in citrus orchards in Catalonia (northeast Spain) and compares them with the ant fauna found in natural communities of the region. In the citrus orchards considered in this study, the most abundant species were Lasius niger and Pheidole pallidula, which are behaviorally dominant species. Two other dominant species, Linepithema...

Sooty mold fungi are often associated with honeydew which insects secrete while feeding on the plant. A great variety of these fungi occur in the North of Iran, especially on Citrus ssp which is one of the most widely cultivated fruit trees in this region. During last 10 years, several collections of these fungi examined and 15 species have been recorded. In this paper seven previously unreport...

Systemic invasion of plants by viruses is thought to involve two processes: cell-to-cell movement between adjacent cells and long-distance movement that allows the virus to rapidly move through sieve elements and unload at the growing parts of the plant. There is a continuum of proportions of these processes that determines the degrees of systemic infection of different plants by different viru...