Pseudococcidae (mealybugs) is a large taxonomic group, including a number of agronomic pests. Taxonomic identification of mealybug species is a recurrent problem and represents a major barrier to the establishment of adequate pest management strategies. We combined molecular analysis of three DNA markers (28S-D2, cytochrome oxidase I and internal transcribed spacer 2) with morphological examination, for the identification of 176 specimens collected from 40 mealybug populations infesting various crops and ornamental plants in Egypt and France. This combination of DNA and morphological analyses led to the identification of 17 species: seven in Egypt (Planococcus citri (Risso), Planococcus ficus (Signoret), Maconellicoccus hirsutus (Green), Ferrisia virgata (Cockerell), Phenacoccus solenopsis Tinsley, Phenacoccus parvus Morrison and Saccharicoccus sacchari (Cockerell)) and 11 in France (Planococcus citri, Pseudococcus viburni Signoret, Pseudococcus longispinus (Targioni-Tozzetti), Pseudococcus comstocki (Kuwana), Rhizoecus amorphophalli Betrem, Trionymus bambusae (Green), Balanococcus diminutus (Leonardi), Phenacoccus madeirensis Green, Planococcus vovae (Nasonov), Dysmicoccus brevipes (Cockerell) and Phenacoccus aceris Signoret), Pl. citri being found in both countries. We also found genetic variation between populations considered to belong to the same species, justifying further investigation of the possible occurrence of complexes of cryptic taxa.
Climate change is relevant to life around the globe. A rise in ambient temperature and carbon dioxide (CO2) may have various impacts on arthropods such as altered life cycles, modified reproductive patterns, and changes in distribution. The sweetpotato whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), is a global pest responsible for significant losses of agricultural yields annually. This study was conducted to determine the impacts of changing temperature and CO2 levels on selected life history parameters of B. tabaci biotype B. Populations were established at three temperature regimes (25,28, and 33°C), and each population was evaluated in all three environments. Collard, Brassica oleracea ssp. acephala de Condolle (Brassicaceae), was used as the host. These results were based on data from 5 to ≈30 generations. Oviposition, nymphal survival, and reproduction were significantly affected by temperature, with net reproductive success declining to 36.4% at 33°C. Overall, 28°C was most favorable for whitefly fitness. However, the optimal temperature for B. tabaci reproduction may be between 28 and 33°C. There were no temperature effects on total nonstructural carbohydrate concentrations in collard, and impacts of the host plant on whitefly development in the different environments were determined to be minimal. An environment of enriched CO2 (750 ppm) was not observed to have an adverse effect on whitefly reproduction. Temperature was negatively correlated with adult body size. Length and width of males and females were affected by temperature. Data regarding population dynamics of B. tabaci in response to climate change are important for accurate predictions and improving management practices.
The citrus mealy bug, Planococcus citri (Risso) (Hemiptera: Pseudococcidae) is attacks many host plants including all orchard trees in Egypt. The aim of this work is to study the survey of host plants, geographical distribution and natural enemies of the citrus mealy bug, P.citri in Egypt as well as the biological studies of this pest on citrus, grape and guava. The results indicated that the citrus mealy bug infested 65 plant species belonging to 56 genera in 36 families and distributed in 20 governorates. Twelve species of parasitoids were collected and recorded one of them is new record. This is Leptomastix abnormis Girault (Hymenoptera: Encyrtidae). Also nine species of predators recorded here attacked P.citri. The results also observed the host plants and temperatures greatly influenced on the development of P. citri. The lowering of the temperature increased the dimension of the mealy bug and lengthened the developmental period. The results on citrus, guava and grape showed that the life cycle of P. citri at 30 o C were 21.4±2.45, 32.6±2.44 and 38.8±1.56 days, respectively. These results indicated that P. citri preferes citrus followed by guava and grape.
The mango shield scale, Milviscutulus mangiferae (Green) (Hemiptera: Coccidae), a serious pest of mango trees in various parts of the world, is reported on Mangifera indica in Egypt which represents the first record of this species in the country.
The fauna of the Encarsia and Eretmocerus species (Hymenoptera: Chalcidoidea: Aphelinidae) from Arasbaran and its vicinity (Northwestern Iran) is studied in this paper. A total of 16 Encarsia species, including E. acaudaleyrodis Hayat, E. aleurochitonis (Mercet), E. aurantii (Howard), E. azimi Hayat, E. berlesei (Howard), E. citrina (Craw), E. elegans (Masi), E. elongata (Dozier), E. fasciata (Malenotti), E. formosa Gahan, E. inaron (Walker), E. lounsburyi (Berlese and Paoli), E. lutea (Masi), E. luteola Howard, E. mineoi Viggiani, E. perniciosi (Tower), and 4 Eretmocerus species (Eretmocerus cadabae Viggiani, Eretmocerus mundus Mercet, Eretmocerus nikolskajae Myartseva, Eretmocerus serius Silvestre) were collected
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