Search

A new species of Euderomphale Girault, 1916 (Eulophidae: Entedoninae), Euderomphale ayeganus Zeya & Shahbazvar, sp. nov., is described from specimens reared from the whitefly Aleyrodes sp. (Hem.: Aleyrodidae) in Iran. The new species is illustrated, and its differences from other species are discussed. [ABSTRACT FROM AUTHOR]

The EFSA Panel on Plant Health performed a pest categorisation of Neomaskellia andropogonis (Hemiptera: Aleyrodidae), the sugarcane whitefly, for the EU territory. N. andropogonis is a tropical and subtropical species that originates in south central Asia and has recently established in Iran and Iraq. N. andropogonis is not listed in Commission Implementing Regulation (EU) 2019/2072. It is oligophagous on Poaceae and most frequently reported on sugarcane (Saccharum officinarum), on which it has become an important emerging pest in western Iran. The larvae feed on the foliage and stalks and can cause a reduction of photosynthesis rate and growth. In heavy infestations, the sugar purity and content are greatly decreased. Honeydew egested by feeding N. andropogonis larvae can promote the growth of black sooty mould over the host. No evidence was found indicating economic damage to other grasses. The ornamental grass hosts Andropogon sp. and Imperata cylindrica are ornamental grasses in the subfamily Panicoideae and are exempt from a general prohibition on Poaceae entering the EU and together with fresh sugarcane, provide potential pathways for entry. An estimated threshold for development from egg to adult of 7.2°C with approximately 500 degree days required for a generation suggests that climatic conditions, together with the availability of grass hosts in the southern EU, would support establishment. Adults disperse naturally by flying and all stages can be moved over long distances by the trade of infested plant material. The pest has the potential to impact sugarcane production in Portugal and Spain. N. andropogonis satisfies all of the criteria that are within the remit of EFSA to assess for it to be regarded as a potential Union quarantine pest. However, this conclusion has high uncertainties regarding the likelihood of entry and the magnitude of potential impact within the EU as the insect is only recorded as an economically important pest in Iran, and its host range is poorly known and understood. [ABSTRACT FROM AUTHOR]

The parasitoid wasp, Eretmocerus delhiensis Mani (Hym., Aphelinidae), is an active ecto-endo and solitary parasitoid in southwestern Iran. To evaluate Er. delhiensis as a biocontrol agent against the greenhouse whitefly, Trialeurodes vaporariorum (Westwood) (Hem., Aleyrodidae) its host stage preference for parasitism and host-feeding was investigated. In this study, choice (multiple-instar) and no-choice (single-instar) tests were conducted under laboratory standard conditions. The results of both tests indicated that Er. delhiensis fed on and parasitized all T. vaporariorum nymphal instars but preferred the 2nd and 3rd nymphal instars for host-feeding and parasitism, respectively. Moreover, it showed the highest and lowest development times were in the 3rd and 1st nymphal instars, respectively. According to our findings, parasitism of the parasitoid wasp, Er. delhiensis, along with its host-feeding on the nymphal instars of the greenhouse whitefly could prove it to be a good candidate for suppressing the greenhouse whitefly populations. [ABSTRACT FROM AUTHOR]

The cotton whitefly, Bemisia tabaci Gen. (Hem., Aleyrodidae), is a key pest of many vegetables. Entomopathogenic fungi are promising microbial control agents against B. tabaci, but limited information is available concerning indigenous Iranian isolates. In this study, three isolates of Akanthomyces lecanii (PAL6, PAL7, and PAL8) and one isolate of A. muscarius (AGM5) were obtained from citrus hemipteran pests, Pulvinaria aurantii Cock. and Aphis gossypii Glover, in Mazandaran province, northern Iran. The isolates were then morphologically and molecularly identified. The efficacies of five different agar media for vegetative growth and conidiation of each isolate were determined. Potato dextrose agar was the medium on which the fungal mycelia developed at a relatively high rate. However, the highest rate of conidiation was found on Sabouraud dextrose agar. To determine the effects of the isolates on B. tabaci, a dose–response bioassay was carried out to estimate lethal concentration (LC50) and lethal time (LT50) values of each fungal isolate to second instar nymphs. The mean LC50 values of A. lecanii isolates ranged from 4.22 × 106 to 7.35 × 1013 conidia ml−1 at 5 to 7 days after the treatment. For A. muscarius, the values varied from 9.2 × 104 to 8.7 × 1010 conidia ml−1 at 5 to 7 days after the treatment. The lowest and the highest mean LC50 values were observed for A. mucarius (AGM5) and A. lecanii (isolate PAL6), respectively. The mean LT50 values of A. lecanii and A. muscarius isolates were 7.1–9.0 and 4.9–7.2 days, respectively. The LT50 values of A. muscarius were significantly lower than the other isolates. Overall, all isolates, especially A. muscarius (AGM5), exhibited appropriate potential as a biological control agent against B. tabaci. [ABSTRACT FROM AUTHOR]

Aleuroclava jasmini (Hemiptera: Aleyrodidae) is a major insect pest of paper mulberry (Broussonetia papyrifera) in Iran, negatively affecting its production. Considering the importance of oils in the integrated management programs of such pests, the present study examined the possibility of whitefly control on paper mulberry plant to assess mortality rate (MR), synergistic rate (SR), resistance rate (RR), and lethal concentration for 50% of the population (LC50) of oils and common insecticide in populations from four areas of Tehran, Iran (one susceptible and three non-susceptible). The best chemical treatments against A. jasmini adults and nymphs in paper mulberry plants were neem oil (1 ml L−1) mixed with deltamethrin (0.5 ml L−1) or with buprofezin (1 ml L−1). The neem, akylarylpolyglyglycol ether and volk oils mixed with deltamethrin or buprofezin also had synergistic effects on adults and nymphs of A. jasmini, respectively, in Azadi, Shahrake Gharb, and Vanak areas (non-susceptible populations), but with higher concentrations (> LC50) and lower SR than in Garm Dareh area (susceptible population). We observed that A. jasmini adults showed the greatest resistance to deltamethrin in Vanak area and nymphs of this pest to buprofezin in Shahrake Gharb area. [ABSTRACT FROM AUTHOR]

Background: The reports of numerous outbreaks of whiteflies from different parts of the world have increased its medical importance. The aim of this study was to determine relationship between environmental changes and climatic factors with the outbreak of the whitefly population in Tehran, the capital of Iran. Methods: This study was carried out in urban areas of Tehran, where the increasing population of whiteflies was reported frequently during 2018. In order to entrap the whiteflies, 20 yellow sticky cards smeared with white refined grease were installed on the trunks of the trees at twice per month as trapping time intervals. The captured flies were transferred and conserved in cans containing 70% alcohol and were counted accurately under a stereomicroscope. To determine the relationship between air quality index, precipitation, air temperature and air humidity as environmental and climatic factors with the abundance of whiteflies, change point analysis and Generalized Estimating Equations (GEE) was used. Results: The most density of white flies per trap was 256.6 and 155.6 in early October and late September respectively. The number moved closer to zero from November to April. The population of whiteflies was inversely correlated with the level of air quality index (p= 0.99) and precipitation (p= 0.95), and it had a direct correlation with the high temperature. Also, the population of whiteflies had a direct correlation with the level of air humidity in the first half of the year Conclusion: According to these findings, during spring and summer from early May to early October. [ABSTRACT FROM AUTHOR]

Functional and numerical responses of Encarsia acaudaleyrodis Hayat parasitizing Bemisia tabaci Gennadius were investigated under laboratory conditions. Newly emerged pairs of parasitoids were confined for 24 h in 8 cm Petri dishes together with 5, 10, 20, 40, 60, or 100 individuals of B. tabaci at their third nymphal stage. The parasitoid exhibited a type II functional response, attacking up to 9.6 nymphs when 100 had been provided. The rate of attack and handling time were 0.0554 and 2.3068 h, respectively. The number of eggs deposited by a single parasitoid depended on the number of host individuals, the maximum being 44.4 when the number of nymphs was 100. At the above-mentioned densities, the parasitoid lived 8.5 days on average. [ABSTRACT FROM AUTHOR]

Abstract: Tomato yellow leaf curl virus (TYLCV) can cause an economically relevant disease in the major tomato growing regions, and no resistance has been identified in commercial and wild tomato cultivars in Iran. In the present study, 34 common bean lines were screened for their reaction to TYLCV-Ir2 under greenhouse conditions. The experiment was conducted in a randomized complete block design with three replications. Bean plants were inoculated at the first trifoliate stage with viruliferous whiteflies (Bemisia tabaci biotype B) and were then sprayed with an insecticide and maintained in whitefly-proof greenhouse. The inoculated plants were monitored for the development of symptoms and the presence of viral DNA by polymerase chain reaction (PCR) four weeks after inoculation. Results revealed that out of the 34 lines, five were resistant. These lines exhibited either no symptoms or very mild symptoms and no viral DNA was detected in them by PCR. Two lines, which showed no typical disease symptoms but contained viral DNA, were identified as tolerant to TYLCV-Ir2. The vector feeding preference for common bean lines was assessed. Results indicated a significant difference in adult whitefly numbers among bean lines but there was no relationship between the number of whiteflies and disease symptom severity. The resistance to TYLCY-Ir2 expressed in common bean lines may be useful as source of resistance for the development of resistant commercial common bean cultivars. [ABSTRACT FROM AUTHOR]