Rhizoctonia solani is a phytopathogenic fungus affecting a wide range of plants hosts including the sunflower causing various diseases such as damping-off. Current management approaches of this pathogen are inadequate. Aim of this study was to assess the potential of eco-friendly control methods, the indigenous biocontrol fungus Trichoderma harzianum and ZnO nanoparticles for controlling of the sunflower damping-off pathogen, R. solani. The biocontrol agent T. harzianum showed a high antagonism effect on R. solani growth. Additionally, growth of R. solani was significantly (p = 0.01) reduced gradually by presence of various concentrations of the ZnO NPs indicating to concentration-dependent toxicity effect. However, a similar impact was also observed on growth of T. harzianum. On the other hand, the percentage of seed germination and stem length of sunflower (Coban cv.) did not affect significantly by ZnO NPs. Conversely, the root lengths were significantly decreased. In the horticultural canopy trial, the best reduction to the sunflower damping-off incidence percentage was achieved by treatment of sunflower seedlings growing in compost inoculated with T. harzianum and R. solani 68.75% comparing to 100% in the control. In contrast, a significant reduction in severity percentage of damping-off symptoms was accomplished in most of the treatments. The best suppression was achieved in treatments of spraying the seedlings with ZnO NPs (15 mg/ml) in two days prior of planting that was 50% in compression with 97.50% in control. These findings can justify the application of the local biocontrol agent T. harzianum alone or in integration with ZnO NPs to be included with current management approaches of sunflower damping-off, which could lead to a diminution in the utilizing of fungicides.

1 Whiteflies are major pests of many crops worldwide. Trialeurodes vaporariorum was introduced into the U.K. approximately 160 years ago. In the present study, we aimed to understand their genetic diversity and population structure and thus their invasion history. 2 Mitochondrial CO1 sequencing showed that T. vaporariorum had a low level of variation. Microsatellite analysis showed a high diversity and indicated the presence 2, 6 and 10 clusters, which were, to a limited extent, linked to locations but not to host plants. The primary symbiont Portiera aleyrodidarum was detected in both sexes of T. vaporariorum, whereas only one secondary symbiont Arsenophonus sp. was detected in almost all females but not males. 3 The population structure suggested that glasshouse agroecosystems restricted gene flow between glasshouse whitefly populations and that the movement of glasshouse whitefly was linked to human-assisted spread. 4 Taken together, the results of the present study suggest multiple but limited numbers of introductions of T. vaporariorum, mainly from countries nearest to U.K.

Whiteflies (Hemiptera: Aleyrodidae) are major pests of many crops worldwide. Bemisia tabaci is a cryptic species complex composed of more than 39 putative species. Understanding which putative species of B. tabaci are predominant in an area is vital for effective pest management since they may vary considerably with respect to insecticide resistance, host plant range and virus transmission. Here, for the first time, the genetic diversity, the symbiont diversity and population structure of B. tabaci in Iraq were studied. Fourteen populations were analysed using mitochondrial cytochrome C oxidase subunit 1 (mtCO1) sequencing and microsatellite genotyping. Symbiotic bacteria were identified using 16S rRNA and 23S rRNA sequencing. MtCO1 sequencing detected two putative species of B. tabaci. The predominant putative species in Iraq was Middle East‐Asia Minor (MEAM) 1 subcladeB2. In addition, one individual was MEAM1‐subcladeB. The second putative species was a single individual of MEAM2. The microsatellite data indicated low genetic diversity, with no biologically informative clustering. All MEAM1 individuals harboured one primary symbiont, Portiera aleyrodidarum, and most (96%) have two secondary symbionts: Hamiltonella sp. and Rickettsia sp. This study has identified the genetic diversity and population structure of B. tabaci in Iraq. Further investigation is needed to update the pest status of B. tabaci in this region. The current data, combined with investigations into the capacity of the various putative species to transmit plant viruses, especially tomato yellow leaf curl virus, will aid pest management and horticultural production.

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Background The green peach aphid, Myzus persicae Sulzer, and the bean aphid, Aphis fabae Scopoli (both Hemiptera: Aphididae), are serious pests of greenhouse vegetable crops in Iraq and other regions of the globe. In this study, two morphological identical isolates (AA80 and AA82) of the entomopathogenic fungus Clonostachys rosea Schroers (Hypocreales: Bionectriaceae) from Iraq were isolated and characterized with phylogenetic analysis based on the internal transcribed spacer (ITS) region. The efficacy of C. rosea against M. persicae and A. fabae was previously unknown. Results In the laboratory bioassays, mortality of adult M. persicae and A. fabae caused by both C. rosea isolates varied according to conidial concentrations, with complete mortality occurring at 1 × 109 conidia ml−1 10 day post treatment. For M. persicae, LC50 values of AA80 and AA80 isolates were 3.6 × 106 and 3.8 × 106 conidia ml−1. For A. fabae, LC50 values of AA80 and AA80 isolates were 4.5 × 106 and 4.35 × 106 conidia ml−1. Infection by both fungal isolates at LC50 values reduced total fecundity of the treated aphids by 20% when compared to the untreated aphids. Conclusions The results from laboratory bioassays showed that C. rosea has potential as a biological control agent of M. persicae and A. fabae which is crucial for ecofriendly biopesticide development. However, further field and greenhouse studies are required for mass production.

The field study included estimating the population density of two species of aphids belonging to Hemiptera: Aphididae, which infect the wheat crop in the Samawah desert in Muthanna Governorate and included the areas of Al-Salhoubi, Al-Sheikhiya, Al-Rehab, Al-Shawiya, Al-Radmiah and Al-Salman. The study showed the presence of two species, Rhopalosiphium padi L. and Schizaphis graminium. The results of the field survey of the species R. padi showed that the highest infection rate and number density reached 87.53 insects/leaf during March in the Al-Rehab area and 49.88 insects/leaves during the same month in the Al-Shawiya area, respectively, while the infection rate and the number density of the same species decreased to 19.80% during January in Al-Salman and 17.75 insects/leaves during the same month in Al-Shikiya, respectively. However, S. graminium, found at the highest rate of infection at 49.33% in the Al-Salman area during March, and it decreased to 21% during January, and the highest rate of population density of the same species was 39.22 insects/leaf in Al-Shawiya during March, and the lowest rate was 8.45 insects/leaf in the Salhoubiyeh area during January. It was noted that the highest rate of infection with R. padi during January and February reached 42 and 59.24%, respectively, in the Al-Rehab area, and the highest rate of population density was recorded during January and February in the Al-Salman area, which reached 25.37 and 39.12 insects/leaf, respectively.

Alsendi, A., A.A. Kareem, M. Havasi and Gh. Golmohammadi. 2023. A Study on the Toxicity and Sublethal Concentrations of Three Insecticides on the Population Dynamics of Green Lacewing Chrysoperla carnea Stephens. Arab Journal of Plant Protection, 41(1): 28-36. https://doi.org/10.22268/AJPP-41.1.028036 The study was carried out to evaluate toxicity and sublethal effects of lufenuron, novaluron, and lambda-cyhalothrin on natural enemies such as Chrysoperla carnea. All sub-lethal concentrations caused a significant decrease in oviposition period, total fecundity, longevity, and total life span of C. carnea compared to the control. Maximum and minimum mean lifespan of C. carnea individuals were observed in the untreated group and LC30 concentration of novaluron. Total fecundity varied from 153.47 offspring/individual in treatment with LC30 novaluron to 300.12 offspring/individual in the control treatment. The highest value for intrinsic and finite rate of increase (r, λ) was obtained by the concentration of lambda-cyhalothrin. The net reproduction rate (R0) reached its lowest level in novaluron treatment. As a result, the effects of sublethal concentrations of lufenuron, novaluron, and lambda-cyhalothrin on C. carnea were assessed and discussed to design improved integrated management programs. Keywords: Integrated pest management, side effects, aphidophagous predators, natural enemies.

The family Chalcididae (Order: Hymenoptera) is known as one of the large chalcidoid wasps with some distinct morphological characters. The first occurrence of two parasitoid species belonging to this family was reported in the Al-Husayniya district Karbala Province, Iraq; which are: Brachymeria podagrica (Fabricius, 1787) and Chalcis myrifex (Sulzer, 1776). Both species were collected by using the sweeping net from orchards during July 2020.