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Risk assessment is utilized to prioritize preventive measures based on the probability of dispersal success of pests. A main part of the risk assessment procedure is to determine the effects of environmental variables on the current and potential geographical distributions. In the present study, the spatial distribution of the Mediterranean pine engraver, Orthotomicus erosus (Wollaston), was mapped and predicted using MaxEnt. Presence records of O. erosus (north, northeast, west and centre of Iran), environmental and topographic variables, with the lowest correlations among themselves and the highest effects on the pest distribution were used. A total of 76 presence records of O. erosus were collected. The results of the distribution prediction modelling revealed that the northern part of Iran and the areas along the Zagros are the most suitable habitats for this species. Examining environmental variable importance on the distribution of O. erosus showed that the variables related to temperature and precipitation had more contribution in the MaxEnt model, respectively than the altitude. Furthermore, the high accuracy of the model (0.928) indicated that the MaxEnt had an acceptable performance for the prediction of O. erosus distribution. These findings would provide primary and critical information about the potential distribution of O. erosus in Iran, which could be effective for the stable population regulation of this destructive pest.

Azolla (Azolla spp.: Salviniaceae) is an aquatic fern that was introduced to the northern region of Iran with the aim of increasing the fertility of paddy fields, but due to suitable climatic conditions and the absence of natural enemies it became a problem in rice production and a destructive factor in aquatic ecosystems. In recent years, the biological control agent of this weed, Azolla weevil Stenopelmus rufinasus Gyllenhal (Curculionidae), was introduced in northern region of Iran. In this study, geographical distribution and seasonal population density of S. rufinasus in northern Iran were investigated through regular monthly sampling. The results showed that the time required to complete one generation in semi-field conditions is about two weeks. Both larvae and adults feed on Azolla. Azolla weevil is well distributed and established in the north regions of Iran and by feeding on Azolla, it has reduced its population in wetlands, permanent ponds and paddy fields. Comparing the population density of the weevil in three regions of Guilan province, indicated that the highest number of total density (667 insect in 1 kg Azolla) and adult (363 adults in 1 kg Azolla) belong to the central region of the province, while the density of larvae (397 larvae in 1 kg Azolla) in the eastern region of the province was higher than other regions. In the survey of the density in different cities, the highest density of total (2690 adults and larvae in 1 kg Azolla) and adult insects (2022 adults in 1 kg Azolla) was observed in Shaft city and the highest density of larvae (1920 larvae in 1 kg Azolla) was observed in the Rudbane of Lahijan. Based on the obtained results, the population density of the weevil is higher in spring and winter, which is not far from the mind considering the climatic conditions of the region and the sensitivity of Azolla to heat and low humidity. Based on the findings of this survey, the weevil has spread and settled well in the northern regions

The Mediterranean pine engraver, Orthotomicus erosus (Wollaston) (Col.: Curculionidae: Scolytinae), is a destructive bark beetle in pine forests worldwide. Regarding the recent outbreak of O. erosus in Iran, its flight activity and population density were monitored in four contaminated sites in western Tehran. These four sampling sites included Tabiat Park, Khargush Darreh Forest Park, Chitgar Park behind Bam Riding Club as well as Chitgar Park 9th Aghaghiya Street (western Tehran). Two pheromone traps (ECONEX ORTHOTOMICUS EROSUS 60 DAYS pheromone, Spain) were installed in each sampling site at the height of 2.5 m in the south direction of the pine trees. The number of trapped adults was recorded at 10-day intervals from April 2019 to March 2020. In total, 8514 adults of O. erosus were collected using pheromone traps during the sampling period. The results showed that the adult flight started from April in four sampling sites. The flight periods of adults continued until November in Tabiat Park, Khargush Darreh Forest Park, and Chitgar Park, behind Bam Riding Club. Differently, the last adults were collected in October in Chitgar Park, 9th Aghaghiya Street. In addition, the flight peaks of O. erosus occurred in August in Tabiat Park, Khargush Darreh Forest Park, and Chitgar Park, behind Bam Riding Club. However, the highest number of adults were trapped in July in Chitgar Park, 9th Aghaghiya Street. Based on our results, the number of trapped adults was significantly different in sampling sites. The mean number of trapped adults was the highest (183.25 ± 0.11) in Chitgar Park, 9th Aghaghiya Street and lowest (106.32 ± 0.07) in Tabiat Park during the whole monitoring experiment. These findings on flight activity and population fluctuation of O. erosus in local conditions could be helpful to establish an efficient and successful management program for this destructive pest.

Increasing insect resistance to the high toxicity of organophosphates and other conventional insecticides highlights the importance of developing and identifying alternative chemicals to successfully manage insect pests, including the striped rice stem borer (SRSB) Chilo suppressalis (Walker). SRSB is one of the most serious pests in paddy fields worldwide, especially in northern Iran. The present study was conducted to determine the efficiency of six insecticides viz., diazinon 10 G (Bazodin) 15 kg/ha; fipronil 0.2 G (Regent) 20 kg/ha; chlorantraniliprole 0.4 G (Ferterra) 12.5 kg/ha; thiamethoxam 25 WG (Actara) 0.2 kg/ha; flubendiamide 20 WG (Takumi) 0.9 kg/ha; dinotefuran 20 SG (Starkle) 0.75 kg/ha against SRSB. The experiments were carried out in randomized complete block design with three replications in experimental paddy fields of Rice Research Institute of Iran, Guilan province, 2018 and 2019. Chlorantraniliprole had the lowest dead heart and whitehead percent and the greatest efficiency against SRSB, followed by flubendiamide and dinotefuran. Our results suggested that chlorantraniliprole, flubendiamide, and dinotefuran can replace diazinon and fipronil in paddy fields. Furthermore, a new equation has been proposed for the calculation efficiency of insecticides based on the SRSB damage percent.

White-Spotted Stink bug, Eysarcoris ventralis (Westwood) (Hem.: Pentatomidae) was reported as one of the major destructive pests attacking rice worldwide. In Iran, it has been recorded on weeds, grape, alfalfa and wheat. In a survey on rice pests in Guilan province (Northern Iran) during 2017-2018, a large number of adult stink bugs were collected on rice panicles feeding on grains. The sucking on rice grains by adults as well as nymphs caused various symptoms, either empty glumes or spots around the feeding site. This is the first report of the damage symptoms caused by E. ventralis on rice in Iran (Guilan province).

The water fern weevil, Stenopelmus rufinasus Gyllenhal (Coleoptera: Curculionidae), is considered as the most important biological control agent of Azolla spp. in the world. Azolla spp. was introduced in Iran in 1986. In August 2017, two specimens of S. rufinasus were collected on Azolla spp. in waterways near Anzali lagoon and Rice Research Institute of Iran (RRII) in Guilan province for the first time. Identification was based on molecular sequencing. This is the first record of S. rufinasus from Iran.

To determine the effective bio-control agents of water fern, Azolla filiculoides, adults and nymphs of water lily aphid, Rhopalosiphum nymphaeae (L.), were collected on A. filiculoides in Guilan Province, Iran, during October 2013. This aphid has been collected extensively from almost all water fern samples during 2013 and 2014. Although R. nymphaeae was reported from numerous host plants in Iran, this species was collected for the first time from water fern. This aphid is heteroecious holocyclic with a sexual phase on Prunus spp., but it is the first report of its sexual phase formation on water fern as secondary host plant.

This paper report on a new species of mites of the genus Myrmozercon associated with ant in Iran – Myrmozercon cyrusi Ghafarian and Joharchi sp. n. was collected associated of the Monomorium sp. in Kenevist Rural District in the Central District of Mashhad County, Khorasan Razavi Province, Iran. This new species is described and illustrations provided. Myrmozercon ovatum Karawajew, 1909 is suspected to be a junior synonym of M. brevipes Berlese, 1902 and host-specificity and host range of Myrmozercon are also reviewed.

This paper reports on three species of mites of the genus Laelaspis in Iran – Laelaspis calidus Berlese from Pheidole pallidula, L. humeratus (Berlese) from Tetramorium caespitum and L. dariusi Joharchi & Jalaeian, sp. n. from soil. The new species is described and illustrations provided.