---

Improved studies on Collembola fauna of Iran have been started only recently and springtails species from many regions of the country are still unknown. This study presents the results of a faunistic survey of springtails from Golestan province, Northern Iran. Samplings were done in different habitats of Gorgan and Kordkuy counties (Golestan province) including forests, agricultural fields and citrus orchards during 2014–2015. In sum 37species from families Entomobryidae, Paronellidae, Isotomidae, Tomoceridae, Onychiuridae and Tullbergiidae were identified. Entomobrya numidica Baquero, Hamra-Kroua & Jordana, 2009; E. nivalis Linneaeus, 1758; E. nicoleti Lubbock, 1868; Cyphoderus agnotus Borner, 1906; Isotomurus cf. balteatus Reuter, 1876; Vertagopus sp.; Protaphorura cf. salsa Kaprus, Pasnik et Weiner, 2014; Mesaphorura yosii Rusek, 1967; Mesaphorura critica Ellis, 1976represent new records for Iranian fauna.

---

The objective of this study was to identify the species of thrips associated with rice crops in order to determine population fluctuation of the dominant species. Studies were conducted during the month of April to August in the year 2017 form different growth stages of rice in Babolsar city, Mazandaran Province (Northern Iran). Samplings were done from four fields located at two sites, KeyxaMahalle and MirBazar. A total of seven species of thrips belonging to four genera and two families (Thripidae and Phlaeothripidae) were identified. Amongst them, Haplothrips eragrostidis Priesner was the dominant species accounting for 75.47% in abundance. This was followed by Thrips hawaiiensis Morgan comprising 6.47%. The other species include Anaphothrips sudanensis Trybom, Frankliniella intonsa (Trybom), F. tenuicornis (Uzel), Thrips tabaci Lindeman and Haplothrips flavicinctus (Karny) which comprised of4.85%, 4.32%, 4.31%, 4.04% and 0.54% respectively. The maximum number of thrips species was found in the middle of July and minimum in the month of May. Assessment of thrips abundance in rice fields were started at the beginning of dough stage and were continued until complete maturity.

---

During the collecting of Hypogastruridae (Collembola) in Mazandaran province, Xenylla mediterranea da Gama, 1964 was reported for the first time from Iran. With the new record in this study, the number of Xynella species known from Iran increased to four. Information for specie including material examined, description, ecology, distribution, and illustrations are given.

---

During the study of flower flies (Diptera: Syrphidae) associated with colza (Brassica napus) fields in Sari (Mazandaran Province, Iran) in 2015–2016, a total of six species i.e. Episyrphus balteatus (De Geer), Eupeodes corollae (Fabricius), Melanostoma mellinum (Linnaeus), Paragus bicolor (Fabricius), Syrphus ribesii (Linnaeus) and Platycheirus jaerensis Nielsen are recorded for this region. Among them, P. jaerensis Nielsen is newly recorded for the Iranian fauna.

---

The family Neanuridae belonging to order Poduromorpha, class Collembola includes terrestrial animals which play vital roles in decomposition and nutrient cycle in soil. Up to now, the fauna of this family has not been investigated in various areas of Golestan national Park (Hyrcanian forests). In order to identifying species of the class Collembola in this park, numerous samplings were carried out from soil, humus, and moss in 2015 and 2016. Then, the Collembola specimens were separated by using Berlese Funnel, stored in 75-85 percent ethyl alcohol and identified according to valid identification keys. Meanwhile, the species Friesea afurcata Tullberg, 1869) from the Neanuridae family is reported for the first time in Iran and Golestan province.

---

Present study was done in forests of northern Iran during 2016 to investigate Entomobryomorpha (Collembola) fauna. Seven genera and nine species belonging to families Tomoceridae and Entomobryidae were found. The genus Pogonognathellus Paclt, 1944 and species P. flavescens (Tullberg, 1871) belonging to Tomoceridae family are recorded for the first time from Iran, also three new records from Entomobryidae of genus Entomobrya Rondani, 1861 are reported for Mazandaran province fauna.

---

In order to extend the work on Iranian Collembolan fauna, several samplings from leaf litter and soils conducted in Ilam province (west of Iran). Specimens were collected from different localities and extracted by Berlese funnels. Results from the study lead to identification of 11 species of five families: Onychiuridae (with two genera and two species), Tullbergiidae (with one genus and one species), Hypogastruridae (with one genus and one species), Isotomidae (with four genera and four species) and Entomobryidae (with one genus and one species). Sminthurus muscicolus Betsch, 1977 from Sminthuridae was new for Iranian fauna. All species from the present study reported for the first time from Ilam province. Short explanation of each collected species including the material studied, a distribution and a short description for the new record and some illustrations are given.

---

Specimens of springtails were collected from soil and leaf litter in the forests of Mazandaran province, north of Iran during 2016–2017. Three species were recorded in this country for the first time, Xenylla szeptyckii Skarżyński, Piwnik & Porco, 2018 (Hypogastruridae), Friesea espunaensis Arbea & Jordana, 1993 (Neanuridae) and Tomocerina minuta (Tullberg, 1877) (Tomoceridae). Detailed descriptions of these species are provided based on the materials collected from Mazandaran province, Iran.

---

View on Scopus
In this study the biodiversity and relative abundance of Collembola was evaluated in two different ecosystems, citrus field and forest in Mazandaran province, Iran. Samples were carried out during 2016 and 2017. In each site, soil was sampled by a collecting core from 5×5 cm in surface area and a depth of 10 cm. Species richness, biodiversity and the indices of similarity were calculated. The results of T-Test showed that in two years (2016 and 2017), the values of Shannon-Wiener diversity and Simpson species diversity index were significantly different between sampling areas (Pvalue<0.05), but the values of Margalef richness and Pielou evenness index were not significantly (Pvalue˃0.05). In the year 2016, Shannon-Wiener index, Simpson index, Pielou evenness and Margalef species richness in Dasht-e Naz forest were 1.92 ± 0.1, 0.83 ± 0.03, 2.01 ± 0.2 and 0.94 ± 0.04 respectively, and in citrus field were 1.44 ± 0.11, 0.73 ± 0.02, 1.46 ± 0.37 and 0.9 ± 0.03 respectively. Also, in the year 2017, Shannon-Wiener index, Simpson index, Pielou evenness and Margalef species richness in Dasht-e Naz forest were 1.79 ± 0.05, 0.81 ± 0.08, 1.38 ± 0.25 and 0.94 ± 0.09 respectively, and in citrus field were 0.98 ± 0.22, 0.58 ± 0.08, 1.02 ± 0.35 and 0.95 ± 0.05 respectively. In general, the results showed that the abundance and biodiversity of Collembola in Dasht-e Naz forest was higher than in citrus field.

---

View on Scopus
Soil-dwelling Entomobryomorphan Collembola from the Northeast of Iran were sampled for the first time as part of a biodiversity surveying study with the aim of improving ecosystem conservation. Materials were obtained by sampling in three different ecosystems including forest, rangeland and agricultural fields between 2018 and 2019. The specimens were cleared using either Nesbitt’s fluid or lactic acid and permanent microscopic slides were prepared using Hoyer’s medium. As the result of this study, twenty-nine species belonging to twenty-two genera and five families of the order Entomobryomorpha were identified. Among them, two genera and eight species are recorded for the first time from Iran. The new records are Desoria trispinata (MacGillivray, 1896), Drepanosira hussi Neuherz, 1976, Heteromurtrella sp., Orchesella flavescens (Bourlet, 1839), Willowsia bartkei Stach, 1965, Agrenia sp., and Isotomiella gracilimucronata Rusek, 1981. Micrographs of their important features and a key to the species are also provided.

---

View on Scopus
The focus of this study was to extend investigations on Collembola fauna in parts of Hyrcanian forests - Hezarjirib forests, located near Neka in Mazandaran province. For this, irregular samplings from leaf litter and soil in different localities were done during 2020–2021. The springtail specimens were extracted by Berlese funnel and after permanent slide mounting identified by relevant taxonomic keys. It resulted in the identification of 25 species belonging to eight families and 19 genera. Three species including Hypogastrura papillata Gisin, 1949 (Hypogastruridae), Lepidocyrtus bicoloris Mateos, 2012 (Entomobryidae) and Folsomia trisetata Jordana & Ardanaz, 1981 (Isotomidae) were recorded for the first time from Iran. Brief information for each species including the material studied, distribution and some illustrations of the new records are given.

---

View on Scopus

To expand study of Iranian Collembola fauna, the present study was conducted to investigate springtails fauna of different ecosystems such as forests, grasslands and gardens in the vicinity of Behshahr in the east of Mazandaran province, during 2020−2021. Several samples of soil and leaf litter were collected and specimens were extracted by Berlese funnel. Collected materials were identified by relevant taxonomic keys. The results indicated 29 species from 21 genera belonging to 10 families. Two species including Sminthurides inaequalis Börner, 1903 (Sminthurididae) and Hypogastrura neglecta Börner, 1901 (Hypogastruridae) were recorded for the first time from Iran. Despite numerous studies to identify Collembola fauna in Iran, many species are still unknown.

---

The study was conducted in oak forests and the conifer stands in Marivan county located in west of Kurdistan province. The leaf litter and soils samples from these forests were taken during 2016 to 2019 and specimens were extracted by the Berlese funnels. Results of the study led to identification of 39 species of 11 families. The three genera Doutnacia Rusek, 1974 (Tullbergiidae), Heterosminthurus Stach, 1955 (Bourletiellidae) and Calx Christiansen, 1958 (Entomobryidae) and eight species including Willemia virae Kapruś, 1997, Xenylla tullbergi Börner, 1903 (Hypogastruridae), Axenyllodes caecus (Gisin, 1952) (Odontellidae), Thalassaphorura franzi (Stach, 1946) (Onychiuridae), Doutnacia xerophila Rusek, 1974 (Tullbergiidae), Calx kailashi Mandal, 2018, Seira dori Gruia, Poliakov & Broza, 2000 (Entomobryidae) and Heterosminthurus insignis (Reuter, 1876) (Bourletiellidae) are new for Iranian fauna. All species from the present study are reported for the first time from Kurdistan province. Short explanation of each collected species including material examined, distribution and short description and illustration for the new records are given.

---

During samplings were performed during 2019 in Birjand area located in South Khorasan province, three species are identified from families Entomobryidae and Bourletiellidae. Drepanura tuxeni Nosek, 1964, Drepanosira gisini Nosek, 1964 and Cassagnaudiella c.f. gamae (Bretfeld, 1994) are newly reported for the Iranian fauna of Collembola. The material examined, brief description and some illustration were given. Cassagnaudiella c.f. gamae represents the second species record of the family Bourletiellidae from Iran.

---

The present study reports new records of the Collembola (Arthropoda: Hexapoda) from the Bula Hyrcanian forest located in Mazandaran province, north of Iran. The results show two genera Spatulosminthurus Betsch & Betsch-Pinot, 1984 (Sminthuridae) and Wankeliella Rusek, 1975 (Tullbergiidae) and five species including Anurophorus alpinus Potapov & Stebaeva, 1990 (Isotomidae), Pseudosinella cf. decipiens Denis, 1924 and P. immaculata (Lie Pettersen, 1896) (Entomobryidae), Superodontella tyverica Kaprus, 2009 (Odontellidae), and Wankeliella bescidica Smolis & Skarżyński, 2004 (Tullbergiidae) are new records for Collembola fauna of Iran.

---

The present study was conducted to investigate springtail fauna of different ecosystems in Savadkuh County, southeast of Mazandaran province, during 2021–2022. Results of the current study led to the identification of 26 species, which were determined as new records for Savadkuh Collembola fauna. Additionally, a new species of Isotomurus Börner of the family Isotomidae is described from northern Iran. The new species, Isotomurus matanicus sp. nov. belongs to a species-group characterized by 3,3,1 trichobothria on Abd. II–IV, 3+3 laterodistal setae on ventral tube, and no seta on mucro. The main differences between I. matanicus sp. nov. and the other species determined in this study are summarized. The list of collected species with the description of the new species is given and illustrated.

---

Ceratophysella Bӧrner, 1932 is the second largest genus of the family Hypogastruridae and contains 146 species from all over the world, with nine species reported from Iran. Specimens were extracted from soil and leaf litter samples using a modified Berlese funnel. The DNA sequences of the mitochondrial COI gene were obtained from the whole body of Ceratophysella specimens. A Maximum Likelihood tree is also generated based on the sequences of COI gene representing the overall phylogenetic affinities of the known Ceratophysella species. In the present study, C. communis (Folsom, 1897) and C. impedita Skarzynski, 2002 are recorded for the first time from Iran. Ceratophysella, communis is re-described, and its diagnostic characters are illustrated. An identification key to Ceratophysella species of Iran is given.

---

In this study a new approach for investigating the flutter speed of nonlinear aeroelastic systems is proposed. In this approach, the compatibility of nonlinear random vibration analysis based on the statistical properties of response is used and extended to the nonlinear aeroelastic systems to analyze the instability of these systems with using neither time domain analysis nor limit cycle oscillations. To this aim a 2-degree nonlinear airfoil with cubic torsional spring under quasi steady flow is considered as an aeroelastic system. At first, one random Gaussian white noise is added to the aerodynamic lift force then the statistical linearization and the random vibration analysis of the nonlinear systems are used to obtain a nonlinear map of response-variance with flow velocity as the control parameter. This nonlinear map leads to a nonlinear algebraic equation which consists of two parameters as the flow velocity and variance of the response. By solving this nonlinear equation for various flow velocities, the flutter speed is considered as the maximum of response-variance. Finally the jump phenomenon is also investigated where tangent bifurcation occurs.