The main purpose of this catalogue was to improve our knowledge of the Lepidoptera fauna of Iran and acquire a better knowledge of the patterns of distribution of this large insect order within the country. These patterns not only show the large-scale structure of the faunal elements of this order in Iran, but also highlight research gaps and and other needs in Iranian lepidopterology, which should be addressed before we lose more habitats and species.

This chapter addresses questions such as: How many lepidopteran species are reported from Iran? How many of them are truly present in Iran? I.e., how many need further confirmation and how many have been erroneously reported? How many of the reported species are regarded as synonyms today? How are they systematically distributed (e.g., how many species are known per family)? How are they geographically distributed, both horizontally and vertically? Which taxonomic groups are especially in need of additional sampling efforts and taxonomic revisions? Finally, how many are endemic to Iran?

Fig. 1.

Summary of the statuses in Iran of the lepidopteran species listed in this catalogue.

Species diversity

In total, 6,191 species-level names are listed in this catalogue as reported from Iran in the literature or for the first time in the present catalogue. Of these, 1,262 are regarded as junior synonyms and 117 as erroneously reported, although 24 are considered likely to occur in the country (see Appendix 1). Of the 4,812 remaining valid species, 4,517 are regarded as definitely resident in Iran, whereas 295 need further confirmation [see Fig. 1 and notes in Rajaei et al. (2023)].

In total, we list 892 endemic species for Iran, corresponding to an endemicity rate of 19.7% (Appendix 2). As can be observed in Fig. 2, over 70% of the endemic species have been collected at altitudes between 1,000 and 3,000 m. Isolation, by reducing gene flow, is an important driver of speciation, and higher per-species speciation rates caused by increasing isolation with elevation are assumed to be one of the most plausible explanations for the globally consistent pattern of higher endemism at higher elevations (Steinbauer et al. 2016). Phylogenetic evidence indicates that many high-elevation endemics across the globe are phylogenetically young taxa resulting from recent rapid diversification, e.g., in the New Zealand Alps (Winkworth et al. 2005), the Andes (Hutter et al. 2013) and East Malaysia (Merckx et al. 2015). These localized areas (i.e., type localities) can be used as a reference for future conservation initiatives.

Fig. 2.

Elevational diversity gradients of the endemic Lepidoptera species of Iran. In (b), each dot represents a species record.

Fig. 3.

Number of known Lepidoptera species per family in Iran.

Distribution of species within families

As can be observed in Appendix 1, some families are more species-rich than others. However, this pattern could simply be an artefact due to some taxonomic groups being less studied (e.g., the microlepidopteran families) when compared to other parts of the world (e.g., Europe or North America). In contrast, some families (e.g., Zygaenidae, Cossidae and nearly all Papilionoidea) are much better known. Fig. 3 shows the number of species per family in Iran.

Fig. 4.

Data on Iranian Lepidoptera, subdivided by province. a. Map showing number of recorded species per province. b. Map showing number of type localities per province. c. Bar chart showing number of recorded species per province.

Horizontal and vertical distribution of Lepidoptera species in Iran

Not only have some lepidopteran lineages been incompletely studied in Iran (e.g., most microlepidopteran families), but some provinces have been insufficiently explored overall. The number of recorded species per province is shown in Appendix 3 and Fig. 4, where it is clear that several provinces (e.g., Ilam and Khorasan-e Jonubi) have been largely neglected in past taxonomic surveys. Of note, the Ilam province is located in a transitional zone between the Zagros Mts. and the desert plains of Iraq, and potentially contains a rich Lepidoptera fauna. Some other provinces (e.g., Ardabil and Khorasan-e Shomali), although much better studied, show a low number of type localities (Fig. 4b), which could be explained by intensive taxonomic studies on the other side of the national borders of Iran, e.g., in the Kopet-Dagh Mts. (Turkmenistan) and Azerbaijan Mts. (Azerbaijan).

Most lepidopterous larvae feed on living plants, many of them on a single plant species (monophagous) or a few related species (oligophagous), and their distribution is therefore dependent on the distribution of their host plants. Areas with a high diversity of plants have, in most cases, a correlatively high diversity of Lepidoptera. In some families of Lepidoptera (e.g., Gracillariidae, Tortricidae and Geometridae), the larvae of a majority of species feed on the leaves of deciduous trees. These families are thus most diverse in forested areas such as mountains and north-facing hills. The larvae of many species of Gelechiidae, Pyralidae and Noctuidae feed on low plants, often in dry areas, and these families are most diverse in steppes and semi-deserts.

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