Nigma

Lehtinen, 1967

Nigma is a of araneomorph in the Dictynidae, established by Pekka T. Lehtinen in 1967. The genus contains approximately fourteen distributed across Eurasia, North America, and Northern Africa. Members are generally small, with N. walckenaeri being among the largest in the family at up to 5 mm body length. The genus is part of the marronoid spider group, which has been subject to recent phylogenetic revision using genetic data from museum specimens.

Nigma by no rights reserved, uploaded by Claire Elliott. Used under a CC0 license.

Nigma by (c) Alexis Tinker-Tsavalas, some rights reserved (CC BY), uploaded by Alexis Tinker-Tsavalas. Used under a CC-BY license.

Nigma by no rights reserved, uploaded by Federico Del Barba. Used under a CC0 license.

Pronunciation

How to pronounce Nigma: /ˈniɡ.ma/

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Identification

Distinguished from other dictynid by translucent green coloration combined with structures. N. walckenaeri identifiable by larger size (up to 5 mm) within . -level identification requires examination of and geographic location. Similar green-colored in other families lack cribellate silk.

Images

Appearance

Translucent green body coloration, sometimes with red or black abdominal markings. N. walckenaeri reaches up to 5 mm in length, making it one of the largest dictynid . shape shows subtle in at least some . -producing structures present.

Habitat

Found on upper surfaces of leaves, particularly of ornamental and agricultural trees such as Ficus nitida and Dalbergia sissoo. Constructs webs in urban and agricultural settings. Specific microhabitat preferences vary by ; some occupy riverine environments separated by natural barriers.

Distribution

Eurasia, North America, and Northern Africa. Documented from Europe (including Portugal, Spain, France), Caucasus, Iran, Turkey, North Africa (Egypt, Algeria, Senegal), East Africa, India, China, and USA. Riverine in Egypt (Sohag Governorate) occur on opposite banks of the Nile River.

Host Associations

Ficus nitida - Ornamental tree; web construction on leaves
Dalbergia sissoo - Agricultural tree; web construction on leaves

Behavior

Constructs irregular, finely meshed webs on upper leaf surfaces. One leaf may hold one to several individuals. Females and males do not occupy the same leaf simultaneously. Web architecture distinctive within .

Ecological Role

of small ; potential agent for agricultural pests. Preys on pest insects in ornamental and agricultural tree .

Human Relevance

Subject of geometric morphometric studies examining shape variation and . Used in demographic studies under laboratory conditions. Featured in phylogenetic studies of marronoid evolution utilizing museum specimens.

Similar Taxa

Other Dictynidae generaNigma distinguished by translucent green coloration; most dictynids lack this coloration
Green-colored spiders in other families (e.g., some Araneidae, Thomisidae)Nigma has structures absent in these ; web architecture also differs

More Details

Phylogenetic significance

Nigma is part of the marronoid group, which has undergone recent taxonomic revision using genetic data from museum specimens, clarifying previously uncertain evolutionary relationships

Sexual dimorphism

Geometric morphometric studies of N. conducens demonstrate significant but subtle in shape, likely due to or adaptive divergence to different microhabitats