The Mediterranean widow spider, or "Dolmak," Latrodectus tredecimguttatus (Rossi, 1790), family Theridiidae, is one of the medically significant spiders. Also, it is listed as a dangerous animal due to its extensive geographic range and its deadly or seriously problematic toxic bites. A holistic understanding of L. tredecimguttatus requires combining knowledge derived from both morphological and molecular investigations. Thus, this study aimed to offer researchers a framework for investigating these essential species and to educate farms and visitors about the importance of avoiding any behaviour that could antagonize the spiders. For this study, specimens of L. tredecimguttatus were manually collected randomly from some olive orchards between September 2023 and August 2024 at Sadat City, Menoufia Governorate, Egypt. The morphological parameters utilized for identification were the total body length, carapace width, abdomen length, and (1st,3rd, and 4th legs) length. Results indicated that the total length of females ranged from 8.92 to 10.15mm. The female dorsal pattern if present; consists of several orange spots (usually in young females). Adult females lack the dorsal pattern and ventral hourglass reduced to two transverse oranges to red Markings. The results of the mitochondrial CO1 gene confirm that our tested species identified as Latrodectus tredecimguttatus under the accession number (PQ358290.1) in GenBank for the first time in Menoufia Governorate, Egypt. So, the identification of a female Black Widow according to morphological and molecular genetic methods is of great importance.

Abstract: Heat-stress resilience is vital for poultry in tropical/subtropical regions where
high temperatures impair productivity. Ake chickens, as the only naked-neck chicken breed
in China, exhibit robust resistance to heat stress, but this breed lacks clarity in its genetic
origins. This study utilized the next-generation sequencing data from 22 chicken breeds
to conduct phylogenetic and population analyses. Gene flow analysis revealed a gene
migration event from Iranian naked-neck chickens and Indian local breeds to Ake chickens,
and population separation estimates suggested that the naked-neck gene was introduced to
China around 500–600 years ago. NJ-tree, PCA, and population structure analyses showed
that Ake chickens cluster with Yunnan native breeds, which diverged only 100–200 years
ago. A selective sweep in the candidate region on chromosome 3 (97.0–97.37 Mb) showed
elevated genetic differentiation (FST) and educed nucleotide diversity (π) compared to
the genome-wide average, indicating rapid fixation of the trait under natural/artificial
selection. Demographic reconstruction indicated that the current effective size of Ake
chickens is stable at 2000–3000 individuals. These findings deepen our understanding of
Ake chicken evolution and provide valuable insights for conservation and the development
of heat-stress-resistant poultry breeds.