A venomous black widow spider sits in a specimen dish after being discovered on a vessel originating from Hawaii on July 15, 2025 at the Jose D. Leon Guerrero Commercial Port. (Guam Customs and Quarantine Agency)
BARRIGADA, Guam – Officers with the Guam Customs and Quarantine Agency’s (CQA) Biosecurity Task Force (BSTF) responded to an alert from Port Authority of Guam personnel of potentially harmful spiders among cargo originating from Hawaii on July 15 at the Jose D. Leon Guerrero Commercial Port.
BSTF officers initiated a physical inspection of the flat rack the spiders were discovered on, as well as the shipping vessel carrying it.
As a result, officers confirmed the presence of two kinds of live spiders - one species that appeared brown in color, and another that appeared to be a venomous black widow spider.
The officers collected specimens of the spiders, which were referred to Guam State Entomologist Christopher Rosario with the Guam Department of Agriculture (DOAG) and University of Guam Extension Entomologist and Assistant Professor of Entomology Alfred Daniel Johnson, Ph.D.
Rosario confirmed one specimen to indeed be a black widow spider, while the other specimen was forwarded to Johnson, who determined it to be an Argiope or Neoscona juvenile spider of the Araneidae family.
(Guam Customs and Quarantine Agency)
“While the spiders were found on open flat racks, unlike fully enclosed shipping containers, flat racks give less protection against invasive species, which can contaminate other containers incoming and transshipping through Guam,” said Rosario.
With concurrence from Rosario, BSTF officers successfully treated the areas where the spiders were found.
The vessel was cleared with no further action required.
“This type of coordinated response reflects the strong value of our continued collaboration with the Guam Department of Agriculture, the Port Authority of Guam, all partners in environmental protection, and the effective execution of established response protocols. Through such efforts, we enhance Guam’s operational readiness and biosecurity posture, helping to prevent the entry of detrimental and injurious species that pose risks to our island’s resilience and security,” said CQA Director Ike Peredo.