The False Black Widow is one species that has been accidentally imported into the United Kingdom. It is native to the south west Mediterranean, including Spain, Portugal and the Canary Islands.
Although related to the Black Widow, it is a less venomous spider. It is not a particularly aggressive spider, but it can bite. The venom can cause illness in children. In adults, although bites cause discomfort, there are no records of serious symptoms. This species is capable of adapting to the British climate and there are reports of it becoming established along the south coast and in Essex.
The female False Black Widow is of similar appearance to the Black widow, a relatively small spider, the female body length being 10-15mm, the male only 3-6mm. The false Black Widow are shiny black and globular like the Black Widow, but they lack the characteristic red double triangle or ‘hourglass’ marking. The abdomen of the immature female has pale chevron markings on the dorsal surface and a white band around the anterior, but these diminish with each moult until the adult abdomen is black except for the band, now turned red.
The most common species of Flea is the Cat Flea, known for readily biting humans. The Bird Flea are next in importance, followed by the rare Dog Fleas, although other species may
become temporarily attached to dogs. Finally Human Fleas which are extremely rare.
Adult fleas are small (averages 2mm in size) wingless insects, with flattened and red-brown, with backwardly directed spines and legs designed for jumping.
All adult Fleas are parasitic on warm-blooded animals. The females lay their eggs after feeding on the infested animal. Female Fleas can live up to two years, during which time they can lay up to 1000 eggs. The eggs drop onto the fl oor and the animal’s bedding. After several days the eggs will develop into larvae. When fully grown the larvae spin well camoufl aged silken cocoons. When fully developed the adult waits within this until it detects the vibrations caused by a potential host. Only then does it emerge. Th e complete lifecycle takes about a month in the summer.
Mainly active in communal rooms where pets sleep and where there is most activity. Fleas are generally found to be living on pets, in carpets, pet bedding and upholstered furniture.
Adult Fleas feed on the blood of humans and animals. The larval stages live in the nest of the host and feed on skin, feathers and, most importantly, the blood-rich faeces of the adult flea.