Hogweed is non-toxic.

Hogweed is a perennial vine with woody or semi-woody stems that climb trees or grow along the ground. The leaves are generally long oval with a caged vine at the end to facilitate climbing. At the end of the cage vines a bottle or funnel shaped trap cage with a lid is formed.

The hogweed grows for many years before flowering, the flowers are usually in racemes, a few panicles, dioecious, small and bland flowers, daytime flavor is light, slightly fragrant; at night the flavor is strong, turn smelly. Its ornamental qualities cannot be compared with those of the trap cage. The fruit is a capsule, which opens at maturity and disperses the seeds.

Expanded information:

The effect of the hogweed trapping mosquitoes:

Frogs are the natural enemy of mosquitoes, and the hogweed will emit aroma in the mouth of the cage to attract mosquitoes. Once the mosquitoes fall into the bottom of the cage, they will be drowned by the liquid in the cage and die, and slowly be "digested and absorbed" by the hogweed. In fact, frogs (or tadpoles) are not to mosquitoes (or their larvae tsetse) as the main food, and placed in the home water tank instead of mosquitoes will provide a place to lay eggs.

And hogweed's staple food is ants and other sugar-loving bugs, which are too inefficient at catching mosquitoes. Home planting of hogweed can at best trap some male mosquitoes that feed on plant sap, and is ineffective against blood-sucking female mosquitoes.

Baidu Encyclopedia - Hogweed (plant)

People's Daily Online - 10 Least Reliable Summer Mosquito Repellent Methods