Invasive crazy ants threaten Christmas Island Red Crab populations, but a certain species of wasp might be able to help.
Christmas Island, a remote Australian territory in the Indian Ocean, is known for an abundance of Red Crabs, a species once recorded in numbers nearing 44 million. The Red Crab has captured the hearts of naturalists and nature novices alike, due to the beauty and magnificence of their yearly mass migration from land to sea to lay their eggs in the ocean. However, in recent years, they have suffered a tremendous decline of roughly 40 million, according to recent population surveys. The cause? Invasive crazy ants, which are believed to have been introduced by a ship sometime during the early 20th century.
In this Q&A article we hear from three PhD students who have collectively spent over 11 years studying at the CABI Switzerland centre in Delémont working with scientists there to improve the monitoring and management of invasive species in Europe and Africa.
Find out from Judith Stahl, Benno Augustinus and Theo Linders about what they did, who they worked with and what’s in store after CABI.
Parthenium hysterophorus is a highly destructive weed which has invaded and is widespread in around 48 countries in Africa, Asia, and the South Pacific. In Pakistan the weed is spreading rapidly westwards and southwards across both rural and urban landscapes, affecting native ecology and harming agriculture.
The start of 2019 brought sad news when George, the last tree snail of his kind (Achatinella apexfulva) died on New Years Day. His death highlights the plight of Hawaiian snails and epitomises the rapid decline of biodiversity on the Hawaiian Islands.
For many, December means celebrating Christmas and a central part of that is a Christmas tree. Evergreen trees have been used in celebration for centuries. The ancient Egyptians, Chinese, and Hebrews used evergreen trees, wreaths, and garlands to symbolize eternal life. Pagans worshiped trees, and Romans used evergreen wreaths during the festival of Saturnalia.
The trees commonly used as Christmas decorations come from the genus Picea which is made up of around 35 species of coniferous evergreen trees in the family Picaceae. Popular Christmas tree species include Balsam Fir, Douglas Fir, and Norway Spruce.
The modern-day Christmas tree is thought to have started in 16th century Germany when Christians brought decorated trees into their homes. The Christmas traditions we know today were shaped by the Victorians, when the first Christmas tree was brought from Germany to the British royal household by Prince Albert in the 1840s. These days, around 7 million real trees are sold each year in the UK, and as many as 30 million in the USA.
In eastern North America a species of weed has become an aggressive invader. Garlic mustard (Alliaria petiolata) is one of the most rapidly increasing woodland invasive plant species, spreading across northeastern and midwestern USA and southeastern Canada ata rate of nearly 2,500 square miles per year.
The plant was most likely introduced to North America in the 19th century, taken from its native habitat of Eurasia by settlers for medicinal and culinary use. Although the crushed leaves and seeds of garlic mustard smell like cultivated garlic and have been used as flavouring in cooking for centuries, the plant actually belongs to the cabbage family.