Biodiversity Fact File: Greater Butterfly-Orchid and Lesser Mottled Grasshopper

Monday 6th February 2017

Greater Butterfly-orchid © Philip Precey

Our Island has a brilliant array of biodiversity and the Manx Wildlife Trust works hard to protect it for future generations to enjoy.

Our biodiversity fact files aim to bring often lesser-known but threatened species to our attention and explain the incredible lives that they lead.

Greater Butterfly Orchid

The Greater Butterfly-orchid (Platanthera chlorantha) is a beautiful flower, which may be found on some of the Trust’s nature reserves. They are 25 to 60cm tall and the flowers which are on spikes can be white/yellow to a greenish colour with an elegant long curved bottom part called a spur. (Which are actually nectar filled tubes). The floral spikes can have as many as 40 flowers on them, quite a sight.

These flowers have a beautiful vanilla like scent, best smelt in the evening or at night. Greater butterfly orchids have a pair of broad leaves at the base of the plant (basal leaves) and smaller narrower leaves along the stem. Located in hay meadows and grasslands, it flowers from June to July.

Darwin made a study of this flower and proposed that because they were scented at night and with their white colour could show up in the dark, that they would be pollinated by moths. Plus with such a long spur to this flower (28mm in length) it would require a moth with a very long tongue! He went on to prove this by realising any moth that visited this flower would also probably have pollen stuck to its eyes! By catching moths at sites containing these orchids he found that indeed this orchid is pollinated by equally beautiful moths such as the Silver Y, Gold Spangles and Burnished Brass, all with long proboscis and pollen stuck to their eyes! Quite a bit of detective work!

Lesser Mottled Grasshopper

The Lesser Mottled Grasshopper (Stenobothrus stigmaticus) is a much over looked species, only found on the Isle of Man and not in the UK at all, and it is found solely in Langness. It holds the title of being the British Isles smallest and rarest grasshopper. It is a green grasshopper with brownish wing, but it’s most identifiable difference, is a tooth on each side of the ovipositor of the female. Ovipositors are long probe like appendages on the end of grasshopper’s abdomens which are pushed into soil to create a hole in which to lay their eggs. Grasshopper eggs hatch into nymphs which look like miniatures of the adults but without wings. These nymphs will shed their skins several times as they grow into adults.

Lesser mottled grasshoppers tend to prefer the coastal grass area of the peninsula, and are quite tolerant of the saline sea spray in the area. It is very curious that this grasshopper is usually found in Northern France and Iberian countries, so why it can be found here is a bit of an enigma. Are they the remnants of a population when times were warmer, or have they come in on exotic plants? The mystery is unsolved despite being subject to a study about them in 1994! You can see a picture of the grasshopper here.

Tagged with: Biodiversity, Flowers, Grasshopper, Greater Butterfly Orchid, Lesser Mottled Grasshopper