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Scuba Flies

Mono Lake in California is a fascinating place, chemically. It sits in a dry basin, with the huge Sierra Nevada Mountains to the west. Runoff and snowmelt from the mountains feeds into Mono Lake, but right now there is no water that flows out. Over time, the lake has become salty – several times as salty as the ocean – and its pH has also gone up, making it alkaline. These flies have developed a fascinating way to live in this water. Insects are small enough for surface tension on water to be a major threat to them. If a water droplet wet a fly, it wouldn’t be able to lift itself. Most insects including regular flies protect themselves by having a combination of small fibers and oils, which separate the insect from raindrops and keep them alive. However, Mono Lake’s high pH, salty environment fights against this defense. The chemistry of the water breaks down insects’ natural defenses against water, so few insects live in this environment…except for this one fly.

Scientists from Caltech observed these flies as they dove beneath water using high-speed cameras and found that this species of fly has an extra-dense coating of fibers around its body. When this fly dives, a little bit of air gets stuck in those fibers, and that air can’t get out – it literally forms a bubble around the fly. These flies are able to dive into the harsh environment of Mono Lake, surrounded by these bubbles, and then re-emerge into the air fully dry. Insects that don’t have this extra protection can’t go into this lake water, so this adaptation allows this species of fly free reign over any food supplies in this lake water.

The scientists also tested treating the flies with a chemical that did dissolve the wax they form on the fibers; when that happened the flies were suddenly unable to enter the water in the same way. So, most insects use a combination of fibers and a waxy surface to protect themselves from water; these flies add in an air bubble. They’re literally scuba flies.

-JBB

Image credit: https://bit.ly/2HqCp72

Reference: https://magazine.caltech.edu/…/greasy-hairy-scuba-diving-fl… https://www.youtube.com/watch?v=Qt_0DxOLbQU

Family of lions with Giraffe kill

The sweet scent of rotting corpse

While these flowers from the genus Rafflesia (named after Sir Stamford Raffles, founder of Singapore and leader of the expedition in Indonesia that found the first species in 1818) are beautiful, you don't want to bring your nose too close since they imitate the smell of old dead meat in order to attract flies to transfer pollen between flowers. There are 28 species in the genus, some of which are amongst the world's largest flowers at over a metre across and 10kg in weight. They are parasitic, meaning that they suck their nourishment out of another life form while conferring no benefit in return. They have no stem, root or leaves, living off the life force of vines, infiltrating them with their tissue with only the flower sticking out of the vine to signal its presence.

They are so parasitic that they have even lost the gene to make chlorophyll (the only land plant known to have done so), meaning that they cannot photosynthesize their own sugars like other plants. The local names in South East Asia are all variants on corpse or meat flower, and it is the state flower of Indonesia and of Sabah in Malaysia and Surat Thani in Thailand.

Loz

Image credit: 1 ma_suska 2: Klaus Polak 3: 80cm flower, Steve Cornish http://www.rafflesiaflower.com/ http://www.arkive.org/rafflesia/rafflesia-spp/ http://bit.ly/1LVFtlY http://bit.ly/1LVFtlY

Surreal Fungoid (from Yith?)

Known to scientists as Clathrus ruber, this smelly mushroom is a member of the stinkhorn family, who imitate rotting corpses to attract spore dispersing flies. It lives on rotting wood or in soil throughout southern Europe, though its range is slowly shifting northwards as the world warms. They grow up to 15cm tall and are called latticed or basket stinkhonrs in old English parlance.

Loz

Image credit: Patricia Woods

http://bit.ly/1Nj9NM4

Chocolate and Midges

The flowering Theobroma cacao tree relies on pollinators to reproduce, and successful fertilization creates the fruit that yields the cocoa beans so many of us love to eat, with lots of sugar and fat mixed in, as chocolate. We tend to think of bees when we think of pollinators, but for feeding our chocolate addictions, we have to thank midges – insects about the size of a pinhead. They belong to a family of small biting flies called Ceratopogonidae.

Theobroma (which translates to “food of the gods”) cacao is a small tropical tree that likes to grow in the shade of taller trees. Once it reaches maturity, the tree continuously produces small pink or white flowers only 1 – 2 centimeters in diameter along the trunk and lower branches. Due to their small size and relatively complicated structure, midges are the only insect which can navigate the flowers and reach the pollen.

Only about 5% of cacao flowers are pollinated. The ones that are will become cacao pods – the oval fruit of the cacao tree. If the pod fully matures over 5 to 8 months, it will eventually contain about 20 to 60 seeds – the cocoa beans. The seeds cannot be released from the pods without human or animal assistance. In the rainforest, monkey, birds, and other animals will open the pod, eat the sweet white pulp of the pod, and spit out the bitter seeds.

The popularity of chocolate has lead to the creation of large cacao tree plantations, often by clearing the rainforest. This puts the trees in the sun, but midges prefer shade. They like decaying plant material on the humid forest floor for habitat and reproducing. This has led to fewer midges on plantations and pollination rates well below the 5% expected.

Some farmers have learned to farm within the forest to ensure the midges find their trees while also keeping the rainforest relatively intact. On existing plantations, scientists have recommended spreading recently cut banana leaves on the soil to provide habitat for the midges. This alone has helped increase pollination by 15%, but it’s still below normal pollination rates. Perhaps that’s because cacao flowers normally produce 75 different aroma ingredients to attract midges, but on plantations, the flowers only produce a few of those.

Ultimately, if farmers are going to keep feeding our chocolate addiction, they may have to move their farms back into the rainforest. Quite simply, if the midges aren’t happy, we don’t get chocolate.

Photo Credit: Tree: Luisovalles - http://bit.ly/1fhzVbH Flower: Domste - http://bit.ly/1GPcPna Chocolates: Klaus Höpfner - http://bit.ly/1N37sSe

References: http://bit.ly/1GZhZyS http://1.usa.gov/1Liej9d http://bit.ly/1CdVf6T http://bit.ly/1LfHKfi

Crickets Falling Silent It’s not unusual to see evolutionary change in response to threats to an animal. The crickets on the islands of Kauai and Oahu, in the Hawaiian archipelago, have begun to fall silent. Normally, crickets rub their wings together to produce their distinctive ‘chirping’ noise. This is used to attract mates, but it also attracts predatory flies. These flies track down the chirping crickets and use them as hosts for their larvae, leaving the unfortunate cricket to be eaten alive by the growing maggots. In order to avoid this gruesome fate, some crickets have developed modified wings. Known as “flatwing” males, these crickets are mute. As such, they can effectively hide from the threat of the flies. The cost of this, though, is that they can no longer chirp to attract females themselves. The innovative solution to this is for the “flatwing” males to simply hang around those males that are still capable of chirping. The flatwings will then attempt to intercept those females that are drawn to the song. This adaptation has proven wildly successful, with over 90% of the crickets on Kauai now no longer capable of chirping. This drastic change began appearing in 2003, the adaptations occurring as a response to the predatory flies arrival on the island from the mainland of the United States. When the same adaptation was found in crickets two years later on the island of Oahu, some 100km from Kauai, it was assumed that the Kauai crickets had hitchhiked there with a little help from humans. Dr. Nathan Bailey, a member of the group that have led the most recent study on the phenomenon, noted that "An egg laid by a female in some soil could hitch-hike on someone's boot". However, a recent study throws doubt on that idea. The team noticed that the wing shapes of the flatwing crickets on the two islands were different, hinting that something unusual was happening. When they ran genetic analysis, they discovered that the flatwing mutation had, apparently, developed twice. The flatwing mutation was confirmed to be due to a mutation on a single gene of the X chromosome, and a multitude of other genetic markers were used to demonstrate the two distinct groups. It was this that finally convinced the team that the mutation had managed to develop in two isolated cases. "Up until my post-doc Sonia showed me the diagram of nearly non-overlapping genetic markers from each island...” Dr. Bailey explained, “I was unconvinced either way about what we were dealing with". This is not the first time the same trait has appeared convergently in two different groups. The projectile tongue of certain salamanders have evolved in isolated populations on more than one occasion. This particular case, however, is notable for the rapidity with which the adaptation occurred. In Dr. Bailey’s own words, "This is an exciting opportunity to detect genomic evolution in real time in a wild system, which has usually been quite a challenge, owing to the long timescales over which evolution acts." - Dale Read More - http://www.bbc.co.uk/news/science-environment-27592656 http://www.cell.com/current-biology/abstract/S0960-9822%2814%2900524-7 http://www.sciencedaily.com/articles/c/convergent_evolution.htm Image Credit – http://bishopmuseum.org/

That last post where I shared video of a swarm of mayflies so big it appeared on radar? The Weather Service shared some photos of what it looked like on the ground.

More here.