A particularly nasty wasp

There are several wasp species across the world that have a life cycle that involves them becoming parasites of other creatures. One of these is a Costa Rican wasp (Hymenoepimecis argyraphaga) that targets a particularly formidable spider (Plesiometa argyra).

The spider is large and fearsome, and therefore avoided by just about every other insect apart from females of the wasp. It hovers above the spider then lands directly on its back, where it lays a single egg before making its escape.

The spider is not affected by this visit at first, but in time the egg absorbs nutrients from the host and the larva that hatches from it injects the spider with a chemical that makes it act in ways that it would not otherwise have done.

The night before the larva is ready to pupate, the spider destroys its web, which is not unusual given that many spiders do so as part of their regular behaviour. However, when a new web is spun, it is very different from what went before because its purpose is entirely to benefit the wasp and not the spider.

This web is hardly a web at all, because it consists of strands of strong silk that provide an anchor to nearby plants. When finished, the spider hangs beneath this framework and never moves again.

The wasp larva then eats the spider, and by dawn it is ready to weave its own cocoon which hangs inside the rough web made by the spider. It will then take its time in transforming into an adult wasp, protected inside its cocoon which in turn is safe from ants and the effects of heavy rain thanks to the strong threads that the wasp forced the spider to weave.

Nature has managed to produce some amazingly unpleasant creatures!

© John Welford

Nautilus

The nautilus (Nautilus pompilius) is a remarkable creature that is regarded as a “living fossil” because it closely resembles animals that lived in the oceans between 400 and 65 million years ago. Six species of nautilus have survived to the present day, with that in the photo living in the western Pacific Ocean and in open waters around Indonesia and southeast Asia. It is found at depths up to 500 metres (1,650 feet).

The shell protects the nautilus from predators and buoyancy is provided by gas trapped in the inner chambers. It swims by using jet propulsion – water is taken into the shell cavity and expelled through a tube which can be directed to propel the nautilus in the required direction.

The head sticks out of the shell and has up to 90 tentacles that are used to trap prey that includes shrimps. The eyes of the nautilus are very primitive, being without lenses and working like pinhole cameras.

The nautilus only becomes sexually mature after about ten years, and then produces as few as twelve eggs per year. Having survived for so long, the species has clearly found an environmental niche that presents few dangers and allows for a slow rate of reproduction.

© John Welford

Box jellyfish

You would not want to get too close to a box jellyfish (Chironex fleckeri). It is thought to be one of the most venomous creatures to exist in the oceans and it can kill a person in only a few minutes. 

Fortunately for most of us, it is mainly confined to waters to the north of Australia and eastern Indonesia, but it is plentiful enough at certain times of the year (November to April in northern Australia) to make it necessary to close beaches to the public. 

It is only a small creature – up to 25 cms (10 inches) in size – but its tentacles can extend up to three metres (10 feet) in length. It is possible to be stung without even seeing the jellyfish itself. Its prey is prawns and small fish that swim in shallow water. 

The name comes from the box-shaped transparent body, from each corner of which hangs a bunch of 15 tentacles. The flattened sides of the box contain sense organs that include remarkably complex eyes. 

Should a swimmer be unfortunate enough to be stung, and not be able to get hold of antivenom, the least he or she can expect is excruciating pain and skin damage that can leave permanent scars. Heart failure is entirely possible, as is drowning following loss of consciousness. 

Despite the extreme dangers presented by contact with this animal, some sea turtles are able to eat box jellyfish without suffering any harm.

© John Welford

Wild liquorice

Wild liquorice (Astragalus glycyphyllos) has the alternative name of milk-vetch, from the former commonly held belief that goats that ate the plant would yield more milk.

It grows in scattered location in Great Britain, in rough grassy places on chalk and limestone, but is absent from Ireland. It is a temperate plant that is also found across much of northern and central Europe as far east as the Caucasus.

Wild liquorice is difficult to spot because it often grows among tall grasses and its greenish-cream flowers blend with the colour of its foliage. 

It is a straggling plant that can grow up to 40 inches (100 cm) in height. It has smooth, trailing stems and many hairless leaflets. The stems bend each time they give rise to a leaf, which makes them zigzag. 

The plant flowers in July and August, many flowers being carried on stalks that are shorter than the leaves. The pods are smooth and curved, with a central division such that several seeds are produced on each side of the “wall”.

Wild liquorice is not the plant from which laxatives and food flavourings are produced. However, the root stems of both wild and true liquorice can be chewed – the botanical name glycyphyllos means “sweet stem”.

© John Welford

Water monitor lizard

The water monitor is one of the largest lizards that ventures into salt water. It inhabits low-lying coasts, rivers and estuaries in south-east Asia, Indonesia and The Philippines.

It grows up to 2.7 metres (9 feet) in length and weighs up to 35 kg (75 lbs). It has a long neck, strong legs and a flattened tail that it lashes from side to side in the water.

The water monitor is a predator with a wide-ranging diet, feeding on anything that it can overpower, either onshore or in the water. In common with other monitors, the water monitor will also feed on carrion.

Water monitors are sometimes seen near human habitations, where they scavenge on discarded food waste.

The water monitor lays eggs which the female places at the end of a burrow.

© John Welford

Blackfin icefish

The blackfin icefish is a remarkable creature that is able to live in the coldest waters to be found on Planet Earth. It inhabits the coastal seas on the Atlantic side of Antarctica, where the temperature can fall to -2°C (28°F). It is found at depths of up to 770 metres (2,500 feet) below the surface.

These conditions would freeze the blood of most fish, but the blackfin icefish has its own natural antifreeze. It appears to be ghostly white, which is due to not having any red blood cells. This makes the blood thin enough to flow in very cold temperatures.

The blackfin icefish grows to 72 cms (28 inches) in length and weighs up to 3.5 kg (7.5 lbs). 

It is a sluggish swimmer that needs little oxygen. Its food consists of krill and small fish.

© John Welford

Sainfoin

Sainfoin (Onobrychis viciifolia) is often seen on chalk and limestone grassland in southern England, although it is almost certainly not a native plant, having been introduced from central Europe where it was traditionally used as fodder for cattle. The name comes from French – “sain” meaning “wholesome” and “foin” meaning “hay”. It has also been thought that a mythical Saint Foyne might have been responsible for the name.

Sainfoin was mentioned by Nicholas Culpeper, the 17^th-century herbalist, as an aid for nursing mothers, based on the plant’s supposed effect on increasing the milk yield of cows. 

Another former medical use for sainfoin was to treat “stranguary” – a painful bladder disease. The leaves were sometimes used as a poultice for reducing boils or they could induce sweating if pulped and mixed with oil.

Sainfoin is an upright, often branched, plant, growing to a height of up to 32 inches (80 cms). The leaves consist of 6-14 pairs of leaflets with a terminal leaflet. 

The flowers appear from June to August. They are bright pink or red, often with purplish veins, carried in conical spikes. Sainfoin is sometimes called “cock’s comb” or “cock’s head”, which refers to the plant’s spiny toothed seed pods. Each pod contains a single seed and it does not split open.

© John Welford