Tag: predators

Desert Skimmer

On By Bernadette SimpsonIn Arthropods2 Comments

Widespread in Africa and the Middle East, the Desert Skimmer (Orthetrum ransonnetii) is mostly found in hot, arid, rocky environments, like Sinai’s desert mountain region.

These dragonflies have almost completely black venation and completely transparent wings. (There is no amber color on the hind wings like in other species.) The males are blue, with an unwaisted body, and females are brown.

Because their larvae and nymphs are aquatic, Desert Skimmers are common at small flowing and standing pools of water, and particularly areas without a lot of vegetation.

Desert Skimmers are known to hang from vertical or sub-vertical rocks and walls. And if the weather is hot, they especially like to hang in shaded places.

Dragonflies are carnivorous, predatory insects, hunting on the wing for other flying insects, including mosquitoes, flies, butterflies and moths, and even smaller dragonflies. Their acute eyesight and strong, agile flight help make them some of the world’s most efficient hunters. Dragonflies catch up to 95% of the prey they pursue. And that’s good, because a dragonfly eats up to 1/5 of its weight every day.

Bedouin in Sinai, at least of the Jebeleya tribe, call a dragonfly a ghizlan غِزْلان

What do you call them in your native language?

Be sure to read the post about the Violet Dropwing where you can learn more about dragonflies’ amazing wings!

Camel Spider

On By Bernadette SimpsonIn Arthropods3 Comments

Camel spiders, sun spiders, barrel spiders, wind scorpions – all of these common names for Galeodes arabs are misleading as these fascinating critters are neither spiders nor scorpions but rather solpugids, a group of arachnids in the order Solifugae. More appropriately, they are also commonly known as Egyptian Giant Solpugids.

You may have heard of them; camel spiders have been the subject of many urban legends about their size, speed, and appetite. Despite knowing that they posed no threat to me – they are not venomous but can inflict a painful bite – seeing my first one last weekend in Wadi Kid still kind of creeped me out, partly because it was as big as my hand!

Camel spiders can grow up to 15 cm long. They have eight legs, as do most arachnids, plus two large pedipalps, or sensory appendages, in the front that look like legs. (The one I spotted was missing its front right leg.) These pedipalps have a “friction-based adhesive quality” that allows the them to grasp their prey and climb smooth surfaces.1 Camel spiders have one pair of small eyes on the top of their heads and, with their eight legs, can move quite quickly – up to 16 kph!

These solpugids are voracious predators and eat insects, rodents, lizards, and even small birds. Their favorite prey are grasshoppers though. Camel spiders have two powerful chelicerae, or jaws, that they use to chop or saw their prey into a pulp. They begin by partially severing the neck, using one pair of chelicerae to hold the prey and the other to cut. Alternating the movements quickly between the two pairs of chelicerae, they continue along the whole body. At the same time, they use regurgitated digestive fluids to liquefy the flesh and suck up the nutrients. (And if this doesn’t sound too horrifying to you, visit the first link in the resources given below to read about their mating practices!)

These two distinctive jaws give rise to the name used by the Jebeliya Bedouin for camel spiders – abu hanakain, the father of two mouths.

Solifugae, the order these camel spiders belong to, means those who flee from the sun in Latin. These solpugids often seek shade from the intense desert sun in a person’s shadow and may seem to be “chasing” a person, but really all they want is a break from the heat.

Have you spotted any Egyptian Giant Solpugids during your wanders through South Sinai?

Resources:

1 – Bittel, J. (2017, August 9). Camel Spiders are Fast, Furious, and Horrifically Fascinating. Smithsonian Magazine.

National Geographic – Camel Spider

Aly, D. & Khalil, R. (2011). Wildlife in South Sinai. Cairo. Funded by the E.U. in cooperation with G.O.S.S.

Sand Wasp

On By Bernadette SimpsonIn ArthropodsLeave a comment

It’s springtime and the air is full of the sweet scent of flowers and the sound of buzzing insects. Some of the buzzers I’ve spotted recently in my garden are strikingly-colored sand wasps (Bembix sp.).

Sand wasps are solitary hunting wasps that build their nests in the ground. Worldwide, there are over 350 different species in the Bembix genus. They are typically yellow and black and are reported to be particularly diverse in dry habitats. Bedouin in Sinai call all wasps dabra.

Adult sand wasps feed on nectar, but the females are skilled hunters, capturing prey to feed their larvae. The females dig nests in the ground using their mandibles and front legs. The nests are simple burrows with an enlarged chamber at the bottom, the brood cell, which they keep stocked with fresh prey for their developing larvae. It is not uncommon for several females to dig their nests in a common area, but they are not social; they do not cooperate or share the labor.

Flies are the most common type of prey hunted, but sand wasps have also been observed preying on damselflies, grasshoppers, mantids, bugs, antlions, lacewings, butterflies, bees and wasps – but not beetles or spiders. The adult sand wasps catch the prey in mid-air, paralyze them with venom, and then carry them back to the waiting larvae.

After they have had their fill, the larvae spin silk cocoons and enter a prepupal stage. Pupation may not occur until the following spring, and then male wasps will emerge before female ones. Adult sand wasps probably live from several weeks to several months and spend much of their time sleeping. They spend this inactive time within their nests or in temporary sleeping burrows. The adult sand wasps may be prey themselves – to birds, lizards, robber flies, antlions, and velvet ants.

One source I consulted reports that these solitary wasps do not attack and sting humans, but another says they can deliver a painful sting if their nest is disturbed. So, like all stinging insects, it is best just to leave them in peace.

Have you spotted sand wasps on your wadi wanders or in your garden?

Resources:

Evans, H. & O’Neill, K. (2007). The Sand Wasps: Natural History and Behavior. Cambridge: Harvard University Press.