Tag: wasps

Oriental Hornet

On By Bernadette SimpsonIn Arthropods1 Comment

Solar-powered insects? Yes! Read on.

Oriental Hornets (Vespa orientalis) have reddish brown bodies, shiny exoskeletons, and bright yellow bands on their abdomens. These bands contain xanthoperin, the pigment that is not only responsible for their yellow coloring but also has the ability to absorb and convert light into usable energy, similar to a solar cell. This allows the hornets to be more active during the hottest part of the day, when other insects are typically resting. Oriental Hornets thrive in bright conditions, using the boost in energy to dig their nests – underground burrows made in sandy soil.

Oriental Hornets are social wasps, living in colonies and employing highly organized and cooperative behavior. The queen hornets are the main reproductive females and are responsible for laying eggs. The workers, all female, are in charge of maintaining the nest, gathering food, and protecting the colony. The job of the male drones is to mate with the new queens.

All of these behaviors follow a seasonal pattern. In the spring, the queens emerge from hibernation and search for appropriate nesting sites. In the summer, it’s time for the workers to forage, care for the larvae, and maintain the nest. In autumn, the new queens and drones mate before the queens enter hibernation and the rest of the colony dies off.

Adult hornets are attracted to sweet food sources – nectar, juice, and the honeydew produced by aphids. But for the larvae, the workers must collect protein – caterpillars, flies, and other insects. The hornets use their strong mandibles to catch and squash their prey, chewing it into a paste before bringing it to the larvae in the nests. Honeybee colonies are a favorite of hornets as they provide both the sweet food source and the protein (in the bee larvae). Hornets are known to attack bee colonies and can quickly annihilate an entire hive.

Hornets may get a bad rap for their painful stings, but they aren’t typically aggressive towards humans unless their nest is disturbed and their stings, while painful, aren’t dangerous unless someone is allergic to their venom. Hornets, however, do provide a few beneficial services to humans. They prey on agricultural pests, helping gardeners and farmers keep their crops healthy. And, while foraging for nectar, hornets also help in pollination.

I have seen Oriental Hornets in the wadis, especially in wadis with water sources, around Dahab and also foraging in my desert garden at home. Have you seen them on your wadi wanderings?

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.

Wasps in Sinai

On By Bernadette SimpsonIn ArthropodsLeave a comment

Wasps are insects in the order Hymenoptera, which also includes sawflies, bees, and ants. Wasps such as hornets are social and live together in a nest. But most wasps are solitary. Wasps can be predators and pollinators. Some are parasitoidal, meaning they lay their eggs IN or ON other insects. The larvae eventually kill the host insect. Solitary wasps often do this to pest insects, so can be a beneficial pest control for crops. 

A collection of images of five different wasps in Sinai.

Pictured here are a handful of the different wasps in Sinai:

Sand Wasp (Bembix sp.)
Caterpillar Hunting Wasp (Delta dimidiatipenne)
Carrot Wasp (Gasteruptiidae family)
Oriental Hornet (Vespa orientalis)
Thread-waisted Wasp (Ammophila sp)