Happy Halloween

Domesticated silkmoth

Meet the domesticated silkmoth (Bombyx mori) better known in its caterpillar state in which it is called silkworm though it’s not a worm at all. This species is an economically important insect, having been domesticated in China from its wild ancestor Bombyx mandarina about 5000 years ago. The adults have actually lost the ability to fly and also lack fear of potential predators. These changes have made the species entirely dependent upon humans for survival and it no longer occurs naturally in the wild.

What makes them so valuable is silk. After they have molted four times the larvae will enter the pupa phase of their life cycle and enclose themselves in a cocoon made up of raw silk produced by the salivary glands or to be more precise - a 900m long single strand of silk. The cocoon provides a protection during the vulnerable, almost motionless pupal state. 

About 3,000 cocoons are required to make half a kilogram of silk. At least 40 million kilograms of raw silk are produced each year, requiring nearly 5 billion kilograms of cocoons.

Great spangled fritillary

Image from ohio-nature.com

The great spangled fritillary (Speyeria cybele ) is a well known butterfly mainly because of its large size, abundance, and widespread range. It is found in northern and central United States and southern Canada. I t is only missing from northern Canada and some of the southern states.

One part of its scientific name (cybele) means “mountain mother” or “earth mother”. The common name comes from a Latin word, fritillus, which means chessboard or dice box.  Another name for these handsome butterflies is silverspots because of the metallic markings on their wing’s undersides. It is possible that this pattern, similar to a leopard’s spots, serves as camouflage when they are resting in places of dappled sun and shade spots.

Like many other butterflies, the great spangled fritillary caterpillars are very picky about what they eat. They do not go for milkweeds as do monarchs; they prefer violets instead. Without violets, there would be no fritillaries. The adults, on the other hand are thirsty for nectar of many different flowers.

American Cockroach

Cockroaches are infamous in part because their presence suggests rather sloppy housekeeping. However, it is not true that cockroaches are only found in dirty and poorly-kept buildings. They can be found in any building. 

Cockroaches, such as today’s species (Periplaneta americana) are also suspected disease carriers. They can carry microbes on their body including those that are potentially dangerous to humans and they are linked to allergic reactions in humans.

Their diet includes almost anything organic and that’s one factor that helped them to thrive for over 280 Million years as some fossils suggest. In their natural habitats they are valuable decomposers, which means they break down dead or decaying organisms. 

The American cockroach is often seen outdoors unlike its relatives that are considered households pests, e.g. the German cockroach (Blattella germanica) that is actually from northern Africa. By the way, the American cockroach probably also originated in northern Africa.

Eastern Hercules Beetle

This massive beetle never fails to draw attention. The eastern Hercules beetle (Dynastes tityus) is among the largest beetles in North America, second only to the western Hercules beetle (Dynastes granti) which has longer horns but is otherwise about the same size.

Only the males have horns which they use in combat against each other against over access to females. The adult beetles feed on tree sap and fruit while the larvae feed on decayed wood inside dead or dying trees.

It may take several years for a Hercules beetle grub before they pupate and change into adult beetles.

These insects are called Hercules Beetles because, pound for pound, they are probably the strongest animal in the world, capable of lifting over 850 times their own weight. That’s like you trying to carry six African Elephants at once.

Horse Guard Wasp

The Horse Guard Wasp (Stictia carolina) is a type of so called sand wasps widespread in eastern North America. The species is named for the behavior of its females, which hover around horses to catch horse flies. These rather large wasps may treat us humans in a similar manner – as fly lures. 

The wasps nest in the sand, sometimes in dense colonies with sometimes thousands of other wasps. A female may take anywhere from 30 to 60 flies as food to provision each one of her nests. Nests are simple burrows up to 15 cm deep, with a single enlarged chamber at the bottom. An egg is laid in the empty chamber, and the female wasp brings back paralyzed flies until the chamber is full, at which point she closes the nest and begins another.

Here a little video about horse guard wasps:

Luna moth

Found across eastern North America, the Luna Moth (Actias luna) belongs to the family that includes Giant Silkworm Moths. These large moths with wingspans of up to 12 cm appear even larger because of long tails on their hind wings. 

The wings of the Luna Moth are marked by eyespots - an adaptation to scare off potential predators. The eyespots are especially noticeable against the uniform pale green of a Luna Moth's wings.  Another obvious characteristic are the large, feathery antennae. In the male Luna Moth, these receptors are especially large and used to pick up minute traces of pheromones--chemicals released by the female that allow males to track her down in complete darkness.  

The caterpillars, which reach lengths of 8 cm, are voracious eaters that dine on leaves of hickories, walnuts, birches, Common Persimmon, and Sweet Gum.  Like other caterpillars, their multiple mouthparts are well adapted for chewing, and they easily make short work of a tasty leaf.