Mimicry and Coloration in Insects

Introduction

Mimicry can be described as the phenomenon of resemblance in physical characteristics or behavioural traits of an animal with a different animal species, usually of different taxa to gain a selective advantage in its environment. Camouflage, on the other hand, refers to the animal species resembling a non-living or inanimate object. Insects constitute a large percentage of mimicry and practice various forms of camouflage and colouration.

Types and Examples

In nature, four types of mimicry can be observed in different species of animals.

Mullerian Mimicry, Batesian Mimicry, Aggressive Mimicry, and Automimicry

Mullerian Mimicry

Mullerian mimicry is observed between unrelated and harmful insects when they appear to mimic body colour and behavioural patterns against predators which recognize the insect markings, appear poisonous and thus avoid eating them. They share an evolutionary advantage across different species, but there is also an evolutionary cost when a few of the insect individuals are sampled by the predators and they learn to avoid such samples in future. This appears for human interventions also, when we encounter an insect colour and pattern with a painful sting in childhood, we tend to avoid such an insect in fear of a sting.

Examples

Mullerian mimicry is most common among stinging insects like bees, wasps, and ants.

Yellowjacket

They are often mistaken for bees, paper wasps and hornets because of similarities in shape, size, and colour. They are aggressive and territorial, causing nuisance near food. The colour and markings of yellowjackets are mimicked by some harmless insects like the longhorn flower beetle, wasp beetle, American hornet moth, and hoverfly to avoid predation.

Honey Bee

They are one of the important pollinators of the world. They visit a wide variety of flowers. They are usually submissive in behaviour, but sting when disturbed. Honeybees are often mistaken for bumble bees because of their similarities.

Bumble Bee

Bumble bees are often mistaken for honey bees. They are usually submissive, but sting when disturbed. They are important pollinators of crops and ornamental plants. A variety of non- stinging insects like bee beetle, American hornet moth, bee fly, and Snowberry clearwing moth mimic bumble bees.

Velvet Ant

They are not ants, but they are a type of solitary wasp. Females are wingless and territorial, and sting when disturbed. Males have wings and look like a wasp in size and shape. They can be found in household gardens. Their bright colours create warning as aggressive and harmful, known as aposematic colouration. Harmless insects like tachinid fly mimic velvet ants.

Monarch and Viceroy Butterfly

Monarch butterflies show bright colouration, warning predators they are poisonous and should be avoided. They are often mistaken for the Viceroy butterfly. Viceroy butterflies have smaller wings and a different pattern of hind wings.

Batesian Mimicry

Batesian mimicry is observed when a harmless insect resembles and behaves like a harmful insect to avoid predation. Harmless insects adapt to the innate and aggressive behaviour of harmful insects, over time sharing the same environment and predators, and mimicry provides extra protection against predation.

Examples

Batesian mimicry is most common in flies, gnats, midges, mosquitoes, beetles, butterflies, and moths.

Wasp beetle

Adults feed on a variety of flowering plants. They are often mistaken for wasps because of their similarity in markings. Their mimics are the flower longhorn beetle, American hornet moth, and hoverfly.

Flower longhorn beetle

They are common visitors to flowering plants. Their colour and marking often appear confusing in resemblance to wasps.

Bee beetle

They are often mistaken for bumblebees due to their similarity in shape, size, and colour. Their mimics are bee fly, and snowberry clearwing moth.

Drone fly

They are relatively robust, hairy structures on their body and are often mistaken for bumble bees and honey bees due to their similar colour, shape, and size.

Hoverfly

They are common pollinators, hovering around flowering plants. They avoid predation by mimicking the bright colouration and behaviour of wasps.

Aggressive Mimicry

In this type of mimicry predators, parasites, or parasitoids share similar characteristics to a harmless insect, to lure their prey.

Examples

Female Fatale Firefly

They are beetles which mimic fireflies by lighting up their abdomen and attracting male fireflies for mating. When a male firefly responds in the hope of mating, they are eaten by these predators.

Orchid Mantid

They resemble an orchid flower with wide limbs and bright colouration-like flower petals. They act as hyper stimuli, luring their prey for real orchids to feed on nectar.

Spotted Predatory Katydid

These insects mimic the mating call of female cicadas and multiple other unknown species. This makes them versatile predators.

Automimicry

Automimicry or intraspecific mimicry is a type of mimicry in which the same species of an animal is mimicked. It is a situation in which one body part of an animal resembles another part, an adaptation to avoid predation.

Examples

Bees and wasps

Males of many bees and wasps resemble their females that are stingers. Some males can have false stingers, without poison and make jabbing movements of the abdomen on disturbance.

Monarch butterflies

Some individuals of Monarch butterflies release noxious chemicals to protect less-defended individuals from predatory birds.

Hairstreak butterflies

Hairstreak butterflies have a small spot on their hindwings-the thecla spot, which resembles an eye with little tails behind the spot giving the appearance of antennae. During a predator attack, due to such confusion, butterflies are saved from their lethal attack.

Camouflage and Cryptic Colouration

A cryptic colouration is a form of camouflage which includes the use of colour, texture, and pattern by an insect to blend with its surroundings to avoid predators or ambush prey.

Examples

Lacewing larvae

Lacewing larvae resemble debris particles to blend with their surroundings.

Praying mantids

Praying mantids are green or brown, blending with the leaves of plants. Flower praying mantids camouflage an orchid flower.

Stick insects

Stick insects look like twigs and sticks.

Katydids camouflage

Katydids camouflage as dead or dying leaves with green and brown markings.

Conclusion

Mimicry and colouration are Nature's advantages to an organism to survive and adapt to its environment. Both predators and prey need such evolutionary advantages to evolve and play their biological roles in their food chain and ecosystem.

FAQs

Qns 1. Do all insects mimic?

Ans. No, insects mimic when required for survival.

Qns 2. Do harmful insects mimic and camouflage?

Ans. In most cases, harmful insects mimic to capture their prey.

Qns 3. Are mimicry and camouflage the same?

Ans. Mimicry is the resemblance to a living organism, while camouflaging is imitating a non- living object.