Difference Between Holometabolous and Hemimetabolous Metamorphosis in Insects

Key Difference – Holometabolous vs Hemimetabolous Metamorphosis in Insects
 

Insects undergo different biological and morphological changes after birth or hatching. These physical changes represent different stages of their life cycle before they grow to a mature insect completely. Abrupt changes in the animal’s body and changes in the feeding patterns can be observed during these developmental stages. This phenomenon of development is known as Metamorphosis. Metamorphosis can be classified mainly as Holometaboly and Hemimetaboly. Holometaboly refers to the complete metamorphosis. Therefore, holometabolous insects are the insects that undergo complete metamorphosis. Hemimetaboly refers to the incomplete metamorphosis. Thus, hemimetabolous insects are the insects that undergo incomplete Metamorphosis. The key difference between Holometabolous and the Hemimetabolous insects is based on the type of metamorphosis they undergo. Holometabolous insects undergo complete metamorphosis whereas Hemimetabolous insects undergo incomplete or partial metamorphosis.

CONTENTS

1. Overview and Key Difference
2. What is Holometabolous Metamorphosis in Insects
3. What is Hemimetabolous Metamorphosis in Insects
4. Similarities Between Holometabolous and Hemimetabolous Metamorphosis in Insects
5. Side by Side Comparison – Holometabolous vs Hemimetabolous Metamorphosis in Insects in Tabular Form
6. Summary

What is Holometabolous Metamorphosis in Insects?

Holometabolous Metamorphosis refers to complete metamorphosis. This type of metamorphosis is shown by the members of the insect groups such as Coleoptera, Lepidoptera, Hymenoptera and Diptera.

• Coleoptera – Beetles.
• Lepidoptera – Moths, Butterflies and Skippers.
• Hymenoptera – Sawflies, Wasps, Ants and Bees.
• Diptera– Flies.

Holometabolous insects have a life cycle where the egg hatches into a larva, then develops into an inactive pupa stage before developing into a complete adult. The classic example of a Holometabolous insect is the butterfly. Upon hatching, the butterfly enters the larva stage, which is the caterpillar stage. Upon completion of the caterpillar stage after obtaining nutrients from plant feed, it develops to the pupa stage. During the pupa stage, the caterpillar is covered and wrapped in a cocoon. Following the pupa stage, the mature butterfly emerges out breaking the cocoon.

The Holometabolous larva has the ability to pupate before emerging as an adult. The Holometabolous larvae are tubular in structures. They are also known as eating machines because during this stage they undergo heavy feeding. The larva stage is a camouflaged stage in the development of these insects. These larvae are camouflaged in order to protect them from being eaten. These larvae are most often very poisonous and may result in harmful allergy outcomes if ingested or touched. The three main types of the holometabolous larva are caterpillars of butterflies and moths, maggots in flies and grubs in beetles.

What is Hemimetabolous Metamorphosis in Insects?

Hemimetabolous metamorphosis in insects refers to incomplete metamorphosis development that takes place in the type of insects belonging to the groups Hemiptera, Orthoptera, Mantodea, Blattodea, Dermaptera and Odonata.  Since they undergo incomplete metamorphosis, thus referred to as Hemimetabolous insects.

• Hemiptera – Scales, Whitefly, Aphid
• Orthoptera – Grasshoppers, Cricket
• Mantodea – Praying mantids
• Blattodea – Cockroaches
• Dermaptera – Earwigs
• Odonata – Dragonflies

During Hemimetabolous metamorphosis of insects, they do not have a mature larva form. Thus, the immature forms of these types of insects are called nymphs. The nymphs do not develop into a pupa stage, and instead, they grow in size and become the adult individual. Thus, incomplete metamorphosis takes place during the development.

The immature stage, which is the nymph stage resembles the adult organism, but they are not metabolically and morphologically active in comparison with the adult. These immature stages are generally referred to as nymphs although in some organisms they are called as hoppers, crawlers and mudeyes.

The feeding habits and the nutrition patterns of these nymphs resemble the adults, but they can have varying forms of locomotion and methods of predation in comparison with the adult stage. For example, the dragonfly nymph is an aquatic predator whereas the adults are flying insects.

What are the Similarities Between Holometabolous and Hemimetabolous Metamorphosis in Insects?

• Both Holometabolous and Hemimetabolous metamorphosis types in insects signify morphological and biological changes taking place during the development of an organism.
• Both Holometabolous and Hemimetabolous Metamorphosis types of insects undergo metamorphosis so that they could gradually get adapted to the environment and as a means of gathering energy.
• Both Holometabolous and Hemimetabolous types of metamorphosis in insects result in different developmental stages.

What is the Difference Between Holometabolous and Hemimetabolous Metamorphosis in Insects?

Summary – Holometabolous vs Hemimetabolous Metamorphosis in Insects

Metamorphosis is the phenomenon where some insects show different developmental stages during their lifetime. Depending on whether they follow the egg stage, larva stage and the pupa stage before becoming the adult, metamorphosis in insects can be of two main types namely holometaboly and hemimetaboly. Holometabolous metamorphosis is seen when the insect shows all the developmental stages. In hemimetabolous metamorphosis, insect does not have a mature larva stage and a pupa stage during their development. Instead, they have a nymph stage that mimics the adult behavioural patterns. This is the difference between holometabolous metamorphosis in insects and hemimetabolous metamorphosis in insects.

Reference:

1.Wigglesworth, Vincent Brian. “Insect.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., 25 Apr. 2017. Available here  
2.David Britton. “Australian Museum.” Metamorphosis: a Remarkable Change – Australian Museum,. Available here  

Image Courtesy:

1.’Holometabolous vs. Hemimetabolous’By Username1927 – Own work, (CC BY-SA 4.0) via Commons Wikimedia  
2.’Life in Water (Dragonfly Nymph)’by leopard gecko (CC BY-SA 2.0) via Flickr