External Features and Life Cycle of Grasshopper: Comprehensive Overview

 Objectives       

This  blog post provides readers with the following objectives. The reader will be able to:
o   Identify Grasshopper.
o   Describe the external features and life processes of Grasshopper.

 

Grasshopper 

Phylum: Arthropoda

Class: Insecta

Order: Orthoptera

Grasshoppers are fascinating insects that exhibit a range of external features and undergo a complex life cycle. Understanding these aspects provides valuable insights into their behavior, development, and ecological impact. This guide explores the external characteristics of grasshoppers and details their life cycle stages, offering a comprehensive overview.


Habitats of Grasshopper

Grasshoppers  are found in; grassland, gardens, farmlands, savanna, forest and field.



Structure of Grasshopper

It has triangular head with a pair of conspicuous compound eyes, a pair of short antennae and biting and chewing mouthparts.

The adults have two pairs of wings; the fore wings and hind wings. The fore wings are narrow, tough and leathery called tegmina or elytra, protecting the hind wings. The hind wings are large, membranous used for flight.

The hind legs are usually enlarged with long and strong femur, modified for jumping or leaping. The femur bears some hook-like structures which rub against the fore wings to produce a characteristic sound. 

The first abdominal segment bears circular patches called Tympana (singular: tympanum) on each side. The tympanum is sensitive to sound vibration. 

The females bear a short ovipositor at the end of the abdomen. The ovipositor has two pairs of valves used to dig a hole in the sand into which eggs are laid.


Structure of a grasshopper

For a detailed look at grasshopper anatomy, visit the Insect Identification Guide.


Mode of Life of Grasshopper

Incomplete Metamorphosis of Grasshopper

They feed on the natural vegetation by cutting off pieces with their jaws. They move by walking, climbing, and hopping but they can fly short distances. Grasshopper are solitary, unlike locust that can co-exist in swarms. Grasshopper develops by incomplete metamorphosis, i.e., there is no larval stage. The female lays the eggs in warm, moist sand by creating a hole with the ovipositor. The eggs are hatch into wingless nymphs which resemble the adults. The nymph molt five times to become adult with wings.

Economic Importance of Grasshopper

1. In certain countries, grasshoppers are eaten as a good source of protein.
2.  Locust swarms can cause massive damage to crops and also reduced crop yield.
3.  Some grasshoppers are important, acting as pests on farmlands.
4.  Transmission of plants pathogens such as bacteria and virus.

 Explore the details of grasshopper reproduction on the Royal Entomological Society's website.


Control of Grasshoppers: Strategies and Techniques for Effective Management

Grasshoppers can be significant agricultural pests, causing substantial damage to crops and vegetation. Effective control measures are essential to manage their populations and minimize economic losses. This guide outlines various strategies and techniques for controlling grasshoppers, focusing on both preventive and reactive approaches.

1. Cultural Control

a. Crop Rotation
  • Description: Rotating crops can help break the life cycle of grasshoppers by disrupting their habitat and reducing their food sources.
  • Implementation: Avoid planting grasshopper-prone crops in the same fields year after year. Alternate with crops that are less attractive to grasshoppers.
b. Field Management
  • Description: Maintaining healthy and well-managed fields can reduce grasshopper infestations.
  • Implementation: Regularly remove weeds and other vegetation that can serve as habitat and food sources for grasshoppers. Use practices like proper irrigation and fertilization to promote robust crop growth.

2. Biological Control

a. Natural Predators
  • Description: Encouraging or introducing natural predators can help control grasshopper populations.
  • Implementation: Beneficial insects such as certain beetles, spiders, and birds feed on grasshoppers. Creating a habitat that supports these predators can aid in natural pest control.
b. Pathogens
  • Description: Certain pathogens, such as fungi and bacteria, can be used to target grasshopper populations.
  • Implementation: Apply biopesticides containing pathogens like Nosema and Metarhizium species, which can infect and kill grasshoppers.

3. Mechanical Control

a. Physical Barriers
  • Description: Physical barriers can prevent grasshoppers from accessing crops.
  • Implementation: Use row covers or netting to protect plants from grasshopper feeding. Ensure that barriers are securely fastened and cover the plants completely.

Explore more about physical barriers at the Extension Foundation.

b. Hand Removal
  • Description: In small-scale settings, manually removing grasshoppers can be effective.
  • Implementation: Regularly inspect plants and hand-pick grasshoppers. This method is labor-intensive but can be useful for controlling small infestations.

Learn more about hand removal techniques at the Missouri Botanical Garden.

4. Chemical Control

a. Insecticides
  • Description: Insecticides can provide immediate control of grasshopper populations.
  • Implementation: Apply insecticides such as carbaryl, chlorpyrifos, or pyrethroids when grasshopper populations exceed economic thresholds. Follow label instructions and use appropriate safety measures.

For guidance on insecticide use, visit the Pesticide Action Network.

b. Biological Insecticides
  • Description: Biopesticides can be used as a less toxic alternative to chemical insecticides.
  • Implementation: Use products containing Bacillus thuringiensis (Bt) or Nosema locustae, which are effective against grasshoppers but generally safer for non-target species.

Learn more about biological insecticides at the EPA's Biopesticides Program.

5. Integrated Pest Management (IPM)

a. Combining Methods
  • Description: IPM involves using a combination of control methods to manage grasshopper populations effectively.
  • Implementation: Develop an IPM plan that incorporates cultural, biological, mechanical, and chemical controls based on monitoring data and economic thresholds.

Explore IPM strategies on the National IPM Database.


Conclusion

Grasshoppers are remarkable insects with distinct external features and a well-defined life cycle. Their specialized anatomy, including their powerful hind legs and complex wing structures, supports their various ecological roles. The gradual metamorphosis from egg to adult allows grasshoppers to adapt to changing environments and continue their lifecycle effectively.

For further reading on grasshoppers and their life cycles, visit the National Park Service's Grasshopper Information Page.

Understanding the external features and life cycle of grasshoppers not only enhances our knowledge of these insects but also aids in managing their populations in agricultural and natural environments.


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