Grasshoppers are a type of insect that belong to the suborder of leaf-eating insects, within the order Orthoptera. They are characterized by their round heads, stout bodies, exceptional jumping abilities, and their tendency to damage green plants. When moving, they can crawl using all three pairs of legs on trees, jump from one tree to another using their hind legs, or leap and then fly into the air with their wings.
- Common Name: Grasshopper
- Scientific Name: Caelifera
- Phylum: Arthropoda
- Class: Insecta
- Order: Orthoptera
- Diet: Herbivorous, feeding on buds and leaves
- Size: 40-45mm in adults
- Behavior: Moves in swarms
Habitat
The ideal habitat for grasshoppers is vast rice fields. It is estimated that there are approximately 2,400 genera and around 11,000 valid species, distributed widely across the globe, primarily concentrated in tropical regions.
Types of Grasshoppers
Some classifications include: ghost grasshoppers, bamboo grasshoppers, elephant grasshoppers, monkey grasshoppers, etc., characterized by their broad heads and hard wings; while those with pointed heads and flexible wings are referred to as “tanh tach.”
Based on the structure of the pronotum, forehead, and head, grasshoppers are divided into four subfamilies: Acridinae (grasshoppers and locusts); migratory grasshoppers; spiny grasshoppers; and true grasshoppers.
In Vietnam, there are typically two types of grasshoppers: rice grasshopper (Oxya chinensis) and bamboo grasshopper.
The ideal habitat for grasshoppers is vast rice fields.
Body Structure
The grasshopper’s body consists of three parts:
- Head: includes antennae, compound eyes, and mouthparts
- Thorax: includes three pairs of legs and two pairs of wings
- Abdomen: composed of several segments, each with a spiracle
Characteristics and Appearance
Grasshoppers have two antennae that are shorter than their bodies and may sometimes have multiple fine strands.
- This insect produces sound by rubbing the hind femurs against the forewings or abdomen, or by rapidly flapping its wings when in flight.
- The hearing membranes of grasshoppers are located on the sides of the first abdominal segment.
- The hind femurs are long and robust, enabling powerful jumping movements.
- They possess wings, but the hind wings are membranous; the forewings are tough and are not used for flight.
- Female grasshoppers are larger than males, with shorter ovipositors.
Agile Movement
Compared to other insects like mantises, leafcutter ants, termites, and dung beetles, grasshoppers exhibit more agile movement thanks to their powerful hind legs, enabling them to spring away from their perch quickly. When they want to travel long distances, they simply jump and spread their wings to fly freely from one place to another. Additionally, grasshoppers can crawl slowly using all three pairs of legs.
Grasshoppers breathe by ‘breathing’ through their abdomen.
Respiratory Mechanism
Grasshoppers breathe by ‘breathing’ through their abdomen. When they are alive, their abdomen continuously expands and contracts to inhale and exhale air through the spiracles on the underside of their abdomen.
Digestive Mechanism
With their strong and sharp mouthparts, grasshoppers can easily grasp food, moisten it with saliva, and collect it in the crop, where it is then ground in the muscular stomach, before being digested with enzymes secreted by the intestines.
Reproductive Traits and Development
Grasshoppers are sexually dimorphic, having cluster-like gonads and tubular accessory glands. During mating, the male mounts the female, opens the cover of his abdomen, and extends his complex penis structure out of his body; it then inflates this structure like a balloon and connects it to the female’s genitalia to start the mating process.
The eggs are laid in the ground in clusters, with several dozen eggs sticking together, surrounded by a layer of foamy substance that prevents them from drying out. The nymphs that hatch resemble adult grasshoppers but are smaller and lack wings, requiring several molts before becoming recognized as adult grasshoppers.
Grasshoppers are sexually dimorphic, with cluster-like gonads and tubular accessory glands.
Life Cycle of Grasshoppers
The life cycle of grasshoppers lasts approximately 200 to 210 days and includes:
- Egg stage: 12 – 21 days
- Nymph stage: 100 days
- Adult stage: about 3 months, with females living longer than males
- Adult grasshoppers start mating 5 – 40 days after reaching maturity; after 10 – 41 days, they lay eggs. Each female can lay 3 clutches, with each clutch containing 10 – 102 eggs.
Grasshoppers grow through incomplete metamorphosis. The nymphs must undergo several molts before becoming adults.
Grasshopper Plagues
Grasshoppers are voracious eaters and reproduce prolifically, laying numerous eggs in each clutch, which poses a significant risk of crop damage and destruction. Throughout the world, including in our country, there have been numerous instances of grasshopper plagues. Wherever they travel, they devastate crops, consuming leaves and rice shoots, causing significant impacts on plant populations and the survival of all other organisms in terrestrial ecosystems.
Young grasshoppers begin their destructive behaviors immediately after hatching. Most of their feeding occurs at night, where they consume leaves, creating holes while leaving the main veins intact, and bite through rice ears, causing blanking. Additionally, grasshoppers are active around 7-10 AM and 4-5 PM each day. They move in swarms, continuously feeding, mating, and reproducing, thus having the potential to obliterate any area containing vegetation.
Some Interesting Facts
- To study the peculiarities of the reproductive system of this species, scientists have raised two grasshoppers in optimal conditions and waited for them to mate, then froze them at -80 degrees Celsius to conduct tomography and analyze the unique aspects.
- There is a species of giant grasshopper; a normal one can weigh over 35g, making them unable to jump like regular grasshoppers.
- Another fact states that the giant grasshopper from Little Barrier Island (New Zealand) is the largest insect in the world, weighing up to 71g and measuring 8.5cm in length; this species is currently at risk of extinction.
- Grasshoppers and locusts are not necessarily two different species, as locusts are merely a growth stage of grasshoppers.
- In addition to their abilities to crawl, jump, and fly, grasshoppers can also swim when they jump into the water.
- Grasshoppers are currently one of the five best jumpers in the world, capable of jumping 20 times their body length; this is equivalent to a human jumping from one end of a basketball court to the other.
Some species of grasshoppers are used to detect explosives due to their keen sense of smell. - Some species of grasshoppers are used to detect explosives due to their keen sense of smell.
