Types of Eggs Laid in Groups

Study Notes

Egg Laying

Eggs can be laid in groups, with different species exhibiting unique characteristics
Pedicellate eggs are laid on plants in silken stalks, around 1.25 mm in length (e.g., green lacewing)
Barrel-shaped eggs are deposited in compact masses (e.g., stink bug)
Ootheca is a brown, chitinous capsule containing eggs, laid by cockroaches
Egg pods are formed by grasshoppers, which secrete a frothy material that encases the eggs
Egg cases or oothecae are formed by mantids, which deposit eggs on twigs in a foamy secretion called spumaline
Egg masses are laid by moths, with eggs stuck together with body hairs (e.g., rice stem borer)
Egg rafts are formed by Culex mosquitoes, consisting of 200-300 eggs laid in water

Larval Stage

The larval stage is the active growing stage, differing radically from the adult stage
There are four main types of insect larvae: protopod, oligopod, polypod, and apodous
Protopod larvae have little yolk, and abdominal segmentation is absent (e.g., endoparasitic Hymenoptera)
Oligopod larvae have thoracic legs and are further divided into campodeiform and scarabaeiform types
Polypod or eruciform larvae have three pairs of thoracic legs and up to five pairs of unjointed abdominal legs or prolegs (e.g., caterpillars)
Apodous larvae are without legs (e.g., house fly larvae)

Nymphs and Metamorphosis

Nymphs are young ones of lower orders, resembling adults except for wings and reproductive organs
Larvae are young ones of higher orders, differing from adults in appearance and growth
There are three types of metamorphosis: ametabola, hemimetabola, and holometabola
Ametabola have no metamorphosis, with little external change during growth (e.g., silverfish)
Hemimetabola have gradual or incomplete metamorphosis, with immature forms called nymphs (e.g., grasshoppers, bugs)
Holometabola have complex or complete metamorphosis, with immature forms called larvae (e.g., butterflies, beetles)

Pupal Stage

The pupal stage is the resting and inactive stage in all holometabolous insects
During this stage, the insect is incapable of feeding and is quiescent
There are three main types of pupae: obtect, exarate, and others
Obtect pupae have appendages glued to the body, with exposed surfaces heavily sclerotized (e.g., moth pupa)
Exarate pupae have free appendages, with the pupa soft and pale (e.g., rhinoceros beetle pupa)

Description

Learn about different types of eggs that are laid in groups by various insects, such as pedicellate eggs, barrel shaped eggs, ootheca, and egg pod. Understand the unique characteristics and features of each type of egg grouping.