TYPES OF EGGS:
a) SINGLY LAID :
1) Sculptured egg : Chorion with reticulate markings and ridges e.g. Castor butterfly.
2) Elongate egg : Eggs are cigar shaped. e.g. Sorghum shoot fly.
3) Rounded egg: Eggs are either spherical or globular. e.g. Citrus butterfly4) Nit : Egg of head louse is called nit. It is cemented to the base of the hair. There is an
egg stigma at the posterior end, which assists in attachment. At the anterior end, there is
an oval lid which is lifted at time of hatching.
5) Egg with float : Egg is boat shaped with a conspicuous float on either side. The lateral
sides are expanded. The expansions serve as floats. e.g. Anopheles mosquito.
b) EGGS LAID IN GROUPS :
1) Pedicellate eggs : Eggs are laid in silken stalks of about 1.25mm length in one groups on plants. e.g. Green lacewing fly.
2) Barrel shaped eggs : Eggs are barrel shaped. They look like miniature batteries. They are deposited in compactly arranged masses. e.g. Stink bug.
3) Ootheca (Pl. Oothecae) :
- Eggs are deposited by cockroach in a brown bean like chitinous capsule.
- Each ootheca consists of a double layered wrapper protecting two parallel rows of eggs.
- Each ootheca has 16 eggs arranged in two rows.
- Oothecae are carried for several days protruding from the abdomen of female prior to oviposition in a
secluded spot. - Along the top,there is a crest which has small pores which permit gaseous exchange without undue water loss.
- Chitinous egg case is produced out of the secretions of colleterial glands.
4) Egg pod : Grasshoppers secrete a frothy material that encases an egg mass which is
deposited in the ground. The egg mass lacks a definite covering. On the top of the egg,the
frothy substance hardens to form a plug which prevents the drying of eggs.
5. Egg cass : Mantids deposit their eggs on twigs in a foamy secretion called spumaline
which eventually hardens to produce an egg case or ootheca. Inside the egg case, eggs are
aligned in rows inside the egg chambers.
6. Egg mass: Moths lay eggs in groups in a mass of its body hairs. Anal tuft of hairs
found at the end of the abdomen is mainly used for this purpose. e.g. Rice stem borer.
Female silk worm moth under captivity lays eggs on egg card. Each egg mass is called a
dfl (diseases free laying).
7. Eff raft : In Culex mosquitoes, the eggs are laid in a compact mass consisting of 200-
300 eggs called egg raft in water.
