The contents of the egg undergo a series of determinate cleavages giving rise to the blastula and triploblastic gastrula stages. Finally, the first stage larva is formed. The embryo and first-stage larvae are highly resistant to moisture stress". The first moult occurs within the egg to give rise to the second-stage larva that is ready to hatch out. The hatching can occur freely in water or moist soil without any requirement of root exudates or hatching factors. However, under adverse conditions of moisture, osmotic pressure, temperature, etc., the hatching is inhibited or postponed to ensure longer survival. The gelatinous egg matrix also assists in survival. For instance, due to hygroscopic nature, it absorbs ambient moisture and the moisture content in the egg sac remains higher than that in drying soil. Further, under high degree of moisture stress the high osmotic pres­sure in the matrix may inhibit hatching.