a female, which may mate several times, can reach 1,180. Eggs take three to eight days to develop and hatch into larvae or caterpillars. The offspring's consumption of milkweed benefits health and helps defend them against predators. Monarchs lay eggs along the southern migration route. Larva The larva (caterpillar) has five stages (instars), molting at the end of each instar. Instars last about 3 to 5 days, depending on factors such as temperature and food availability. The first-instar caterpillar that emerges from the egg is pale green or grayish-white, shiny, and almost translucent, with a large, black head. It lacks banding coloration or tentacles. The larvae or caterpillar eats its egg case and begins to feed on milkweed with a circular motion, often leaving a characteristic, arc-shaped hole in the leaf. Older first-instar larvae have dark stripes on a greenish background and develop small bumps that later become front tentacles. The first instar is usually between long. The second-instar larva develops a characteristic pattern of white, yellow, and black transverse bands. The larva has a yellow triangle on the head and two sets of yellow bands around this central triangle. It is no longer translucent, and is covered in short setae. Pairs of black tentacles begin to grow, a larger pair on the thorax and a smaller pair on the abdomen. The second instar is usually between and long. The third-instar larva has more distinct bands and the two pairs of tentacles become longer. Legs on the thorax differentiate into a smaller pair near the head and larger pairs further back. Third-instar larvae usually feed using a cutting motion on leaf edges. The third instar is usually between long. The fourth-instar larva has a different banding pattern. It develops white spots on the prolegs near its back, and is usually between long. The fifth-instar larva has a more complex banding pattern and white dots on the prolegs, with front legs that are small and very close to the head. Fifth-instar larvae often chew a shallow notch in the petiole of the leaf they are eating, which causes the leaf to fall into a vertical position. Its length ranges from . As the caterpillar completes its growth, it is long (large specimens can reach ) and wide, and weighs about , compared to the first instar, which is long and wide. Fifth-instar larvae greatly increase in size and weight. They then