Unknkown scarb larva from Tanguisan Bay, Guam; head capsule width = 2.6 mm
1st instar Oryctes rhinoceros larva from Tumon, Guam; head capsule width = 3.1 mm
2nd instar Oryctes rhinoceros larva from Tumon, Guam; head capsule width = 5.6 mm
3rd instar Oryctes rhinoceros larva from Tumon, Guam; head capsule width = 10.6 mm
PDF showing relative sizes of head capsules