feeding opportunities. When a mother gets signaled by a false alarm and she cannot detect a predator she will send out her signal to the nymphs alerting them that there is no predator. This signal acts as a negative feedback signal essentially training the nymphs to be less sensitive to disturbances and become more accurate in detecting potential threats. Sibling rivalry When a large number of offspring are attacked by a predator, the risk factor is spread unequally amongst all the young. Certain circumstances lead to sibling rivalry in a brood of thorn bugs. Whether or not the mother is present can determine if a brood will compete with one another. When the female is present, a predator is only successful in removing a nymph 25% of the time, this number jumps to 95% when the female is absent. If a predator approaches the aggregation, it is more likely to take a nymph that is on the margin on the congregate, this produces a rivalry for sibling to want to be in the center of the brood and will fight over who will be on the outside because they have a higher risk of being preyed on. Another major factor leading to competition is the closeness of the nymph to the mother. The average time it takes the mother to travel 1.5 cm (about the body length of the mother) is 7.7 seconds, this is plenty of time for a predator like a wasp to circle the brood and move away from the mother. Because of this, siblings will fight for spots closest to the mother for better protection. References External links Umbonia crassicornis on the University of Florida / Institute of Food and Agricultural Sciences Featured Creatures Membracinae Insects described in 1843 Hemiptera of North America