Georgia Pesticide Applicators Practice Exam

What structures do Aphis have on both sides of their rears?

1. Wings

2. Antennas

3. Cornicles

4. Claspers

The correct answer is: Cornicles

Aphis, commonly known as aphids, have cornicles located on both sides of their rears. Cornicles are specialized, tubular structures that protrude from the abdomen of aphids and serve various functions, one of which is to excrete defensive secretions. These structures can produce alarm pheromones to alert other aphids in the colony to potential threats and can also release honeydew, which is a sugary substance that can attract predators and ants. The presence of cornicles is a distinctive feature used to help identify aphid species and understand their behavior in their ecosystems. In contrast, wings are present in some (but not all) aphid morphs, mainly during certain life stages or environmental conditions, and do not always appear on all aphids. Antennas are sensory organs found on all insects, but they are not unique to aphids or indicative of any specific behavior. Claspers are typically used in mating and are not structures associated with aphid identification or their typical behavioral characteristics.