Species-specific multiplex-PCR for rapid identification of armored scale insects (Diaspididae) on Hass avocados from Mexico

Armored scale insect species (Hemiptera: Diaspididae) are numerous and include some of the most damaging and refractory pests of perennial crops. Hass avocado fruit imported into California from Mexico are infested with high levels of armored scales, creating concern over the possible introduction of new species into Californian agriculture. Reliable morphological identification of armored scales often requires careful preparation of slide-mounted specimens, expert knowledge of the group, and may take several days. Traditional taxonomic keys are based largely on characteristics of adult females, and as a result, their application is also limited to adult females. We present a simple, quick, and accurate means to identify all life stages (male and female) of eight armored scale species found on Mexican avocados, using the polymerase chain reaction (PCR) and a set of species-specific PCR primers.