Morphs

Aphids species each exhibit several biologically and morphologically different forms

Aphid species can exhibit as many as 12 different forms, or morphs, during the course of their seasonal life-cycle. AphID only considers adult female viviparae, apterous and alate. It does not treat males, oviparae, immatures, or any number of other specialized morphs. Before using AphID, it is important to confirm that the unidentified specimen is an adult female vivipara, and NOT an immature, an ovipara, or a male.

Aptera

The adult apterous vivipara is specialized for asexual (parthenogenetic) reproduction. She gives live birth to genetic clones of herself.
Alata

The alata is equipped with wings for migration or movement from one host to another. She is also very fecund, although does not typically produce quite as many offspring as her apterous sister.
Adult vivipara

The adult vivipara can be recognized by the presence of a genital plate and rudimentary gonapophyses. It also frequently has embryos visible within its abdomen.

The genital plate is pointed to above and three rudimentary gonapophyses are below. These structures can be hard to distinguish if the specimen is poorly mounted.
Genital plate

The genital plate is characteristic of adult aphids.

The genital plate is circled and pointed to in this image. Note the clustering of setae on the bottom end of the sclerite, with only a few setae towards the front, and none in the middle. This is a common (but not universal) pattern of genital plate setae.
Rudimentary gonapophyses

Viviparae also exhibit these structures, which are reduced and modified genitalia used in live birth. The number of gonapophyses is standard among aphid groups, there usually being three or four.

Three rudimentary gonapophyses are covered in small setae.
Ovipara

The ovipara is usually easily recognized by having a large number of pseudosensoria on her metatibia. In some instances, if she has mated, she may also be carying eggs.

Pseudosensoria on the tibia are clearly visible here. Note also the large and conspicuous eggs.
Male

The adult male has obvious genitalia. In poor specimen preparations, however, the genitalia may be hard to distinguish from the rest of the generally heavily sclerotized rear end of the aphid.

The genitalia on this male are clearly visible.

Morphs

Aphids species each exhibit several biologically and morphologically different forms

Aptera

Alata

Adult vivipara

Genital plate

Rudimentary gonapophyses

Ovipara

Male