Group of interest: Coccoidea
Scale insects and mealybugs or Coccoidea are hemipterans (insects with sucking mouthparts), which closest relatives are the aphids. As phytophagous insects, they count some of the most destructive crop pests in the world and significantly influence human activity.
Scale insects are atypical because of their extreme sexual dimorphism. Adult females look like juveniles and are sedentary wingless insects, although their male counterparts are mobile, ephemeral, wing bearing insects.
Besides their negative impact in agriculture and horticulture, some scale insects are considered beneficial, by producing dyes or lacquers. They also have been frequently used for biological control.
Neococcoids and "archeococcoids"
Scale insects comprise about 8000 described species grouped in 32 families (in the current classification). They have been traditionally divided in the monophyletic neococcoid assemblage and the paraphyletic "archeococcoids". The neococcoids comprise the most derived-featured families; they include the well known families as the Coccidae (soft scales), Diaspididae (armored scales) or Pseudococcidae (mealybugs), but also less common ones such as the cochineal of Mexico that produces red dye (Dactylopiidae).
In contrast, the "archeococcoids" group comprise all the rest of the scale insects, which represent 15 families but only 700 species. Those families include the Margarodidae (ground pearls) or the worldwide pest Icerya purchasii, which belongs to the Monophlebidae. These families have their representatives bearing "primitive" characters such as the presence of abdominal spiracles (lost in the Neococcoids), or the compound eyes of the males.
Dissertation project
My research project aims to reconcile the study of fossil taxa (paleontology) and extant taxa (neontology). Attempting to incorporate fossils of scale insects preserved in amber in a phylogeny including extant taxa may help understanding the relationships of the archeococcoid families.
