Chalcid Wasps Overview

Definition

• Chalcid wasps: Derived from Greek 'khalkos' meaning 'copper', referring to their metallic color.
• Part of the Chalcidoidea superfamily within the order Hymenoptera.

Diversity

• Contains about 22,500 known species.
• Estimated total diversity exceeds 500,000 species, suggesting most species are undiscovered.

Terminology

• "Chalcid" often confused with "Chalcidid":
  • "Chalcidid" refers to the family Chalcididae.
  • "Chalcidoid" refers to members of the superfamily Chalcidoidea.

Time Range

• Existence from the Cretaceous period to the present.

Scientific Classification

• Domain: Eukaryota
• Kingdom: Animalia
• Phylum: Arthropoda
• Class: Insecta
• Order: Hymenoptera
• Suborder: Apocrita
• Infraorder: Proctotrupomorpha
• Superfamily: Chalcidoidea

Physical Characteristics

• Generally small, averaging 1.5 mm, usually less than 3 mm.
• Metallic body color.
• Wings: Developed, reduced, or absent; if developed, often with reduced venation.
• Morphological diversity with sizes ranging from 41.7 mm (females of Doddifoenus wallacei) to 0.13 mm (males of Dicopomorpha echmepterygis).

Biological Roles

Parasitoids

• Most are parasitoids preying on:
  • Insects, spiders, ticks, mites, pseudoscorpions, and gall-forming nematodes.
• Host range varies from broad to specific.
• Includes primary, secondary, and tertiary parasitoids; ecto- and endoparasitoids; solitary and gregarious.

Herbivorous

• Found in families such as Agaonidae, Epichrysomallidae, etc.
• Agaonidae develop within figs.

Predation

• Some Encyrtidae prey on coccid eggs; some Eurytomidae prey on Cynipidae larvae.

Importance in Ecosystems

Biological Control

• Essential for controlling pest insects in natural and agricultural ecosystems.
• Trichilogaster acaciaelongifoliae used for controlling the weed Acacia longifolia.

Agricultural Pests

• Some act as pests, attacking plant seeds.
  • Bruchophagus: Seeds of legumes.
  • Systole: Seeds of Apiaceae.
  • Megastigmus: Seeds of Pinaceae.

Pollination

• Females of Agaonidae pollinate figs.

Scientific Research

• Trichogramma and Nasonia used as model organisms.
• Studies on sex determination, bacterial endosymbionts, and genetics of speciation.
• Copidosoma floridanum genome sequenced in i5K project.

Family Classification

• Chalcidoidea family classification is subject to change with molecular systematics.
• Comprises fifty extant families and three extinct families.
• Notable families include Agaonidae, Aphelinidae, Chalcididae, etc.

Extinct Families

• Diversinitidae, Khutelchalcididae, Protoitidae.

Additional Resources

• Universal Chalcidoid Database for images and more information.
• Resources available at MorphBank and Ponent for visual aids.