"Specimen" - what is it, definition of the term
A specimen is an individual organism or part of an organism collected for scientific observation, documentation, or analysis; in entomology it denotes a single representative of arthropods such as ticks, true bugs, lice, or fleas, preserved or examined to illustrate morphological characteristics, taxonomy, life‑cycle stage, or physiological traits.
Detailed information
A collected individual of ticks, true bugs, lice, or fleas serves as the primary material for identification, research, and disease monitoring. Specimens are obtained from hosts, environments, or traps and must be handled to preserve diagnostic features.
Taxonomic placement of these arthropods follows a hierarchical structure. Ticks belong to the subclass Acari, order Ixodida. True bugs are members of the order Hemiptera, suborder Heteroptera. Lice are classified within the order Phthiraptera. Fleas fall under the order Siphonaptera. Each group exhibits distinct morphological traits that separate it from the others.
Key morphological characteristics:
- Ticks: dorsoventrally flattened body, scutum (hard shield) in adult males, capitulum bearing chelicerae and palps, eight legs in all stages.
- True bugs: elongated hemelytra covering forewings, piercing‑sucking mouthparts (rostrum), scent glands on the abdomen, six legs.
- Lice: laterally compressed body, reduced eyes, clawed tarsal segments for grasping hair shafts, three pairs of legs throughout life.
- Fleas: laterally flattened body, robust hind legs adapted for jumping, genal and pronotal combs in some species, siphonate mouthparts for blood feeding.
Standard procedures for handling include:
- Capture using fine‑tipped forceps or aspirators to avoid damage.
- Placement in ethanol (70 %–95 %) for molecular work; slide‑mounting in Hoyer’s medium for morphological study.
- Labeling with collection date, locality, host species, and collector’s name.
- Storage at low temperature to prevent degradation of nucleic acids.
Research and diagnostic applications rely on these samples to determine species distribution, assess vector competence, and detect pathogen presence through microscopy, PCR, or serological assays. Accurate documentation of each individual enhances epidemiological surveillance and informs control strategies.