Collection, Preservation and Rearing of Insect Samples March 27, 2009

The Entomologist at the Crime Scene Should be at scene with initial investigation team Should have access to autopsy Request scene photos Proper collection kit

Collection kit Net Vials and Kill Jars Forceps and small paint brushes Live specimen containers, foil, vermiculite, and food Labels (adhesive and non-adhesive) #2 graphite pencil Hand trowel or garden spade Thermometers Camera Ruler Preservation and collection chemicals (Ethyl alcohol ethyl acetate) Small backpacking stove or other heat source and Beaker, Water Paper towels Disposable gloves Sifting screens Death scene form

Scene Observations and Weather Data Contact officer in charge Observations of the scene (use death scene form) General habitat/location of body Sun, shade, vegetation, proximity to doors/windows (esp. if open) Insects and stages, locations Vertebral scavenging Predation of insects Possible insect artifacts on body

Collection of meteorological data at the scene Ambient air temperature (approx. chest height) Maggot mass temperature Ground surface temperature Between body and ground Soil under body Max/min daily temperatures at scene for 3-5 days

Weather data Approx. 2 weeks before--3-5 days after discovery Nearest weather station Max and min daily temperatures Rainfall

Insect collection at the scene: From the Body Adults first Pinned/in alcohol Label correctly--inside and out Use pencil only Larval Collection Largest most important preserved, others live for rearing Representative sample of everything Geographical Location Date/hour of collection Case # Location on Body Name of Collector

Insect collection at the scene: Around the body Exam area around in body Concentric circles Soil samples Beneath body esp. near maggot mass Litter Samples

Insect collection at Autopsy May find different stages Clothing, body bag, other areas of bodies Take into account cooling

Chain of Evidence

Identification and Rearing Identify largest insects first Maggots may be hard to identify Rear out live insects to identify adults Estimate degree days

Larvae Identification Larvae look similar Easiest to identify 3rd instar Spiracles, mouth hooks Larger, easier to see 1st and 2nd instar: 2 spiracle slits 3rd instar: 3 spiracle slits

Larvae Identification Mouth hooks Spiracles Move by extension/contraction of body Change slightly each instar PS: pharyngeal sclerite DC: dorsal lobes of PS VC: ventral cornua of PS HS: hypostomal sclerite MS: mandibular sclerite DS: dental sclerite MH: mouth hook DO: external dorsal sensory organs Muscid PhormiaLucillia

PeritremeOuter slit Middle slit Inner slit Button

Identification and Rearing Identify largest insects first Maggots may be hard to identify Rear out live insects to identify adults Estimate degree days

Any Questions?