HEMIPTERA (TRUE BUGS): Cicadas and Plant Hoppers
 All members of this group are plant feeders, and many are vectors of fungal and viral diseases of plants. Entomologists do not know what the big, long “noses” on the lanternflies (A) are used for. Notice how tree hoppers (H) have bodies the shape of thorns on plants.

A. Lanternflies (Fulgoridae )
B. Cicadas (Cidadidae)
C. Froghoppers (Cercopidae)
D. Planthoppers (Cicadellidae)
E. Dictyopharid hoppers (Dictyopharidae)
F. Flatid hoppers (Flatidae)
G. Scale insect (Margarodidae)
H. Treehoppers (Membracidae)

HEMIPTERA: True Bugs
Most hemipterans feed on plants, using their sucking and piercing mouthparts to extract plant sap. Some are bloodsucking, while others are predators that feed on other insects or small invertebrates.

A. Water scorpion (Nepidae)
B. Water strider (Gerridae)
C. Creeping water bugs (Naucoridae)
D. Backswimmers (Notonectidae)
E. Giant water bugs (Belostomatidae)
F. Toad bugs (Gelastocoridae)
G. Water boatmen (Corixidae)
H. Plant bugs (Miridae)
I. Bed bugs (Cimicidae)
J. Ambush bugs (Phymatinae)
K. Flat bugs (Aradidae)
L. Stink bugs (Pentatomidae)
M. Shield bugs (Scutellaridae)
N. Squash bugs (Coreidae)
O. Assassin bugs (Reduviidae)
P. Seed bugs (Lygaeidae)
Q. Scentless plant bugs (Rhopalidae)

AQUATIC INSECTS
Primitively insects were terrestrial, but during their evolution there have been multiple times when insects invaded freshwater habitats. Some of these insects spend only a portion of their life in the water (semi-aquatic) while others are entirely restricted to the water (fully aquatic). Look at these different insect orders and see where they are placed on the interactive phylogenetic tree. Notice that they are spread out across the entire tree.

A. Hemiptera (True bugs)
B. Plecoptera (Stoneflies)
C. Trichoptera (Caddisflies)
D. Coleoptera (Beetles)
E. Odonata (Dragonflies and Damselflies)
F. Megaloptera (Dobsonflies)
G. Ephemeroptera (Mayflies)
H. Diptera (flies)

VARIATION IN A SPECIES
Just as there is variation among individual humans, there is variation in populations for all species. This is the variation that natural selection works on during evolution. When entomologists collect insects, they try to collect more than one individual so that they have a “series” of specimens from the same collecting event. By collecting more than one specimen, we can better understand this variation for these species.

These rhinoceros beetles are all males that occur in Utah. Notice the variation in horn length, body size, and coloration along their backs.