Identification of Insects and Mites

Lepidoptera (Moths, Butterflies, and Skippers)

I. Background information

A. Origin of name

1. lepido(s), scaly; ptera, wings

B. Classification

1. 110,000 families worldwide
2. 75 families, 11,000 species in North America
3. Old: moths - Heterocera; butterflies and skippers - Rhopalocera
4. New: 5 suborders
   1. Zeugloptera
      1. Adults have mandibulate mouthparts
      2. Similar venation on front wing and hind wing
      3. No spurs on middle tibia
   2. Dacnonypha
      1. Similar venation on front wing and hind wing
      2. Adults have vestigial mandibles
      3. Females - horny piercing ovipositor
      4. Exarate pupae - appendages are free and not glued to the body
      5. Larvae - leafminers
      6. Middle tibia with spurs
   3. Exoporia
      1. No coiled proboscis
      2. Mandibles and maxillae present
      3. Large wing span 25-100mm
      4. Similar venation on front wing and hind wings
      5. Legs without tibial spurs
      6. Called "swifts"
   4. Monotrysia
      1. Short proboscis
      2. Front wing and hind wing not similar in shape or venation R1 and RS reduced
   5. Ditrysia - most moths and butterflies
      1. wing venation diverse
      2. RS not branched in hind wing
      3. coiled proboscis present but can be rudimentary
      4. no function mandibles

C. Common names

D. Type of metamorphosis - complete

E. Phylogenetic relationships

1. Earliest fossil record - Lower Tertiary
2. Closely associated with flowering plants which evolved in the Cretaceous (just before the Tertiary)
3. Close relation to Trichoptera - both evolved from a panorpoid ancestor

II. Morphological characteristics

A. Head - large compound eye; most without mandible; most with proboscis

B. Cervix - connects head to thorax; sometimes paired sclerites are present

C. Thorax - front legs present, but may be modified

D. Epiphysis - spur-like structure on protibia; most butterflies have them to clean antenna

E. Tympanum

1. "Ear" on metathorax of Noctuid's, Notodontid's, Arctiid's, Lymantridae
2. Behind wing, close to abdomen
3. Channel changers - bats

F. Wings

1. Wing - coupling 2 basic types
   1. Frenulum - spine on hind wing that projects into modified setea on front wing
   2. Wing venation - very important but beyond the scope of this class
      1. generally "full" venation based on Comstock-Needham systems
      2. difference between front and hind wings
      3. mounted specimen - wet underside of wing with alcohol
      4. slide mound 95% - xylene - Canadian balsan on slide
2. Lobes - expanded aread of the wing that overlap or push on adjacent wings
   1. examples
      1. fibula - lobe on top of hind wing
      2. jugum - lobe overlaps hind wing
      3. expanded humeral angle of hind wing

G. Scales - modified setae - 2 kinds

1. Macrotrichia
   1. large articulated hair-like to flattened form (scales)
   2. nearly all colors from scales
2. Andronconia - scent scales
   1. outlets for scent glands
   2. STIGMA are patches of androconia either scattered or in stigma

H. Abdomen

1. 10 Segments, 1st reduced
2. 1st segment with tympanum in the Pyralid's, Geometrid's, Drepanid's (hook-tip moth) and related families
3. Male genitalia important for species identification

III. Biological summary for the order

A. Life history

1. Most are one generation a year
2. Usually overwinter as larva or pupa
   1. some as eggs
   2. very few as adults
3. Some - multiple generation per year
4. Some - several years per generation

B. Habitat and habits

1. Adults - fly and frequent vegetation usually
   1. most moths fly at night (nocturnal)
   2. most butterflies and skippers fly during the day (diurnal)
   3. don't feed much - nectar and pollen or not at all
2. Larvae - do most of the feeding and habitat is determined by food source
   1. include plants, aquatic plants, dead plants (dry), fruit, nuts, fungi, lichens, parasites, dead meat, hair/wool, dung, carrion
3. Pheromones
   1. volatile chemicals released to be detected by members of the same species
   2. usually female to male moths
   3. usually distinct for each species - can be used to distinguish species

C. Collecting and preserving

1. Black lights
2. Bait - sugar, dead animals, dung, puddle clubs
3. Nets for dayflying (extend-a-poles)
4. Pinned spread and dried with minimum of scale disturbance, or
5. Rear for perfect specimens or to associate larvae with adults (be sure to save cast larval skins)

D. Significance

1. Many are pests (larval pests)
2. For many crops, the major pest is a caterpillar
3. Defoliator, borers
4. Gypsy moth, European corn borer, armyworms, meal moths
5. Many pests are in the families Noctuidae, Pyralidae, Tineidae