Defoliators: Sawflies

Question 1

2 major suborders

Answer 1

Symphyta: associated with plants
-feed on plants
- abdominal segment (1st) is the propodeum (looks attached to the thorax)
-broad waste without the propodeum means they eat plants

Apocrita: associated with anything but plants
-narrow waist with propodeum means they do not feed on plants

Question 2

General characteristics of Sawflies

Answer 2

Not flies: adult females have an ovipositor with a serrated tip (saw-like)
-slices plant tissue and lays eggs in it
-pests of 2-20ft tall plants/trees
-adults are not the defoliators
-larvae feed on foliage (leaves and needles)
-anti-predator defense: start twitching/flicking and then will vomit out/exude resinous droplets

Question 3

Morphology as adults

Answer 3

Antennae that varies between male/females
-males=super feathery antennae that will pick up female pheromones
-females=regular, pointy antennae
-

Question 4

How to distinguish sawfly larvae

Answer 4

Count the prolegs! (On abdomen)
-Leps- 5 pairs or fewer
-have hooks known as crochets
-6 simple eyes (seen in lab)

-sawfly- 6-8 pairs
-1st abdominal segment is skipped
-no crochets! Smooth!
-simple eyes (light sensing organs). 1 on either side of head

Question 5

From other larval sawflies

Answer 5

Color, markings, what host plants, larval feeding period

Question 6

Several ways to organize sawflies

Answer 6

Taxonomically:
-Diprionidae: mostly feed on pines
-Tenthridinidae: mostly feed on spruce, for, hardwoods

Question 7

Seasonal feeding groups

Answer 7

Spring: less damaging, Eggs are overwintering stage.
-find eggs on previous years needles
-feed on older foliage only
-univoltine

Summer: much more damaging, will defoliate nursery stock and can kill them
-prepupae or pupae in the duff layer in spring
-feed on older foliage in early summer but in late summer, new and old
-bivoltine

Question 8

Management

Answer 8

Seldom necessary BUT small, ornamental trees, nursery, Christmas tree plantation, etc might need management

Mechanical: Prune the tree for light infestations when skeletonizing their first tuft of needles

Chemical: contact insecticide as needed

Biological: virus control on the market for sawflies somewhere

Question 9

Red headed Pine sawfly

Answer 9

Summer
Prefers red and jack pine

Question 10

Introduced pine sawfly

Answer 10

Summer
2 generations
Prefers white pine
Solitary feeders

Question 11

European pine sawfly

Answer 11

Spring
Only feed on previous years needles

Question 12

Larch sawfly

Answer 12

Summer
One generation
Lays eggs into shoots (cause growth deformity)

Question 13

Yellow head spruce sawfly

Answer 13

Summer
Does NOT have a yellow head
Brown head

Question 14

Green alder sawfly

Answer 14

Breaks rules for spring or summer sawfly
Eggs can be found anytime
Defoliates alders