Other bark beetles Flashcards
Dendroctonus pseudotsugae:
host, ID features, life cycle, problems
HOST: Fd, sometimes Lw
LIFE CYCLE:
- 1 yr, similar to IBM but attacks weakened or fallen trees;
- over winters as adults and larvae;
- main flight in May-June(over winter adults)
- Second flight in July-August(overwinter pupae and/or re emerging adults)
Epidemic conditions occur in years following abnormal blowdown events, causing IBD to become primary agent in mortality of standing live trees.
Mature weakened trees most desirable.
PROBLEMS:
- No pitch tubes, woodpecker activity not common
- majority of attacks occur above 2 m
- sometimes needles drop without discoloration
Dendroctonus rufipennis:
host, ID features, life cycle, problems
HOSTS: Se, Sw, Sx, Ss
LIFE CYCLE:
- Normally 2 years to complete
- 1-3 years depending on environmental conditions
- can overwinter as larvae or adults, but must over winter as an adult before attacking new host
live healthy trees attacked when downed material is running out
IDENTIFICATON:
- boring dust in bark creivces and at base of tree
- woodpecker activity
- larvae with 2 anal shields
- no foliage discoloration for 18 months
- needles may drop before discoloration
- sometimes very small pitch tubes
- foliage turns bright red, yellowish green to grey
Dendroctonus brevicomis:
host, ID features, life cycle, problems
HOST:
- Mature Py stressed by drought or root disease
- epidemic levels-younger healthier trees also attacked
Initial attack in middle bole, later attacks occupy tree above and below
1 generation/year at higher elevations, potential for 2 generations/year at lower elevations
ID:
- winding egg galleries
- frass and small pitch tubes
- woodpecker activity
- first instar in phloem, then moves to outer bank
Ips spp:
host, ID features, life cycle, problems
- secondary agent-weakened or dead hosts
- can attack healthy trees when populations are high
- males attack first, construct nuptial chamber, send out pheromones, 1-5 females join him
- 1-3 generations/year
DETECTION:
- Y shaped gallery (ips pini)
- No frass in galleries
- concaved depression, spines on elytra(wing case of beetle)
Scolytus spp:
host, ID features, life cycle, problems
- Host: True firs (fd, sx)
- Attack weakened trees pole size and larger
- also in slash
ID:
- Galleries
- Adult has incurved abdomen
Dryocoetes confusus:
host, ID features, life cycle, problems
- HOST: mature Bl (Ba, Sx)
- significant damage province wide
- males construct nuptial chamber, attract 3-4 females.
- 2 year life cycle, females can lay up to 3 broods
- overlapping life cycles, assessment difficult
- attack occurs mid bole
- incidence usually less than 5%, but a chronic problem in ESSF stands
ID:
- Frass, galleries
- red-brown hairs covering adults
- red foliage in years (1-5) following attack
Dendroctonus murryanae:
host, ID features, life cycle, problems
- Not aggressive like IBM. attacks lower bole and root collar of Pl
- Pitch tubes occur at root collar
- Like IBS, two anal shields on larvae
- galleries run together and become indistinct
Dendroctonus valens
- Host: mature Py and Pl
- largest of dendroctonus spp, aduts avg 8mm, red brown color
- attacks lower bole or root collar
- creates VERY large pitch tubes
- not an aggressive killer, weakens trees
