The ambrosia beetle, Xylosandrus crassiusculus, is a wood-boring insect found in various regions including India and the coastal forests of North America, known for creating tunnels in host trees and feeding on symbiotic fungi. Identification features include small size, dark reddish-brown coloration, and smooth bodies, with females being slightly larger than males. Management strategies include removing affected plants, trapping emerging beetles with bait, and using chemical sprays such as pyrethroids to prevent infestations.

1. Ambrosia Beetle Xylosandrus crassiusculus
Taxonomy
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Coleoptera
Family: Scolytidae
Genus: Xylosandrus
Specie: crassiusculus
• Scientific Name:
Xylosandrus crassiusculus

2. Ambrosia Beetle Xylosandrus crassiusculus
India, Bangladesh,
Myanmar, Taiwan, Japan,
Coastal forest of British
Columbia,
South east Alaska,
Coastal forest of Washington,
Oregon and northern California.

3. Ambrosia Beetle Xylosandrus crassiusculus
Hosts
Dog wood, Magnoli
Redbud Cacao, Camphor,
Coffee, Mahogany,
Mango, Papaya,
Rubber, Tea,
Teak, Beech,
Cherry, Chinese elm,
Crape myrtle, Golden rain tree,
hickory, locust,
maple, mimosa,
Oaks, peach,
percimon, Tulip,
Walnut, sweet gum,
Australian pine.

4. Ambrosia Beetle Xylosandrus crassiusculus
Hosts
Beach Tree

5. Ambrosia Beetle Xylosandrus crassiusculus
Hosts
Brich Tree Dog wood Tree

6. Ambrosia Beetle Xylosandrus crassiusculus
Hosts
Pine Tree Cone Red Cedar

7. Ambrosia Beetle Xylosandrus crassiusculus
Hosts
Willow Tree Pond Spice

8. Ambrosia Beetle Xylosandrus crassiusculus
Hosts
Spruce Tree

9. Ambrosia Beetle Xylosandrus crassiusculus
Identification
Adults
1. Female are 2.1-2.9 mm long.
Males are much smaller
2. The body is smooth and shining
3. Adult color is dark reddish
brown, darker on the elytral
declivity.
4. Male are flight less
5. Ambrosia beetle bore and feed
on fungi that cultivate on the
wall of the tunnel.

10. Ambrosia Beetle Xylosandrus crassiusculus
Identification
Larva
1. Larvae are white legless,
”C”shaped and have well
developed head capsule.
2. Eggs larva and pupae are
found together in the
tunnel system.
3. There are no individual
eggs niches, larval tunnel
or pupal chamber.

11. Ambrosia Beetle
Xylosandrus crassiusculus
Introduction
1. Ambrosia beetle are small dark wood-boring insects.
2. Ambrosia beetle are known as ambrosia because the
adults and larvae/grubs feeds on a fungus, called
ambrosia.
3. These beetles are also known as pin worms, pinhole
beetles and shot hole borer.
4. The beetles and the fungus are in symbiotic relation
with each other.
5. The spores of the fungus are carried by the adult
beetle into wood galleries.

12. Ambrosia Beetle Xylosandrus crassiusculus
Identification
Introduction
6. These beetles make galleries/tunnels in dead,
weakened and unseasonal logs.
7. Galleries are mostly initiated by male beetles.
8. But some species may also attack on living trees.
9. About 3,000 beetle species are recorded in
different wood trees.
10.Most species of beetle doesn’t ingest the wood
tissues.

13. Ambrosia Beetle
Xylosandrus crassiusculus
Life History
1. Adult emerge in spring and look for new sites to make
tunnels and lay their eggs.
2. Female breed in large diameter of host plant.
3. They bore into the trees, but do not digest the wood.
4. They introduce a fungus called ambrosia but
sometime other fungi may be also introduced, such as
Fusarium.
5. Eggs, larvae, pupae and adults are found together.

14. Ambrosia Beetle
Xylosandrus crassiusculus
Life History
6. High humidity is required for successful reproduction.
7. Males are small, rare, and flightless and probably
remain in the galleries.
8. Females remain with their brood until maturity.
9. Female mate with the males of new generation just
before emerging from the galleries to attack a new
host.
10. Life cycle is completed in about 2 months when
environmental conditions are favorable.
11. The beetles produce 2 generations per year.

15. Ambrosia Beetle Xylosandrus crassiusculus
Identification
Damages
1. The female bore into
trunk, twigs, branches of
the susceptible woody
plants and excavate a
system of tunnel in the
wood
2. While making tunnels,
push the frass out of the
galleries in a typical
toothpick fashion.

16. Ambrosia Beetle
Xylosandrus crassiusculus
Damages
3. The beetle inoculate the
galleries with symbiotic
ambrosia fungus.
4. And produce a brood and
feed on ecto-symbiotic
fungi which they introduce
to their tunnel.
5. Gallery patterns vary with
the diameter and species of
the host material.

17. Ambrosia Beetle
Xylosandrus crassiusculus
Management
1. Affected plants should be
removed and burnt.
2. Emerging ambrosia beetle
can be trapped using an
ethyl alcohol bait trap
3. Prevent stress as much as
possible by watering the
tree deeply during dry spell.
4. Regular fertilization

18. Ambrosia Beetle
Xylosandrus crassiusculus
Management
Chemical Control
1. Spray that contain pyrethroids
are effective at preventing
ambrossia beetle.
a. Permthrin.
b. Cypermthrin.
c. Deltamthrin.
2. Organic product such as
pyrenone or pyganic can be
used