Dysschema sacrifica Hubner (Lep: Arctiidae)
from Brazil: A Biological Control Candidate for C. odorata
(L.) R.M. King & H. Robinson (Asteraceae) in South
R.L. Kluge and P.M. Caldwell
Plant Protection Research Institute
Cedara Weeds Laboratory
Private Bag X 9059
Republic of South Africa
odorata is thought to have been introduced into South Africa
in the 1940s. Spreading rapidly, the plant now occurs along
the Natal and Transkein coastal belts. It is also a serious
weed of crops, plantations and pastures in southern Asia and
arctiid moth, Dysschema sacrifica Hubner1 was collected on
C. odorata (unconfirmed but closely resembling our local
form) about 50 km north of Rio de Janeiro, Brazil, and
imported into South Africa for preliminary screening as a
biological control candidate of C. odorata in South
larvae were reared through to maturity on the local form of
C. odorata in a quarantine laboratory maintained at
20-26°C. The adults were kept in fine gauze cages (40 x
40 x 50 cm or 90 x 90 x 90 cm) with C. odorata bouquets.
was poor and only five of the 60 females laid eggs. The
number of eggs in each batch was 392, 328, 263, 215 and 53
respectively. The flattish, dome-shape eggs were
approximately 1 mm in diameter and cream colored. The eggs
hatched after nine days.
are seven larval instars ranging from 2-30 mm in length. The
larvae are yellow with maroon lines running the length of
the body between the tubercles and the legs. The number and
definition of these lines increases with succeeding instars.
The body is covered with long dark brown to black setae. The
head is dark brown to black and the anal plate is yellow
with a central dark spot.
overall color of the adults is dark grey to black with pale
yellow markings on the abdominal segments. A broad white to
pinkish band runs across the length and the width of the
forewings. The hindwinds of the female and male are grey and
white, respectively, with red, black and cream markings
along the fringe which are bolder in the female.
total of 11 test plants were screened against newly hatched
D. sacrifica first instar larvae. These included C. odorata
and three near relatives, i.e. Ageratina adenophora,
Ageratina riparium and Ageratum houstonianum; four composite
weeds, i.e. Bidens pilosa, Tagates minuta, Galinsoga
parviflora and Wedelia glauca, and another common weed,
Lantana camara all from South America; and two commercially
important species, Chrysanthemum sp. and Dahlia rosea.
of succulent apical growth tips of the test plants were
offered to the larvae in 90 x 25 mm glass tubes with
absorbent cotton-wool stoppers. Wet cotton wool was wrapped
around the cut end of the bouquets. Bouquets were changed
about twice a week or replaced as required. Ten newly
hatched first instar larvae were transferred to each test
plant. Feeding and survival of the larvae was recorded
on the survival of the larvae, the test plants can be
divided into three groups. All the larvae died in the first
instar on plants in the first group: A. adenophorum, A.
riparium, G. parviflora and Chrysanthemum sp. A few feeding
lesions and faecal pellets were recorded on A. adenophorum,
A. riparium, G. parviflora and W. glauca.
the second group, larvae developed through to the second
instar on A. houstonianum and T. minuta making numerous
feeding lesions on the leaves.
the third group some larvae completed their development on
C. odorata, D. rosea, L. camara and B. pilosa. B. pilosa was
the best and most consistently acceptable host yielding 15
pupae (50%). The performance of the larvae on the other
three plants was variable; a few pupated (in total four) but
in some replicates all the larvae died in the early
results would suggest that this arctiid is oligophagous and
not host specific to C. odorata. D. sacrifica is, therefore,
not suitably host specific to be considered further as a
biocontrol candidate for C. odorata.
1 Identified by M. R. Honey of the British Museum. Pinned
specimens (AcCe 1) are housed at the National Collection of
Insects, Private Bag X134, Pretoria 0001, South Africa.