HOST-RANGE STUDY ON THE STEM-BORING WEEVIL
(LISTRONOTUS
SETOSIPENNIS
(COLEOPTERA:
CURCULIONIDAE) FOR THE CONTROL OF PARTHENIUM
HYSTEROPHORUS IN ETHIOPIA
By Sintu Alemayhu
OBJECTIVE
 To
evaluate the safety of the stem-boring
weevil, Listronotus setosipennis non-target
plant species
DESCRIPTION AND LIFE CYCLE

stem
boring
weevil
Listronotus
setosipennis
(Hustache) [Coleoptera: Curculionidae] originally
from Argentina, were introduced from Agricultural
Research
Council-Plant
Protection
Research
Institute (ARC-PPRI) of South Africa in December
2009, to be used for studies in Ethiopia
Listronotus setosipennis (Coleoptera: Curculionidae
Nocturnal adults feed on
leaves and flowers
Lay eggs in flower
heads or leaf bases
hatch 3-5 days later
pupate in soil inside Complete life cycle of Listronotus takes 30-35
days.
fibrous capsules
DAMAGE
o
Adult feeding damage is negligible.
o
Larval feeding has the ability to kill or prevent further
development of parthenium seedlings.

In glasshouse conditions, infestation by Listronotus
weevil at high densities significantly reduced the plant
biomass by 21.9% and flower production by 75%.
HOST SPECIFICITY
o
Host specificity testing is a critically important step
in the process of introducing natural enemies for
classical weed biological control.
o
It provides information upon which the suitability of
a proposed biological control agent can be
assessed (Marohasy1998).
CONT…

Evaluation of the host range of any bioagent comprises
of no-choice tests (test plant species only), followed by
choice tests (test plant with Parthenium) if feeding,
oviposition or development is observed under no-choice
testing on non-target species

The safety of Listronotus setosipennis (Hustache) to
non-target plants was tested under quarantine on
economically important members of the Asteraceae
family and indigenous weed species through no-choice
tests
SELECTION OF NON-TARGET SPECIES

The selection of non-target species for host preference testing
was made by a taxonomist from Addis Ababa University.

The centrifugal phylogenetic method was followed in selecting
test plants for testing candidate control agents

The test plant species were identified based on how closely
related they are to Parthenium, whether they are strictly
endemic, near endemic, cultivated, or indigenous to Ethiopia.
Figure 1. Diagrammatic representation of the tribe
Heliantheae and some crop plants (adapted by
Lorraine Strathie from Wapshere, A. J. 1974).
MATERIALS AND METHODS
Area description
 The
experiment was conducted under quarantine
condition at Ambo Plant Protection Research Center
(APPRC) 109km West of Addis Ababa.
 The
average temperature is ranges from 10o to 30o
C and relative humidity at 50-87 % in the quarantine
facility
CULTURING OF L. SETOSIPENNIS

Adult
feeding
and
oviposition were tested
using nylon mesh test
cages
with
metal
frames(0.5m x 0.5m x
1m), with two holes for
potted plants.

All corners and joints
were
sealed
with
silicone to prevent
escape
of
weevils
through gaps.

The safety of Listronotus setosipennis (Hustache)
to 39 non-target plants consisting of
 nineteen major crop species mostly used as
food and export
 Twenty crops and other plant species, belonging
to the family Asteraceae which includes two
species of Helianthus annus , six species
Guizotia abyssinica, both of which are important
oil crops in the country . and four species of
Bidens
CONT…
o
No-choice tests were designed to test whether the bio-agent
feeds, lay eggs and survive on a test plant when it has no
access to target weed Parthenium.
o
All the test plants were grown or transplanted into plastic
pots(22cm X 18 cm),
containing the mixture of sand 25%,
compost/humus 25% and 50% soil
o
grown up to the required test
stage by providing every
agronomic management under lath-house
CONT…
o
Healthy and similar size Plant with flowers, were
selected and placed in a cage after being washed
o
Five mating pairs of adult L. setosipennis, obtained
from same age group of adults that had been kept
for 2-3 weeks, were released into each cage.
o
Sodium hypochlorite solution (2%) was sprayed on
the leaves and soil to prevent any disease
occurrence.
o
The experiment was replicated three times in CRD
and one plant per cage was used.
CONT…

After 7 days of exposure all adults were removed
from each test plant and the number of adults that
survived, died and missed was recorded

All plant parts, including leaf axils, stems and
petioles, were carefully examined for ovipostion and
feeding. Eggs were counted after dissecting flowers
and examining plants under a microscope.
•The blue arrow shows frass
•The read arrow shows egg
Tagetes minuta
Helianthus annus (oissa)
Bidens pachyloma
G.abysinica (kuyyu)
Vernonia galamensis
Table 1. Result of Host-Specificity of Listronotus setosipennis (Hustache) on major crops
No
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19
Scientific Name
Parthenium
hystrerophorous
(control)
Eragrostis tef
Eragrostis tef
Sorghum bicolor
Zea mays
Hordeum vulgare
Triticum aestivum
Cicer arietinum
Lens cultinaris
Gossipium sp.
Sesamum indicum
Sesamum indicum
Sesamum indicum
Pisum sativum L.
Vicia faba
Lathyrus sativus
Solanum tuberosum
Solanum lycopersicum
Capsicum sp.
Corchorus sp.
Common name /
variety
partehnium
Total no of Total mean
egg
8648
38.96
S.D
S.E
50.01
3.37
Teff
Teff v DZ-c37
Sorghum
Maize
Barley
Wheat
Chick pea
Lentil
Cotton var, Arba
Sesame
var. Abasena
var. Tate
var.5
Field peas
Faba beans
Grass pea, Indian vetch
Potato local
Tomato
Pepper
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Evaluation of species related to Parthenium
Total mean S.D
S.E
niger seed
niger seed
niger seed
niger seed
niger seed
niger seed
sunflower
Total no of
egg
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Helianthus annuus (R.B)
sunflower
0
0
0.00
0.00
9.
10.
11.
12.
Carthamus tinctorius
Vernonia galamensis
Lactuca sativa
Safflower
Iron Weed
Lettuce
Bidens pilosa
Black jack
0
0
0
0
0
0
0
0
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
13
Bidens Pachyloma
Adeyabeba (Amharic)
0
0
0.00
0.00
14
15
16
17.
Bidens ghedoensis
Bidens sp
Guizotia scabra
Metch (Amharic)
Conyza bonariensis
Horseweed, Asthmaweed
0
0
0
0
0
0
0
0
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
18.
19.
Galinsoga parviflora
Tagetes minuta
0
0
0
0
0.00
0.00
0.00
0.00
20.
21.
Flaveria trinervia
Parthenium hysterophorus
Gallant soldier
Black mint
Clustered yellow tops
parthenium
0
8648
0
38.96
0.00
50.01
0.00
3.37
No
Scientific/variety name
Common name
1.
2.
3.
4.
5.
6.
7.
Guizotia abyssinica (Local)
G. abyssinica (Fogera)
G. abyssinica (ESTE)
G. abyssinica (Kuyu)
G. abyssinica (Shambu)
G. abyssinica (Ghinchi)
Helianthus annuus (oissa)
8.
CONCLUSION

The concern that the agent, Listronotus setosipennis, might
attack non- target crops and plants was resolved through a
quarantine test against crops and plants that are closely
related to Parthenium and others that are economically
important and indigenous to Ethiopia.

Therefore there was no need to go for choice test since no
oviposition took place in no choice test