The effects of host plant
odours on the calling behaviour, egg maturation and
mating success of the cotton bollworm,
Helicoverpa armigera (Lepidoptera: Noctuidae)
Copyright
O.L.
Kvedaras 1 , P.C. Gregg 1 , A.P. Del Socorro 1 ,
D. Alter 1 & C. Moore 2
1
School of Rural Science and Nat. Res., Univ. of New
England, Armidale, New South Wales, Australia 2351;
2 Queensland Dept. of Primary Industries,
Yeerongpilly, Queensland, Australia 4105
The influence
of host plant odours on the calling
behaviour and egg maturation of the female
cotton bollworm, Helicoverpa armigera
was investigated. Host plants included
flowering cotton, maize and pigeon pea.
Females were held in cages for a period of 6
days from the time of emergence and exposed
to either no host (control) or a host plant.
The time calling was initiated, time spent
calling and the mean number of calling bouts
were recorded. A selection of females that
initiated calling for the first time 1-6
days after emergence were sacrificed to
determine the stage of ovarian development
at the onset of calling. In a separate
experiment the sex pheromone released by
individual calling females of H. armigera
was trapped within the stem of Pasteur
pipettes. Individual females were exposed to
host plant odours and one female was exposed
only to filtered air as a control. Host
plants included, cotton, pidgeon pea and
sunflower. The time spent calling was
recorded and the amount of pheromone trapped
quantified. Pheromone collection and
behavioural observation commenced halfway
into scotophase which is generally when
female H. armigera start calling.
Trapped pheromone was analysed by Gas
Chromatography-Mass Spectrometry. Field
studies were conducted in the Darling Downs,
Queensland, Australia, during the 1996/97
and 1997/98 cotton growing seasons. Mating
tables were used to determine the mating
success of H. armigera. Moth
abundance was assessed using light and
pheromone traps. A series of comparisons of
three or four crops were used. They
included: mature corn; immature, flowering
and mature cotton and soybeans; immature and
flowering sunflower and sorghum. Fallow land
was also included. Laboratory reared virgin
females with their wings clipped were placed
in mating tables in various crops where they
remained until collection and dissection the
following morning to determine whether they
had been mated. These studies indicate that
host plants did not significantly influence
the chance of being mated, despite
substantial variation in moth abundance
between the crops.
Index
terms: Helicoverpa armigera, host
plants, mating tables, ovarian development,
sex pheromone
Copyright:
The copyrights of this original work
belong to the authors (see right-most
box in title table). This abstract
appeared in Session 4 – CHEMICAL AND
PHYSIOLOGICAL ECOLOGY Symposium and
Poster Session, ABSTRACT BOOK I –
XXI-International Congress of
Entomology, Brazil, August 20-26, 2000.
|
|
Click on the picture to go to
Dr. Miller's Lab Web Page. |
|
Click on Picture to go to the
link |
Page Designed by
Harald Baella. Last updated
04-27-05
Copyright © 2003-05 Miller Web Design.
|