Abstract:
Purpose : Fall Armyworm, Spodoptera frugiperda (J. E. Smith) (Lepidoptera, Noctuidae) was recently reported
for the first time in Sri Lanka in Oct 2018 as a new invasive pest of maize. Therefore, the objectives of present
study were to study biology and to evaluate feeding preferences of S. frugiperda on maize and selected vegetable
crops.
Research Method : During the experiment, newly hatched larvae were fed with maize, cabbage, okra, beans, radish
and brinjal leaves under laboratory conditions. Maize was used as the positive control. Duration of development from
larva to adult, pupal weight, pupal length, sex ratio, survival percentage, and oviposition (Choice and No-Choice test)
on different vegetable crops were evaluated.
Findings : Results of the feeding preference test envisaged that there was no host dependent variability
among neonate larvae for maize, cabbage, raddish and brinjal. The highest damage (50-75%) was reported
in larvae fed on okra, and (25-50%) damage was showed in beans after 24 hours of inoculation. The highest
survival percentage of larvae (80%) and shortest larval development period (23.8±0.3days) were reported
in larvae fed with maize where as it was the longest in brinjal. The highest oviposition (4.1±1.2 in Choice
test and 3.6±0.7 in No-choice test) was observed in maize compared to other crops. With the absence of the
most preferred host (maize) for oviposition, other hosts were used by the pest. During the off season Fall
armyworm could survive in alternate crops.
Research Limitations : Field observations were not carried out to confirm (validate) the laboratory
observations with the time limitation.
Originality/ Value : The research provides interest and idea about the survival mechanism of S. frugiperda
during off season of maize and potential alternative host plants of the pest. It identifies the possibility of
moving of S. frugiperda into five vegetable crops and thereby make awareness of the farmers about the pest
to follow the suitable management practice of the S. frugiperda.
