Biological study of Tuta absoluta (Meyirck) (Lepidoptera: Gelechiidae) on tomatoes and potatoes in Fars province

Abstract

Introduction: Tuta absoluta (Meyrick) is one of the most important pests of tomatos
and potatos, causes lots of damage and reduces the quality and quantity of the crop.
Materials & Methods: This experiment was performed as completely randomized
blocks with 10 replications in Shiraz in 2017-2018 with two factors including plant type
(Tomato and Potato) and cultivation conditions (greenhouse and field).
Result: The results of analysis of variance of biological parameters of the pest on
tomatoes and potatoes in greenhouse and field conditions showed that the type of host
plant and cultivation conditions on embryonic, larval, pupal stage (only in host plant
type) and female lifespan were significant at the level of 1% and 5%, but their interaction
was not significant. The results showed that the maximum and minimum life span of
embryonic, larval and pupal stages of the pest were treated by a2b1 with 6.9 and a1b2
with 4.3 days a2b1 with 14.5 and a1b2 with 11.7 days, a2b2 with 9.5 and a1b2 with 4.7
days while the maximum and minimum lifespan of the female belonged to the treatment
of a1b2 with 17.2 and a2b1 with 9.9 days. Also, the type of host plant and culture
conditions were significant on the average total spawning rate of female insects at the
level of 1% but their interaction was significant. Moreover, the results of insect
oviposition revealed that the highest and lowest number of eggs were in the treatment of
a1b1 with 128.6 and a2b2 with 86.1 eggs, respectively.
Conclusion: The high nutritional quality of tomatoes compared to potatoes and also the
short life cycles of insects on tomatoes make tomatoes preferable to potatoes.