Flight Activity and Mating Behavior of IrradiatedSpodoptera litura(Lepidoptera: Noctuidae) Males and Their F₁Progeny for Use of Inherited Sterility in Pest Management Approaches

Abstract

The dose of radiation applied to the Oriental leafworm (also known as the common cutworm), Spodoptera litura (F.) (Lepidoptera: Noctuidae) for use in inherited sterility (IS) sterility programs must not materially reduce the quality and competitiveness of the released males. To assess the quality of sub-sterilized male moths and their F 1 progeny, their flight and mating behaviors were investigated. Thus, parental (P) generation S. litura males that had been irradiated with either 100 or 130 Gy and their F 1 male descendants were subjected to flight assay tests to assess flight ability, orientation towards a pheromone source and mating behavior, i.e., mating performance using various sex ratios, sequential matings, and effect of female age. The orientation behavior of either P or F 1 males towards pheromone-baited traps was not different from that of non-irradiated males. Mating abilities of irradiated P generation males and their F 1 male progeny with non-irradiated females were studied using several sex ratios, but large differences were not found even when the sex ratio was increased from 1:1 to 5:1. A study on sperm use patterns revealed the precedence of sperm of the last male to mate, for example, when a non-irradiated female was sequentially mated with a non-irradiated P male, followed by an irradiated P male and finally by an F 1 male, as well as in all other possible sequences of such males. Mating success, remating propensity and fertility were significantly influenced by mating sequences that included irradiated males. Further, the age of the female at the first mating influenced fertility in matings with F 1 males, and mating success and remating propensity were reduced in several of sequences of matings involving non-irradiated and irradiated males and F 1 males, with reductions being more apparent when females were aged 5-6 d. The present study indicates that gamma doses of either 100 or 130 Gy are suitable for the suppression of S. litura using an IS approach.

Effect of X-ray irradiation on development, flight, and reproduction of Spodoptera litura

“…Furthermore, flying ability is an essential factor to be concerned in the SIT program ( Seth et al, 2016b ). According to Stephens et al (2006) , the flight ability of sterile painted apple moths was not significantly affected after being irradiated with γ-rays at 100 Gy.…”

“…As a result, populations for genetic sex separation (GSS) from released insects should be developed before SIT technology can be used on a large scale, such as C. capitata, Bombyx mori, P. gossypiella (Peloquin et al, 2000;Tamura et al, 2000;Sahara et al, 2003;Augustinos et al, 2017). Furthermore, flying ability is an essential factor to be concerned in the SIT program (Seth et al, 2016b). According to Stephens et al (2006), the flight ability of sterile painted apple moths was not significantly affected after being irradiated with γ-rays at 100 Gy.…”

Reproductive Behaviour of 150-Gy-Treated Female Lobesia botrana (Lepidoptera: Tortricidae)

“…In other words, sperm from successive matings in L. botrana did not compete in a random manner, but the sperm transferred during the most recent mating was predominately utilized to fertilize the eggs. Complete last-male sperm precedence was found in many economic lepidopteran species, including Ephestia kuehniella (Zeller) (Lepidoptera: Pyralidae), Spodoptera litura (F.) (Lepidoptera: Noctuidae), and P. operculella [34][35][36].…”

“…Complete last-male sperm precedence was found in many economic lepidopteran species, including Ephestia kuehniella (Zeller) (Lepidoptera: Pyralidae), Spodoptera litura (F.) (Lepidoptera: Noctuidae), and P . operculella [ 34 , 35 , 36 ].…”

Overview of Technological Advances Toward Greater Efficiency and Efficacy in Sterile Insect-Inherited Sterility Programs Against Moth Pests

“…A study on sperm use patterns in Oriental leafworm males revealed the precedence of sperm of the last male to mate; also their mating success, remating propensity and fertility were significantly influenced by mating sequences that included irradiated males (Seth et al 2016b, in this special issue). Thus the age of the female at her first mating with an F 1 male influenced her fertility.…”