Egg cluster characteristics of fall armyworm, <em>Spodoptera frugiperda</em> (Lepidoptera: Noctuidea) in Sri Lanka under laboratory conditions

Abstract

Purpose: Spodoptera frugiperda is a recently introduced alien invasive pest in Sri Lanka which can be a threat to many crops including maize, paddy, sugarcane, green gram, vegetables and fruits. Identification of this pest at the egg stage is important in controlling the larval stages of development. Therefore, the present study was conducted to record the morphological and morphometric characters of the eggs of S. frugiperda for accurate identification at the initial stage.Research Method: Thirty-six egg masses of laboratory reared S. frugiperda were observed and measured under a dissecting microscope. Position of the egg clusters on plant, characters of the egg cluster and eggs, number of eggs per egg cluster and diameter of eggs were recorded. Findings:The study revealed that the female S. frugiperda laid eggs mainly on the underside of the leaf blade as clusters containing 9 -200 (73 ± 7) eggs. Eggs were mostly arranged as single layers and when arranged in multiple layers, the bottom layer had a larger number of eggs than the upper layers. Most of the egg clusters were irregular in shape and some were covered with hairs. Eggs were spherical and initially creamy white in colour that gradually turned light grey when about to hatch. The diameter of eggs ranged from 0.38 mm to 0.55 mm. Originality/value:The study documents the morphological and morphometric characters of S. frugiperda eggs for accurate identification. Early detection of the insect pest facilitates the management of their population before causing an economic damage.

A possible terrestrial egg cluster in driftwood from the Lower Jurassic (Late Pliensbachian) of Buttenheim (Franconia, Germany)

“…Some extant Lepidopterans produce mono-layered and crescent-sized egg clusters which are similar in size of their egg capsules and in shape of the cluster to our fossil, for example, Spodoptera frugiperda (see fig. 02(f), Kasige et al 2022).…”

Augmentative Biological Control of Spodoptera Frugiperda Using Trichogramma Species: A Review

“…While some eggs are laid in multiple layers, most are found in a single layer of foliage. The eggs are very small, have a shiny exterior, and possess a uniform colour that changes from cream to pale yellow, pearl-white, and ultimately light grey as they mature (Kasige et al, 2022). S. frugiperda egg clusters are covered with hair-like strands released by the female moth's anal area, which are physical barriers against predators and prevent rain damage.…”

“…frugiperda eggs with multiple layers are harder for parasitoids to penetrate and lay eggs compared to single-layer eggs (Beserra et al, 2005;Hou et al, 2022;Jin et al, 2021), likely due to the layered structure serving as a defense mechanism against parasitoids. As a result, Trichogramma species have lower natural infestation rates on fall armyworm eggs (Beserra et al, 2002;Kasige et al, 2022). While Trichogramma species struggle to penetrate multiplelayered S. frugiperda eggs, they can parasitize eggs on the top, edges, and single-layer egg masses (Maize et al, 2020).…”

Diversity and Habitat Preferences of Moths (Insecta: Lepidoptera) in Indikadamukalana, a Lowland Wet Zone Forest in Sri Lanka

“…The studies conducted since then have mainly focused on species of economic importance such as pest species, with studies on diversity and abundance of a few selected groups (Jayaneththi, 2016). The recent invasions by the Fall Armyworm, Spodoptera frugiperda, on maize cultivations in the dry zone of Sri Lanka, initiated several investigations on the life history characteristics and management of this moth (Kasige et al, 2022a(Kasige et al, , 2022b. A few studies have focused on using moth larvae as hosts for rearing parasitoids and other biological control approaches (Karunarathne et al, 2020;Sammani et al, 2020;Singhamuni et al, 2021).…”