Laboratory Observations of the Veronicellid Slug Biology Laevicaulis stuhlmanni aegypti Ali & Robinson, A new Subspecies and Record in Egyptian Agro-system

Abstract

First time finding the veronicellid slug Laevicaulis stuhlmanni aegypti Ali & Robinson as new subspecies was recorded in Egyptian environment, which is considered as a serious agro-horticultural pest and introduced. This invasive species remains the possibility of being introduced further in other closer sites with threat to agriculture or to the environment. Veronicellids are mainly tropical and subtropical terrestrial slugs (Order: Systellommatophora), they are known for attacking number of ornamental plants including flower beds, as a serious garden pest that causing big damage to seedlings and plants with significant agricultural, environmental, and garden impacts with significant losses to numerous crops (

Morphological description of Laevicaulis stuhlmanni (Simroth, 1895) (Pulmonata, Veronicellidae) from Egypt

“…The species Laevicaulis stuhlmanni was reported for the first time under the nomen nudum L. stuhlmanni aegypti (Ali 2017a, Ali 2017b, and the biological attributres such as life cycle, reproductive output, generation period and life span had been documented and described.…”

“…de Férussac, 1822) has been introduced by human activity to other areas of the world, where it has become abundant and causes considerable damage to agricultural crops (Gomes and Thomé 2004). Recently three Laevicaulis species have been reported in agricultural fields and gardens in north-eastern Africa: Laevicaulis alte and Laevicaulis stuhlmanni (Simroth, 1895) from Egypt (Ali 2017a, Ali 2017b, Ali and Robinson 2020 and Laevicaulis striatus (Simroth, 1896) from Libya ( Liberto et al 2021). In this paper, the external morphology and genitalia of Laevicaulis stuhlmanni from Egypt is described in detail, comparing these characters in Laevicaulis striata from Libya and with the available literature data.…”

Morphological description of Laevicaulis stuhlmanni (Simroth, 1895) (Pulmonata, Veronicellidae) from Egypt

“…The species Laevicaulis stuhlmanni was reported for the first time in Egypt under the nomen nudum L. stuhlmanni aegypti ( Ali 2017a , Ali 2017b ) and the biological attributes, such as life cycle, pre-oviposition period, oviposition period, post-oviposition period, reproductive output, incubation period, generation period and life span, were documented and described.…”

“…However, mating or cross-fertilisation was not observed for this species under laboratory conditions. The reproductive season of this species starts in March, when the seasonal temperature rises and lasts until November ( Ali 2017b ). The incubation period for the eggs to hatch averaged 15 days with ranges from 10 to 19 days at a temperature of 29 to 31°C and a humidity between 52% and 64%.…”

“…However, Laevicaulis alte (A. Férussac, 1822) has been introduced by human activity to other areas of the world, where it has become abundant and causes considerable damage to agricultural crops ( Gomes and Thomé 2004 ). Recently, three Laevicaulis species have been reported in agricultural fields and gardens in north-eastern Africa: L. alte and L. stuhlmanni (Simroth, 1895) from Egypt ( Ali 2017a , Ali 2017b , Ali and Robinson 2020 , Ali and Robinson 2022 ) and Laevicaulis striatus (Simroth, 1896) from Libya ( Liberto et al 2021 ). In this paper, the external morphology and genitalia of L. stuhlmanni from Egypt are described in detail, comparing them whith L. striatus from Libya and with the available literature data.…”