Nala Lividipes Research Articles

First occurrence of the black field earwig, Nala lividipes (Dermaptera: Labiduridae) in Greece

The cosmopolitan black field earwig, Nala lividipes (Dufour, 1820) (Dermaptera: Labiduridae) is observed for the first time in Greece. A photographic record was obtained by the first author in 2016, from Salamis Island followed by a photographic citizen-science observation from Rhodes in 2021. Despite frequent inspections and efforts to raise public awareness, no additional samples or observations have been recovered. The poor study of Dermaptera in Greece and the absence of early warning systems for alien insects, may have delayed the detection of this alien species in the country. However, given the agricultural significance of N. lividipes, a short description is given to assist further data collection and monitoring. Finally, the potential establishment of the earwig in Greece, along with the impacts on the native flora and fauna are discussed.

The dual role of earwigs (Dermaptera) in winter grain crops in Australia

AbstractEarwigs have been observed as an irregular pest of increasing concern to farmers growing canola and other winter grain crops in Australia over the past decade. In this study, we tested how abiotic and biotic factors influence the feeding behaviour of earwigs. Studies were conducted with two Australian native species, Labidura truncata and Nala lividipes, and the introduced European earwig, Forficula auricularia. We constructed field‐based exclusion plots that prevented F. auricularia from moving in or out of a small area of canola. We monitored F. auricularia activity and the feeding damage to canola plants throughout the winter growing season. In the laboratory, we established microcosms containing crop seedlings, as well as aphids as an alternate food source, to examine the feeding behaviour of all three species. The native earwigs L. truncata and N. lividipes did not cause feeding damage to canola or wheat but were found to actively consume aphids when present. We conclude that these species are unlikely to cause significant (economic levels) of pest damage in a field environment. In the microcosm trial, F. auricularia caused considerable damage to canola seedlings and readily consumed aphids. Forficula auricularia also caused feeding damage to canola seedlings early in the winter growing season in the field trial. However, by the end of the season, F. auricularia presence was associated with increased canola biomass. Furthermore, F. auricularia did not damage canola until all nearby aphids were consumed. Together, our field and laboratory studies suggest F. auricularia can be an important predator of aphid pests in canola, indicating a dual role of this species as both a pest and a beneficial species in winter grain systems.

Random or handedness? Use of laterally paired penises inNalaearwigs (Insecta: Dermaptera: Labiduridae)

AbstractAnimals can show bias in their use of laterally paired organs that do not have any conspicuous anatomical differentiation between the right and left organs. Like right handedness in humans, males of the giant earwig Labidura riparia (Labiduridae: Labidurinae) preferentially (~90%) use the right one of their laterally paired penises for copulation. To elucidate the evolutionary origin of this lateralization, patterns of penis use were examined for the related species of the genus Nala (Labiduridae: Nalinae). In multiple populations and broods of both Nala lividipes and Nala nepalensis, males that were ready to use the right or left penis were equally frequent, providing a striking contrast to Labidura. Surgical ablation of one of the two penises revealed that both penises are functionally competent in N. lividipes. Nevertheless, each male almost consistently used only one of the paired penises, either the right or the left one. Changes in penis use were estimated to occur only once per 64–143 days per male. The present study is the first report of individual-level lateralization for animal genitalia that do not show any conspicuous anatomical differentiation between the right and left organs. Possible advantages of lateralization are discussed in relationship to co-evolution of the genitalia between the sexes.

Management implications of earwigs' overwintering sites in a Mediterranean citrus grove

ABSTRACTTo promote earwigs as natural enemies of pests, or to control their populations if they damage crops, earwigs can be managed during their overwintering period on the ground. Here, we obtained more than a ton of soil to study earwigs' overwintering sites in a citrus grove. We found four species of earwigs: Forficula pubescens, Euborellia annulipes, Euborellia moesta, and Nala lividipes. Surprisingly, and although the European earwig Forficula auricularia is abundant in the citrus canopies the rest of the year, we did not find any F. auricularia, indicating that this species spends the winter outside the citrus grove. Therefore, farmers willing to manage European earwig populations in citrus orchards need to consider the possibility that earwigs may spend the winter outside the field. Earwigs that were overwintering in the citrus grove were more abundant at the south side beneath the canopies than at the north side or between rows, indicating that management practices such as soil tillage can impact overwintering earwigs only beneath the canopies, but not between citrus rows. Overall, our results provide insights into how earwig populations can be successfully managed during winter in citrus orchards.

Phenology and interspecific association of Forficula auricularia and Forficula pubescens in apple orchards

The European earwig Forficula auricularia L. (Dermaptera: Forficulidae) has been widely studied as a key predator of pests in temperate regions, but its phenology and behavior may differ in warmer areas such as the Mediterranean. Here we assessed the phenology, aggregation, and interspecific association of F. auricularia and Forficula pubescens Gené, the only two species found consistently in both ground and canopy shelters in Mediterranean apple orchards. In addition to F. auricularia and F. pubescens, three other earwig species, namely Labidura riparia Pallas, Nala lividipes Dufour and Euborellia moesta Gené, were found occasionally. The mature stages of F. auricularia were observed mainly from May to November in tree shelters and immature ones from October to June in ground shelters. Adult individuals of F. pubescens were observed year-round and nymph instars were detected from April to June in ground as well as in tree shelters. The suitability of the current degree-days models for temperate regions was evaluated for the prediction of European earwig phenology in a Mediterranean climate. Regarding interspecific association, F. auricularia and F. pubescens co-occurred in canopies without apparent competition. This study provides useful weekly data about the phenology of the two earwig species throughout the year that can be used to detect the key periods during which to enhance their populations in pip fruit orchards or to control them in stone fruit crops. Furthermore, our results are of relevance for the development of new phenological models of earwigs in Mediterranean areas where nymphs hibernate, a feature that makes current models inaccurate.

EFFECTS OF TEMPERATURE ON THE DEVELOPMENT, LONGEVITY AND FECUNDITY OFNALA LIVIDIPES(DUFOUR) (DERMAPTERA: LABIDURIDAE)

AbstractThe influence of temperature on the development and survival of Nala lividipes was determined for eggs at constant temperatures, and for nymphs at constant and fluctuating temperatures. Adult longevity and fecundity were also assessed at constant temperatures. Eggs failed to hatch at 15 and 18°C. Survival was low at 20, 32.5 and 35 °C, but was relatively constant, at a mean of 64.3%, for temperatures between 22 and 30°C. Survival of nymphs was maximal at 29 °C. Linear models adequately described the development rates of eggs and nymphs reared at the constant temperatures. The nymph model was an unsuitable descriptor of development of nymphs under fluctuating temperatures, and a new linear model was required. The sex ratio at any temperature did not differ significantly from 1:1. Oviposition did not occur at 20 °C; it increased to a maximum at 30.5 °C before declining. There were insignificant differences in longevity between males and mated or virgin females. Longevity was inversely related to temperature. Population increases are possible between 22 and 32.5°C, with a doubling time of 1.9 weeks at 30°C.

EFFECTS OF GERMINATING SEEDS ON THE DEVELOPMENT AND REPRODUCTION OFNALA LIVIDIPES(DUFOUR) DERMAPTERA: LABIDURIDAE)

AbstractThe survival of nymphs and adults of the black field earwig, Nala lividipes, was best when they were reared on germinating seeds of wheat, sorghum, maize and sunflower. Survival was very low for earwigs reared on soybean, and no nymphs survived to adulthood in the absence of seeds or when reared on chickpea or cotton. Life‐table data indicated that population increases were possible only when the earwigs were reared on sorghum, maize, and wheat in ascending order. Numbers remained constant when fed on sunflower and declined if soybeans were the only food available. Rearing was at a constant temperature of 28°C (± 0.5°C) with a black cracking clay at 40% moisture.

IMMATURE STAGES OF NALA LIVIDIPES (DUFOUR) (DERMAPTERA: LABIDURIDAE)

AbstractThe egg and five nymphal instars of Nala lividipes are described. Instars are defined by the number of antennal segments and degree of wingbud development. Measurement and analyses of other body characters confirmed such definitions, although some overlap between instars occurred within each character, especially between later instars. Nymphs of N. lividipes can be distinguished easily from those of Labidura truncata Kirby (Labiduridae), Marava sp. (Spongiphoridae) and an unidentified species (Anisolabididae) using pygidial morphology.

An improved soil insect rating for seedling sunflowers

A complex of soil-dwelling insects damages sunflower (Helianthus annuus L.) and other seedlings in Queensland. This paper compares the relative damage potential of the black field earwig, Nala lividipes (Dufour) (Dermaptera:Labiduridae), and crickets Lepidogryllus spp. and Teleogryllus oceanicus (Le Guillou) (Orthoptera : Gryllidae) to sunflowers in laboratory feeding studies. The results were converted to injury equivalents based on documented damage caused by Pterohelaeus alternatus Pascoe (Coleoptera : Tenebrionidae). The injury equivalents were added to the existing multispecies soil insect rating model currently used for other soil-dwelling insect pest species of sunflowers. Populations of additional pest species can now be more accurately assessed for their damage potential before crop planting.

DAILY TRAP CATCHES OF TWO EARWIG (DERMAPTERA) AND THREE CRICKET (ORTHOPTERA) SPECIES IN CENTRAL QUEENSLAND

AbstractDaily light trap catches of Nala lividipes (Dufour), Labidura truncata Kirby (both Dermaptera: Labiduridae), Teleogryllus oceanicus (Le Guillou), Lepidogryllus comparatus (Walker), and L. parvulus (Walker) (all Orthoptera: Gryllidae) from 1 September 1986 to 31 August 1989 at Emerald were recorded. In 1986/87 and 1988/89 more N. lividipes, L. truncata and Lepidogryllus spp. were trapped than in 1987/88. More T. oceanicus were trapped in 1988/89 than the previous 2 years. More females than males were trapped for each species, and for the Dermaptera, more major than minor males. Significant (P < 0.01) regressions of numbers caught were obtained for all species using a multiplicative logistic curve utilising average air temperature and wind‐run as the independent variables, except for T. oceanicus where average temperature alone was suitable. Daily catch numbers for these species are interpreted and discussed from the prediction equations. Further sampling of the Lepidogryllus spp. and N. lividipes over a wider range of ecosystems is suggested. Field sampling should be done concurrently to correlate relative and absolute population estimates.

EFFECTS OF SOIL TYPE AND MOISTURE ON DEVELOPMENT AND REPRODUCTION OF NALA LIVIDIPES (DUFOUR) (DERMAPTERA: LABIDURIDAE)

Abstract Nala lividipes were reared from egg to adult using a loamy sand (sand) and a black cracking clay (clay) at moisture levels of 0, 5, 10 and 20% and 0, 15, 30,40 and 50%, respectively, at 29°C and a 12h: 12h photoperiod. Germinating grain sorghum was used as food. The longevity and fecundity of surviving adults were assessed using the same treatments as they experienced as immatures. Moisture had no influence on the duration of the egg stage. Nymphs took 2 weeks longer to complete development in sand at 5% than in other sand or clay treatments. Life‐table data indicate that population increases are possible when soil moisture is greater than 5% for sand, and at 30% or higher for clay. The most rapid population increases were in clay at 40% and 50% moisture. Equations were developed to predict soil moisture‐dependent survival of nymphs, fecundity of adults and total longevity.

Soil-insecticide bioassays and seed treatments for soil-insect control in Central Queensland, Australia

Twelve insecticides were tested as seed treatments or as banded applications in laboratory soil bioassays against striate false wireworm larvae ( Pterohelaeus alternatus Pascoe). The systemic carbamate insecticides carbofuran and furathiocarb, when applied as seed treatments, protected sorghum from damage at rates ⩾0.7 kg a.i./100 kg seed. These chemicals did not kill a high proportion of larvae, and feeding deterrence as the mode of action was indicated. The soil-active synthetic pyrethroids tefluthrin and bifenthrin, applied as banded sprays, protected seedlings and killed larvae at rates as low as 0.05 kg a.i. ha −1. The most effective organophosphate was ebufos, which protected seedlings at rates > 1.0 kg a.i. ha −1. In field trials on the Central Highlands of Queensland, seed treatments of carbofuran and furathiocarb significantly increased establishment of cotton and sorghum, but not that of sunflower, when false wireworm adults and wingless cockroaches ( Calolampra elegans Roth and Princis) were present. The carbamates were superior to pyrethroids in protection of emerging seedlings. Systemic insecticides did not prevent lethal damage to emerging sunflower seedlings when surface-active insect densities were similar to the numbers of seedlings (45 000 ha −1). Thiodicarb seed treatment in cotton (at 0.7 kg a.i./100 kg seed) significantly reduced numbers of black field earwig ( Nala lividipes Dufour).

MORPHOMETRIC ANALYSIS OF VARIATION IN NALA LIVIDIPES (DUFOUR) AND LABIDURA TRUNCATA KIRBY (DERMAPTERA: LABIDURIDAE)

AbstractTwo male morphs occur in populations of Nala lividipes (Dufour), the black field earwig, and of Labidura truncata Kirby, the common brown earwig, distinguished by the presence or absence of a tooth at the mid‐point on each forceps branch. Multivariate morphometric analyses using discriminant function analysis applied to measurements of various body parts of wild‐caught specimens showed that the morphs were statistically separate in both species. In each species female size is intermediate to that of the 2 male morphs. The results are discussed on the basis of natural selection, and possible reasons given for the maintenance of 2 male morphs but only 1 female morph.

NATURAL ENEMIES AND OTHER SPECIES ASSOCIATED WITH SACCHARICOCCUS SACCHARI (COCKERELL) (HEMIPTERA: PSEUDOCOCCIDAE) IN THE BUNDABERG AREA, SOUTHEAST QUEENSLAND

AbstractThe pathogenic fungus Aspergillus parasiticus Speare, a “habitat destroyer”Cacoxenus perspicax (Knab), and a parasitoid Anagyrus saccharicola Timberlake are the major natural enemies of the sugarcane mealybug Saccharicoccus sacchari (Cockerell) in the Bundaberg area. Their abundance varied over a 17‐month period and may have been linked to January‐March rainfall. The number of An. saccharicola emerging from a mummy depended on the host size. Five insect predators, Chrysopa innota Walker, Elaunon bipartitus (Kirby), Nala lividipes (Dufour), Halmus ovalis (Blackburn) and Isauria aphidovora (Meyrick) and 3 additional fungal pathogens, Metarhizium anisopliae (Metschnikoff), Penicillium sp. and Cordyceps sp. are recorded. A parasitoid of C. perspicax, Chartocerus (Xana) sp. is also recorded. The ants, Pheidole megacephala (F.), Paratrechina obscura Mayr and Iridomyrmex sp. are involved in mutualistic behaviour with S. sacchari.

The use of germinating-seed baits to detect soil insect pests before crop sowing

Germinating crop seed baits buried at shallow depth in moist fallow fields attracted soil-dwelling insects that adversely affect crop establishment. Presoaked grain sorghum seed attracted all potential pests found in soil samples in Central Queensland trials within 4-7 days from placement. Subterranean insects such as Tenebrionidae, Elateridae and Scarabaeidae larvae, black field earwig [Nala lividipes (Dufour)] and seed-harvesting ants (Pheidole sp.) were found near the seed and the seedling roots, while seedling shoots attracted surface-active feeders [wingless cockroaches (Calolampra elegans Roth and Princis), adult Tenebrionidae and Gryllidae]. The germinating seed bait method was superior to existing methods (insecticide-treated surface baits and soil sampling), both in the variety of species detected and in reduction in labour required. Germinating sorghum, wheat, sunflower and soybean seeds were equally attractive to wingless cockroaches, in 2 trials. Numbers of C. elegans/bait.day on germinating seed baits were correlated with numbers on insecticide-treated baits (r2 = 0.60, P(0.01).

Immunological investigation of prey-predator relationships for Pieris rapae (L.) (Lepidoptera: Pieridae)

AbstractAn enzyme-linked immunosorbent assay (ELISA) was used to examine the digestive tracts of potential predators collected from an experimental cabbage plot in Victoria, Australia, for antigens of Pieris rapae (L.). The rabbit serum used in the study was made against an extract of all immature stages of the prey species and was shown to interact with proteins representing all immature stages. The serum was also shown not to react with antigens from other pest species collected from the experimental plot or with predators not exposed to the prey. The main predators found using the assay were the labidurids Nala lividipes (Dufour) and Labidura riparia truncata Kirby, the staphylinid Thyreocephalus cyanopterus (Erichson) and the eusparassid Olios diana (L. Koch). These results agree closely with laboratory observations on predation. The assay was sensitive, allowing 2000 assays to be performed per millilitre of serum and thus a single serum collection of 20 ml permitted about 40 000 assays.

USE OF INSECTICIDES AND A PRESS WHEEL TO CONTROL SOIL INSECTS AFFECTING SORGHUM AND SUNFLOWER ESTABLISHMENT IN SOUTHERN QUEENSLAND

AbstractField trials at 5 sites in southern Queensland were used to determine the effectiveness of soil compaction with a press wheel and various methods of application of 4 insecticides for the control of soil insect pests of sorghum and sunflower seeds and seedlings. The pests involved were black field earwigs, Nala lividipes (Dufour), sugarcane wireworms, Agrypnus variabilis (Candèze), seedharvesting ants (Pheidole sp. and an unidentified species), and false wireworms, Pterohelaeus alternatus Pascoe, P. darlingensis Carter, Gonocephalum macleayi (Blackburn), Cestrinus trivialis Erichson.Some of the techniques of insecticide application improved establishment at 4 of the sites. Heptachlor was the most effective insecticide overall and caused no phytotoxicity to either crop. Chlorpyrifos and terbufos had apparent phytotoxic effects in some trials. Carbaryl which was applied only by water injection, was less effective than heptachlor and (sometimes) chlorpyrifos.Where insecticides caused no apparent phytotoxicity, applications by seed dressing, presoaking, water injection, and in‐furrow spray generally were equally effective in improving establishment. Seed dressing and presoaking required less active ingredient and were the most efficient ways of applying insecticide.Soil compaction with a press wheel also significantly increased establishment, at all sites for sunflower and at 4 sites for sorghum. Response to compaction by the press wheel at 2 sites was attributed solely to insect control as soil water was adequate and control plots had extensive insect damage and low emergence.

Studies on Two New Species of Cephaline Gregarines (Apicomplexa: Sporozoea) of the Genus GregarinaDufour, 1828 from Insects

Summary The paper contains descriptions of two new species of cephaline gregarines (Apicomplexa: Sporozoea) of the genus Gregarina Dufour , 1828 from insects of the orders Dictyoptera and Dermoptera. The new species are (1) Gregarina ischnopterae sp. nov. from Ischnoptera sp. and (2) Gregarina nalae sp. nov. from Nala lividipes ( Dufour ). The entire life history of these parasites has been worked out and incorporated in the communication.

Arthropod Ground Strata Composition of the Cotton Ecosystem in South-Eastern Queensland, and the Effect of Some Control Strategies.

A record is provided of 23 arthropod species inhabiting the ground strata of cotton fields in south-eastern Queensland. The Coleoptera were the most diverse group (14 species) and Labidura riparia truncata Kirby, and Nala lividipes (Dufour) (both Labiduridae : Dermaptera) were the most abundant species caught in pitfall traps. Changes in the ecosystem in response to different pest control strategies were considered; broad-spectrum insecticide use resulted in the suppression of most species. Resurgence of L. riparia was evident in fields treated with DDT-toxaphene. Possible resurgence of four other species was observed after the removal of insecticide pressure. Several of these species may be of importance because of their predatory function.

Population dynamics ofNala lividipes(Dermaptera : Labiduridae)

Abstract Nala lividipes (Dufour) (Dermaptera: Labiduridae) is reported for the first time from Orissa- Population of Nala lividipes shows two annual peaks in September and May. Three distinct age groups were found in different proportions in different seasons. Population dynamics in relation to relative humidity, air temperature and other factors is discussed. Activity of the insect is more prominent in the post rainy season than in the summer and winter acclimatized ones. The population consists of more females (60%) than males (40%).