Spider Egg Sacs Research Articles

New mycoparasitic species in the genera Niveomyces and Pseudoniveomycesgen. nov. (Hypocreales: Cordycipitaceae), with sporothrix-like asexual morphs, from Thailand.

Four new species of the genus Niveomyces are described from Thailand. They were found as mycoparasites on: Ophiocordyceps infecting flies (Diptera) for Niveomyces albus; ants (Hymenoptera) for N. formicidarum; and leafhoppers (Hemiptera) for N. hirsutellae and N. multisynnematus. A new genus, Pseudoniveomyces with two species: Pseudoniveo. blattae (type species), parasitic on Ophiocordyceps infecting cockroaches, and Pseudoniveo. arachnovorum, found on a spider egg sac, are also described. These fungi share a common feature which is a sporothrix-like asexual morph. Based on our molecular data, Sporothrix insectorum is shown to be affiliated to the genus Niveomyces, and thus a new combination N. insectorum comb. nov. is proposed. Niveomyces coronatus, N. formicidarum and N. insectorum formed the N. coronatus species complex found on ant-pathogenic Ophiocordyceps from different continents. Pseudoniveomyces species are distinguished from Niveomyces spp. based on the presence of fusoid macroconidia in culture and a red pigment diffused in the medium, resembling to Gibellula and Hevansia. The molecular phylogenetic analyses also confirmed its generic status. The host/substrates associated with the genera within Cordycipitaceae were mapped onto the phylogeny to demonstrate that mycoparasitism also evolved independently multiple times in this family. Citation: Kobmoo N, Tasanathai K, Araújo JPM, Noisripoom W, Thanakitpipattana D, Mongkolsamrit S, Himaman W, Houbraken J, Luangsa-ard JJ (2023). New mycoparasitic species in the genera Niveomyces and Pseudoniveomyces gen. nov. (Hypocreales: Cordycipitaceae), with sporothrix-like asexual morphs, from Thailand. Fungal Systematics and Evolution 12: 91-110. doi: 10.3114/fuse.2023.12.07.

Bhushaniella gen. nov. (Cordycipitaceae) on spider eggs sac: a new genus from Thailand and its bioactive secondary metabolites

Fungal specimens parasitic on spider egg sacs (Araneidae sensu lato) were collected, isolated, and identified based on molecular phylogenetic analyses of five nuclear loci (ITS, LSU, TEF1, RPB1 and RPB2) combined with morphological data. In this study, one novel monotypic genus is described, Bhushaniella rubra for Thailand. Bhushaniella rubra is characterized by producing superficial perithecia. Its anamorph has a unique character by producing verticillate phialides with a slightly curved neck. A concurrent evaluation of the secondary metabolites of the mycelial extracts of the new fungus revealed the presence of picoline alkaloids of the penicolinate type, for which we propose the trivial names penicolinates F and G. Their chemical structures were elucidated by two-dimensional nuclear magnetic resonance (2D-NMR) spectroscopy and high resolution mass spectrometry (HR-MS). They only showed weak to no antibiotic activity and were devoid of significant cytotoxic effects.

Indian palm squirrel (Funambulus palmarum) feeds on spider egg sacs

The Indian palm squirrel, Funambulus palmarum (Linnaeus, 1766) (Rodentia: Sciuridae) is known to feed on a wide range of plant items in the wild, including nuts, seeds, fruit, and bark, and will readily consume discarded food around human habitations. The species has been observed to prey opportunistically on insects such as termites and beetles. In addition, cannibalistic behaviour has also been recorded. Here we report the first observation of F. palmarum preying on spider egg sacs.

Metabolome analysis reveals the toxic effects of cadmium exposure on the egg sac of spider Pardosa pseudoannulata

The investigation of the toxic effects of cadmium (Cd) on rice field invertebrates has attracted accumulating attention. Spider grants a novel insight into the impacts of Cd stress on invertebrates, but the effects of Cd-induced toxicity and molecular response mechanism of related metabolites in spider's egg sacs remain elusive. This investigation found that Cd stress distinctively decreased vitellogenin (Vg) content and hatched spiderlings numbers in the egg sac of Pardosa pseudoannulata. In addition, Cd stress exerted oxidative stress in the egg sac, manifested as the increase of superoxide dismutase and malondialdehyde levels. Further results showed that Cd exposure could affect egg sacs' energy metabolism, including protein and lipid contents. Metabolome analysis generated 73 up-regulated and 63 down-regulated differentially expressed metabolites (DEMs), mainly affecting phenylalanine metabolism, alpha-linolenic acid metabolism, pentose phosphate pathway, and biosynthesis of amino acids. Specifically, pathway analysis showed that Cd exposure down-regulated several key factors, including tyrosine, L-phenylalanine, O-phospho-L-serine, and L-cystathionine, and inhibited the metabolism of amino acids in the egg sacs. The subsequent correlation analysis found that three metabolite indicators, 9-Oxo-ODE, PG (17:0/18:2), and PE (17:0/20:5), were the dominant contributors to the egg sec's properties (i.e., Vg content and gained spiderlings). Collectively, this study hopes to provide valuable data for the protection of rice field spiders and offer novel perspectives for Cd pollution assessment and management.

Spider Parental Care and Awe-Inspiring Egg Sac (Cocoon)

Spiders (Arachnida, Araneae) represent one of the largest groups of organisms on Earth with more than 45,000 recorded species found in nearly all terrestrial communities. In these communities, spiders are obligate predators and generalist consumers regulating the density of pests. Spiders have a stupefying array of prey hunting strategies ranging from ambushing to the use of complex silk nares. Spider silk is incredibly tough and can be used for many applications such as wrapping and immobilization, catching prey, as dragline to connect spiders to the web, as ballooning to aid dispersal of juveniles, as shelters in burrows, for mating, and as egg sacs (or cocoons). Typically, spider egg sacs are multilayered, complex structures that physically protect the eggs and hatchlings against parasitoids, predators as well as changing temperatures. Much research has been undertaken to elucidate the ecological role of spiders and the mechanical characteristics of silks. However, few studies have examined the parental care of spiders and the role of egg sacs. This review goes into great detail about spider parental care and the functions of egg sacs.

Extreme natural size variation in both sexes of a sexually cannibalistic mantidfly.

In sexually cannibalistic animals, the relative sizes of potential mates often predict the outcome of aggressive encounters. Mantidflies are spider egg predators as larvae and generalist predators as adults. Unlike most cannibalistic species, there is considerable individual variation in body size in both sexes. Using preserved collections of Dicromantispa sayi, we focused on three body size metrics that we found to be positively correlated and accurately measured across researchers. We found extreme size variation in both sexes: the largest 10% of females were 1.72× larger than the smallest 10%, and the largest 10% of males were 1.65× larger than the smallest 10%. On average, females were 7.94% larger than males. In exploring possible causes of this variation, we uncovered differences among populations. To explore the effect of spider egg sac size on adult mantidfly size, we reared mantidfly larvae on egg sacs from two jumping spider species with small or large egg sacs. Mantidfly larvae reared on small egg sacs were smaller than those reared on large egg sacs. This study provides the groundwork to design ecologically relevant experiments exploring the causes and consequences of extreme size variation in an understudied system with intriguing natural history.

FERN-ARTHROPOD INTERACTIONS FROM THE MODERN UPLAND SOUTHEAST ATLANTIC RAINFOREST REVEALS ARTHROPOD DAMAGE INSIGHTS TO FOSSIL PLANT-INSECT INTERACTIONS

ABSTRACTFerns were among the first broadleaved plants in the fossil record. We assessed fern-arthropod interactions in modern ferns (Monilophyta) as a model for comparison with damage on ferns in the fossil record. We found that the functional feeding groups of margin feeding, hole feeding, surface feeding, piercing and sucking, oviposition, mining, and galling was present on 13 species of ferns at elevations ranging from 750 to 900 meters along mountain slopes of the Brazilian Atlantic Rainforest. We recognized 17 damage types (DTs), including one new DT, and provide implications for interpreting damage on leaves in the fossil record. Nine fossil DTs with modern analogues were found on ferns. Evaluation of damage on modern ferns demonstrate that the variation in the abundance and damage signatures of external feeding, piercing and sucking, galling, and mining enhances understanding of damage patterns on fossil leaves. The taphonomic implications to fossil plant-insect interactions are provided based on the sampling of modern arthropod damage and the preservation biases on ferns. Arthropod remains that are poorly attached to ferns, such as silk webs, eggs, and spider egg sacs, as well as insect exuviae, pupae, and body parts, might provide an important feature for arthropod preservation associated with fern leaves in the plant fossil record. This integrative method demonstrates that DT signatures on modern ferns indicate that ferns are an important host plant for herbivorous arthropods. Consequently, the same importance of ferns as host plants of arthropod herbivores likely was present in deep time.

Differential parasitism of native and invasive widow spider egg sacs

AbstractDuring colonization, invasive species establish and spread to new locations, where they may have an advantage over native species. One such advantage may be avoidance of predators or parasites by means of better defenses or due to lower suitability as a host. We conducted field surveys and lab behavioral experiments to investigate the differential susceptibility of two widow spider species—one native to Israel, the white widow spider Latrodectus pallidus, and one invasive species, the brown widow spider, Latrodectus geometricus—to an egg sac parasitoid wasp, Philolema latrodecti. In collections of egg sacs from six paired sites of L. geometricus and L. pallidus populations in the Negev Desert, Israel, we found higher parasitism rates on the egg sacs of the native L. pallidus. In no-choice trials, we found that wasps were more likely to parasitize and oviposited longer on L. pallidus egg sacs than on L. geometricus egg sacs. In two-choice tests with spider webs and egg sacs, parasitoids made first contact with L. pallidus webs more often and faster. After developing inside of L. pallidus egg sacs, more parasitoids emerged and were larger than those emerging from L. geometricus egg sacs. Potentially better defense of the L. geometricus egg sacs as well as the parasitoid’s fitness advantages gained from parasitizing L. pallidus egg sacs may explain the higher parasitism rate in the native species. Our results suggest that the invasion and establishment success of L. geometricus is due, in part, to its ability to escape parasitism.

Egg sac recognition and fostering in the wolf spider Pardosa milvina (araneae: lycosidae) and its effects on spiderling survival

AbstractMany animals provide parental care to increase the success of offspring. Parental behaviors can be costly, and should only be directed toward related young. Offspring recognition and differential effort are ways that animals ensure that care is directed toward related individuals. Pardosa milvina is a small wolf spider that provides parental care for their young, carrying first their egg sac and later their spiderlings. This species is known to pick up abandoned egg sacs. We conducted a study to determine whether female P. milvina differentiated between her own egg sac and a conspecific's egg sac and whether there was a benefit to spiderlings in being raised by their biological mother, and whether age, when removed from the mother, influenced the outcome. In one experiment, we removed the egg sac from a female and gave her a choice of items to reattach: their own egg sac, another spider's egg sac, or a plastic bead. Females were more likely to pick up their own egg sac than another spider's. In another experiment, we removed a female spider's egg sac either 1 day or 7 days after the eggs were produced and gave them either their own egg sac or another spider's egg sac to care for. We measured hatching success and offspring survival. Spiders manipulated after 7 days were more likely to be abandoned as eggs, whether cared for by their biological mother, and reached adulthood less often. However, cross‐fostering had no effect on spiderling success whether the transfer occurred after 1 day. Our data showed that P. milvina can recognize their own egg sac, but there was no evidence of differential parental care provided to the biological offspring.

First record of egg sac predation of the fly Pseudogaurax cingulatus Sabrosky (Diptera, Chloropidae) upon spider Tetragnatha sp. (Araneae, Tetragnathidae) in northern Brazil

Pseudogaurax Malloch is a worldwide genus of Chloropidae with 33 species in the Neotropical region and 12 occurring in Brazil. The genus is well-known for the feeding habits of its larvae which attack egg masses and larvae of several arthropods, usually breeding in the egg sacs of spiders. In this study, we expanded the distribution of P. cingulatus to northern Brazil and recorded for the first time the species preying on Tetragnatha egg sacs. In addition, diagnosis, digital images and a distribution map are provided.

Who wins? Ray spiders (Theridiosoma gemmosum) (Araneae: Theridiosomatidae) versus egg sac parasitoids

This is the first report on the parasitoids of egg sacs of Theridiosoma gemmosum (L. Koch, 1877) (Theridiosomatidae). The parasitic wasps Gelis melanocephalus (Schrank, 1781), Gelis mangeri (Gravenhorst, 1815) (Ichneumonidae) and Pachyneuron solitarium (Hartig, 1838) (Pteromalidae) were recorded as solitary parasitoids of egg sacs of T. gemmosum in Poland. The degree of parasitism of T. gemmosum egg sacs in three different years was 21.4–42.9%, and the reproductive fitness of female spiders in all cases of parasitized cocoons was zero. It seems that the suspension system of the egg sacs of ray spiders is not a barrier against egg sac parasitoids, including apterous species. We hypothesize that, at least in the case of G. melanocephalus, the size of the spider's egg sac is implicated in the ovipositional decision of the female parasitoid.

Two hymenopteran egg sac associates of the tent-web orbweaving spider, Cyrtophora citricola (Forskål, 1775) (Araneae, Araneidae).

We report the discovery of two wasp species emerging from egg sacs of the spider Cyrtophoracitricola (Forskål 1775) collected from mainland Spain and the Canary Islands. We identify one as Philolemapalanichamyi (Narendran 1984) (Hymenoptera, Eurytomidae) and the other as a member of the Pediobiuspyrgo (Walker 1839) species group (Hymenoptera, Eulophidae). This is the first report of Philolema in Europe, and the first documentation of hymenopteran egg predators of C.citricola. The latter finding is particularly relevant, given the multiple invasive populations of C.citricola in the Americas and the Caribbean, where neither egg sac predation nor parasitism is known to occur. We describe rates of emergence by Ph.palanichamyi from spider egg sacs collected from the southern coast of Spain and estimate sex ratios and body size variation among males and females. We also re-describe Ph.palanichamyi based on the female holotype and male paratype specimens.

Natural spider silk as a photonics component for humidity sensing.

Biological microfibers are remarkable materials with diversity in their chemistry, structure and functions that provide a range of solutions for photonic structures. Here we proposed and demonstrated a humidity detection technique for spectral tuning of whispering gallery modes (WGMs) in a cylindrical microresonator formed by a piece of spider egg sac silk (SpEss) from Araneus Ventricosus. We launched a supercontinuum laser into the SpEss via a tapered single-mode fiber to excite WGMs. When the ambient humidity changed, the profile diameter and effective refractive index of the SpEss changed, which caused the WGM resonant dips to shift. The experimental results showed that when the relative humidity (RH) changed from 20% to 75% RH, the average testing sensitivity of the proposed sensor was 389.1 pm/%RH and the maximum testing sensitivity was 606.7 pm/%RH in the range of 60% to 75% RH. Also, the proposed SpEss-based humidity sensor showed a fast response time of 494 ms and good repeatability with fluctuations less than 8% compared with the initial test values. The SpEss-based sensor expanded the application of spider silk as a biodegradable and biocompatible material in biochemical sensing.

Spider silk-based humidity sensor

We select a section of spider egg sac silk (SESS) from an Araneus ventricosus for humidity sensing. SESSs are composed of tubiliform fibers, which suggests that the silk fibroin is more sensitive to ambient humidity. We employ a section of single mode fiber (SMF) and a section of SESS to configure an interference-cavity structure. The change of ambient humidity will cause a change in the SESS diameter, which will change the length of the interference-cavity. The change of the interference-cavity length will cause the interference spectrum to redshift, and the SESS-based sensor will perform the humidity-sensing characteristic. The testing results indicate that the higher the ambient humidity, the higher the sensitivity. The maximum value of the sensitivity is 0.99 nm/%RH in the humidity range of 90%–99%. The sensor is protected from temperature disturbance, and the temperature sensitivity is 33 pm/°C. Spider silk is a kind of natural moisture-sensitive material, which is environmentally friendly and does not demand additional sensitization. Therefore, the spider silk is very promising candidates for optical-based chemical and biological sensors that are biocompatible, biodegradable, and highly sensitive.

Morphology of the primary larva of Mantispa aphavexelte Aspöck & Aspöck, 1994 (Neuroptera: Mantispidae) and phylogenetic implications to the order of Neuroptera

The external and internal morphology of the primary larva of Mantispa aphavexelte was studied and documented with a broad spectrum of techniques. The cephalic anatomy, which is very similar to conditions found in other neuropteran immatures, is mainly affected by the formation of specialized mandibulo-maxillary sucking tubes and associated internal features. The postcephalic anatomy largely follows a generalized holometabolan pattern, with well-developed muscles in the thorax and the abdominal segments, an elongate, uncondensed ganglionic chain, and well-developed Malpighian tubules. The phylogenetic analysis of 70 larval characters suggests a weakly supported clade comprising Dilaridae, Berothidae, Rhachiberothidae and Mantispidae. Mantispoidea comprising Rhachiberothidae, Berothidae and paraphyletic Mantispidae is suggested by overlapping scales on antennae and maxillae, thoracic “trichobothria”, and hypermetamorphosis with scarabaeiform 2nd instar larvae. The relationships of the mantispoid terminals are not resolved, and Mantispa (Mantispinae) and Plega (Symphrasinae) are not retrieved as sister taxa. Spider parasitism and feeding in spider egg sacs is characteristic for Mantispinae, whereas immatures of Berothidae and non-mantispine mantispid larvae prey on the offspring of social or non-social aculeatan Hymenoptera, on termites, or on immatures living in soil or under bark, for example scarab larvae. Specializations of the legs like a trumpet-shaped empodium and a fixed tarsal pseudoclaw, enable mantispine larvae to cope with functional challenges linked with their specialized form of parasitism, like entering a host or penetrating its egg sack. The largely immobilized and straight sucking stylets are suitable for piercing eggs of spiders, but not for grasping prey. The terminal eversible attachment structure probably provides anchorage of the abdominal apex and thus may facilitate the penetration of the egg sac or membranes of the body surface of a spider. It may also facilitate boarding a passing suitable host. Very small size of the 1st instars and hypermetamorphosis are likely linked with parasitism. Even though the primary larvae of M. aphavexelte belong to the smallest immatures in Neuroptera, the effects of miniaturization are very limited.

Semi-aquatic spider silks: transcripts, proteins, and silk fibres of the fishing spider, Dolomedes triton (Pisauridae).

To survive in terrestrial and aquatic environments, spiders often rely heavily on their silk. The vast majority of silks that have been studied are from orb-web or cob-web weaving species, leaving the silks of water-associated spiders largely undescribed. We characterize transcripts, proteins, and silk fibres from the semi-aquatic spider Dolomedes triton. From silk gland RNAseq libraries, we report 18 silk transcripts representing four categories of known silk protein types: aciniform, ampullate, pyriform, and tubuliform. Proteomic and structural analyses (scanning electron microscopy, energy dispersive X-ray spectrometry, contact angle) of the D.triton submersible egg sac reveal similarities to silks from aquatic caddisfly larvae. We identified two layers in D.triton egg sacs, notably a highly hydrophobic outer layer with a different elemental composition compared to egg sacs of terrestrial spiders. These features may provide D.triton egg sacs with their water repellent properties.

Nest site choice by the intertidal spider Desis formidabilis (Araneae: Desidae) and nest utilisation by its hymenopteran egg parasitoid

1. Echthrodesis lamorali Masner, 1968 is the only known parasitoid of the eggs of the intertidal rocky shore spider Desis formidabilis O.P. Cambridge 1890 and is endemic to a small area of South Africa.2. The abundance of spider nests and parasitoid presence were assessed in relation to their in‐ and between‐shore location at multiple sites within the distribution of E. lamorali along the Cape Peninsula (Western Cape, South Africa).3. Desis formidabilis nests were more abundant in the mid‐shore zone than higher up or lower down the shore. Spider population sizes also differed between collection sites, with higher numbers recorded on the cooler western coast of the peninsula.4. Evidence of parasitoid activity was recorded in 43.31% of the 127 nests and 13.85% of the 592 egg sacs they contained.5. Where parasitoids gained entry to a spider egg sac, oviposition took place into all of the eggs present.6. Incidence of wasp activity was positively correlated with spider nest concentration, not with height up the shore, suggesting that both the host and parasitoid are tolerant of salt‐water inundation.7. These results should assist managers of the Table Mountain National Park, in which the full distribution of E. lamorali falls, to better understand this component of rocky shore community dynamics.

A new species and notes on unusual natural history of Cladochaeta Coquillett, 1900 (Diptera: Drosophilidae).

A new species of Cladochaeta Coquillett (Diptera: Drosophilidae) is described, C. caxiuana sp. nov. from the Brazilian Amazon, based on 10 male and 10 female specimens obtained from nymphs of Sphodroscarta trivirgata (Amyot Serville, 1843) (Hemiptera: Auchenorrhyncha: Aphrophoridae). The female of Cladochaeta atlantica Pirani Amorim, 2016 is described based on specimens reared from spider egg sacs of the spider Cryptachaea migrans (Keyserling, 1884) (Araneae: Theridiidae) obtained in the state of Espírito Santo, Brazil. This is the first record of this fly genus attacking a spider egg sac. The species Cladochaeta sororia (Williston, 1896) is recorded for the first time from Brazil, based on specimens collected in an urban garden in the Amazon. In addition, an unidentified female specimen of Cladochaeta Coquillett, 1900 was obtained from the cocoon of a spider wasp of the genus Notocyphus Smith (Hymenoptera: Pompilidae).

White plant shoots, wax-producing insects and other white structures made by arthropods: A mimicry complex?

Many insects masquerade as parts of plants, such as bark or leaves, or mimic poisonous organisms in order to defend themselves against predators. However, recent studies indicate that plants may mimic insects and other arthropods to deter herbivores. Here, I report visually similar white structures of plants and arthropods in Japan and suggest they are part of a mimicry complex. Young shoots covered with white trichomes or waxy substances may mimic wax-producing insects, such as woolly aphids, coccids and caterpillars, potentially resulting in reduced herbivory. Since wax-producing insects would reduce plant quality and quantity, be distasteful and attract natural enemies, herbivorous insects and mammals may avoid such white shoots. Furthermore, fungus-infected insects, gregarious braconid cocoons, spider egg sacs and froth made by froghopper nymphs or blasticotomid sawfly larvae are also conspicuously white and impose risks for herbivorous insects. Thus, these white structures may be mimicry models for white shoots and are likely to be part of a defensive mimicry complex. Although this study focuses on defence against herbivores, there are simultaneous physiological roles for white colouration that will not be discussed in depth here.

Egg sac parasitism: how important are parasitoids in the range expansion of the wasp spiderArgiope bruennichi?

Abstract During recent decades, the wasp spider, Argiope bruennichi (Scopoli, 1772), has expanded relatively quickly towards north Europe. As a consequence of its spreading, it is newly exposed to various factors of selection. We studied the impact of egg sac parasitoids on the mortality of A. bruennichi in three regions differing in climate conditions and time of settling by this spider. Parasitism of wasp spider egg sacs was relatively low (0–3.9%) and no significant differences between studied regions were found. One primary parasitoid, Tromatobia ornata, was reared; in approximately 60% of these parasitized cocoons, the entire content of the egg sac was destroyed.