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Understanding why animals avoid some locations is needed to improve the theory of habitat selection. This is key in semi‐sedentary organisms, such as antlion larvae, because once established they rarely move, and their performance largely depends on local environmental conditions.Antlion larvae are sit‐and‐wait predators that build conical pitfall traps in sandy soils to capture passing prey. They clean constantly their traps, expelling soil, prey carcasses and debris out of the pit to maintain their trapping success. Therefore, we propose that they avoid soils with leaf litter because leaves hinder the maintenance of their pits; a hypothesis that has not yet been tested.We first demonstrated that antlion larvae (Myrmeleon inmaculatus) are rare from soils with leaf litter in a tropical semi‐deciduous forest in Mexico. We then experimentally tested the effect of leaf litter on pit maintenance by adding debris in 90 antlion traps, 45 of which were covered with a leaf, and 45 remained uncovered. Two hours after adding the debris, we recorded its location and quantified the variation in depth and diameter of the pits.Larvae in uncovered traps were twice as effective at cleaning up the debris than larvae in covered traps. Furthermore, in just 2 h, covered traps were on average 21% shallower than control traps, probably because unsuccessful attempts to clean debris caused sand slides to fill the pit partially.Leaf litter seems to hinder the proper maintenance of antlion traps, explaining at least partially, why these animals are rare under leaf litter. [ABSTRACT FROM AUTHOR]

The study of Neuroptera from the Horn of Africa preserved in collections of the Museum of Zoology of the University of Rome "La Sapienza" and those collected several years ago by the late entomologist Prof. A. Vigna Taglianti (Rome), contributes to increasing our knowledge of the neuropterological fauna for this part of East Africa. We give a description of the female of Apertochrysa eurydera (Navás, 1910) and a comparison between the male of Stenares completus Banks, 1915 (of which only the female was known) and that of S. irroratus Navás, 1912 (based on a specimen preserved in the Museum of Zoology of the University of Florence). [ABSTRACT FROM AUTHOR]

The antlion species Myrmeleon trigonois Bao & Wang, 2006 is endemic to Chinese mainland; it has pronotum with a pair of pale yellow spots, and modifi ed ectoproct, forming a hook-like projection posteroventrally. Based on morphological comparison and molecular evidence, we found that all paratypes of M. trigonois represent a diff erent species than its holotype. Here, Myrmeleon shalulianus Zheng & Liu, sp. nov., is described to accommodate all paratypes of M. trigonois and a series of newly supplemented specimens from Yunnan (China). The distribution pattern of these two species is clarifi ed. Larvae of both M. trigonois and M. shalulianus sp. nov. are described and compared. Furthermore, the bee fl y parasitoid (Diptera: Bombyliidae) of the genus Taiwanon Evenhuis, 2018 was reared from the immature stages of M. trigonois in an artifi cial environment. Taiwanon is newly recorded from the Chinese mainland. [ABSTRACT FROM AUTHOR]

Traps are an efficient method of capturing prey for ambush predators, but trap building and maintenance are costly. We describe suitable hunting sites for pit-building antlion larvae living in sand dunes based on its cost–benefit relationship. In the field, antlion pits were located near natural barriers, such as cliffs, rocks and vegetation, but not closest to these barriers. Our results show that this pattern of pit location did not differ between populations; neither with or without the influence of a specific dipteran parasitoid of antlion larvae. Artificial pitfall traps deployed in their habitats revealed that invertebrates move along barriers, likely through thigmotaxis (wall hugging or wall-following), and drop sands in the traps set at barrier edges. In the laboratory, repeated artificial destruction of pits from larval antlions induced frequent pit relocation and rebuilding. This task reduces life history parameters, such as the larval growth and food conversion rates, suggesting a high cost of pit maintenance. Thus, antlion pits might shift away from barrier edges where more prey is available but pit destruction occurs more frequently due to wall-following invertebrates. Such disturbance may explain why antlions are not located closest to these barriers. [ABSTRACT FROM AUTHOR]

Simple Summary: The larvae of owlflies and antlions (here shortly embraced by the term "owllions") are ambush predators. Their mouthparts are transformed into teeth-bearing stylets and used for catching prey and sucking, which is characteristic for neuropteran larvae. Here we used the morphology of the stylets and the head capsules of a large number of extant and fossil larvae as a proxy for the morphological diversity over time. The created dataset comprises outlines of stylets and head capsules of specimens from the literature, collections, databases and the herein described and depicted 38 fossil ones. Fossils in the whole dataset come from deposits with an age of about 20, 40, and 100 million years (Miocene, Eocene, and Cretaceous, respectively). In addition to the shape analysis of the outlines from the dataset, we conducted a statistical analysis as well. Eocene and Miocene samples did not result in a clear output, but Cretaceous samples allowed for some conclusions: The morphological diversity of owllion larvae increased over time, even though some morphologies of Cretaceous larvae went extinct. Among lacewings (Neuroptera), representatives of the groups Ascalaphidae (owlflies) and Myrmeleontidae (antlions) are likely the most widely known ones. The exact taxonomic status of the two groups remains currently unclear, each may in fact be nested in the other group. Herein, we refer to the group including representatives of both with the neutral term "owllion". Owllion larvae are voracious ambush hunters. They are not only known in the extant fauna, but also from the fossil record. We report here new findings of a fossil owlfly larva from Eocene Baltic amber, as well as several owlfly-like larvae from Cretaceous Kachin amber, Myanmar. Based on these fossils, combined with numerous fossil and extant specimens from the literature, collections, and databases, we compared the morphological diversity of the head and mouthpart shapes of the larvae of owllions in the extant fauna with that of owllion-like larvae from three time slices: about 100 million years ago (Cretaceous), about 40 million years ago (Eocene), and about 20 million years ago (Miocene). The comparison reveals that the samples from the Eocene and Miocene are too small for a reliable evaluation. Yet, the Cretaceous larvae allow for some conclusions: (1) the larval morphological diversity of owllion larvae increased over time, indicating a post-Cretaceous diversification; (2) certain morphologies disappeared after the Cretaceous, most likely representing ecological roles that are no longer present nowadays. In comparison, other closely related lineages, e.g., silky lacewings or split-footed lacewings, underwent more drastic losses after the Cretaceous and no subsequent diversifications. [ABSTRACT FROM AUTHOR]

Three species of Myrmeleontidae are currently known from Denmark: Myrmeleon bore, Myrmeleon formicarius and Euroleon nostras. Despite their unique and interesting life history, the faunistics of antlions in Denmark are in need of an update. Here, we primarily use the collections from the Natural Museum of Denmark and the Natural History Museum Aarhus to document the species distribution and richness. The antlion specimens were databased according to the distribution data, and distribution maps were created for each species. The maps are compared to previous analyses of Danish antlion faunistics as well as available online sources. The occurrence of the species in neighbouring countries is also considered. Identification keys to both larvae and adults of the Danish species are provided. Interspecific competition could explain why some locations only contain one species. In Denmark, there seems to be a marked correlation between the occurrence of antlions and the presence of aeolian sand. Aeolian sand is an excellent substrate for the larval funnels and is probably the core habitat of the antlion species occurring in Denmark. [ABSTRACT FROM AUTHOR]

Myrmeleon trivialis was originally described by Gerstaecker in 1885 based on the description of one female specimen from Himalayas, India. However, this species is now widely spread in Pakistan, China, Nepal, Thailand and Vietnam. In India, it is known from Arunachal Pradesh, Darjeeling, Himachal Pradesh, Sikkim, and West Bengal. The present study communicates the new record of Myrmeleon trivialis from Kashmir Valley (Hirpora Wildlife Sanctuary, District Shopian), India. The study constitutes the first evidence of the occurrence of this species from the North-Western Himalayan Region of Kashmir Valley (Jammu and Kashmir, Union Territory) and extending the range of species into the Kashmir Himalayas. The addition of this species to the Jammu and Kashmir UT fauna makes a remarkable contribution to the Order Neuroptera, as the Neuropteran species from the Kashmir Himalayan region of India have been less explored compared to that of other Insect orders and families from the region. [ABSTRACT FROM AUTHOR]

The omnipresence of pathogens makes them a strong selective pressure for most organisms, generating a variety of defensive responses to fight them. One mechanism by which organisms can release this pressure is avoidance of the pathogens in a spatial or temporal context. To date, only a few biological systems provide evidence that habitat selection can favour an escape from pathogens. An abiotic factor that varies across habitats and influences the evolution of host life history is humidity, which correlates positively with pathogen levels in the environment. Entomopathogenic fungi are abundant in soils and are obligate killers that require humidity for host infection. Antlions (Neuroptera: Myrmeleontidae) are typical soil‐dwelling insects that can live several years as larvae, buried in dry and fine substrates where they build their traps. This lifestyle may release them from selective pressure by entomopathogenic fungi. Here, we investigated whether living underground provides protection against the generalist entomopathogenic fungus Beauveria bassiana (Bals.‐Criv.) Vuill. in the antlion Myrmeleon timidus Gerstaecker under low or high humidity in the environment. Individuals that were inoculated with the fungus showed greater survival rates when buried in dry sand compared to individuals that were kept half‐buried or without sand, with similar outcomes across humidity levels. Given that the diversity of antlions is higher in arid environments, this benefit obtained from pit‐building behaviour seems to be a coincidental by‐product of this foraging strategy, which would be particularly beneficial in environments where fungal pathogens are common. [ABSTRACT FROM AUTHOR]

Neuroptera is one of the smaller ingroups of Holometabola, the ingroup of Insecta characterised by "complete" metamorphosis. Neuroptera comprises about 6000 species in the modern fauna, but appears to have been more diverse in the past. While adults distantly resemble certain moths or damselflies, the larval forms of Neuroptera are mostly fierce predators with prominent venom-injecting stylets. The most well-known of these larvae are probably those of antlions. Antlions and their closer relatives (silky lacewings, split-footed lacewings, ribbon-winged lacewings, spoon-winged lacewings, and owlflies) form a distinct monophyletic ingroup of Neuroptera, Myrmeleontiformia, hence the antlion-like forms. The fossil record of antlion-like larvae dates back far into the Cretaceous; many forms are known by exceptionally wellpreserved specimens entrapped in amber. The oldest fossil record of a neuropteran larva (not an antlion-like form) comes from Lebanese amber. Interestingly, the supposedly oldest record of an antlion-like larva is preserved in rock and comes from the famous Lower Cretaceous Crato Formation. We re-evaluate this fossil based on high-resolution composite photography. Due to the non-availability of many key characters, standard procedures for identifying the specimen to a more narrow ingroup remains challenging. Therefore, we used a morphometric approach. A combination of non-metric multidimensional scaling (NMDS), parallel coordinate plots and discriminant function analysis indicates that the fossil is a representative of the group Ascalaphidae (owlflies) + Myrmeleontidae (antlions). We discuss implications of this result for the fossil record of neuropteran larvae. These include the rather derived morphology of the oldest fossil larva of Myrmeleontiformia in contrast to previous expectations. Furthermore, fossils from soil dwellers can not only be expected to be found in amber, but also as compression fossils. [ABSTRACT FROM AUTHOR]

Neuroptera is one of the smaller ingroups of Holometabola, the ingroup of Insecta characterised by "complete" metamorphosis. Neuroptera comprises about 6000 species in the modern fauna, but appears to have been more diverse in the past. While adults distantly resemble certain moths or damselflies, the larval forms of Neuroptera are mostly fierce predators with prominent venom-injecting stylets. The most well-known of these larvae are probably those of antlions. Antlions and their closer relatives (silky lacewings, split-footed lacewings, ribbon-winged lacewings, spoon-winged lacewings, and owlflies) form a distinct monophyletic ingroup of Neuroptera, Myrmeleontiformia, hence the antlion-like forms. The fossil record of antlion-like larvae dates back far into the Cretaceous; many forms are known by exceptionally wellpreserved specimens entrapped in amber. The oldest fossil record of a neuropteran larva (not an antlion-like form) comes from Lebanese amber. Interestingly, the supposedly oldest record of an antlion-like larva is preserved in rock and comes from the famous Lower Cretaceous Crato Formation. We re-evaluate this fossil based on high-resolution composite photography. Due to the non-availability of many key characters, standard procedures for identifying the specimen to a more narrow ingroup remains challenging. Therefore, we used a morphometric approach. A combination of non-metric multidimensional scaling (NMDS), parallel coordinate plots and discriminant function analysis indicates that the fossil is a representative of the group Ascalaphidae (owlflies) + Myrmeleontidae (antlions). We discuss implications of this result for the fossil record of neuropteran larvae. These include the rather derived morphology of the oldest fossil larva of Myrmeleontiformia in contrast to previous expectations. Furthermore, fossils from soil dwellers can not only be expected to be found in amber, but also as compression fossils. [ABSTRACT FROM AUTHOR]

Co-occurring species often compete with each other directly and indirectly. Intra-guild predation (IGP) is an extreme manifestation of direct competition, which involves the attack, killing and eating of potential competitors. We studied the competitive interactions between two pit-building antlion species that co-occur in the Israeli desert: Myrmeleon hyalinus residing in the more productive sandy soil, and Cueta lineosa solely inhabiting poorer loess soils. To understand the mechanisms driving C. lineosa away from the more productive habitat, we explored the factors triggering IGP of one antlion species on the other. We tested whether IGP is affected by soil type, depth and temperature. IGP was asymmetrical with M. hyalinus preying on C. lineosa , and it intensified as the size difference favoring the former increased. Interactive rather than additive effects governed IGP, which was lowest in sandy soil combined with low temperature, and highest in shallow loess soil. C. lineosa possesses a smaller head and thorax relative to its abdomen compared to M. hyalinus , providing a possible explanation for the advantage of M. hyalinus in direct competition. We then focused on the weaker competitor, C. lineosa , examining how it copes with competition induced by M. hyalinus. Both the growth and survival rates of C. lineosa declined in the presence of M. hyalinus. The asymmetrical IGP C. lineosa experiences from M. hyalinus combined with its competitive inferiority may explain why it is mostly found in poor habitats, while its intra-guild competitor is abundant in the more productive habitats. [ABSTRACT FROM AUTHOR]

Antlions (Neuroptera) are a group of sit-and-wait predator insects, with some species further specializing in digging conical pit-traps in the ground in order to catch prey. Studies on antlions' predators are scarce with only few generalist predators known to feed on them. Here we report for the first time on field observations of antlions' predation by three scorpion genera. We suggest that scorpions may be common predators of antlions, at least in the hyper-desert environment of southern Israel. The effects of predation risk on the behavior of sit-and-wait and particularly on trap-building predators received little attention in the literature. In light of our observations, we posit that predation risk must be taken into serious consideration in future research of antlions in particular, and sit-and-wait predators in general. [ABSTRACT FROM AUTHOR]

The first large‐scale, total‐evidence phylogeny of the owlflies (Neuroptera, Ascalaphidae) is presented. A combined morphological and molecular dataset was analysed under several analytical regimes for 76 exemplars of Myrmeleontiformia (Psychopsidae, Nymphidae, Nemopteridae, Myrmeleontidae, Ascalaphidae), including 57 of Ascalaphidae. At the subordinal level, the families were recovered in all analyses in the form Psychopsidae + (Nymphidae + (Nemopteridae + (Myrmeleontidae + Ascalaphidae). In the DNA‐only maximum‐likelihood analysis, Ascalaphidae were recovered as paraphyletic with respect to the Myrmeleontidae and the tribe Ululodini. In both the parsimony and Bayesian total‐evidence analyses, however, the latter with strong support, traditional Ascalaphidae were recovered as monophyletic, and in the latter, Stilbopteryginae were placed as the immediate sister group. The long‐standing subfamilies Haplogleniinae and Ascalaphinae were not recovered as monophyletic in any analysis, nor were several of the included tribes of non‐ululodine Ascalaphinae. The Ululodini were monophyletic and well supported in all analyses, as were the New World Haplogleniinae and, separately, the African/Malagasy Haplogleniinae. The remaining Ascalaphidae, collectively, were also consistently cohesive, but included a genus that until now has been placed in the Haplogleniinae, Protidricerus. Protidricerus was discovered to express a well‐developed pleurostoma, a feature previously only encountered in divided‐eye owlflies. The feature traditionally used to differentiate the Haplogleniinae and Ascalaphinae, the entire or divided eye, can no longer be regarded as a spot‐diagnostic synapomorphy to separate these groups within the family. A new subfamilial classification based on these results is proposed and includes the following five subfamilies: Albardiinae, Ululodinae, Haplogleniinae, Melambrotinae and Ascalaphinae. In addition, the monophyletic containing group (Myrmeleontidae + (Palparidae + (Stilbopterygidae + Ascalaphidae))) is elevated to the rank of superfamily, as Myrmeleontoidea, in order to accommodate much‐needed taxonomic and nomenclatural restructuring anticipated to occur within the Ascalaphidae in the future. A list of genera included in each subfamily of Ascalaphidae is provided. [ABSTRACT FROM AUTHOR]

Myrmeleontidae (antlions) is the most species-rich family of the holometabolous order Neuroptera. Evolutionary history of this diverse lacewing family remains largely unexplored. Here we report on three new genera and four new species of antlions from the mid-Cretaceous amber of Myanmar, namely Allopteroneura burmana Lu, Zhang & Liu gen. et sp. nov., Phylloleon elegans Lu, Wang & Liu gen. et sp. nov., Phylloleon stangei Lu, Ohl & Liu gen. et sp. nov. and Nanoleon wangae Hu, Lu & Liu gen. et sp. nov. A phylogenetic analysis of the Burmese amber antlions is performed based on morphological characters. The result shows that the antlion species presently described belong to different major clades across the phylogenetic tree, suggesting a diverse palaeofauna of this family from the mid-Cretaceous of Myanmar. The phylogenetic status of the extinct subfamily Araripeneurinae is also discussed. [ABSTRACT FROM AUTHOR]

In areas of the Cerrado biome (Brazilian savanna) with well‐defined rainy and dry seasons, changes in climate and landscape affect the abundance and seasonality of insects. Larvae of the antlion Myrmeleon brasiliensis (Návas) (Neuroptera: Myrmeleontidae) are predators that build traps in dry sandy soil to capture prey. Here we determined the effect of rain on trap building by M. brasiliensis larvae in a riparian forest in the Cerrado biome. Differences in population size and developmental stage were found between the rainy and dry seasons. In the laboratory, the effect of rain‐soaked soil on trap building was evaluated. Fewer antlion larvae were found in the rainy season. Moreover, a greater abundance of larvae in the final stage of development (third instar) was found in the dry season, whereas more first instars were found in the rainy season. The latter revealed that wet soil affects the trap building of the larvae, as smaller traps were built in the treatment with soaked soil (simulated rain), whereas the larvae in the control treatment (no rain) continued building traps with no change in size. The findings indicate that seasonality in the Cerrado biome exerts a short‐term influence on M. brasiliensis larvae (larvae build fewer traps) as well as a long‐term influence (association with life cycle). [ABSTRACT FROM AUTHOR]

Larvae of pit-building antlions are expected to be more efficient at capturing prey than those of non-pit-builders. To test this prediction, feeding behaviors were compared in the same experimental conditions among pit-building Baliga micans and Myrmeleon bore, and non-pit-building Distoleon contubernalis. The number of prey eaten did not differ between species. D. contubernalis larvae used the walls of the experimental chamber as fence traps to capture prey. In the field, they were also found near edges of natural barriers, such as rocks, stones, tree roots, and plant stems. Artificial pitfall traps captured more arthropods near the edges of fences than farther from them. Larvae of the two pit-building species were located in the central part of the experimental chamber. In their natural habitats, the number of arthropods captured by artificial pitfall traps increased with pit size; thus, larger pits may be more efficient for capturing prey. In conclusion, pit-building and non-pit-building antlion larvae are both efficient hunters; the former hunt efficiently by making larger pitfall traps, and the latter do so by waiting for prey at the edge of the natural fences along which arthropods walk. [ABSTRACT FROM AUTHOR]

The extinction of a single species from a local community may carry little cost in terms of species diversity, yet its loss eliminates its biotic and abiotic interactions. We describe such a scenario in the Arava desert, where different cultural and law enforcement practices exclude Dorcas gazelles ( Gazella dorcas (Linnaeus, 1758)) from the Jordanian side of the border while protecting their populations on the Israeli side. We found that gazelles break the soil crust, formed in desert systems after annual flooding, thereby creating patches of loose and cooler sand that are used by pit-building antlions (Neuroptera: Myrmeleontidae). When we artificially broke the soil crust on both sides of the border, we found a significant increase in antlion density in these patches, but only on the Israeli side. On the Jordanian side, where no gazelles have been observed since the early 1980s, no antlions colonized either control or manipulated plots. Additional choice/no-choice feeding experiments, in which we offered antlions to lizards and birds, revealed that the effect of humans on gazelles cascades farther, as antlions serve as a palatable food source for both groups. Thus, the human-mediated loss of nontrophic interactions between gazelles and antlions cascades to the loss of trophic interactions between antlions and their predators. [ABSTRACT FROM AUTHOR]

Animals in nature generally face fluctuating rather than constant environmental conditions. When given a choice, animals usually seek to minimize the variance of gain. However, it is clear that the avoidance of variance in energetic gain depends on several factors, including hunger level. While holding the mean prey encountered constant, we studied the effect of variance in prey arrival on the growth rates of two pit-building antlion species, Myrmeleon hyalinus and Cueta lineosa. Both species construct pit-traps in loose soils and ambush small prey in the same desert habitats, while differing in their preferred microhabitat: shaded vs. exposed to direct sunlight. We expected the light-preferring species to better tolerate variance in feeding than the shade-preferring species, owing to the former's higher stress tolerance and natural occurrence in microhabitats that are more likely poor with prey. While increasing variance in prey arrival reduced the growth rates of both species, this decrease was more pronounced in the species inhabiting the shaded and most likely prey-richer microhabitat. The greater variance tolerance of the light-preferring species stems from its ability to capture several prey items when almost simultaneously encountered. It could also be that this species has lower basal metabolic rate, which improves its starvation tolerance. These two antlion species differed in their prey capture success, starvation and thermal tolerance, and we thus suggest that their tolerance to variance in feeding opportunities and functional response offer an additional axis that enables them to coexist in the same desert habitats. [ABSTRACT FROM AUTHOR]

Pit-building antlions and wormlions are 2 distantly-related insect species, whose larvae construct pits in loose soil to trap small arthropod prey. This convergent evolution of natural histories has led to additional similarities in their natural history and ecology, and thus, these 2 species encounter similar abiotic stress (such as periodic starvation) in their natural habitat. Here, we measured the cold tolerance of the 2 species and examined whether recent feeding or food deprivation, as well as body composition (body mass and lipid content) and condition (quantified as mass-to-size residuals) affect their cold tolerance. In contrast to other insects, in which food deprivation either enhanced or impaired cold tolerance, prolonged fasting had no effect on the cold tolerance of either species, which had similar cold tolerance. The 2 species differed, however, in how cold tolerance related to body mass and lipid content: although body mass was positively correlated with the wormlion cold tolerance, lipid content was a more reliable predictor of cold tolerance in the antlions. Cold tolerance also underwent greater change with ontogeny in wormlions than in antlions. We discuss possible reasons for this lack of effect of food deprivation on both species' cold tolerance, such as their high starvation tolerance (being sit-and-wait predators). [ABSTRACT FROM AUTHOR]

Phylogenetic relationship within Neuroptera is controversial, particularly for the various hypotheses based on both morphological and molecular evidence. In the present study, we determined the complete mitochondrial genome (mitogenome) of Gatzara jezoensis , which is the second representative of the tribe Dendroleontini. The G. jezoensis mitogenome contained the conserved set of 37 mitochondrial genes and a putative control region, with a conserved gene arrangement which was similar to that of most sequenced neuropteran mitogenomes. All transfer RNAs exhibited the canonical cloverleaf secondary structure, except for trnS (AGN) . The control region contained two conserved elements (ploy-T stretch and ATGGTTCAAYAAAATAAYYCYCTC motif) and abundant microsatellite-like elements. The phylogenetic analysis of sequenced neuropteran mitogenomes using the concatenated protein-coding genes (PCGs) and ribosomal genes recovered the monophyly of Myrmeleontidae, which revealed this dataset could generate the more robust phylogeny of Neuroptera than that of 13 PCGs dataset. [ABSTRACT FROM AUTHOR]

In this study, we reconstruct the first time-calibrated phylogeny of the iconic antlion family, the Myrmeleontidae (Neuroptera: Myrmeleontiformia). We use maximum likelihood and Bayesian inference to analyse a molecular dataset based on seven mitochondrial and nuclear gene markers. The dataset encompasses 106 species of Neuroptera, including 94 antlion species. The resulting phylogenetic framework provides support for a myrmeleontid classification distinguishing four subfamilies: Acanthaclisinae, Myrmeleontinae, Palparinae, and Stilbopteryginae. Within Myrmeleontinae, Myrmecaelurini and Nemoleontini are recovered as monophyletic clades; Gepini also appears as a valid tribe, distinct from Myrmecaelurini whereas Myrmecaelurini and Nesoleontini on one hand and Brachynemurini and Dendroleontini on the other hand, appear closely related. Some preliminary information related to generic and specific levels are also implied from our results, such as the paraphyly of several genera. Dating analyses based on thoroughly evaluated fossil calibrations indicate that the antlion family likely originated in the Cretaceous, between 135 and 138 million years ago (depending on the set of fossil calibrations), and that all higher-level lineages appeared during the Early Cretaceous. This first phylogenetic hypothesis will provide a valuable basis to further expand the taxonomic coverage and molecular sampling, and to lay the foundations of future systematic revisions. [ABSTRACT FROM AUTHOR]

Cannibalism, the process of killing and consuming conspecifics, can become enhanced by various environmental stresses. Organisms inhabiting Mediterranean habitats are better adapted for coping with competition-an adaptation that can manifest itself in increased cannibalism. Conversely, desert environments are characterized by long periods of food shortage, also selecting for cannibalism to overcome starvation. We tested for differences in the frequency of cannibalism between Mediterranean and desert populations of pit-building antlions. We also quantified the frequency of cannibalism within and between these populations. We could not detect a significant geographic variation in the frequency of cannibalism. We suggest that strong plastic responses to environmental stresses buffer against divergent selection, and thus no significant differentiation in cannibalism rate should occur. Cannibalism frequency was higher in mixed pairs comprised of individuals originating from different populations within and between climate regions, compared with that observed within populations. We suggest that this intraspecific discrimination ability is mediated by behavioral and/or chemical cues, associated with co-occurrence in a common environment, as well as by genetic relatedness. [ABSTRACT FROM AUTHOR]

Sand-dwelling wormlion and antlion larvae are predators with a highly specialized hunting strategy, which either construct efficient pitfall traps or bury themselves in the sand ambushing prey on the surface. We studied the role substrate particle size plays in these specialized predators. Working with thirteen species of antlions and one species of wormlion, we quantified the substrate particle size in which the species were naturally found. Based on these particle sizes, four substrate types were established: fine substrates, fine to medium substrates, medium substrates, and coarse substrates. Larvae preferring the fine substrates were the wormlion Lampromyia and the antlion Myrmeleon hyalinus originating from desert habitats. Larvae preferring fine to medium and medium substrates belonged to antlion genera Cueta, Euroleon, Myrmeleon, Nophis and Synclisis and antlion larvae preferring coarse substrates were in the genera Distoleon and Neuroleon. In addition to analyzing naturally-occurring substrate, we hypothesized that these insect larvae will prefer the substrate type that they are found in. Specifically, we tested substrate preference in a choice experiment for four species of antlions. This was then compared to the substrate that the larvae were naturally found in. Larvae of the four antlion species were allowed to choose among eight substrates differing according to their particle size. Our findings show that the majority of M. hyalinus larvae built pits in the finest sand fraction, and the majority of N. microstenus larvae were found in a coarser fraction. The other two species, M. immaculatus and E. nostras, constructed majority of their pits in a medium sand fraction. These results support the hypothesis that neuropteran larvae prefer specific substrates for pitbuilding or ambushing prey, and that this -- in combination with other abiotic and biotic factors -- may drive selection of appropriate habitats. [ABSTRACT FROM AUTHOR]

Cannibalism is a common trophic interaction in size-structured populations, having important ramifications for population and community dynamics. Although the main factors potentially influencing cannibalism are apparently well investigated, relatively little is known on how these factors interact to influence the frequency of cannibalism. We performed 2 complementary experiments to test if cannibalism in larvae of the pit-building antlion Myrmeleon hyalinus is influenced by size differences within and between developmental stages, as well as by sand depth (potential refuge), conspecific density, and hunger level. Our working hypothesis was that cannibalism should act as a threshold event governed by the interactive (rather than additive) effects of intrinsic and extrinsic factors. As expected, the frequency of cannibalism was higher between than within developmental stages, with more advanced instar larvae feeding on smaller instars. Notably, decreased density significantly lowered the frequency of cannibalism; however, this pattern was evident only in deep sand, which provides a potential refuge from predators. Deep sand also lessened the positive effect of body size difference on the frequency of cannibalism. Hunger level increased the frequency of cannibalism; however, the identity of the cannibal was almost exclusively determined by its initial size advantage rather than by its hunger level. Our results demonstrate that, despite their sedentary nature, the frequency of cannibalism in pit-building antlion larvae can be relatively high. Furthermore, this trophic interaction is governed by the interactive rather than additive effects of intrinsic and extrinsic factors influencing cannibalism.Despite their sedentary nature, the frequency of cannibalism in pit-building antlion larvae can be higher than that of other cannibalistic predators. In contrast to traditional thinking, we show that the frequency of cannibalism in pit-building antlion larvae is strongly influenced by the interactive, rather than the additive, effects of intrinsic (body mass difference, hunger level) and extrinsic factors (density, sand depth). [ABSTRACT FROM PUBLISHER]

Stressful or stochastic environments may have significant selective effects, leading to increased plasticity or stress resistance. Starvation is a type of stress commonly encountered among organisms inhabiting stochastic environments. Indeed, starvation endurance is an important trait, especially in sit-and-wait predators, which experience frequent fluctuations in prey arrivals because of their limited mobility., Differences in starvation endurance between antlions originating from Mediterranean (benign and predictable) and desert (harsher and stochastic) regions were investigated by exposing them to starvation in a fully factorial experiment using climate chambers simulating Mediterranean or desert climatic conditions., A trade-off between growth rate and starvation endurance was also investigated by feeding the antlions at two different frequencies pre-starvation. Additionally, the existence of growth compensation was tested for by measuring relative growth rate when feeding was resumed post-starvation., Population of origin did not significantly affect rates of body mass loss during starvation or relative growth rates when feeding was resumed. Antlions that were fed less frequently during the feeding phase lost mass faster during the starvation phase, but grew faster during the compensation phase., This study emphasises the importance of testing responses to stress when investigating life-history trade-offs. Some phenotypic differences between populations might be apparent only when exposing the experimental organisms to external stress. Conversely, phenotypic differences apparent under stress-free conditions might be masked by the effects of the stress factor. Adopting such an integrative approach allows elucidation of the level of plasticity in response to stress in different populations. [ABSTRACT FROM AUTHOR]

The Myrmeleontidae fauna of Albania was studied in July of 2012. The study revealed 14 antlion species, which included new records for the country. Among collected species, Myrmeleon hyalinus Olivier, 1811, Euroleon nostras (Geofroy in Fourcroy, 1785), Macronemurus appendiculatus (Latreille, 1807), Macronemurus bilineatus Brauer, 1868, and Neuroleon arenarius (Navás, 1904) are new records for the Albanian fauna. Sand dune habitat in the national park Divjakë Karavasta represents the northernmost known locality of Myrmeleon hyalinus in the Balkan Peninsula. [ABSTRACT FROM AUTHOR]

Environmental predictability has for many years been posited to be a key variable in whether learning is expected to evolve in particular species, a claim revisited in two recent papers. However, amongst many researchers, especially neuroscientists, consensus is building for a very different view, namely that learning ability may be an emergent property of nervous systems and, thus, all animals with nervous systems should be able to learn. Here we explore these differing views, sample research on associative learning in insects, and review our own work demonstrating learning in larval antlions (Neuroptera: Myrmeleontidae), a highly unlikely insect candidate. We conclude by asserting that the capacity for associative learning is the default condition favored by neuroscientists: Whenever selection pressures favor evolution of nervous systems, the capacity for associative learning follows ipso facto. Nonetheless, to reconcile these disparate views, we suggest that (a) models for the evolution of learning may instead be models for conditions overriding behavioral plasticity; and, (b) costs of learning in insects may be, in fact, costs associated with more complex cognitive skills, skills that are just beginning to be discovered, rather than simple associative learning. [ABSTRACT FROM AUTHOR]

Abstract: Competition in trap-building predators such as antlion larvae is a complex biotic interaction, potentially involving exploitation competition, sand throwing (i.e., interference competition), cannibalism and intra-guild predation. We investigated the short-term behavioral and developmental responses of the strict sit-and-wait antlion predator Myrmeleon hyalinus to sand disturbance (i.e., quantification of the impact of severe sand throwing), and to con- and hetero-specific competition by a larger sit-and-pursue antlion species Lopezus fedtschenkoi. We found that antlions subjected to sand disturbances reduced their pit construction activity and relocated less often. Furthermore, the reduction in pit construction activity was stronger among antlions subjected to disturbances prior to feeding. Almost no death occurred during the sand disturbance experiment, but as expected, disturbances caused reductions in the relative growth rates of antlions. This negative effect was stronger in the group exposed to sand disturbances prior to feeding. The presence of the sit-and-pursue competitor led to reductions both in pit construction and in relocation activities of M. hyalinus. Although the per-capita food supply was identical in both experiments, only 48% of M. hyalinus larvae survived the competition experiment, and this pattern was consistent between the con- and hetero-specific treatments. However, in the presence of hetero-specific competitors, the relative growth rate of surviving larvae was significantly lower than that measured in the presence of con-specific competitors. Our study demonstrates that investigating the different components of complex biotic interactions can markedly improve our understanding of how these different factors interact to influence the behavior and life history of organisms. [Copyright &y& Elsevier]

Pit-building antlion larvae are sit-and-wait predatory insects that construct conical pits, from which they ambush prey, in sandy soils. We examined the behavioural responses of antlions to the detection of various sized prey, which they were not allowed to capture. We found that antlions responded faster to smaller prey items, probably because larger prey may be considered a source of disturbance rather than a food source. Antlion response time to provided prey decreased after feeding and was negatively correlated with antlion body mass. Both of these results were indicative of a response to prey that depended on both internal and external factors. Pit dimensions increased with time at a constant rate among antlions in the unsuccessful prey capture or fed groups, but at a decelerating rate in the unfed control group. Contrary to our expectation, we could not detect differences in the rate of mass loss between antlions that were unfed and those experiencing unsuccessful prey captures. We also posited that antlions should exploit a specific prey type more efficiently as the number of encounters they had with it increased. However, there was no support for this prediction in our study. Exploring the responses of predators to prey in general, and in light of the conditions characterizing their natural habitat in particular, can improve our understanding of how predators adapt to cope with environmental variability. [Copyright &y& Elsevier]

The seasonality of insect assemblages in Africa is poorly investigated. To provide information on the relationships between climate and insect assemblages in the Sudanian region, strongly affected by climate change, we studied Myrmeleontidae and Ascalaphidae assemblages (Insecta: Neuroptera) for 7 and 5 consecutive years respectively in southern Mali. To make the species inventory as exhaustive as possible, we performed weekly sampling by netting and light trapping. For both assemblages, results showed very similar patterns of variation in species diversity throughout the year. Adults of Myrmeleontidae and Ascalaphidae were active all year, and the species succession was influenced by a strong temporal segregation. Species diversity peaked at the end of the rainy season and surprisingly during the dry season. Principal component analysis of the climatic factors followed by co-inertia analysis applied to two data sets, one comprising climatic factors and the other reporting presence/absence of species, showed a good association between the annual trend of climatic factors and the species diversity. But no well defined species grouping was clearly linked to a particular period of the year. This tight association between climate and species composition suggests that even small climate changes could modify significantly species assemblage characteristics. [ABSTRACT FROM AUTHOR]

Trade-offs have a central role in evolutionary ecology and life-history theory. Here, we present evidence for the existence of a rarely studied trade-off between growth rate and starvation endurance in larvae of a pit-building antlion. We first manipulated antlions’ feeding regime and obtained a spectrum of growth rates. Next, we starved the antlions and documented their rate of mass loss. Antlions growing faster during the feeding phase also lost mass faster during the successive starvation period, implying the existence of an induced trade-off between fast growth and starvation endurance. Finally, we fed all antlions with prey items of similar mass and measured both the giving-up prey mass (i.e. the remaining body mass of the prey that was not converted into predator body mass), and growth efficiency of antlions (i.e. proportion of prey consumed, negatively correlated with giving-up prey mass). The giving-up mass was negatively correlated with the growth rate of the antlions during the feeding phase, and positively correlated with their growth rate during the starvation phase (the opposite pattern was evident when examining growth efficiency), incongruently with the common phenomenon of growth compensation (i.e. extracting more of the prey after a starvation period). We suggest that antlion larvae can adopt a physiological mode bounded by two extremes: one extreme is adapted to starvation, involving reduced metabolic rates but also reduced capability to exploit prey, while the other is adapted to fast growth, allowing an efficient exploitation of prey, but at the expense of lowered starvation endurance. [ABSTRACT FROM AUTHOR]

Abstract: We report here on two complementary experiments examining the effect of climate on morphological and life-history traits of antlion adults. We first examined whether body size and wing loading of emerging adults are plastic by raising larvae, collected from five antlion populations along Israel''s sharp climatic gradient, in two environmental chambers simulating temperature and humidity of desert and Mediterranean climates. The variance in adult morphology was mostly related to body size, with adults of Mediterranean populations being larger than those of desert populations. Wing-to-thorax ratio was negatively correlated with temperature, compensating for the decrease in wing-beat frequency in colder environments. Differences between climatic treatments were significant for body size but not for the wing-to-thorax ratio, suggesting that body size is more plastic than the ratio between different body components. We next investigated how the exposure of antlion pupae to different climatic conditions influences the emerging adults. Adult body mass increased with final larval body mass at a faster rate when exposed to Mediterranean rather than desert conditions. Duration of the pupa stage was positively correlated with final larval mass, but only under Mediterranean conditions. Adult survival increased with initial mass (after eclosion), but was lower under desert conditions. Similarly, adults lost mass at a faster rate when exposed to desert conditions. Notably, the exposure of the pupae to varying climatic conditions had no effect on adult morphology. Climate is a major factor affecting insect life span and body size. Since body size is strongly linked to fecundity and survival, climate thus has a twofold effect on fitness: directly, and indirectly through body size. [Copyright &y& Elsevier]

Abstract: Pit-building antlions, the larvae of a winged adult insect, capture food by digging funnel-shaped pits in sand and then lying in wait, buried at the vertex, for prey to fall inside. The sedentary nature of this sit-and-wait predatory behaviour and, especially, antlions’ innate ability to detect prey arrival, do not fit the typical profile of insects that possess learning capabilities. However, we show, for the first time, that learning can play an important role in this unique form of predation. In three separate experiments, individual antlions received, once per training day, either a vibrational cue presented immediately before the arrival of food or that same cue presented independently of food arrival. Signalling of food not only produced a learned anticipatory behavioural response (Experiment 1), but also conferred a fitness advantage: Associative learning enabled antlions to dig better pits (Experiments 2 and 3), extract food more efficiently (Experiments 2 and 3), and, in turn, moult sooner (Experiment 3) than antlions not receiving the associative learning treatment. [Copyright &y& Elsevier]

1. Pit-building antlions are small sit-and-wait arthropod predators, which dig conical pits in sandy soils. We studied how biotic (conspecific density and feeding regime) and abiotic (sand depth) factors affect pit diameter and depth, while taking into account the larval body mass. 2. Pit diameter increased with larval body mass at a decelerating rate. In addition, larger larvae tended to relocate less frequently than smaller ones. 3. Sand depth positively affected overall pit size, while increasing conspecific density had a weaker but negative effect on pit size. 4. Feeding the antlions resulted in an increase in pit diameter compared with an unfed control group. However, as prey size increased this positive effect diminished. This result suggests that the existence of prey provides information about the quality of the microhabitat, triggering pit extension. However, similarly to the reduction in the foraging effort of saturated predators, antlions provided with large prey invested only little effort in pit enlargement. 5. Antlions were previously shown to be sensitive to prey and conspecific vibrations in the sand. We thus expected the feeding regime of the neighbour to affect antlion behaviour – surrogate of discriminating between local and global shortage of prey. Nevertheless, antlions with fed neighbours (a local prey shortage) did not show different behaviour compared with a control group in which both antlions were unfed (a global prey shortage). [ABSTRACT FROM AUTHOR]

Pit-building antlion larvae are small sit-and-wait arthropod predators that dig conical pits in sandy soils. We investigated the effect of exposure to constant light versus constant dark conditions on antlion behaviour. Antlions tended to relocate less often, construct pits more frequently and construct larger pits in constant light. We interpret this as an indication of dichotomous behaviour under light versus dark conditions such that antlion larvae hunt during the day and modify their positions at night. Antlion larvae immediately responded to the complete switch in this illumination treatment and adapted their behaviour to fit the new conditions. Prey capture success did not differ between the constant light and constant dark conditions. When provided with a choice between light and dark conditions, the vast majority of larvae preferred the former. Those that preferred constant dark, however, were on average larger than those that preferred constant light. We thus suggest that since larger antlion larvae possess larger fat reserves, they can afford reductions in foraging activity (possibly to increase safety). An examination of the antlion trade-off between their preference for light and their preference for sand depth (which may affect their ability to evade predators) showed that their response to illumination was much more prominent, irrespective of the sand depth. Finally, combining light with other factors such as temperature and density may further elucidate microhabitat selection in pit-building antlion larvae. [Copyright &y& Elsevier]

Abstract: Pit-building antlion Euroleon nostras constructs efficient traps in sand to catch its prey. The predator is known to react to substrate vibrations produced by movements of its prey outside the pit with sand-tossing behaviour but it has not yet been ascertained if this reaction is directed towards the prey. The accuracy of the sand-tossing response in the presence of four prey species was measured using a video recording method. The sand-tossing angle was highly positively correlated with the prey angle. Sand tossing was most frequently elicited when prey was on the posterior sand surface. Covering the larval photoreceptors did not influence the antlion''s localizing behaviour. [Copyright &y& Elsevier]

We performed a transplant experiment to compare the life histories and morphologies of five geographically representative antlion Myrmeleon hyalinus populations along a sharp climatic gradient, from a Mediterranean climate in Israel’s north to a desert climate in the south. Larvae were raised in two environmental chambers simulating Mediterranean and desert climates to investigate the extent to which the different populations exhibit phenotypic plasticity. Along the north-to-south climatic gradient, we observed a gradient in body mass prior to pupation and in pupation rate. Mediterranean populations suffered higher mortality rate when exposed to desert conditions, whereas the mortality rate of desert populations was consistent between Mediterranean and desert conditions. Our results regarding body mass, pupation rate and mortality rate suggest that Mediterranean populations had a more flexible response compared with desert populations. An analysis of digital photographs was used to measure population morphological differences, which were usually indicative of a decrease in trait size along the north-to-south gradient. We show how climatic gradients translate into phenotypic differences in an antlion population and provide a morphometric tool to distinguish between instar stages. [ABSTRACT FROM AUTHOR]

The larvae of the pit-making antlion Myrmeleon bore Tjeder live in open sand in riverbeds with a substratum consisting of various particle sizes. We analyzed the spatial distribution of their pits in a sandy floodplain to determine their larval and adult responses to the heterogeneous substrate. The spatial distribution pattern of their pits had an aggregated distribution, and there was a significant positive correlation between pit density and the ratio of medium-size sand particles to total weight of sand. We examined the size of sand particles selected in the larval pit-building behavior and the oviposition behavior of the adult. Both larvae and adults selected medium-size sand particles. The larvae of M. bore are relatively sedentary predators and rarely move great distances. Thus, the present results suggest that habitat selection by adult females is a major factor causing the aggregative distribution of the pits. [ABSTRACT FROM AUTHOR]

The larvae of the antlionEuroleon nostrasare pit-builders, constructing pitfall traps in loose sand. The number of pits and the pit diameter are recorded when larvae are kept in substrates with different particle sizes. The most convenient pit-building sand fractions are two fractions with fine sand (≤ 0.23 mm; 0.23–0.54 mm). The largest pits are constructed in sand with a particle size of 0.23–0.54 mm. In this sand fraction, larvae of all three instars most readily build pits. No pits are constructed in sand with a particle size greater than 1.54 mm. First- and second-instar larvae avoid building pits in substrates of particle size 1–1.54 mm, but third-instar larvae construct pits in this sand fraction. It is assumed that the antlion is capable of distinguishing between substrate types and this hypothesis is tested by giving larvae the choice of building a pit in one of four particle-size fractions. Larvae of all three instars prefer to build pits in the fraction with a particle size of 0.23–0.54 mm. Only third-instar larvae build pits in all four fractions, but only occasionally in the coarser fraction. [ABSTRACT FROM AUTHOR]

Antlion larvae that construct conical pits to capture prey may strongly affect foraging of ants and other arthropods, yet are usually abundant only in sheltered microhabitats. Larval antlion (Myrmeleon crudelis Walker) densities increased in exposed areas in central Texas in late summer and early autumn of 1998, presumably because of extended dry conditions. I conducted a study to quantify larval antlion pit densities in sheltered and exposed areas over time, and to examine the effect of variation in pit density on the foraging activity of ants and other arthropods. Isolated rainfall events decreased pit densities in exposed areas, sometimes to zero, but pit densities returned to high levels as the soil dried out. Pitfall traps at sheltered sites caught significantly fewer ants and other arthropods inside antlion zones (i.e., areas of high antlion density) than in adjacent areas without antlions. At exposed sites, pitfall traps caught significantly fewer ants in antlion zones when pits were present (dry conditions) than when they were absent (wet conditions); there was no significant difference in foraging outside the antlion zones in wet compared with dry conditions. Significantly fewer ants were caught inside antlion zones at sheltered sites (that were permanent) compared with exposed sites (that were transient), although pit densities were similar at both types of sites. Attraction of ants to baits revealed similar patterns. Spatiotemporal variation in antlion pit densities and the associated predation risk to ants and other arthropods may result in behavioral modifications of foraging patterns, higher mortality rates, or both. [ABSTRACT FROM AUTHOR]

The higher-level phylogeny of Neuroptera is explored here based on the newly determined mitochondrial genomic data, with a special focus on the interfamilial relationships of this group. Despite considerable progress in our understanding of neuropteran relationships, several mutually exclusive hypotheses have come out according to morphology-based analyses and molecular sequence data. The evaluation of these hypotheses is hampered by the limited taxonomic coverage of previous studies. In this paper, we sequenced four mitochondrial genomes to improve the taxonomic sampling for families: Myrmeleontidae, Ascalaphidae and outgroup Corydalidae. Phylogenetic analyses were run using various inference methods to (1) confirm that Coniopterygidae is sister to all other Neuroptera; (2) place Hemerobiidae as sister to Chrysopidae; (3) support the monophyly of Myrmeleontiformia and define its interfamilial relationships; and (4) recover Myrmeleontidae as paraphyletic due to the nested Ascalaphidae. [ABSTRACT FROM AUTHOR]

In this study, the complete mitochondrial genome sequence ofMyrmeleon immanisWalker, 1853 (Neuroptera: Myrmeleontidae) has been obtained with PCR, which is a circular molecule of 15,802 bp in length, contains 37 typical mitochondrial genes: 13 protein-coding genes (PCGs), 2 ribosomal RNAs, 22 transfer RNAs and a non-coding AT-rich region. The nucleotide composition is biased toward A and T as in most other insects. The A + T content of the whole genome, PCGs, tRNAs, rRNAs and the control region is 75.6%, 74.3%, 73.6%, 76.2%, 79.6%. All PCGs start with a typical ATN codon except for the COI which uses ACG as its start codon; all PCGs terminate in the common stop codon TAA or TAG, except for the COI, COII which use single T as their stop codons. [ABSTRACT FROM AUTHOR]