Termite Specialist Research Articles

Termite cuticular extracts improve acceptance of bait for controlling invasive Asian needle ants, Brachyponera chinensis.

The Asian needle ant, Brachyponera chinensis, is an invasive ant currently spreading in urban and natural habitats throughout the eastern United States. Recent studies have documented the negative impact of B. chinensis on native ecosystems and human health, yet effective control strategies are lacking. Control difficulties are, in part, due to the unique biology of B. chinensis, which is a predatory ant and a termite specialist. Given that subterranean termites are an important nutritional resource for B. chinensis, the current study evaluated the potential of termite cuticular extract to improve the target-specificity and efficacy of commercial bait used for B. chinensis control. The efficacy of bait augmented with termite cuticular extracts was evaluated in laboratory and field trials. In laboratory assays, B. chinensis colonies were offered granular bait treated with termite cuticular extract. Results demonstrated that the acceptance of commercial bait is significantly increased by the addition of termite cuticular extract or synthetic (Z)-9-pentacosene, a major component of termite cuticular extract. Foraging activity of Asian needle ants was significantly greater on baits augmented with termite cuticular extract or (Z)-9-pentacosene relative to standard bait. Furthermore, bait augmented with termite cuticular extract worked substantially faster relative to standard bait. To evaluate population effects, field studies were conducted in forested areas invaded by B. chinensis. Bait treated with termite cuticular extract scattered on the forest floor provided rapid control of B. chinensis and ant densities throughout the treated plots declined by 98% within 14 days. The incorporation of termite cuticular extracts and individual cuticular hydrocarbons such as (Z)-9-pentacosene into traditional baits used for B. chinensis control may offer a novel tool to manage this increasingly problematic invasive ant. © 2023 The Author. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Infested empire: architecture and entomology in colonial Japan

As Japan’s colonial empire pushed westward in the early twentieth century, insects pushed back. Colonists in Taiwan were besieged by the Formosan termite, a voracious but then relatively mysterious species that ate everything from government buildings to Shinto shrines. The Japanese government dispatched termite specialists to the island in response to document the damage and develop a solution. The problem was not only that termites could eat away at architecture in Taiwan; more dire was the possibility that they could travel throughout the empire and back to the mainland. Such an existential threat prompted entomologists to collaborate with architects and engineers and develop novel methods of study. Looking at entomological reports, architectural histories, and buildings that were both destroyed by termites and dedicated to displaying them, I show how termite-pocked buildings were mediated to map the Japanese colonial empire and physicalise its potentially dangerous interdependence. By approaching the special issue’s theme of ‘unmaking’ as an act of insect-led destruction, I argue that vulnerable wooden architecture served as a medium of connection between human and insect actors as both came to terms with empire.

Genome reduction and relaxed selection is associated with the transition to symbiosis in the basidiomycete genus Podaxis

SummaryInsights into the genomic consequences of symbiosis for basidiomycete fungi associated with social insects remain sparse. Capitalizing on viability of spores from centuries-old herbarium specimens of free-living, facultative, and specialist termite-associated Podaxis fungi, we obtained genomes of 10 specimens, including two type species described by Linnaeus >240 years ago. We document that the transition to termite association was accompanied by significant reductions in genome size and gene content, accelerated evolution in protein-coding genes, and reduced functional capacities for oxidative stress responses and lignin degradation. Functional testing confirmed that termite specialists perform worse under oxidative stress, while all lineages retained some capacity to cleave lignin. Mitochondrial genomes of termite associates were significantly larger; possibly driven by smaller population sizes or reduced competition, supported by apparent loss of certain biosynthetic gene clusters. Our findings point to relaxed selection that mirrors genome traits observed among obligate endosymbiotic bacteria of many insects.

Odor-Mediated Group Organization and Coordination in the Termite-Raiding Ant Megaponera analis (Mayr)

Visual and olfactory communications are vital for coordinated group hunting in most animals. To hunt for prey, the group-raiding termite specialist ant Megaponera analis, which lacks good vision, must first confirm the presence or absence of conspecific raiders. Here, we show that M. analis uses olfactory cues for intraspecific communication and showed greater preference for conspecific odors over clean air (blank) or odors from its termite prey. Chemical analysis of ant volatiles identified predominantly short-chained hydrocarbons. Electrophysiological analysis revealed differential sensory detection of the odor compounds, which were confirmed in behavioral olfactometric choice assays with odor bouquets collected from major and minor castes and the 2 most dominant volatiles and n-undecane n-tridecane. A comparative analysis of the cuticular hydrocarbon profile with those of the short-chained odor bouquet of different populations shows a high divergence in the long-chained profile and a much-conserved short-chained odor bouquet. This suggests that there is less selection pressure for divergence and individual recognition in the short- than the long-chained odor profiles. We conclude that olfactory communication serves as an alternative to visual or sound communication, especially during group raids in M. analis when ants are not in direct contact with one another.

Spatial and temporal variation in the use of supplementary food in an obligate termite specialist, the bat-eared fox

The bat-eared fox (Otocyon megalotis) is considered a termite specialist. However, studies of its diet have been limited to indirect methods, such as scat and stomach content analyses, resulting in intraspecific dietary variations due in part to methodological differences. Because diet plays a central role in the social dynamics of these canids, we hereby contribute further to our knowledge about their dietary habits. We present 2-year data of direct observations of foraging bouts of 19 habituated bat-eared foxes in the kalahari desert of South Africa, as well as data on seasonal variation in invertebrate prey communities obtained through pitfall and sweep net trapping. Despite showing a diet breadth reflective of a specialised forager across all seasons, foxes exhibited substantial seasonal variation in diet breadth with a broader range of food categories utilised in summer compared to the other seasons. Supplementary food categories appear to not have been utilised opportunistically, but it is unclear what drove the preference for some food categories over others. A literature review indicated strong effects of local conditions on the utilisation of supplementary food across southern Africa. Our data support bat-eared foxes as obligate termite specialists but highlight that they appear to have the ability to show dietary flexibility based on both temporal and spatial variations in food abundance.

Individual versus collective decision making: optimal foraging in the group-hunting termite specialist Megaponera analis

Collective decision making is one of the main mechanisms of organization in social insects. However, individual decision making can also play an important role, depending on the type of foraging behaviour. In the termite-hunting ant species Megaponera analis information about foraging sites is collected by only a handful of individual scouts that have to convey this information to the colony as accurately as possible to optimize their foraging behaviour. We therefore looked at predictions made by optimal foraging theory to better understand the interplay between collective and individual decision making in this obligate group-raiding predator. We found a clear positive relation between raid size (200–500 ants) and termite abundance at the foraging site thereby confirming predictions of the maximization of energy theory. Furthermore, selectivity of the food source increased with distance, thus confirming central place prediction theory. The confirmation of these theories suggests that individual scouts must be the main driver behind raid size, choice and raiding behaviour. The marginal value theorem was also confirmed by our results: time spent at the hunting ground increased with distance and prey quantity. This raises questions on how foraging time at the food source is regulated in a group-hunting predator. Hunger decreased selectivity of scouts with respect to food sources, while average raid size increased and more scouts left the nest in search of prey, thus implying that scouts are aware of the hunger state of the colony and adapt their decision making accordingly. Remarkably, most central place foraging behaviours in M. analis were not achieved by collective decisions but rather by individual decisions of scout ants. Thus, 1% of the colony (10–20 scouts) decided the fate and foraging efficiency of the remaining 99%.

Mammals of the Mazie National Park, Southern Nations, Nationalities and Peoples Regional State, Ethiopia

A study to investigate the diversity of the mammalian fauna of the Mazie National Park (mnp) was carried out from October 2007 to March 2008. Based on topographic maps, and a preliminary survey, four habitat types (riverine forest, grassland with scattered trees, savannah grassland, and bush land) were identified. Mammals were recorded in representative samples of each vegetation type in the park. A total of 39 mammalian species were recorded in mnp. Of these, 30 were medium to large-sized mammals, 6 were small rodents and 3 were shrews. The observed mammals of the study area were grouped into eight categories based on their feeding habits as meat eaters (23%), fruit and leaf eaters (8%), termite specialists (3%), root eaters (8%), grazers and browsers (10%), small gleaners (13%), bulk feeders (3%) and others (32%).

In Memoriam: Robert R. Sokal (1926–2012)

Robert R. Sokal, Distinguished Professor Emeritus in the Department of Ecology and Evolution at the State University of New York at Stony Brook, Long Island, New York, died on 9 April 2012, at the age of 86 years. It is particularly appropriate that he be remembered in this Journal, for his first academic position, in which he developed one of the fields for which he is best known, was in the Department of Entomology, University of Kansas. Throughout his career he was involved in the development and use of a wide variety of statistical methods for evaluating similarities among organisms (hence numerical taxonomy) and for analyzing spatially distributed variations such as patterns in human genetic and linguistic data. He published widely in these fields and is probably most widely known for his book (coauthored with F. James Rohlf), Biometry, which has influenced the training and practice of many biologists, especially in fields of evolution, ecology, and anthropology. Born in Vienna, Austria (13 January 1926), he left there in 1939 with his family at the same time as many other European Jews, to escape the Nazi regime. By way of train to Italy and by ship to China, they settled in Shanghai where he continued schooling. From St.John’s University in Shanghai he received a bachelor’s degree (biology) in 1947. There also he met Julie Chenchu Yang who played an important role throughout his subsequent life. At St.John’s he wrote for publication his first scientific paper, a study of the head morphology of a dragonfly. In the same year, 1947, he entered the University of Chicago as a graduate student, and in 1948 he and Julie were married. At Chicago he worked under the direction of Alfred E. Emerson (ecologist and termite specialist) and Sewall Wright (population biologist). His dissertation was a statistical treatment of the geographical variation in morphology of a poplar gall aphid, Pemphigus populitransversus, for which he received a Ph.D. degree in 1952. At that time he moved to the Department of Entomology at the University of Kansas, first as an Instructor, then in the usual academic sequence. His first study at Kansas had to do with the evolution of insect behavior and of insect resistance to insecticides. Specifically, he asked if Drosophila melanogaster, so well known genetically, would develop insecticide resistance as do many insect pests, and if so, what could be learned about the genetics and evolution of such resistance. He reared Drosophila larvae in food medium containing DDT at levels that killed some of the larvae. After several generations with larvae in this environment, mature larvae were leaving the food and pupating on the glass walls of the food containers. Thus behavior had evolved, and apparently as a result, some change in resistance by larvae to DDT in their environment. Later, Sokal began a study for which he is well known, concerning classification of organisms. Traditionally classifications had been based on subjectively determined phylogenetic ideas, the views of specialists, Sokal said by intuition. When different

Living with your food: geckos in termitaria of Cantão

AbstractWe tested three non‐exclusive hypotheses that the lizard, Gymnodactylus carvalhoi, lives in termitaria to avoid thermal extremes, to avoid predators, or because of an abundance of food (dietary specialist). We first confirm that these geckos are restricted to termitaria in the region studied. Body temperatures (Tb) of geckos averaged below environmental temperatures during day outside of termitaria and above outside temperatures at night; Tb averaged only slightly higher than temperatures inside termitaria. We conclude that thermal constraints in Cerrado habitats lacking rocks restrict Gymnodactylus to termite nests. High frequencies of tail loss and the presence of many potential predators within termitaria suggest high encounter rates with predators, indicating that predation pressure does not restrict these geckos to termite nests. Dietary data indicate that G. carvalhoi is a termite specialist. Published data indicate that other Gymnodactylus species and populations are also termite specialists, even though several live primarily outside termitaria (in crevices and under rocks). An evolutionary history of termite specialization and low thermal requirements in the clade (Gymnodactylus) predispose them to feed on termites within the termitaria.

Diet of amphibians and reptiles from the Engare Ondare river region of central Kenya, during the dry season

In seasonally arid environments many species undergo some form of dormancy, such as aestivation. The dietary habits of those species during the period of seasonal aridity are poorly known. Little is known of the seasonal variation in the diet of the amphibians and reptiles of Kenya. This project examines the diets of several species of frogs and lizards collected during the dry season in an arid part of central Kenya. Some of the species were thought to be dormant during that season and others were thought to be actively feeding. The incidence of feeding may be used to determine if an animal is dormant. The dormancy may be brief and interrupted or protracted and continuous. Stomach contents were removed by dissection and analyzed in the laboratory. We identified 6,238 prey items to the lowest taxonomic unit possible, usually order, family, or genus. Definite prey items were all Arthropoda except for a single frog in one stomach and skink scales in a few stomachs. Within Arthropoda, Isoptera and Hymenoptera (ants) were the most abundant (5,662 items), followed by Coleoptera and Orthoptera (205 items). Eruciform and scarabaeiform larvae were recorded separately from adults. At least ten other orders of arthropods were recovered. Spiders were present in 12.4% of the stomachs. Specialization was exhibited by some species that utilized termites or ants extensively. A few nematodes were found. Inanimate objects were also found, including miscellaneous plant material, rocks, and charcoal. Termites were more important in reptile diets than in amphibian diets and were used almost exclusively by ground dwelling lizards. Termite specialists contained 87% or more termites and ant specialists contained 72% or more ants. Ptychadena anchitae and P. mascareniensis were the only generalists, based on a Shannon Diversity Index of >0.75. Active and reproductive species had a significantly higher number of food events than active and non‐reproductive species. All of the species examined were secondary, or partially tertiary, consumers and the prey taxa were mostly primary consumers, but included several secondary consumers. Reproductive species and non‐reproductive species in the same genus had different diets and preferences.

Morphological evolution of the lizard skull: A geometric morphometrics survey

Patterns of diversity among lizard skulls were studied from a morphological, phylogenetic, and functional perspective. A sample of 1,030 lizard skulls from 441 species in 17 families was used to create a lizard skull morphospace. This morphospace was combined with a phylogeny of lizard families to summarize general trends in the evolution of the lizard skull. A basal morphological split between the Iguania and Scleroglossa was observed. Iguanians are characterized by a short, high skull, with large areas of attachment for the external adductor musculature, relative to their sister group. The families of the Iguania appear to possess more intrafamilial morphological diversity than families of the Scleroglossa, but rarefaction of the data reveals this to be an artifact caused by the greater number of species represented in Iguanian families. Iguanian families also appear more dissimilar to one another than families of the Scleroglossa. Permutation tests indicate that this pattern is real and not due to the smaller number of families in the Iguanidae. Parallel and convergent evolution is observed among lizards with similar diets: ant and termite specialists, carnivores, and herbivores. However, these patterns are superimposed over the more general phylogenetic pattern of lizard skull diversity. This study has three central conclusions. Different clades of lizards show different patterns of disparity and divergence in patterns of morphospace occupation. Phylogeny imposes a primary signal upon which a secondary ecological signal is imprinted. Evolutionary patterns in skull metrics, taken with functional landmarks, allow testing of trends and the development of new hypotheses concerning both shape and biomechanics.

HOW OFTEN DO LIZARDS “RUN ON EMPTY”?

Energy balance is relevant to diverse issues in ecology, physiology, and evolution. To determine whether lizards are generally in positive energy balance, we syn- thesized a massive data set on the proportion of individual lizards (N = 18 223) with stomachs (127 species), representing nine families distributed on four continents, primarily in temperate zone deserts but also in the neotropics. The average percentage of individuals with stomachs is low (13.2%) across all species, even among desert lizards, sug- gesting that most lizards are in positive energy balance. Nevertheless, species vary sub- stantially in this regard (among all species, 0% to 66% of individuals have stomachs). Several patterns are detectable among species with unusually high frequencies of stomachs. In particular, nocturnal lizards run on empty more often on average than do diurnal species (24.1% vs. 10.5%); and this pattern holds even for nocturnal vs. diurnal geckos (21.2% vs. 7.2%, respectively). Several (but not all) top predators have a higher frequency of stomachs than do species that feed at lower trophic levels. Diet breadth and body size appear unrelated to frequency of stomachs. Widely foraging species sometimes have a high frequency of stomachs relative to sit-and-wait species, but patterns vary among continents and appear to be confounded by phylogeny and trophic level. Ant-eating specialists have uniformly low frequencies of stomachs. Diurnal termite specialists also have low frequencies of stomachs, but nocturnal ones have high frequencies. Lizards from certain families (Gekkonidae (including Pygopodidae), Gym- nophthlamidae, and Varanidae) are more likely to have stomachs than are those of other families (Agamidae, Iguanidae, Lacertidae, Scincidae, and Teiidae).

Longevity, reproductive effort and movements of three sympatric Australian arid-zone geckos

Three sympatric diplodactyline geckos were studied in chenopod shrubland over a six-year period in northern South Australia. Females of each species were significantly larger than males. Rhynchoedura ornata and Diplodactylus conspicillatus, both termite specialists, consistently produced multiple clutches of two eggs in a long breeding season each year, whereas the reproductive output of D. stenodactylus, a dietary generalist, was more erratic. Females of the two Diplodactylus species bred in three consecutive years, whilst R. ornata seldom lived for more than two years. Mean relocation distances ranged from 26 to 35 m, which suggests that some individuals of all species maintained home ranges. However, many individuals of each species, especially R. ornata, were apparently transitory over areas greater than the 1-ha study site.

Ecological Shifts in Sympatry: Kalahari Fossorial Lizards (Typhlosaurus)

Two species of legless, fossorial skinks (Typhlosaurus) are partially sympatric in the Kalahari Desert. Typhlosaurus lineatus occur both in the sandridge and flatland geographic provinces of the Kalahari, in dune streets and on sandridgesmicrogeographically in sympatry, and primarily under log and leaf litter microhabitats. Typhlosaurus gariepensis, always microgeogrphically, and primarily in basal roots of bunch grass microhabitats. Microhabitat overlap in sympatry is low. Morphologically, T. lineatus differ from T. gariepensis in being longer and in having a longer and wider head. Snout—vent lengths, head dimensions, and proportional head lengths of sympatric T. lineatus are larger than those of allopatric T. lineatus; thus T. lineatus displace from T. gariepensis in sympatry. Both species are viviparous, have one brood per year, and give birth in summer after a 5—mo gestation period. Maturity is reached at minimum ages of one and two—thirds yr. Mean litter size of T. lineatus is 1.6, whereas T. gariepensis have but one young. A response to competition between the two species is suggested by the facts that offspring of sympatric T. lineatus are significantlyheavier than those of allopatric females, and that fewer sympatric T. lineatus females are reproductive than allopatric females. Because Typhlosaurus are termite specialists (92.4% of diet by volume), termitesin guts were identified to species and caste. Compared with sympatric T. lineatus, T. gariepensis eat more Psammotermes workers, fewer Allodontermes major workers, and scarcely any Hodotermes. Sympatric T. lineatus eat fewer Psammotermes workers and more Allodontermes major workers than do allopatric T. lineatus. Prey size differences parallel lizard size differences. Because of dietary shifts by T. lineatus in sympatry, dietary overlap with T. gariepensis is substantially reduced for females and immatures, although not for males. Strong morphological and dietary evidence support, for T. lineatus females and immatures, the hypothesis that behavioral and morphological character displacement has occurred which reduces dietary overlap with T. gariepensis. Dietary data for male T. lineatus are possibly conflicting.