Difference in leaf herbivory between two plant-ant taxa associating with a myrmecophytic species, Macaranga lamellata

Macaranga lamellata (Euphorbiaceae) is a myrmecophytic species that is protected against herbivorous insects by two plant-ant taxa, Colobopsis macarangae (Formicinae) and Crematogaster spp. (Myrmicinae). Although a single M. lamellata tree houses one plant-ant colony of either of the two taxa, both coexist in a population of M. lamellata in a Bornean rainforest. To elucidate the extent of herbivory damage upon M. lamellata trees associated with Colobopsis relative to trees associated with Crematogaster, we counted the number of leaf galls and measured the leaf loss area chewed by leaf-chewing insects on M. lamellata in the forest. The occurrence of gall midges was not significantly different between the trees associated with the two plant-ants, while the degree of leaf-chewing herbivory was significantly higher on Crematogaster-associated trees than Colobopsis-associated trees. The data gathered on chewing traces observed on Crematogaster-associated trees indicated that most herbivory damage was caused by a phasmid species. These results suggest that the herbivory pressures and occurrences of different herbivore species differ between Crematogaster-associated and Colobopsis-associated trees within a population of M. lamellata

Evidence in stable isotope ratios for lichen‐feeding by Lithosiini moths from a tropical rainforest but not from a temperate forest

Lithosiini (Lepidoptera: Erebidae: Arctiinae) is distinctive in having some species that feed on lichens, whereas the majority of moths feed on vascular plants. However, the larval diet of most Lithosiini species is poorly known. This study examines whether Lithosiini species, collected in a tropical rainforest of Borneo (nine species) and a temperate forest of Japan (eight species), feed on lichens as larvae, based on stable isotope analyses. As a result, the δ¹⁵N values for eight of nine Lithosiini species collected from Borneo were notably lower than those of nine co-occurring herbivorous non-Lithosiini species, and were similar to those of sympatric, lichen-feeding termites; however, δ¹³C and δ¹⁵N values of one Lithosiini species (Adites sp.) were significantly higher than those of the other moth species and similar to those of humus-feeding termites and predatory insects occurring at the same site. These results have suggested that the Lithosiini in the Southeast Asian tropical rainforests contain some species that feed on lichens as their larval main diet and at least one species whose larvae feed on humus or animal-derived materials. In contrast, the δ¹³C and δ¹⁵N values of all examined Lithosiini species (eight species) in the temperate forest have suggested that their larvae fed on plants and not on lichens. Our stable isotope ratio analysis presented quantitative evidence suggesting lichen-feeding by Lithosiini moths in a tropical rainforest without observation of feeding behavior during the larval stages

Timing of butterfly parasitization of a plant-ant-scale symbiosis

In the Southeast Asian tropics, Arhopala lycaenid butterflies feed on Macaranga ant-plants inhabited by Crematogaster (subgenus Decacrema) ants tending Coccus-scale insects. A recent phylogenetic study showed that (1) the plants and ants have been codiversifying for the past 20-16 million years (Myr), and that (2) the tripartite symbiosis was formed 9-7 Myr ago, when the scale insects became involved in the plant-ant mutualism. To determine when the lycaenids first parasitized the Macaranga tripartite symbiosis, we constructed a molecular phylogeny of the lycaenids that feed on Macaranga by using mitochondrial and nuclear DNA sequence data and estimated their divergence times based on the cytochrome oxidase I molecular clock. The minimum age of the lycaenids was estimated by the time-calibrated phylogeny to be 2.05 Myr, about one-tenth the age of the plant-ant association, suggesting that the lycaenids are latecomers that associated themselves with the pre-existing symbiosis of plant, ant, and scale insects.ArticleECOLOGICAL RESEARCH. 27(2):437-443 (2012)journal articl

Biological notes on herbivorous insects feeding on myrmecophytic Macaranga trees in the Lambir Hills National Park, Borneo

Myrmecophytes are plants that harbor ant colonies in domatia, which are hollows in the plant body. Most ant species that colonize myrmecophytes aggressively attack and regulate the abundances of herbivorous insects that would otherwise feed on the leaves of host trees. Although previous studies have described the interactions between myrmecophytes and herbivorous insects, a large proportion of herbivores that are able to feed on these trees are still unrecorded and details of their feeding habits are largely unexplored. Here, we compile biological notes on some of the herbivorous insects that feed on several species of Macaranga (Euphorbiaceae) growing in the Malayan archipelago, including those that are myrmecophytic. The information assembled here is based on our field observations, sampling, and rearing of insects, which we have conducted since 1994 in the tropical lowland forest of the Lambir Hills National Park, Sarawak, in Malaysian Borneo. We also summarize existing published information. For the convenience of future studies of herbivores that feed on Macaranga, we have included a large selection of images to show the morphologies and ecological traits of herbivores, including their structures at different growth stages and the marks made by their activities, such as leaf-chewing, leaf-mining, and gall formation. Among the herbivorous insects that feed on Macaranga species, we focus on butterflies, phasmids, gall midges, and myrmecophilous bugs

<S2-3> Chemical ecology of ant-plant dwellers and interactions with the ants

This proceeding is a compilation of findings and progress activities of research collaboration between the Forest Department Sarawak (FDS) and the Japan Research Consortium for Tropical Forests in Sarawak (JRCTS). To highlight the research findings, An International Symposium entitled "Frontier in Tropical Forest Research: Progress in Joint Projects between the Forest Department Sarawak and the Japan Research Consortium for Tropical Forests in Sarawak" was ii held in Kuching, Sarawak on 21-22 September 2015.Two myrmecophilous insect taxa on myrmecophytes (ant-plants) were studied, Arhopala (Lycaenidae) butterfly larvae feeding on Macaranga ant-plants and a monotypic cockroach genus inhabiting epiphytic ant-ferns. The chemical profiles of cuticular hydrocarbons did not always match between these myrmecophilous insects and the associated ants on the ant-plants. Chemically, Arhopala dajagaka showed good mimicry of the host ant species, A. amphimuta does not mimic, and A. zylda lacked hydrocarbons and thus appeared to be chemically insignificant. The cuticular hydrocarbons of Pseudoanaplectinia yumotoi cockroach were propagated among the host ant colonies. It is suggested that considerable variations exist in the chemical strategies that the myrmecophilous insects on ant-plants use in order to avoid ant attack and profit from the ant-plant associations

<S2-2> Geographical variation of mutualistic relationships between Macaranga myrmecophytes and their ant partners: research plans in Sarawak

This proceeding is a compilation of findings and progress activities of research collaboration between the Forest Department Sarawak (FDS) and the Japan Research Consortium for Tropical Forests in Sarawak (JRCTS). To highlight the research findings, An International Symposium entitled "Frontier in Tropical Forest Research: Progress in Joint Projects between the Forest Department Sarawak and the Japan Research Consortium for Tropical Forests in Sarawak" was ii held in Kuching, Sarawak on 21-22 September 2015.Myrmecophytes have mutualistic associations with plant-inhabiting ants (so-called plant-ants). They provide plant-ants with nest space and sometimes foods, and in return, the plant-ants protect their host-plants against herbivores, pathogens and climbing plants. In the tree genus Macaranga (Euphorbiaceae), 26 species are myrmecophytic, among which 18 species are distributed in Sarawak. The relationships between Macaranga myrmecophytes and plant-ants are remarkable for their high species-specificity and strong interdependency. For 20 years, we have studied the myrmecophyte-plant-ant relationships and their effects on the herbivorous insect assemblage associated with Macaranga plants at Lambir Hills National Park (LHNP), where 17 Macaranga species, including 12 myrmecophytic species, are distributed. Here, we describe 1) some ecological characteristics of Macaranga myrmecophytes, 2) the main results of our studies on the character of the mutualisms and their ecological consequences, and 3) our new research plans in Sarawak to investigate the geographical variations in the mutualisms. In our future research, we will enhance collaboration with Sarawakian researchers

Floristic Composition of Vascular Epiphytes in Lambir Hills National Park, Sarawak, Malaysia in Borneo

To assess the diversity of vascular epiphytes in primary lowland mixed dipterocarp forest in Borneo, field surveys were conducted in Lambir Hills National Park, Sarawak, Malaysia in 2014–2019. A total of 183 species including 72 species of eudicots (2 species were unknown at family level) (39 %), 71 monocots (39 %), 37 pteridophytes (20 %) and 3 lycophytes (2 %), are recorded. A checklist, with voucher specimens and notes on their identification and ecological information for each species, are provided. Dapania racemosa Korth. (Oxalidaceae) formerly recognized as a liana, was observed as an epiphyte for the first time

A new genus and a new species of Schizomyiina (Diptera: Cecidomyiidae: Asphondyliini) inducing petiole galls on Macaranga bancana (Miq.) in Borneo, Malaysia

Elsayed, Ayman Khamis, Shimizu-Kaya, Usun, Itioka, Takao, Meleng, Paulus, Yukawa, Junichi, Tokuda, Makoto (2018): A new genus and a new species of Schizomyiina (Diptera: Cecidomyiidae: Asphondyliini) inducing petiole galls on Macaranga bancana (Miq.) in Borneo, Malaysia. Zootaxa 4482 (1): 188-196, DOI: https://doi.org/10.11646/zootaxa.4482.1.1

Various Chemical Strategies to Deceive Ants in Three <i>Arhopala</i> Species (Lepidoptera: Lycaenidae) Exploiting <i>Macaranga</i> Myrmecophytes

<div><p><i>Macaranga</i> myrmecophytes (ant-plants) are generally well protected from herbivore attacks by their symbiotic ants (plant-ants). However, larvae of <i>Arhopala</i> (Lepidoptera: Lycaenidae) species survive and develop on specific <i>Macaranga</i> ant-plant species without being attacked by the plant-ants of their host species. We hypothesized that <i>Arhopala</i> larvae chemically mimic or camouflage themselves with the ants on their host plant so that the larvae are accepted by the plant-ant species of their host. Chemical analyses of cuticular hydrocarbons showed that chemical congruency varied among <i>Arhopala</i> species; <i>A</i>. <i>dajagaka</i> matched well the host plant-ants, <i>A</i>. <i>amphimuta</i> did not match, and unexpectedly, <i>A</i>. <i>zylda</i> lacked hydrocarbons. Behaviorally, the larvae and dummies coated with cuticular chemicals of <i>A</i>. <i>dajagaka</i> were well attended by the plant-ants, especially by those of the host. <i>A</i>. <i>amphimuta</i> was often attacked by all plant-ants except for the host plant-ants toward the larvae, and those of <i>A</i>. <i>zylda</i> were ignored by all plant-ants. Our results suggested that conspicuous variations exist in the chemical strategies used by the myrmecophilous butterflies that allow them to avoid ant attack and be accepted by the plant-ant colonies.</p></div