Apicrenus fossilis, a new neotropical apiomerine fossil genus, is described and compared with annectant genera. This new genus is distinguished from other consubfamilials by the following combination of characters: anteriorly located eyes, with their margins flushing with the lateral margins of the head, anterior acetabula not visible from above, absence of collar, and presence of two triangular discal corial cells in the fore wing.
Aggregations of conspecifics are ubiquitous in the biological world. In arthropods, such aggregations are generated and regulated through complex interactions of chemical and mechanical as well as abiotic and biotic factors. Aggregations are often functionally associated with facilitation of defense, thermomodulation, feeding, and reproduction, amongst others. Although the iconic aggregations of locusts, fireflies, and monarch butterflies come to mind, many other groups of arthropods also aggregate. Cycloalexy is a form of circular or quasicircular aggregation found in many animals. In terrestrial arthropods, cycloalexy appears to be a form of defensive aggregation although we cannot rule out other functions, particularly thermomodulation. In insects, cycloalexic-associated behaviors may include coordinated movements, such as the adoption of seemingly threatening postures, regurgitation of presumably toxic compounds, as well as biting movements. These behaviors appear to be associated with attempts to repel objects perceived to be threatening, such as potential predators or parasitoids. Cycloalexy has been reported in some adult Hymenoptera as well as immature insects. Nymphs of the orders Hemiptera (including Homoptera) as well as larvae of the orders Neuroptera, Coleoptera, Diptera, Hymenoptera, and, in a less circular fashion, the Lepidoptera, cycloalex. There are remarkable convergences in body form, life habit, and tendencies to defend themselves in the social larval Coleoptera, particularly chrysomelids, social larval Lepidoptera, and social larval Hymenoptera. In immature insects, the cycloalexing organisms can be arranged with either heads or abdominal apices juxtaposed peripherally and other conspecifics may fill in the center of the array. In the Chrysomelidae, the systematic focus of this review, species in the genera Lema, Lilioceris (Criocerinae), Agrosteomela, Chrysophtharta, Eugonycha, Gonioctena, Labidomera, Paropsis, Paropsisterna, Phratora, Phyllocharis, Plagiodera, Platyphora, Proseicela, Pterodunga (Chrysomelinae), Coelomera (Galerucinae), and Acromis, Aspidomorpha, Chelymorpha, Conchyloctenia, Ogdoecosta, Omaspides and Stolas (Cassidinae) are reported to cycloalex although cycloalexy in other taxa remains to be discovered. Other types of aggregations in insects include stigmergy, or the induction of additional labor, and epialexy, or the positioning of conspecifics organisms over the midvein or an elongated aspect of a leaf.
Insects are the most diverse group of life on Earth and their history extends well into the Paleozoic, making them among the oldest of terrestrial animal lineages. They are critical to the well being of ecosystems from the equator to the poles, and are inexorably tied to the well being of our world. Whether beneficial or malignant, insects wield an overwhelming influence on our health, economy, and security. It is little wonder that insects so consistently appear in our cultures, religions, and mythologies. Given such realities, it is vital that we gain a better understanding and appreciation of Nature’s ‘inordinate fondness’. Indeed, there is considerable wisdom to be found in the study of these marvels of evolution, and what better way to understand their present and future than to peer back into their distant past.
Here presented are some of the results of the 6th International Congress on Fossil Insects, Arthropods and Amber (FossilX3) held in Byblos, Lebanon in April, 2013. In the tradition of previous congresses, researchers from around the world gathered to discuss the latest developments and to build new co-operative endeavours. Recognizing that the future of our science is one of interdisciplinary collaboration, these meetings steadily grow in importance, and proceedings such as this reveal the latest hypotheses and conclusions, while inspiring others toward newer and greater goals.