Long-Lost Relative Claims Orphan Gene: oskar in a Wasp

Organismic and Evolutionary Biolog

Contrasting Micro/Nano Architecture on Termite Wings: Two Divergent Strategies for Optimising Success of Colonisation Flights

Many termite species typically fly during or shortly after rain periods. Local precipitation will ensure water will be present when establishing a new colony after the initial flight. Here we show how different species of termite utilise two distinct and contrasting strategies for optimising the success of the colonisation flight. Nasutitermes sp. and Microcerotermes sp. fly during rain periods and adopt hydrophobic structuring/‘technologies’ on their wings to contend with a moving canvas of droplets in daylight hours. Schedorhinotermes sp. fly after rain periods (typically at night) and thus do not come into contact with mobile droplets. These termites, in contrast, display hydrophilic structuring on their wings with a small scale roughness which is not dimensionally sufficient to introduce an increase in hydrophobicity. The lack of hydrophobicity allows the termite to be hydrophilicly captured at locations where water may be present in large quantities; sufficient for the initial colonization period. The high wettability of the termite cuticle (Schedorhinotermes sp.) indicates that the membrane has a high surface energy and thus will also have strong attractions with solid particles. To investigate this the termite wings were also interacted with both artificial and natural contaminants in the form of hydrophilic silicon beads of various sizes, 4 µm C18 beads and three differently structured pollens. These were compared to the superhydrophobic surface of the planthopper (Desudaba psittacus) and a native Si wafer surface. The termite cuticle demonstrated higher adhesive interactions with all particles in comparison to those measured on the plant hopper

Genetic variation among species, races, forms and inbred lines of lac insects belonging to the genus Kerria (Homoptera, Tachardiidae)

The lac insects (Homoptera: Tachardiidae), belonging to the genus Kerria, are commercially exploited for the production of lac. Kerria lacca is the most commonly used species in India. RAPD markers were used for assessing genetic variation in forty-eight lines of Kerria, especially among geographic races, infrasubspecific forms, cultivated lines, inbred lines, etc., of K. lacca. In the 48 lines studied, the 26 RAPD primers generated 173 loci, showing 97.7% polymorphism. By using neighbor-joining, the dendrogram generated from the similarity matrix resolved the lines into basically two clusters and outgroups. The major cluster, comprising 32 lines, included mainly cultivated lines of the rangeeni form, geographic races and inbred lines of K. lacca. The second cluster consisted of eight lines of K. lacca, seven of the kusmi form and one of the rangeeni from the southern state of Karnataka. The remaining eight lines formed a series of outgroups, this including a group of three yellow mutant lines of K. lacca and other species of the Kerria studied, among others. Color mutants always showed distinctive banding patterns compared to their wild-type counterparts from the same population. This study also adds support to the current status of kusmi and rangeeni, as infraspecific forms of K. lacca

Do Termites Avoid Carcasses? Behavioral Responses Depend on the Nature of the Carcasses

BACKGROUND: Undertaking behavior is a significant adaptation to social life in enclosed nests. Workers are known to remove dead colony members from the nest. Such behavior prevents the spread of pathogens that may be detrimental to a colony. To date, little is known about the ethological aspects of how termites deal with carcasses. METHODOLOGY AND PRINCIPAL FINDINGS: In this study, we tested the responses to carcasses of four species from different subterranean termite taxa: Coptotermes formosanus Shiraki and Reticulitermes speratus (Kolbe) (lower termites) and Microcerotermes crassus Snyder and Globitermes sulphureus Haviland (higher termites). We also used different types of carcasses (freshly killed, 1-, 3-, and 7-day-old, and oven-killed carcasses) and mutilated nestmates to investigate whether the termites exhibited any behavioral responses that were specific to carcasses in certain conditions. Some behavioral responses were performed specifically on certain types of carcasses or mutilated termites. C. formosanus and R. speratus exhibited the following behaviors: (1) the frequency and time spent in antennating, grooming, and carcass removal of freshly killed, 1-day-old, and oven-killed carcasses were high, but these behaviors decreased as the carcasses aged; (2) the termites repeatedly crawled under the aging carcass piles; and (3) only newly dead termites were consumed as a food source. In contrast, M. crassus and G. sulphureus workers performed relatively few behavioral acts. Our results cast a new light on the previous notion that termites are necrophobic in nature. CONCLUSION: We conclude that the behavioral response towards carcasses depends largely on the nature of the carcasses and termite species, and the response is more complex than was previously thought. Such behavioral responses likely are associated with the threat posed to the colony by the carcasses and the feeding habits and nesting ecology of a given species

Distribution, Morphology, and Geochemistry of Manganese Nodules from the Valivia 13/2 Area, Equatorial North Pacific

Manganese nodules were collected during cruise 13/2 of R.V. Valdivia in 1976 in a small area of the equatorial north Pacific characterized by abyssal hill topography. The sediments are dominantly siliceous oozes in which extensive dissolution ofsiliceous material has taken place. Three principal nodule morphologies were recovered: polynucleate nodules, mononucleate nodules, and manganese crusts. Polynucleate nodules occur throughout the entire depth range studied whereas mononucleate nodules are found principally below 5000 m; manganese crusts are restricted to the abyssal hill environments. Nodule density remains on average roughly constant (> 7 kg/m2) with water depth (although varying considerably, 0-27 kg/m2, throughout the area), but the form in which the nodules occur changes with water depth. Nodule composition was investigated as a function of water depth, nodule size, and nodule morphology and shown to be related principally to nodule morphology. Mononucleate nodules have higher contents of Mn, Ni, Cu, and Zn and lower contents of Fe and Co than polynucleate nodules. The lithogenous fraction in the nodules is similar in both morphologies, although it varies considerably with nodule size. Both morphologies contain todorokite andJ-Mn02as the principal manganese oxide phases, but todorokite is relatively more abundant in the mononucleate nodules. The data are best interpreted in terms of the diagenetic supply of the transition elements Mn, Ni, Cu, and Zn to the nodules resulting from the in situ dissolution of siliceous tests in the sediment column. This process is more pronounced in the abyssal regions than on the flanks of the abyssal hills and leads to the enrichment of these elements in the larger mononucleate nodules embedded at the sediment -water interface there. This enhanced supply of transition elements also leads to the stabilization of todorokite in these nodules. Polynucleate nodules appear to be preferentially formed under conditions of higher sedimentation rate on the flanks of abyssal hills in an environment where abundant seeds are available. Mononucleate nodules are formed in abyssal environments characterized by lower sedimentation rate where enhanced rates of supply of biogenically derived elements can take place