Temporal Patterns of Territorial Behavior and Circulating Testosterone in the Lapland Longspur and Other Arctic Passerines

We studied territorial aggression in relation to circulatingtestosterone levels in free-living birds of four species innorthern Alaska. The Lapland longspur, Calcarius lapponicus,is an abundant breeding passerine on the arctic tundra. Unlikemany passerines at lower latitudes, male Lapland longspurs donot defend a "multiple-purpose territory" that serves to providenest sites, food and shelter. Rather, after arrival on the breedinggrounds, they perform aerial display flights over a looselydenned "nest area" for a very brief period of two days or so,showing tolerance of other males. This song display may be involvedin courtship. During this phase, male longspurs show a briefand pronounced peak in circulating testosterone levels, andare not aggressive toward simulated territorial intrusions (STIs).Males then "guard" their sexually receptive mates for aboutten days, during which they are highly aggressive toward STIs,but do not sing as much. During the next phase, incubation,the males become very tolerant of conspecific males. Their circulatingtestosterone levels decline to baseline levels, and they generallydo not sing or display aggression in response to STIs. Threeother passerines, the white-crowned sparrow, Zonotrichia leucophrysgambelii, American tree sparrow, Spizella arborea, and savannahsparrow, Passerculus sandwichensis, show patterns of territorialaggression typical of species studied at lower latitudes. Welldefinedterritories are defended for several weeks, during which thereis a prolonged peak in plasma concentrations of testosterone.These three species continue to sing and display aggressioneven late in the season, unlike the longspurs. The peak of testosteronein the longspurs occurs simultaneously with the peak in songdisplay, while in mid-latitude species it occurs with the peakin reproductive aggression. These data suggest that the interrelationshipof testosterone and aggression in Lapland longspurs may be differentfrom that of passerines with multiple-purpose territories, andmay be related to the constraints of breeding in the open arctictundra.     

Modulation of the Adrenocortical Responses to Acute Stress in Arctic Birds: A Possible Ecological Basis

There is considerable evidence that the increases in circulatingcorticosterone levels following acute stress, such as suddenstorms, can trigger facultative behavioral patterns designedto maximize survival. During the breeding season, adrenocorticalresponses to aseasonal storms may trigger facultative behavioralpatterns resulting in temporary disruption of nesting. A renestingcycle often follows when conditions become favorable again.However, in arctic ecosystems the brief breeding season limitsthe capacity of most avian populations to renest, and yet springweather may be extreme. This led to the hypothesis that arcticbirds may down-regulate their sensitivity to acute stress (suchas severe storms) so that breeding can begin and be completedbefore the first storms of autumn (only 6–8 weeks later).To test this we have used the "stress-series protocol" thattakes advantage of the fact that capture, handling and restraintconstitutes a more-or-less equal stress among all vertebratespecies, and that corticosterone concentrations in small bloodsamples collected during the first hour post-capture indicatesensitivity of the hypothalamo-adenohypophysial- adrenal axisto acute stresses in general. Comparisons of the increases inplasma levels of corticosterone following capture in severaltaxa of arctic birds indicated that suppression of the adrenocorticalresponse to acute stress was not ubiquitous. Although some speciesdid show low amplitude responses of the circulating corticosteroneincrease during the stress series protocol, others did not,and some (especially males) showed an increase in sensitivityto acute stress. Additional hypotheses were suggested as follows:1) species with greater body mass have larger relative energyreserves and would be more able to resist acute stresses thansmaller energy reserves and would be more able to resist acutestresses than smaller species; 2) short-lived birds with anexpectancy of one or two breeding seasons should be more resistantto acute stress than long-lived birds that may have many attemptsat successful breeding; 3) resistance of the adrenocorticalresponse to stress is a function of the degree of parental careprovided by the individual (also takes into account sex differencesin parental investment). Correlations of the maximum corticosteronelevel and the ratio of maximum to minimum corticosterone levelsgenerated during the stress series protocol with body mass andlongevity were not significant. However, maximum corticosteronelevel was significantly lower in birds providing most parentalcare and almost significant for the ratio of maximum to minimumcorticosterone levels. These comparative data from free-livingarctic birds suggest an ecological basis for modulation of theadrenocortical responses to stress. In at least one species,up-regulation of the response appears to involve a change insensitivity to glucocorticosteroid feedback. Further investigationswill explore neuroendocrine mechanisms further in the lightof these ecological bases.     

Gould on Laws in Biological Science

Are there laws in evolutionary biology? Stephen J. Gould has argued that there are factors unique to biological theorizing which prevent the formulation of laws in biology, in contradistinction to the case in physics and chemistry. Gould offers the problem of ’’complexity‘‘ as just such a fundamental barrier to biological laws in general, and to Dollo‘s Law in particular. But I argue that Gould fails to demonstrate: (1) that Dollo‘s Law is not law-like, (2) that the alleged failure of Dollo‘s Law demonstrates why there cannot be laws in biological science, and (3) that ’’complexity‘‘ is a fundamental barrier to nomologicality.     

New Aegisthidae (Copepoda: Harpacticoida) from western Pacific cold seeps and hydrothermal vents

Hyperbenthic harpacticoid samples from Japanese hydrothermal vents in the Okinawa Trough and cold seep sites in Sagami Bay were examined and resulted in the discovery of four new species belonging to three new genera of Aegisthidae (Copepoda: Harpacticoida). Females of Nudivorax todai gen. et sp. nov. possess a large area of flexible integument between the cephalosome and the first pedigerous somite which is suggestive of a gorging feeding strategy. Main diagnostic characters separating the new genus from other Aegisthidae are provided by the unusually short caudal rami, the complete lack of intcgumcntal surface lamellae, and the presence in the male of a linear array of pores along the rostral margin which appears to be sensory in function. Scabrantenna yooi gen. et sp. nov. displays several similarities with Aegisthus aculeatus Giesbrecht, 1891 but is highly distinctive in its male morphology which includes extremely atrophied mouthparts and a unique prehensile antenna. Jamstecia terazakii gen. et sp. nov. is only known from a single female caught in the Okinawa Trough. Jamstecia gen. nov. is most closely related to Andromastax Conroy-Dalton & Huys, 1999 but can be distinguished on the basis of the elongate antennules, the antennary morphology, the absence of lateral spinous processes on the cephalosome and swimming legs 2–4, and differences in the mandibular palp and armature of the maxilliped. Andromastax cephaloceratus sp. nov. differs from the type species A. muricatus Conroy-Dalton & Huys, 1998 primarily in the presence of long spinous processes on the cephalosome and the absence of the inner seta on the female P5.     

Effect of Plant Factors, Sugar Contents, and Control Methods on the Top Borer (Scirpophaga nivella F.) Infestation in Selected Varieties of Sugarcane

Sugarcane (Saccharum officinarum L.) varieties CP‐43/33 and L‐118 susceptible, BF‐162 and SPSG‐26 resistant while CP‐72/2086 as intermediate were screened for studies on top borer, Scirpophaga nivella Fabricus (Pyralidae: Lepidoptera). Morpho‐physio chemical plant factors as well as quality of sugar were examined to elucidate the relationship between pest infestations. The observations on leaf thickness 0.735* and moisture contents 0.771* showed positive and significant correlation with the pest infestation at tillering stage. Total minerals, manganese and copper contents did not show significant correlation with the pest infestation, whereas nitrogen, potassium, calcium, magnesium and ferrous contents manifested positive and significant correlation with the pest infestation. Phosphorous, carbohydrates, fats and zinc produced significant and adverse effect on the pest infestation at tillering stage. Zinc contents with contrasting behaviors appeared to be the most important character with co‐efficient value of 0.764 followed by ferrous with positive sign. The effect of borer infestation was significantly negative on pol (sucrose), Brix contents (total soluble solids), and CCS (commercial cane sugar). The coefficient of determination value was 0.821, obtained by computing fiber content, pol, Brix and CCS factors together for multivariate regression models. Application of trash mulching at the time of sowing proved to be the most effective treatment with minimum infestation (3.91%) of borer and maximum protection level (62.87%) followed by Furadan®, removal of dead hearts + spike thrust, hand collection of egg masses, and cutting of shoots at 15 days interval.     

Cloning of Immune Protein Hemolin cDNA from the Indianmeal Moth, Plodia interpunctella, and its High Induction During Development and by Bacterial Challenge

Partial cDNA of hemolin, an insect immune protein, was cloned from indianmeal moth, Plodia interpunctella, and the rates of hemolin mRNA expression were demonstrated in each stage of development and also by bacterial injections. A deduced amino acid sequence from the cloned hemolin cDNA was approximately 44‐54% similar to hemolins of 5 other moths. During development the level of hemolin mRNA was the highest at the time of the larval‐pupal matamorphosis. Hemolin was also rapidly induced by the injection of bacteria into the 4^th or the 5^th instar larvae. Hemolin induction rate by bacterial challenge was higher in the 5^th instar larvae than in 4^th instars. Our results suggest that hemolin could have multiple roles that act both on cellular processes during development and on the immune reactions for the resistance to pathogen invasion.     

Three-Dimensional Reconstruction of Hematopoietic Organ of Bombyx mori Larva

Three‐dimensional reconstructions of a hematopoietic organ (HPO) from Bombyx mori larva were undertaken using light and electron microscopy. Each compact islet varied in sizes, but in the central area of the HPO their size became smaller. Compact islets and loose islets were made up of prohemocytes, plasmatocytes, and reticular cells, but there were differences in the proportions of these cells. Within the cytoplasm of reticular cells and within their cell projection, vacuoles were observed. Cell proliferation occurs primarily in the compact islets, and differentiation associated with the reticular cells occurs primarily in the loose islets. It can be inferred that reticular cells have a significant influence on proliferation and differentiation associated with hematopoiesis. According to the results of the 3‐D reconstruction, one reticular cell is in contact with eight or nine hemocytes. Each reticular cell is presumably of approximately ten hemocytes. Movies relevant to Figs. 3, 4 and 5 can be found at http://biotech.korea.ac.kr/ cellbio/pages/ 3D‐results.html.     

INTERACTIONS OF 1-METHYLADENINE AND THE SURFACE OF STARFISH OOCYTE

Three metabolic inhibitors, mycostatin, concanavalin A (Con A) and cytochalasin B (CB) were used to study the interactions between l-methyladenine (1-MA) and the starfish oocyte surface leading to germinal vesicle breakdown (GVB). Mycostatin and Con A had no obvious effects on GVB. CB did not inhibit, but did delay GVB. This delaying effect was interpreted as having multiple 1-MA reactive "sites" on the surface. The results also suggested that not all of them were needed to react with 1-MA to bring about GVB.