Sex,life history and morphology drive individual variation in flight performance of an insect parasitoid

1. The movement of organisms can be driven by multiple factors and has implications for fitness and the spatial distribution of populations. Insects spend a large proportion of their adult lives foraging by flying for resources; however, their capability and motivation to move can vary across individuals. 2. The aims of this study were to examine interindividual and sex differences in flight performance and flight characteristics, using a flight mill bioassay, in Megarhyssa nortoni (Hymenoptera; Ichneumonidae), a parasitoid of the invasive woodwasp Sirex noctilio (Hymenoptera: Siricidae), one of the most important pests of pine afforestation worldwide. We also assessed the influence of morphological traits in combination with sex on flight and explored the cost of flight on longevity and mass loss. 3. The results show a difference between sexes in flight characteristics and performance. Females show greater total distance flown than males, and have a better capacity to undergo sustained flight. Sexual size dimorphism was also found and it was noted that size positively affects distances travelled. Females have a longer life span than males, yet no differences were noted in longevity within sex between individuals that did not fly and those that flew. Age did not influence flight performance of females or impacted on post‐flight longevity. Females lost less body mass than males even after flying longer distances. 4. These results suggest that sex‐specific behaviours probably govern flight abilities together with (and not only because of) morphological traits. The paper discusses sex‐specific life‐history strategies in parasitoids and their implications for biocontrol programmes.     

Non-native fish species are related to the loss of ecological integrity in Neotropical streams: a multimetric approach

Hydrobiologia - The use of multimetric indices (MMIs) became a common practice for evaluating ecological integrity of aquatic ecosystems. However, most developed MMIs ignore non-native species as...     

Photosynthesis, photorespiration and nitrogen metabolism

Abstract. The ATP and reduced ferredoxin generated in photosynthetic reactions in the chloroplast are utilized for a large number of reactions other than CO₂-fixation. Quantitatively the most important reaction is the reassimilation of ammonia liberated during photorespiration in C₃ plants via the glutamate synthase cycle. Chloroplasts are also able to reduce nitrite to ammonia, sulphate to sulphide, and synthesize a number of amino acids. The amino acids essential for human nutrition are all synthesized in the chloroplast and evidence is presented to suggest that they may be the sole site of such biosynthetic reactions.     

Changes in the electroretinogram and rhodopsin content in hunter rats during the development of hereditary degeneration of the retina

Changes in the electroretinogram were studied and the rhodopsin content determined in the retina and optic cup of Hunter rats during development of hereditary degeneration of the retina. Changes in the rhodopsin content in the retina and optic cup were found to take place differently in time. The content of visual pigment in the optic cup increased until the 45th day, and then it fell slowly; in the retina it increased until the 25th day and fell sharply after the 35th day after birth. The amplitude of the electroretinogram recorded during stimulation of all intensities from threshold to saturating fell steadily from the 17th to the 35th day; later a sharp fall in the amplitude of the response to weak stimulation with disappearance of thea wave of the electroretinogram took place. The 35th day is thus the critical period in the development of the disease. The possible role of disturbances of rhodopsin resynthesis in the phenomena observed is discussed.I. M. Sechenov Institute of Evolutionary Physiology and Biochemistry, Academy of Sciences of the USSR, Leningrad. Research Institute of Human Morphology, Academy of Medical Sciences of the USSR, Moscow. Translated from Neirofiziologiya, Vol. 9, No. 5, pp. 527–531, September–October, 1977.     

INTRASTRIATAL ADMINISTRATION OF AN OLIGODEOXYNUCLEOTIDE ANTISENSE TO THE D2 DOPAMINE RECEPTOR mRNA INHIBITS D2 DOPAMINE RECEPTOR-MEDIATED BEHAVIOR AND D2 DOPAMINE RECEPTORS IN NORMAL MICE AND IN MICE LESIONED WITH 6-HYDROXYDOPAMINE

Previous studies have shown that the intracerebroventricular injection of antisense oligodeoxynucleotides targeted to the mRNAs encoding the different subtypes of dopamine receptors inhibited behaviors mediated by these receptors. The present studies were designed to determine whether such antisense oligodeoxynucleotides could produce similar effects when injected into a discrete brain area. A D₂ dopamine receptor antisense oligodeoxynucleotide (D₂ antisense) was repeatedly injected into one corpus striatum of either normal mice or mice with unilateral lesions of the striatum induced by 6-hydroxydopamine. In the latter, intrastriatal injection of D₂ antisense blocked the contralateral rotational behavior induced by the parenteral administration of the D₂ dopamine receptor agonist quinpirole. The inhibitory effect of D₂ antisense was dose- and time-related and was reversed upon cessation of D₂ antisense treatment. This inhibitory effect was also selective in that D₂ antisense treatment inhibited the rotational behavior induced by quinpirole but not that induced by the D₁ dopamine receptor agonist SKF 38393 or by the muscarinic cholinergic agonist oxotremorine. Following repeated intrastriatal injections of D₂ antisense into normal mice, parenteral administration of quinpirole caused rotational behavior ipsilateral to the side in which the D₂ antisense was injected. No such rotational behavior was seen when similarly treated mice were challenged with SKF 38393 or oxotremorine. The quinpirole-induced rotational behavior in mice given intrastriatal injections of D₂ antisense disappeared upon cessation of D₂ antisense treatment. Repeated intrastriatal administration of D₂ antisense also caused a significant reduction in the levels of D₂, but not D₁, dopamine receptors in striatum, as determined by receptor autoradiography. The levels of D₂ dopamine receptors returned to normal upon cessation of D₂ antisense treatment. Intrastriatal administration of an oligodeoxynucleotide with randomly placed nucleotides failed to alter the rotational response to quinpirole in either 6-hydroxydopamine-lesioned or normal mice and failed to alter the levels of D₂ dopamine receptors in striatum. These results show that selective inhibition of behavioral responses mediated by D₂ dopamine receptors can be achieved by the direct injection of a D₂ antisense oligodeoxynucleotide into a discrete brain area. Copyright © 1996 Elsevier Science Ltd     

Do feral honey bees (Apis mellifera) and regent parrots (Polytelis anthopeplus) compete for nest sites?

Abstract Surveys of nesting sites of feral honey bees (Apis mellifera) and regent parrots (Polytelis anthopeplus) were made in the red gum/black box woodlands of Wyperfeld National Park, Victoria, Australia. Data on tree species and size, and number of hollows were collected from all trees within seven 500 × 100m plots. Nest site characteristics were quantified for both bees and parrots. We found 27 feral honey bee colonies, suggesting a density of 77.1 colonies per km². The average occupation rate for bees was 1.3% of trees and 0.7% of available hollows. The height, aspect and entrance characteristics of honey bee nests at Wyperfeld were not qualitatively different to those reported elsewhere. We found 15 pairs of nesting regent parrots. Nest sites chosen by these birds overlapped those chosen by honey bees, but 52% of bee nests were in cavities unsuitable for regent parrots. We suggest that honey bee population growth may be limited in the park by a lack of water.     

Management of Roadside Salt Pools to Reduce Moose-Vehicle Collisions

ABSTRACT Wildlife-vehicle collisions cause numerous human fatalities and injuries, and generate considerable expenses in property damage each year. Certain characteristics of the road and its surroundings are known to have an impact on collision probability. Roadside salt pools increase the risk of collision by attracting moose (Alces alces) to the side of the road. In the Laurentides Wildlife Reserve of Québec, Canada, roadside salt pools were drained and filled with rocks to deter moose from drinking. We surveyed 12 roadside salt pools during 3 consecutive summers (2003–2005) from mid-May to mid-August. Seven salt pools were managed in autumn 2004, and 5 pools were left untreated. We equipped all 12 sites with electronic apparatus that allowed us to detect moose attendance and study their behavior. We also measured physical, chemical, and environmental characteristics of these pools and other unvisited pools in order to correlate moose attendance with specific habitat criteria. We found that moose mostly attended roadside salt pools from mid-June to mid-July, with a decrease in August. Moose attendance was significantly correlated with visual obstruction toward the road and water availability. Management of the pools caused a decrease in mean length of time moose spent at them. Number of visits decreased significantly at night (by 90%), which was when most visits occurred, but not during the day. The proposed management practice prevented all visiting moose from drinking brackish water. These results suggest that moose should eventually lose interest in treated salt pools, therefore decreasing the risk of moose-vehicle collisions on the road.     

Minimizing Leg-Hold Trapping Trauma for Otters With Mobile Phone Technology

ABSTRACT We present and evaluate a protocol for the capture of otters (Lutra lutra) using padded leg-hold traps coupled with Global System for Mobile communication (GSM) trap alarms. The trapping method was highly efficient, capturing 46 otters at 6.9 trap-nights each. Functioning alarms allowed us to remove 36 otters from their traps within 22 (SD = 14) minutes of capture. We caught 10 otters in trap sets with malfunctioning trap alarms and retrieved them the following morning, after ≤24 hours. Functioning alarms reduced the injuries suffered from an average cumulative score of 77.7 to just 5.5 on the International Organization for Standardization 10990-5 trauma scale (Z=-5.074, P ≤ 0.001). As a result, we strongly encourage the use of GSM trap alarms under the principle of refinement in animal experiments.     

Do Embedded Shotgun Pellets Have a Chronic Effect on Body Condition of Pink-Footed Geese?

Abstract: Hunting with shotguns inevitably causes wounding of game that are hit by pellets but not retrieved by the hunter. We examined the effects of pellets on body condition in a total of 2,164 pink-footed geese (Anser brachyrhynchus) that were captured by cannon-nets, x-rayed, and banded with neck collars after the closure of the hunting season in Denmark. All geese were sexed, aged, weighed, and wing lengths measured. In the overall material, 23.8% and 11.6% of adults and first-winter birds, respectively, carried pellets outside the gizzard. We derived an index of the body condition of individual birds as the residuals of linear regression of log-transformed wing length and weight. Statistical analyses showed a highly significant relationship between body condition, sex, and year, whereas number of pellets was not significantly related to body condition. The results suggest that geese that have been hit by shotgun pellets but have survived the hunting season, so-called lightly crippled individuals, are not injured to an extent to have detectable chronic effects.