Recaptures Of Males Research Articles

Comparative Fitness of Irradiated Light Brown Apple Moths (Lepidoptera: Tortricidae) in a Wind Tunnel, Hedgerow, and Vineyard

Light brown apple moth, Epiphyas postvittana (Walker) (Lepidoptera: Tortricidae), is the target of the sterile insect technique, but reduced moth fitness from irradiation lowers the effective overflooding ratio of sterile to wild moths. New measures of insect quality are being sought to improve field performance of irradiated insects, thus improving the cost effectiveness of this technique. Male pupae were irradiated at intervals between 0 and 300 Gy, and adult flight success was assessed in a wind tunnel equipped with flight track recording software. A dose response was evident with reduced successful search behaviors at higher irradiation doses. Irradiation at 250 Gy reduced arrival success to 49% of untreated controls, during 2-min assays. Mark-release-recapture of males irradiated at 250 Gy indicated reduced male moth recapture in hedgerows (75% of control values of 7.22% +/- 1.20 [SEM] males recaptured) and in vineyards (78% of control values 10.5% +/- 1.66% [SEM] recaptured). Males dispersed similar distances in both habitats, and overflooding ratios dropped off rapidly from the release point in both landscapes. Transects of traps with central releases proved to be an efficient method for measuring the quality of released males. Relative field performance of moths was greater than suggested by wind tunnel performance, which could be due to time differences between the two assays, two-minute wind tunnel tests compared with days in the field treatments. Release strategies involving ground releases should consider the effect of limited postrelease dispersal. Aerial release could solve this problem and warrants investigation.

Temporal dynamics of relative-mass variation of red-sided garter snakes (Thamnophis sirtalis parietalis) at a communal hibernaculum in Manitoba

An animal's relative body mass (i.e., mass adjusted for length or some other size dimension) is a potential indicator of its body condition, which in turn can influence demographic traits. In this study, I revisited data collected in 1969–1970 on garter snakes, Thamnophis sirtalis parietalis, at a communal hibernaculum in Manitoba, to test hypotheses generated by more recent literature. First, I compared fall-through-spring variation in relative mass to a similar study of another species of Thamnophis in a milder, Mediterranean climate and found a similar temporal pattern, suggesting common features across a wide latitudinal range. Female snakes had a higher relative mass than males and experienced lower decline in relative mass overwinter and through the spring. This suggests different hibernation strategies of the 2 sexes, possibly involving different temperatures or differences in metabolism, and also reflects the preoccupation of males upon spring emergence with searching for mates, at energetic cost while not feeding. Comparison of my data with a second study of the same species at another den in Manitoba indicated nearly identical patterns of loss of mass, based on recaptures of males throughout the spring, and also corroborated that study's finding that initially relatively heavy males remained at the den longer. Thus, males that have accumulated more capital the previous year presumably have more opportunities to mate. Although recapture intervals of most males were only a few days long, similar to the previous study, some males remained in the vicinity of the den for up to 5 weeks. These findings underscore the fundamental differences between males and females in the temporal distribution of their costs of reproduction.

Autumn swarming of the pond batMyotis dasycnemeat hibernation sites in Latvia

Capturing of swarming bats was carried out at five hibernation sites in Latvia in 2005- 2007. In total 436 pond bats Myotis dasycneme were caught and marked with forearm rings. The most prominent swarming was observed in August-September, which corresponds with relevant results from other countries. Most bats caught were adults, with the domination of adult males. Spearman's rank correlation showed statistically significant changes in numbers of different age and sex groups of bats during the swarming season. Behavioural observations of bats and recaptures of males indicate that possibly the main reason for the swarming activity of pond bats is mating.

Experience‐dependent recapture rates and reproductive success in male grey mouse lemurs (Microcebus murinus)

Male mating tactics can vary according to the potential for scramble or contest competition but also as a consequence of individual characteristics, such as body condition and previous experience. The influence of experience, i.e., residency, on male recapture rates and reproductive success was studied in a population of free-living grey mouse lemurs. Long-term capture data from 320 individuals revealed that both sexes had very low recapture probabilities within their first year in the study population, but recapture rates declined less sharply during the following years. Capture results and telemetric analyses on 12 focal males revealed that resident males had larger body mass and larger home ranges than new males. Home range size correlated with the number of accessible females, indicating that resident males had higher probabilities to meet mates than new males. The reproductive success of 132 candidate fathers, representing both resident and new males, was determined by means of molecular genotyping. Paternity determination was successful in 38 cases (success rate: 19%). Sixteen resident males and seventeen new males sired offspring. However, in relation to the number of candidate fathers being present in the mating season, resident males were twice as likely to reproduce successfully as new males. These findings suggest experience-dependent reproductive tactics that most likely correspond to a differential spatial knowledge of resources, mates and potential threats. The results generally agree with the predictions made for a scramble competition regime and demonstrate substantial behavioral plasticity in a nocturnal primate species with a dispersed multi-male/multi-female mating system.

The blue tit's song is an inconsistent signal of male condition

Sexually selected traits are often hypothesized to signal male condition or quality, though empirical evidence is mixed, and a number of alternative models of sexual selection do not require condition dependence. We examined the relationship between various measures of condition and dawn songs in male blue tits (Cyanistes caeruleus). We detected 6 largely independent measures of variation (i.e., variables) in these songs. None of these variables were related to blue tits' ultraviolet–blue plumage, a demonstrated sexual signal, thus failing to support the redundant signal hypothesis. We found some evidence that the song variables we measured signaled male quality. There were correlations between body size and certain song traits, though neither male age nor male recapture in the subsequent breeding season (apparent local survival) predicted any song variation. We combined our results with published effect sizes comparing blue tit song with male quality variables using meta-analysis and found that a few song measures are correlates of male quality, though as in our field data, neither male age nor survival appeared related to song. Our relatively large sample sizes (>60), combined with our meta-analytical integration of 89 effect sizes, make the results regarding the signaling value of our measured components of blue tit song robust. These results demonstrate that 1) only certain aspects of signal variation may be condition dependent and 2) even when components of a sexual signal appear correlated with condition in some studies, these signal components may be unrelated or inconsistently related to a variety of condition indices.

Performance of Irradiated Teia anartoides (Lepidoptera: Lymantriidae) in Urban Auckland, New Zealand

The Australian moth Teia anartoides Walker has been the target of a major eradication program in Auckland, New Zealand. Information on cold torpor and dispersal was needed to help interpret catches of sterile and wild males in female-baited delta traps operated in a grid of up to 1,696 traps at 500-m spacings across the city. Laboratory experiments indicated male flight was enabled at temperatures above 17 degrees C (confirmed by field trapping of wild and recaptured moths). Male survival in the field or in field cages was determined to be limited to approximately 4 d. Sterilization of males for dispersal studies was achieved by exposing male pupae to either 160 or 100 Gy by using 1.25 MeV gamma rays from a Cobalt source, before release as fluorescent-dyed emerged adults. Dispersal was determined by recapture of males in the trapping grid of 1,696 delta traps baited with virgin female moths and placed at spacings of 50-500 m. Irradiated sterile males dispersed up to a maximum recorded distance of 4,500 m (160 Gy) and 10,000 m (100 Gy). At 100 Gy, the median dispersal distance was 300 m, with 90% of males dispersing 1,600 m or less.

North Atlantic climate variation influences survival in adult fulmars

There is increasing evidence that large scale climate variation influences reproductive parameters of seabirds, but fewer studies have investigated possible effects on adult survival. Previous work has shown that climate variation reflected by the winter North Atlantic oscillation (WNAO) influences reproductive success in northern fulmars. Here, we use a 34 year long (1962–1995) individual‐based data set to investigate inter‐annual and inter‐individual variation in adult survival in this species. Breeding success in the previous and current seasons, and both the WNAO and one‐year lagged WNAO indexes, were considered as potential sources of inter‐annual variation in survival and recapture probabilities. Sex and an index of body size were considered as potential sources of inter‐individual variation in survival and recapture probabilities. Body size effects were not significant, but males and females differed in both their survival and recapture probabilities. Probability of recapture of females was positively correlated with breeding success in both the current and previous breeding seasons, whereas male recapture probabilities were correlated only with previous breeding success. Male and female survival decreased over the study period, suggesting that there had been a degradation of environmental conditions. This hypothesis was supported by the detection of a negative correlation between survival and the WNAO, which, in turn, showed a positive increase over this period. The negative correlation between female adult survival and WNAO did not result only from the long term behaviour of the two time series, but persisted for higher frequency fluctuations. In contrast, the correlation between male survival and WNAO seemed to result only from the long term behaviour of the two time series. Despite uncertainties over causal mechanisms, these findings add to the body of evidence that large scale climate variation could dramatically affect seabird population dynamics. Furthermore our results suggest that climate variation can differentially influence individuals with distinct phenotypic characteristics.

Dispersal of the lycaenidPlebejus argusin response to patches of its mutualist antLasius niger

We examined the movement rates of individuals of an obligate myrmecophilous butterfly,Plebejus argus(Lycaenidae: Lepidoptera), in relation to a patch of its mutualist ant,Lasius niger. Marked male and femaleP. argusfrom local (resident), fragmented and continuous populations were released into and away from (>100m) a patch ofL. niger, and subsequently searched for in a 500×500 m area. Recaptures of males and females from all populations were strongly associated with the target patch of mutualist ants. First day recapture displacements were significantly higher for releases away from the target patch for males, but not for females. Mutualist ant presence was shown to be more important than nectar source density in determining persistence ofP. argusin release squares. There was no significant difference in displacement distances or recapture frequencies (standardised for search effort) in the target patch of individuals from local (resident of target patch), fragmented and continuous populations. The recapture frequency in the target patch of males from the local population released outside the target patch was greater than expected from a null model of random straight line movement, suggesting non‐random (systematic or orientated) search behaviour. The number of males remaining in the target patch following release into the target patch was greater than expected from a simple diffusion model, suggesting a behavioural response to patch boundaries or other cues related to the patch.

Effects of methoxyfenozide-treated surfaces on the attractiveness and responsiveness of adult codling moth (Lepidoptera: Tortricidae).

The attractiveness and responsiveness of adult codling moth, Cydia pomonella (L.), exposed to surfaces treated with the ecdysteroid agonist methoxyfenozide was investigated in wind tunnel and orientation tube assays. When males were exposed to either water- or surfactant-treated surfaces for 48 h, and regardless of what treatment surfaces the females had been exposed to, the mean percent recaptures of such treated males in the wind tunnel assay were sometimes significantly greater than the recaptures of males that had been exposed to methoxyfenozide. Similarly, in the orientation tube assay, males exposed to methoxyfenozide-treated surfaces almost always had significantly lower mean levels of individuals exhibiting sexual excitability and the mean distances traveled upwind, regardless of female exposures. The two assays demonstrated that male codling moths exposed to methoxyfenozide-treated surfaces were not as responsive to calling females (treated and nontreated) as were the nontreated males. Conversely, females exposed to methoxyfenozide-treated surfaces were just as attractive to nontreated males as were nontreated females. It appears that a male's ability to respond to a calling female is more negatively affected by the ecdysone agonist than a female's ability to call and attract males.

Effects of methoxyfenozide‐treated surfaces on the attractiveness and responsiveness of adult leafrollers

Abstract The attractiveness and responsiveness of the adult redbanded leafroller, Argyrotaenia velutinana (Walker), and obliquebanded leafroller, Choristoneura rosaceana (Harris), exposed to surfaces treated with the ecdysteroid agonist methoxyfenozide were investigated in wind tunnel and orientation tube assays. For both species, when males were exposed to water‐treated surfaces for 48 h, and regardless of what treatment surfaces the females had been exposed to, the mean percentage recaptures of such treated males in the wind tunnel assays were always significantly greater than the recaptures of males that had been exposed to methoxyfenozide. However, exposure to surfaces treated with surfactant (Latron B‐1956) also negatively affected the responsiveness (or attractiveness) of both moth species. In the orientation tube assays, males exposed to methoxyfenozide‐treated surfaces always had significantly lower mean levels of individuals exhibiting sexual excitability, and the mean distances traveled upwind, regardless of females’ exposure. In addition, exposure to surfactant‐treated surfaces did not affect mean levels of sexual excitibility and distances traveled upwind. The two bioassays demonstrated that male A. velutinana and C. rosaceana exposed to methoxyfenozide‐treated surfaces were not as responsive to calling females (treated and non‐treated) as were the non‐treated males. Conversely, females exposed to methoxyfenozide‐treated surfaces were just as attractive to non‐treated males as water‐treated females. It appears that a male's ability to respond to a calling female is more negatively affected by the ecdysone agonist than a female's ability to call and attract males.

Further development of a low-cost release method for sterile Queensland fruit fly Bactrocera tryoni (Froggatt) in rural New South Wales

Sterile Queensland fruit fly (QFF) Bactrocera tryoni (Froggatt) were released using a pupal-release technique in part of Wagga Wagga. Between August 1997 and May 1998, sterile flies were released using initially sand and later vermiculite mediums in the bed technique. A total of 234.16 million pupae were delivered, with an overall emergence rate of 41.4% and male recapture rate of 0.0365% based on emerged flies. A male recapture rate of 0.0141% was calculated from the male pupae deployed, not corrected for emergence. Released sterile flies were recaptured up to 74 days after release. Of the 16 563 males recaptured, 99.3% of sterile flies were trapped within 1�km of release sites. The CLIMEX model was used to rank the climate at Wagga Wagga to better understand emergence and recapture rates during this and earlier programs. CLIMEX indicated that the 1997–98 year was hotter and drier than both the 2 previous years and the long-term average. The Meats daily survival rate decrement formula was also used to compare quality of sterile flies. Results from previous suppression programs were compared using these parameters. In winter 1998 at Junee, pupae were deployed in foam eskies where emergence varied from 0 to 29%, with CLIMEX Cold Stress at an average of 481. Emergence occurred over a 4-week period. In the 1998–99 summer at Lake Cargelligo, sterile flies were deployed using the pupal-release technique. Foam containers replaced the metal trays from the previous season to afford better insulation from the heat. The average emergence rate was 64% for the program. A male recapture rate of 0.071% was calculated from the 9.12 million pupae deployed or 0.11% from the estimated emerged males. An overflooding ratio of 3.2 was achieved for the season, with some apparent suppression of wild fly populations. The last recaptured sterile fly was trapped 77 days after the final release. CLIMEX, with and without irrigation, was used to assess the suitability of Lake Cargelligo and surrounding rural areas for QFF survival.

Development of a low-cost pupal release strategy for Sterile Insect Technique (SIT) with Queensland fruit fly and assessment of climatic constraints for SIT in rural New South Wales

Sterile pupae of Queensland fruit fly (Qfly) Bactrocera tryoni (Froggatt) were released to suppress wild Qfly populations at 3 sites in New South Wales and to assess a pupal release strategy using the bed technique. Sterile pupae were released from September 1997 to June 1998 from sand and vermiculite beds. A total of 24.6 million pupae were released with a male recapture rate of 0.101% (not corrected for adult emergence rate). Adult emergence rates were 25% at Tullibigeal; 39% at Ungarie and 46, 41, 71 and 54% respectively at 4 locations at Lake Cargelligo (mean 46%). Corrected recapture rates using cue-lure traps were 0.88% at Tullibigeal, 0.08% at Ungarie and 0.15% at Lake Cargelligo (mean 0.21%). When wild fly populations increased at Lake Cargelligo, a bait spraying program was used which substaintially reduced the catches of both sterile and wild flies in traps. Analyses using the CLIMEX model showed that the climate at Lake Cargelligo town (with irrigation) was suitable for fruit flies. CLIMEX indicated that the unmodified rural environment was unsuitable for fruit fly survival due to a summer moisture deficit. The Meats daily survival rate decrement of 58–72% was similar to that found for some similar studies in Australia but lower than for certain other release programs. No significant bird or ant predation was observed.

Assessing the Quality of Mass-Reared Codling Moths (Lepidoptera: Tortricidae) by Using Field Release-Recapture Tests

Following small-scale field releases of sterile, mass-reared codling moths, Cydia Pomonella (L.), in the spring of 1995, significantly higher numbers of adults originating from larvae that had been induced into diapause were recaptured in passive interception traps compared with standard (nondiapaused) colony moths reared under either constant or fluctuating temperatures. When releases were made in the summer, significantly more diapaused females were again recaptured and similar numbers of diapaused and fluctuating temperature-reared standard males were trapped. Our field data showed that both male and female codling moths dispersed farther as ambient temperatures increased. When standard and diapaused sterile codling moths were released into replicated l-ha plots under large-scale Sterile Insect Release program conditions in the summer and fall of 1996 and the spring of 1997, the proportion of recaptured diapaused males was significantly higher than for standard (nondiapaused) moths. This was true for recapture of males with passive interception, pheromone-baited, and virgin female-baited traps.

Population Ecology of the Kamehameha Butterfly (Lepidoptera: Nymphalidae)

Mark-recapture studies of the endemic Hawaiian Kamehameha butterfly, Vanessa tameamea Eschscholtz, were conducted at five sites on Tantalus Mountain, Oahu, where adults fed on sap oozing from injured Acacia koa Gray (Mimosaceae) trees. Males outnumbered females at the sap fluxes by 4.5 to 1, but females accounted for 58% of 137 specimens collected at diverse sites during the last century. Thus, we infer that the proportion of time spent at sap fluxes was greater for males than females. Males showed high site fidelity; none of 51 recaptures of males were transfers between sites. Males' expected residence time was 16 d. The estimated number of males at the most intensively studied site varied from 13 to 36 during a 35-d period. On the island of Hawaii, a search of 16,360 leaves of Pipturus albidus (Hooker & Arnott) Gray (Urticaceae), the primary larval host plant, yielded one larva of V. tameamea . Although habitat destruction may have reduced the distribution of V. tameamea , results suggest that food for larvae is not a limiting resource for extant populations.

Long-Range Host-Finding Behavior and Colonization of Onion Fields by Delia antiqua (Diptera: Anthomyiidae)

The importance of directed movement by adults of the onion maggot, Delia antiqua (Meigen), in the colonization of new onion fields was assessed. In two mark-recapture experiments where flies were released in the center of circular bands of onions or nonhost vegetation, recaptures of mated females in the host and nonhost circle were distributed randomly. Recaptures of males were distributed randomly in the nonhost circle and directionally in the host circle, either downwind (release 1) or upwind (release 2) of the release point. In six similar releases in two nonhost environments, recaptures of females were randomly distributed regardless of mating status. Recaptures of males were often significantly directional but not correlated with wind direction. Mating status and ovarian development of feral D. antiqua trapped at three sites with different cropping histories were measured. Ovarian development and mating status of flies recaptured in nonhost vegetation 1.2 km from the nearest onion field or overwintering site were similar to those trapped in an onion field. Flies trapped at an overwintering site with no host plants were, on average, younger and less likely to be mated. These results suggest that long-range directed movement has little influence on the probability or extent of colonization of new onion fieldsby D. antiqua .

Movement of Heliothis virescens (Lepidoptera: Noctuidae) in Mississippi in the Spring: Implications for Area-Wide Management

About 250,000 internally marked, sterile male and sterile-male-producing female Heliothis virescens (F.) were released over a 238-km2 area in the Delta of western Mississippiin spring 1982 and 1983. Recaptures of males in 120 pheromone traps over an area of 1,500 km2 indicated that approximately 30% of the population could be accounted for within that area but that density of released males at distances greater than about 7.5 km from the edge of the release area was low relative to that at the center. Recovery of progeny of released females indicated that female movement is at least as great as that of males. In addition, males moved an average of 0.6 km upwind over a lifetime of about 9 d. The density of native males is patchy over a spatial scale of 10 km, and the location of patches is variable from year to year. These results lead to recommendations that experimental units for testing area-wide management tactics for H. virescens in areas similar to the Mississippi Delta should be at least 15 km in diameter, separated from one another by at least 50 km, and replicated.

Pink Bollworm (Lepidoptera: Gelechiidae): Further Tests with (Z,Z)-Isomer of Gossyplure1

Effects of a single application of 78 g (AI)/ha of the (Z,Z)-isomer (89% pure) of gossyplure, the sex pheromone of the pink bollworm, Pectinophora gossypiella (Saunders), or applications of conventional insecticides on trap catches and boll infestations by the moth, were compared in 2-ha fields of cotton, Gossypium hirsutum L. Traps were baited with 1 mg of 9:1, 3:1, or 1:1 ratios of (Z,Z)- to (Z,E)-isomers to monitor blend preferences of native and released male moths. Additional field plot tests were conducted to determine the effects of (Z,Z)-isomer on male moths surrounding a 0.6-ha treated plot and to compare the effects of treatments of gossyplure or (Z,Z)-isomer on trap catch for 2 mo after treatment. Trap catches in the field treated with (Z,Z)-isomer were reduced 97% in June and July compared with the insecticide-treated field, and males were primarily caught in traps baited with 9:1 ratio. Boll infestations were comparable in the two fields until the third month after treatment, when the field treated with (Z,Z)-isomer became heavily infested (35.0 compared with 1.0 pink bollworms per 50 bolls in late August). Recapture of males released 90 d after treatment in the field treated with (Z,Z)-isomer was reduced 95% compared with recapture in an untreated field. Males in the field surrounding a O.6-ha block treated with (Z,Z)-isomer showed an altered response (50% of catch in traps baited with 9:1 ratio) to the maximum test distance of 214 m during a 2-wk period after treatment. Total trap catches of 18, 14, or 3,598 males per plot were obtained in other plots treated with (Z,Z)-isomer, gossyplure, or left untreated during a 2-mo period after treatment.

Attraction of Female and Male Caribbean Fruit Flies 1 to Food-Baited and Male-Baited Traps Under Field Conditions 2

Sexually mature 9-day-old male Caribbean fruit flies, Anastrepha suspensa (Loew), attracted both female and male flies under field conditions. Male-baited sticky traps captured females and males in equal numbers while McPhail traps baited with an aqueous preparation of yeast hydrolysate attracted from 1.4–1.8 times as many females as males. The presence of released males did not reduce the recapture percentage of females, nor did the presence of females influence recapture of males. Males released in the absence of females Were as strongly attracted to males as when females were present.

Captures of markedspodoptera littoralis (boisd.) male moths in virgin female traps: Effects of wild male population, distance of traps from release point, and wind

Field experiments were conducted to clarify the effective sphere of pheromone traps for capturingS. littoralis males. Most males were recaptured on the night of release and only a few were trapped on the following night. Recapture of males was not affected by the number of wild males present in the field. Percent recapture was negatively correlated with the distance of traps from the release point, decreasing markedly at distances beyond 100 m. Percent recapture was not affected by wind speeds ranging from <1 to 5 knots per hour, but was affected by wind direction.

Recapture of Sugarcane Borer (Diatraea saccharalis (F)) Males Released at Different Distances from Pheromone-Baited Traps

Stikem-coated traps constructed from 5-gallon plastic cans and baited with virgin females of Diatraea saccharalis (F.) were more effective in recapture of males than comparable wire traps. Percent recapture for males released at 120 feet, 180 feet, and 220 feet from traps baited with virgin females were 18.6, 23.0 and 24.3 percent, respectively. Higher numbers were recaptured when males were released upwind from pheromone traps than when releases were made downwind, thus indicating that the male response to the pheromone may be through chemical olfactory receptors. Cool temperatures, arthropod predation and poor trap design can be responsible factors for inefficient recapture of released males.