PHYSICAL COMPARISONS OF FOUNDRESSES OF THE PAPER WASP, POLISTES METRICUS (HYMENOPTERA: VESPIDAE)

1981 ◽  
Vol 113 (6) ◽  
pp. 457-461 ◽  
Author(s):  
Jennifer A. Dropkin ◽  
George J. Gamboa

AbstractIn the paper wasp, Polistes metricus Say, subordinates and single foundresses of early colonies (< 16 days old) nesting in the same habitat were very similar in size, reproductive condition, and probability of being fertilized suggesting that these types of foundresses are comparable in reproductive potential. Queens of multiple foundress, early colonies were significantly larger, had larger ovaries, and more oocytes than their subordinates. In late colonies (> 30 days old) the differences in reproductive condition between queens and their subordinates were more pronounced. Reproductive condition and body size are likely to be important characters for sorting foundresses into hierarchies.

1980 ◽  
Vol 112 (3) ◽  
pp. 239-248 ◽  
Author(s):  
Constance M. Haggard ◽  
George J. Gamboa

AbstractSeasonal morphometric analysis of 788 adult Polistes metricus Say showed that: (1) Queens sampled throughout the colony cycle were of similar body size but significantly smaller than fall gynes. (2) Queens’ ovaries are large in the spring, decline early in the colony cycle, peak near the mid-postemergence period and decline late in the colony cycle. (3) There are no significant correlations between head width, ovary width, and size of nest in workers or queens. (4) Early and late workers are small but workers emerging during the mid-postemergence period are large. (5) All workers and gynes emerge with small, similar sized ovaries but older workers may develop larger ovaries. (6) Queens are larger than early and late workers but the same size as workers emerging during the mid-postemergence period. (7) The class with the largest adults were intermediates collected when colonies began production of males. These adults, intermediate in fat content between workers and gynes, comprised a large proportion of females emerging late in the colony cycle. (8) The body size of gynes is independent of colony size. (9) Males were significantly more variable in body size than gynes.


Author(s):  
Carolina Manzano ◽  
Eduardo G. Virla ◽  
Maria V. Coll Araoz ◽  
Erica Luft-Albarracin

Abstract The reproductive traits of the mymarid wasp Cosmocomoidea annulicornis (Ogloblin) (Hymenoptera: Mymaridae) attacking eggs of the sharpshooter Tapajosa rubromarginata (Signoret) (Hemiptera: Cicadellidae) were evaluated under laboratory conditions. Bioassays were carried out to estimate the realized fecundity and egg load of females. The ovigeny index was calculated and different biological traits, such as body size, oöcyte length, gaster length and wing length, were analysed to assess significant associations between these traits and the species fitness. In addition, the effect of host availability and feeding on longevity and potential fecundity throughout life and the effect of female age on egg maturation dynamics were assessed. The results showed that C. annulicornis is a strongly synovigenic species. A positive correlation was found between fecundity and longevity of the females and between body size and oöcyte length. Contrary to expected, body size was not related to fecundity and longevity. Females lived significantly longer in the presence of hosts and honey than when they were host-deprived and honey-fed or both host and honey deprived. Host availability had a significant effect on the amount of eggs laid by C. annulicornis females. Female age was negatively associated with oöcyte length. Furthermore, females were able to mature additional eggs as they aged, nevertheless, when host-deprived, senescent females presented significantly less mature eggs than younger ones, suggesting a possible egg oosorption. These results might contribute to a better understanding of the reproductive potential of this species as a biocontrol agent.


Aquaculture ◽  
2013 ◽  
Vol 384-387 ◽  
pp. 134-139 ◽  
Author(s):  
Joshua T. Patterson ◽  
Taylor G. Allgood ◽  
Christopher C. Green

1989 ◽  
Vol 67 (1) ◽  
pp. 68-72 ◽  
Author(s):  
James L. Vial ◽  
James R. Stewart

The dimorphic expression of body size, body – head size relationships, and chromatic characters among anguid lizards is reviewed. These characteristics are quantitatively examined in a population of Barisia monticola. No sexual differences are found in body size. Head size is positively correlated with body size; however, allometric growth rates in head size are significantly greater in adult males than in females or juveniles. Adult males also differ significantly in eight of nine chromatic characters, the most pronounced being the presence of light dorsal scale markings. These differences are explored in the context of both natural and sexual selection. We hypothesize that the absence of dimorphism in overall body size is the result of natural selection operating to maximize female reproductive potential. In contrast, we predict that dimorphism expressed in body – head size relationships and dichromatism are consequences of sexual selection relating to agonistic and reproductive behavior of males.


Author(s):  
Stanisław Bury ◽  
Bartłomiej Zając ◽  
Henryk Okarma ◽  
Aleksandra Kolanek

AbstractDepletion of free-living populations is often associated with changes in fitness-related traits, e.g., body size. Ongoing decrease in body size has been reported in most vertebrates, but reptiles remain understudied. Moreover, sexual size dimorphism, commonly observed in reptiles, indicates that environmental pressures on body size may appear sex-specific. This can also result in shifts in sex ratio, an aspect even less studied. We investigated body size and sex ratio in population of grass snake (Natrix natrix) surveyed over 40 years ago in comparison with the current state. We found that both sexes express similar magnitude in body size decline. The current sex ratio does not deviate from 1:1, while in the past, females outnumbered males. The observed changes are likely an outcome of several non-mutually exclusive factors. In the studied area, an increase in road traffic and human presence and a drop in prey availability have been documented. Both factors may exert higher pressure on larger individuals, particularly females, due to their high costs of reproduction. It is recorded here that increase in ambient temperatures and summer duration may additionally enhance the mortality risk and resource requirements. Shifts in body size and sex ratio can catalyze further declines in abundance and reproductive potential of the population.


2020 ◽  
Vol 113 (6) ◽  
pp. 2613-2618
Author(s):  
Kinjo Misa ◽  
Chihiro Himuro ◽  
Atsushi Honma ◽  
Yusuke Ikegawa ◽  
Tsuyoshi Ohishi

Abstract Artificial diets have been employed for the mass-rearing of numerous insects because of their ease of use and standardized quality. An ability to store artificial diets under nonrefrigerated conditions over the long term could improve the efficacy of mass-rearing systems considerably. However, it remains largely unknown how long artificial diets can be stored at such temperatures without any adverse effects on the insects reared. In this study, we investigated yield, body size, and reproductive potential of West Indian sweet potato weevil, Euscepes postfasciatus (Fairmaire), which is a major sweet potato pest, under management using the sterile-insect technique in Japan and reared using artificial diets with different storage periods (14, 28, and 42 d) at nonrefrigerated temperatures (25 ± 1°C), and compared them with those of the control (0 d). Notably, E. postfasciatus yield and reproductive potential increased significantly with an increase in storage period (28 and 42 d). Conversely, male body size decreased significantly following feeding with artificial diet stored for 42 d, when compared with the control, while there were no significant differences in female body size between the control and all the treatments. We discuss the potential causes of such varying effects between yield and body size and conclude that E. postfasciatus artificial diet can be stored for at least 28 d without any adverse effects on weevil yield and weevil quality. To the best of our knowledge, this is the first report revealing the positive effects of long-term storage of the artificial diet on mass-reared insects.


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