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Fighting changes courtship activity in the male cricket
Abstracts
453
wetas, the amount of unsaturated hydrocarbons is not essential for their overwintering.
crickets is elicited by diens and polar substances in the male cuticular substances.
doi:10.1016/j.cbpb.2008.09.021
doi:10.1016/j.cbpb.2008.09.023
21. Male crickets accomplish copulation without courtship stridulation
23. Fighting changes courtship activity in the male cricket
Takashi Nagao, Masakazu Hara, Akio Kishigami, Human Inform. Sys. Lab., Kanazawa Instit. Tech., Hakusan 924-0838, Japan Adult male crickets Gryllus bimaculatus sing by their spread and raised forewings. Their songs are made by rubbing a scraper on the inner margin of the left forewing along a row of tiny file on the undersurface of the upper forewing. Therefore, a male cricket cannot sing without forewings. Since the male which cannot sing cannot call a female, he cannot advance to sexual behavior. Many studies have supported that courtship stridulation is a releaser which causes female copulation in male crickets. To understand the mechanism to compensate the stridulation difficulties in males and the auditory difficulties in females, sexual behavior were investigated when the forewings of males were excised and when the tympanal organs of females were received disorder. When forewings were excised, males exhibited normal courtship behavior without sound and the copulation ratio became high according to the number of forewings. Many of females whose tympanal front leg was removed responded to males' courtship behavior. Furthermore, some of them accomplished the copulation. Thus, it is probable that not only courtship stridulation but the vibration from the forewing or the body which follows courtship stridulation plays an important role in the motivation of sexual behavior in female crickets.
Yuri Ogawa, Masaki Sakai, Grad. Sch. Natur. Sci. Tech, Okayama Univ., Okayama 700-8530, Japan Some spices of crickets are known to be highly aggressive. When males of Gryllus bimaculatus were paired, they started fighting and their status was quickly decided within 1–5 s. After fighting, they were left for 60 min in aφ15 cm case. Then, 90% of the dominants began to court near the subordinate, while subordinates were always silent. In the isolated condition, the dominant showed no courtship. When the isolated dominant was artificially stimulated with the wing of a neutral male having no experience of fighting, 90% of the dominants showed courtship. On the other hand, subordinates and neutral males showed courtship to the wing at 40% and 60%, respectively. These suggest that the sexual motivation of the dominant is facilitated by winning the fight, while that of the subordinate is inhibited by losing the fight. doi:10.1016/j.cbpb.2008.09.024
24. Age-related memory impairment in the cricket Gryllus bimaculatus Yukihisa Matsumoto, Toshihumi Takahashi, Chihiro Sato, Makoto Mizunami, Grad. Sch. Life Sci., Tohoku Univ., Katahira 2-1-1, Aoba-ku, Sendai 980-8577, Japan
doi:10.1016/j.cbpb.2008.09.022
22. Biochemical analysis of aggressive behavior-inducing components of the cuticular substances in the male cricket Gryllus bimaculatus Madoka Yamazaki a, Midori Sakura b, Hitoshi Aonuma b, Toshiharu Akino a, Ryohei Yamaoka a, a Department Applied Biol., Fac. Textile Sci., Kyoto Institute of Technology, Kyoto 606-8585, Japan; b Res. Inst. Electoronic Sci., Hokkaido Univ., Sapporo 060-0812, Japan When a male cricket finds another male, they show intensive aggressive behaviors and start to attack each other. The aggressive behavior is also induced by presenting the male cricket an isolated forewing of another male. Thus it is considered that the male cricket detects the cuticular substances of other males by the antennae and expresses aggressive behavior, although the chemical components of the cuticular substances are still unclear. In this study, we try to clarify the aggressive behavior-inducing components of the male cuticular substances using chromatography and the behavioral bioassay. First, the crude extract of the male forewings were fractionated by silica-gel column chromatography into the hydrocarbons and other polar substances. The behavioral responses of the male crickets to each fraction were observed by presenting a piece of filter paper soaked with the substances. Most crickets showed clear aggressive behavior both to the hydrocarbons and the polar substances. Next, the hydrocarbons were further fractionated using AgNO3 silica-gel column chromatography. The male crickets responded with the highest percentages of aggressive behavior to the fraction containing dienes. Our results suggest that the aggressive behavior in the male
Age-related memory impairment (AMI) is reported in many animals including insects. We have found that crickets have excellent olfactory learning and memory capability. Here, to investigate whether AMI is observed in crickets, we trained male crickets of different ages either by multiple-trial olfactory appetitive conditioning or aversive conditioning and then tested their odor preference after training. Crickets aged three weeks after the final molt (3-weekold crickets) exhibited normal levels of retentions at 1 h after both conditionings but they showed significantly decreased levels of 1 day retention in comparison with 1-week-old crickets. These results indicate that, in olfactory learning of crickets, AMI was observed in long-term memory, but not in medium-term memory. Moreover, we have also investigated whether AMI was observed in visual pattern learning or color learning. Three-week-old crickets trained by visual pattern conditioning or color conditioning exhibited normal levels of retention at 1 h after training but they showed significantly decreased levels of 1 day retention in comparison with 1-week-old crickets, indicating that AMI in crickets was observed in visual pattern memory and color vision memory. doi:10.1016/j.cbpb.2008.09.025
25. Effects of the delay of artificial air puff from the start of walking on the compensation of escape direction in unilaterally cercus-ablated crickets Hiroyuki Takuwa a, Shinji Ota b, Masamichi Kanou b, a Mol. Imag. Cent., Nat. Inst. Radiol. Sci., Anagawa 263-8555, Japan; b Department Biol., Grad. Sch. Sci. Eng., Ehime Univ., Bunkyo-cho 790-8577, Japan
453
wetas, the amount of unsaturated hydrocarbons is not essential for their overwintering.
crickets is elicited by diens and polar substances in the male cuticular substances.
doi:10.1016/j.cbpb.2008.09.021
doi:10.1016/j.cbpb.2008.09.023
21. Male crickets accomplish copulation without courtship stridulation
23. Fighting changes courtship activity in the male cricket
Takashi Nagao, Masakazu Hara, Akio Kishigami, Human Inform. Sys. Lab., Kanazawa Instit. Tech., Hakusan 924-0838, Japan Adult male crickets Gryllus bimaculatus sing by their spread and raised forewings. Their songs are made by rubbing a scraper on the inner margin of the left forewing along a row of tiny file on the undersurface of the upper forewing. Therefore, a male cricket cannot sing without forewings. Since the male which cannot sing cannot call a female, he cannot advance to sexual behavior. Many studies have supported that courtship stridulation is a releaser which causes female copulation in male crickets. To understand the mechanism to compensate the stridulation difficulties in males and the auditory difficulties in females, sexual behavior were investigated when the forewings of males were excised and when the tympanal organs of females were received disorder. When forewings were excised, males exhibited normal courtship behavior without sound and the copulation ratio became high according to the number of forewings. Many of females whose tympanal front leg was removed responded to males' courtship behavior. Furthermore, some of them accomplished the copulation. Thus, it is probable that not only courtship stridulation but the vibration from the forewing or the body which follows courtship stridulation plays an important role in the motivation of sexual behavior in female crickets.
Yuri Ogawa, Masaki Sakai, Grad. Sch. Natur. Sci. Tech, Okayama Univ., Okayama 700-8530, Japan Some spices of crickets are known to be highly aggressive. When males of Gryllus bimaculatus were paired, they started fighting and their status was quickly decided within 1–5 s. After fighting, they were left for 60 min in aφ15 cm case. Then, 90% of the dominants began to court near the subordinate, while subordinates were always silent. In the isolated condition, the dominant showed no courtship. When the isolated dominant was artificially stimulated with the wing of a neutral male having no experience of fighting, 90% of the dominants showed courtship. On the other hand, subordinates and neutral males showed courtship to the wing at 40% and 60%, respectively. These suggest that the sexual motivation of the dominant is facilitated by winning the fight, while that of the subordinate is inhibited by losing the fight. doi:10.1016/j.cbpb.2008.09.024
24. Age-related memory impairment in the cricket Gryllus bimaculatus Yukihisa Matsumoto, Toshihumi Takahashi, Chihiro Sato, Makoto Mizunami, Grad. Sch. Life Sci., Tohoku Univ., Katahira 2-1-1, Aoba-ku, Sendai 980-8577, Japan
doi:10.1016/j.cbpb.2008.09.022
22. Biochemical analysis of aggressive behavior-inducing components of the cuticular substances in the male cricket Gryllus bimaculatus Madoka Yamazaki a, Midori Sakura b, Hitoshi Aonuma b, Toshiharu Akino a, Ryohei Yamaoka a, a Department Applied Biol., Fac. Textile Sci., Kyoto Institute of Technology, Kyoto 606-8585, Japan; b Res. Inst. Electoronic Sci., Hokkaido Univ., Sapporo 060-0812, Japan When a male cricket finds another male, they show intensive aggressive behaviors and start to attack each other. The aggressive behavior is also induced by presenting the male cricket an isolated forewing of another male. Thus it is considered that the male cricket detects the cuticular substances of other males by the antennae and expresses aggressive behavior, although the chemical components of the cuticular substances are still unclear. In this study, we try to clarify the aggressive behavior-inducing components of the male cuticular substances using chromatography and the behavioral bioassay. First, the crude extract of the male forewings were fractionated by silica-gel column chromatography into the hydrocarbons and other polar substances. The behavioral responses of the male crickets to each fraction were observed by presenting a piece of filter paper soaked with the substances. Most crickets showed clear aggressive behavior both to the hydrocarbons and the polar substances. Next, the hydrocarbons were further fractionated using AgNO3 silica-gel column chromatography. The male crickets responded with the highest percentages of aggressive behavior to the fraction containing dienes. Our results suggest that the aggressive behavior in the male
Age-related memory impairment (AMI) is reported in many animals including insects. We have found that crickets have excellent olfactory learning and memory capability. Here, to investigate whether AMI is observed in crickets, we trained male crickets of different ages either by multiple-trial olfactory appetitive conditioning or aversive conditioning and then tested their odor preference after training. Crickets aged three weeks after the final molt (3-weekold crickets) exhibited normal levels of retentions at 1 h after both conditionings but they showed significantly decreased levels of 1 day retention in comparison with 1-week-old crickets. These results indicate that, in olfactory learning of crickets, AMI was observed in long-term memory, but not in medium-term memory. Moreover, we have also investigated whether AMI was observed in visual pattern learning or color learning. Three-week-old crickets trained by visual pattern conditioning or color conditioning exhibited normal levels of retention at 1 h after training but they showed significantly decreased levels of 1 day retention in comparison with 1-week-old crickets, indicating that AMI in crickets was observed in visual pattern memory and color vision memory. doi:10.1016/j.cbpb.2008.09.025
25. Effects of the delay of artificial air puff from the start of walking on the compensation of escape direction in unilaterally cercus-ablated crickets Hiroyuki Takuwa a, Shinji Ota b, Masamichi Kanou b, a Mol. Imag. Cent., Nat. Inst. Radiol. Sci., Anagawa 263-8555, Japan; b Department Biol., Grad. Sch. Sci. Eng., Ehime Univ., Bunkyo-cho 790-8577, Japan