Entity

Time filter

Source Type


Nishide Y.,National Institute of Agro biological science at Ohwashi | Tanaka S.,National Institute of Agro biological science at Ohwashi
Entomological Science | Year: 2013

A short-winged morph was recently discovered in the migratory locust, Locusta migratoria. It is different from the normal, long-winged morph not only in forewing length but also in hind femur length, displaying a dimorphism. To understand the significance of this dimorphism, other morphological characters were compared between the two morphs, and the time of differentiation of wing-pad length was investigated. Wing weights were heavier in the long-winged morph than in the short-winged morph. This result showed that the short-winged morph is not formed by a failure of wing expansion. No obvious morph-specific differences were observed in wing venation, but wing allometry studies indicated that the distal areas of the fore- and hindwings were disproportionally reduced in the short-winged morph compared to the long-winged morph. The morphological differentiation of the wing pad between the two morphs was observed at the penultimate nymphal stage. The flight muscle was well developed in the two morphs, and no sign of flight muscle histolysis was detected in either morph after adult emergence. An analysis of adult body dimensions suggested that the density-dependent phase shifts known for the long-winged morph of this locust were also exhibited by the short-winged morph, demonstrating that these shifts are not specific to the migratory long-winged morph. © 2013 The Entomological Society of Japan. Source


Nishide Y.,National Institute of Agro biological science at Ohwashi | Tanaka S.,National Institute of Agro biological science at Ohwashi
European Journal of Entomology | Year: 2013

A short-winged morph, whose occurrence is controlled by a simple recessive Mendelian unit, was recently discovered in Locusta migratoria. The existence of trade-offs between flight capability associated with wing length and other fitness-related traits are often documented for insects. The present study investigated the evolutionary significance of the short-winged and long-winged morphs of this locust using two laboratory strains showing wing dimorphism. The life-history traits examined included nymphal development, adult body weight, percentage adult survival, age at first reproduction, egg production and hatchling body weight. The results indicate that there are no consistent morph-specific differences in any of these traits. Of the several possibilities considered, the most likely is that the short-winged morph of this locust is an aberration or represents an initial stage in the evolution of this species. Source


Harano K.-I.,National Institute of Agro biological science at Ohwashi | Tanaka S.,National Institute of Agro biological science at Ohwashi | Watari Y.,Ashiya University | Saito O.,Ashiya University
Journal of Insect Physiology | Year: 2012

This study examined the effects of parental and progeny rearing density on locomotor activity of 1st-stadium nymphs of the desert locust, . Schistocerca gregaria, using an actograph. Progeny obtained from solitarious (isolated-reared) or gregarious (crowd-reared) locusts were reared in isolation or in a group of 30 nymphs. Crowding after hatching had a slight influence on mean activity shortly after the start of measurements, but no clear effect was detected until day 2, when maximum activity during the 6-24. h of observation was significantly higher than that of the nymphs kept in isolation. On the other hand, the effects of parental rearing density on locomotor activity manifested at all ages examined (0-2. days old). Progeny of gregarious locusts showed consistently higher activity than those of solitarious locusts. In newly hatched nymphs, the effect of parental rearing density was explained by variation in body size at hatching, one of the phase-dependent characteristics. Hatchling body color was also correlated with locomotor activity and body weight. Similar levels of locomotor activity were exhibited when green, solitarious and black, gregarious nymphs were similar in body weight. These results suggested that parental rearing density indirectly influences locomotor activity in the progeny shortly after hatching by affecting their body size as eggs or hatchlings. © 2012 Elsevier Ltd. Source


Tanaka S.,National Institute of Agro biological science at Ohwashi | Nishide Y.,National Institute of Agro biological science at Ohwashi
Journal of Insect Physiology | Year: 2012

Various sensory stimuli have been suggested to induce gregarious body coloration in locusts, but most previous studies ignored the importance of substrate color. This study tested the effects of visual, olfactory and tactile stimuli from other locusts on the induction of gregarious body coloration in single (isolated-reared) Schistocerca gregaria nymphs housed in yellow-green cups. Odor from gregarious (crowd-reared) locusts, which is believed to induce black patterns in single locusts, had little effect when applied to visually isolated nymphs at the 2nd stadium onward, and all test nymphs remained green without black patterns at the last stadium, as in controls reared without odor and visual stimuli. Visual stimuli alone induced black patterns when a single solitarious nymph was allowed to see other locusts in another cup. The degree of black patterns increased as the number of locusts shown increased, and some test nymphs developed body coloration typically observed in gregarious forms. A classical morphometric ratio (hind femur length/head width) shifted toward the value typical of gregarious forms when the single nymphs were allowed to see 5 or 10 locusts. Single nymphs also developed black patterns when presented green conspecific nymphs and adults of two hemipteran species kept in another cup. No synergetic effects of visual and odor stimuli were detected. Movies of locusts, crickets and tadpoles were found effective in inducing black patterns in single locusts. Ontogenetic variation in the sensitivity to crowding and experimental methodology might be responsible for some discrepancies in the conclusions among different researchers. © 2012 Elsevier Ltd. Source


Tanaka S.,National Institute of Agro biological science at Ohwashi | Nishide Y.,National Institute of Agro biological science at Ohwashi
Journal of Orthoptera Research | Year: 2012

Short-winged adults appeared in the 2nd generation of inbred colonies of migratory locusts, Locusta migratoria, originating from Tsushima Island, Japan. Of 14 family lines, two produced several short-winged adults in the 2nd generation. These short-winged adults also had shorter hind femora than long-winged adults, indicating they may represent 'the short-winged morph' rather than monsters with abnormally short wings. The two wing morphs could be separated by the ratio of forewing length to head width. Crosses between the two wing morphs revealed that the short-winged morph was controlled by a simple recessive Mendelian unit. It is unknown whether the short-winged morph occurs in the field. Source

Discover hidden collaborations