Trigonotylus Caelestialium Research Articles

A multi-species pheromone lure: A blend of synthetic sex pheromone components for two mirid species, Stenotus rubrovittatus (Matsumura) and Trigonotylus caelestialium (Kirkaldy) (Heteroptera: Miridae)

Two mirid bugs, Stenotus rubrovittatus (Matsumura) and Trigonotylus caelestialium (Kirkaldy) (Heteroptera: Miridae), are sympatric pests that infest rice in many regions of Japan. Three components, hexyl butyrate, (E)-4-oxohex-2-enal and (E)-hex-2-en-1-yl butyrate, in S. rubrovittatus and three other components, hexyl hexanoate, (E)-hex-2-en-1-yl hexanoate and octyl butyrate, in T. caelestialium, were identified as sex attractant pheromone components in these species. The synthetic pheromone lures for S. rubrovittatus do not attract T. caelestialium and vice versa. The attractiveness of the combination of two separate lures for the two mirid bugs within one trap (combination lures) and the attractiveness of a mixed lure, in which all six synthetic-pheromone components of both species were loaded onto a single septum, were compared with that of separate lures for each species in field experiments. Both the combination lures and the mixed lure were as attractive to males of both mirid bugs as the separate lures for each species in fields with gramineous plants. In paddy fields, the mixed lure was also as attractive to males of both species of mirid bugs as the separate lures for each species. These results suggest that the mixed lure and the combination lures could be useful as simultaneous monitoring tools for two sympatric major rice pests using a single trap.

Effect of seasonal variation in host‐plant quality on the rice leaf bug, Trigonotylus caelestialium

AbstractThe rice leaf bug, Trigonotylus caelestialium (Kirkaldy) (Heteroptera: Miridae), is an important insect pest, causing pecky‐rice damage in Japan. This bug has a multivoltine life cycle and feeds on various species of the Poaceae. The phenology of the host‐plants differs between species and the plant quality of a single host species may change with the seasons. The fitness of the bug may be affected by these seasonal changes in host‐plant quality. In the current study, the effects of such quality changes on adult and nymphal performance were examined using a population of bugs collected in Joetsu, Niigata, Japan. Rearing of newly emerged adults collected from spring to autumn from Italian rye grass, Lolium multiflorum Lam., and southern crabgrass, Digitaria ciliaris (Retz.), showed that body size and performance of adults differed between collection seasons and plant species, indicating that nymphal conditions including host‐plant quality have crucial effects on their fitness. Rearing nymphs from hatching to adult emergence on various field‐collected grasses under laboratory conditions showed that the performance of nymphs depends on the plant species and varies greatly with the season, within a given species. In general, nymphs performed more poorly on most of the plants collected late in the season, but they performed well on some plants unavailable early in the season. Therefore, in T. caelestialium, seasonal and spatial variations are important factors that affect fitness of nymphs and adults, and this suggests that oviposition of diapause eggs in summer is an adaptation to deteriorating food conditions.

Artificial selection for responsiveness to photoperiodic change alters the response to stationary photoperiods in maternal induction of egg diapause in the rice leaf bug Trigonotylus caelestialium

Female adults of the rice leaf bug Trigonotylus caelestialium (Kirkaldy) (Heteroptera: Miridae) produce non-diapause eggs under long-day conditions, whereas they produce diapause eggs under short-day conditions. These egg-production modes change following a photoperiodic change from long-day to short-day conditions or vice versa, with individual variations in responsiveness shown in the time from the photoperiodic change to the mode change. Strains of this insect with higher or lower responsiveness to photoperiodic change were established after several generations of selection, indicating that the individual variation has a genetic basis. The selected strains that were more responsive and less responsive to one photoperiodic change were found to be less responsive and more responsive to the opposite photoperiodic change, respectively, indicating a significant negative correlation between responsiveness to reciprocal photoperiodic changes. The selected strains also had a significantly different incidence of diapause-egg producers in stationary photoperiods compared to a non-selected strain, showing that selections for responsiveness to photoperiodic change were essentially the same as selections for a higher or lower incidence of diapause-egg producers. These results indicate that responsiveness to photoperiodic change is one aspect of the tendency to produce diapause or non-diapause eggs.

Effect of rice ripening stage on occurrence of white spots in rice grains caused by Trigonotylus caelestialium and Stenotus rubrovittatus

Effect of rice ripening stage on occurrence of white spots in rice grains caused by <i>Trigonotylus caelestialium</i> and <i>Stenotus rubrovittatus</i>

Occurrence of White Spots in Rice Caused by Rice Leaf Bug Trigonotylus caelestialium

Occurrence of White Spots in Rice Caused by Rice Leaf Bug <i>Trigonotylus caelestialium</i>

Fungal loline alkaloids in grass–endophyte associations confer resistance to the rice leaf bug, Trigonotylus caelestialium

AbstractPlant symbiotic fungi (endophytes) of the genus Neotyphodium [anamorphs, asexual derivatives of Epichloë (Ascomycota: Clavicipitaceae)] often associate with grass species of the subfamily Pooideae, which includes important forage and turf species. These endophytes are known to produce a range of alkaloids that enhance their host's resistance to insects or are toxic to grazing animals. Among the alkaloids, loline alkaloids (saturated 1‐aminopyrrolizidines) are generally observed in the highest concentrations in many Neotyphodium–grass symbiotic associations, and are known to be toxic to insects but not to mammals. Some Neotyphodium‐infected grasses have enhanced resistance to rice leaf bug, Trigonotylus caelestialium (Kirkaldy) (Heteroptera: Miridae), one of the major pests for rice production in Japan. Our laboratory experiments quantified the effects of purified loline (N‐formylloline) and in planta synthesis of loline alkaloids by meadow fescue [Lolium pratense (Huds.) S.J. Darbyshire (syn. Festuca pratensis Huds.)]–Neotyphodium uncinatum (Gams, Petrini &amp; Schmidt) Glenn, Bacon &amp; Hanlin and Italian ryegrass (Lolium multiflorum Lam.)–Neotyphodium occultans Moon, Scott &amp; Christensen associations on the development and survival of T. caelestialium. No‐choice feeding assays with laboratory populations of the insect revealed that their growth was significantly decreased by the infected grasses, and the effect was greater for N. uncinatum than for N. occultans, in keeping with differences in N‐formylloline concentrations in the plants. Artificial feeding of N‐formylloline through feeding sachets indicated that the chemical has an adverse effect on survival of larvae, even at the lowest concentration tested (50 µg/g), which was considerably lower than the typical concentrations in many Neotyphodium–grass associations. The results confirmed the ability of Neotyphodium‐infected forage grasses to control T. caelestialium propagation in meadows, which may cause damages to nearby rice paddies.

Impact of Bt-corn MON88017 in comparison to three conventional lines on Trigonotylus caelestialium (Kirkaldy) (Heteroptera: Miridae) field densities

In Europe, Bt-corn resistant against the European Corn Borer has until now been the only genetically modified plant to be grown commercially. With the advent of the Western Corn Rootworm Bt-corn varieties with resistance against Coleoptera will become important. The cultivation of Bt-plants may have negative impacts on non-target organisms, i.e. all species not explicitly targeted by a given Bt-crop. One prominent non-target group in corn are the herbivorous plant bugs (Heteroptera: Miridae). They are common, abundant and exposed to the Cry-protein. We therefore assessed the potential impact of the cultivation of the Cry3Bb1-expressing Bt-corn variety MON88017 and three conventional varieties on this group. Trigonotylus caelestialium (Kirkaldy) was the most abundant plant bug at the experimental field. There was no evidence for a negative impact of MON88017 on this species, despite its considerable exposure to Cry3Bb1 demonstrated with ELISA. The conventional corn varieties, however, had a consistent and significant influence on the field densities of this species over all three growing seasons.

Exposure of non-diapause eggs to low temperature: the effects on egg hatching, nymphal survival, and developmental periods in Trigonotylus caelestialium (Heteroptera: Miridae)

We exposed non-diapause eggs of the rice leaf bug Trigonotylus caelestialium to a low temperature (4°C) and investigated the effects on hatching, nymphal survival, and developmental periods with a view to obtaining many newly hatched nymphs or newly emerged adults on the same day. When eggs were stored at a constant temperature of 25°C, 54.1% of nymphs and 50.9% of adults emerged on the 7th day and the 20th day after collecting them for 24 h, respectively. The hatching rates of eggs exposed to the low temperature for 7, 10, and 13 day were significantly lower than that of eggs maintained at 25°C. However, compared to the non-exposure group, only a small decrease in the hatching rate was observed in the 4-d exposure group (8.1%). Further, exposing the eggs to the low temperature did not affect the survival of the nymphs to adult emergence or the developmental periods. These results suggest that the exposure of eggs to the low temperature for 4 d or less should be a simple and useful method for obtaining many nymphs and adults on the same day.

Effects of the Number of Split-Hull Paddies and Ripening Stage of the Rice Plant on Nymphal Survival and Growth of the Rice Leaf Bug, Trigonotylus caelestialium (Heteroptera: Miridae)

Effects of the Number of Split-Hull Paddies and Ripening Stage of the Rice Plant on Nymphal Survival and Growth of the Rice Leaf Bug, <I>Trigonotylus caelestialium</I> (Heteroptera: Miridae)

Resistance to the rice leaf bug (Trigonotylus caelestialium) is conferred by Neotyphodium endophyte infection of Italian ryegrass (Lolium multiflorum)

AbstractMany grasses in the subfamily Pooideae form symbioses with Neotyphodium fungal endophytes. This relationship provides a competitive advantage for the host plant in many ways. The endophyte of meadow fescue (Festuca pratensis), Neotyphodium uncinatum, is considered to produce no mammalian toxins, but produces metabolites giving insect resistance and other ecological benefits. To determine the potential of N. uncinatum strains to reduce the development of rice leaf bug (Trigonotylus caelestialium), we investigated the effect of artificial inoculation of Italian ryegrass (Lolium multiflorum) with N. uncinatum on the feeding of T. caelestialium. T. caelestialium larvae significantly preferred endophyte‐free to endophyte‐infected plants. Survival of insects was very high on endophyte‐free plants, but it rapidly declined on infected plants. These results indicate that N. uncinatum‐infected Italian ryegrass has enough resistance to T. caelestialium and it means the control of T. caelestialium may be possible using this endophyte.

쌀 생산조정 휴경논에 발생하는 노린재 종류와 기주식물

2004년부터 2005년까지 호남지방의 쌀 생산조정지를 중심으로 노린재류의 발생과 기주식물을 조사하였다. 노린재류는 총 8과 26종이 조사되었으며, 중산간지인 무안에서 시골가시허리노린재의 발생이 가장 많았고, 발생최성기는 7 월이었다. 평야지인 완주는 2004 년에는 전반적으로 노린재류의 발생량이 적었고, 2005 년에는 시골가시허리노린재 발생최성기는 7월과 8월이었다. 쌀 생산조정지에서 인근 벼 포장으로 이동하는 시기는 시골가시허리노린재 등 5종은 8월, 우리가시허리노린재 등 3종은 9월이었다. 또한, 쌀 생산조정지에서 잡초를 섭식하는 노린재 종류는 시골가시허리노린재, 우리가시허리노린재, 북쪽비 단노린재, 더듬이긴노린재, 빨강촉각장님노린재, 메추리노린재, 가시점둥글노린재, 풀색노린재였다. Stink bug species and host plants occurred in fallow lands for rice product regulation were studied in Honam area from 2004 to 2005. A total of 26 bug species in 8 families were surveyed in the fallow lands. Population density of Cletus punctiger adult reached its peak in July and was higher in fallow lands close to mountain area in Muan. Population density of stink bug species occurred in plain area of Wanju were significantly low in 2004 and population density of C. punctiger adult reached its peak in July and August in fallow lands in 2005. Five species of stink bug including C. punctiger immigrated from fallow lands to rice fields in August, and three other species including Cletus schmidti in September. Eight stink bug species which were observed to feed on weeds in fallow lands were C. punctiger, C. schmidti, Eurydema gebleri, Pachygrontha antennata, Trigonotylus caelestialium, Aelia fieberi, Eysarcoris aeneus, and Nezara antennata.

Olfactory response of Trigonotylus caelestialium (Het.: Miridae) to rice plant and gramineous weeds

Abstract: The olfactory response of Trigonotylus caelestialium, to rice, Oryza sativa L., and two species of gramineous weeds, Poa annua and Digitaria ciliaris, was investigated with an olfactometer to clarify the role of host‐plant odours as olfactory cues in their host‐finding behaviour. Third‐instar nymphs and adult males were significantly attracted to whole plants (above ground parts) of P. annua. However, adult females were not significantly attracted to whole plants of P. annua. Attractancy of rice to T. caelestialium differed with the growth stage and part of the plant. Adult females were significantly attracted to stems and leaves in the panicle‐formation stage, and panicles in the flowering stage. They were not attracted to stems and leaves in the fourth‐leaf stage and flowering stage, or to panicles in the milk‐and full‐ripe stages. Although adult males were significantly attracted to stems and leaves in the panicle‐formation stage, they were not attracted to the other rice structures tested. Both females and males were significantly attracted to stems and leaves, as well as panicles of D. ciliaris in the flowering stage. The findings suggest that T. caelestialium use host‐plant volatiles as olfactory cues to find their host plants and their invasion to paddy fields were caused by olfactory responses to rice plant.

アカヒゲホソミドリカスミカメ雌の性フェロモン放出と交尾行動の日周性

The daily periodicity of sex pheromone emission by females of the rice leaf bug, Trigonotylus caelestialium, was examined. Male bugs were captured at any time of the day in traps baited with 10 virgin females placed in a field overgrown with weeds. In the laboratory, thirty pairs of virgin adults three days after emergence were released in the rearing cage at different times of day, and the number of mated females was checked 4 h later. The percentage of mated females was more than 60% regardless of the time of release and the light conditions. These results suggest that there is no daily periodicity in sex pheromone emission by females and mating.

Relationship between Occurrence of Rice Leaf Bug, Trigonotylus caelestialium (Heteroptera: Miridae) and Meteorogical Conditions

Relationship between Occurrence of Rice Leaf Bug, <I>Trigonotylus caelestialium</I> (Heteroptera: Miridae) and Meteorogical Conditions

アカヒゲホソミドリカスミカメ雌の雄に対する誘引性―雌の交尾の有無と羽化後日齢の影響―

The effect of mating status and adult age of the rice leaf bug, Trigonotylus caelestialium, on the attractiveness of females to males was investigated. A trap baited with virgin females tended to attract more males than one baited with mated females. This result indicates that the sex pheromone emitted by females may decrease after mating. Furthermore, more males tended to be captured in the trap baited with virgin females at three days after emergence compared with those aged six days. This result suggests that the sex pheromone emitted by virgin females may decrease with age.

Comparison of Occurrence of Rice Leaf Bug Trigonotylus caelestialium in Italian Rye Grass and Centipedegrass Fields

Comparison of Occurrence of Rice Leaf Bug <I>Trigonotylus caelestialium</I> in Italian Rye Grass and Centipedegrass Fields

餌植物の有無がアカヒゲホソミドリカスミカメによる斑点米発生に及ぼす影響

餌植物の有無がアカヒゲホソミドリカスミカメによる斑点米発生に及ぼす影響

Relationships among Pecky Rice, Hull-Cracked Rice and Rice Leaf Bug, Trigonotylus caelestialium (Heteroptera: Miridae)

Relationships among Pecky Rice, Hull-Cracked Rice and Rice Leaf Bug, <I>Trigonotylus caelestialium</I> (Heteroptera: Miridae)

Control of Rice Leaf Bug, Trigonotylus caelestialium (Heteroptera: Miridae) by Application of Herbicide to their Source of Immigration

Control of Rice Leaf Bug, <I>Trigonotylus caelestialium</I> (Heteroptera: Miridae) by Application of Herbicide to their Source of Immigration

アカヒゲホソミドリカスミカメの交尾と産卵の関係

The age at which the rice leaf bug, Trigonotylus caelestialium, starts to copulate after adult emergence was determined by mating experiments. Females started to copulate 30 h after emergence and all females copulated after 102 h, when maintained under 16L:8D conditions at 25°C. After copulating once females were individually caged with a male 3, 24, 48 h after the initial copulation to determine if females copulate more than once. Multiple copulations were observed in 17 females among 22 females examined. To determine the effect of multiple mating on the reproductive performance of the bugs, fecundity, longevity and fertility of the eggs laid were investigated under different mating conditions. Newly emerged females were divided into three groups: virgin females, females constantly with a male and females with a male until the first oviposition was observed. There was no significant difference in the preoviposition period and total number of eggs laid between the three female groups. Although the longevity of virgin females was significantly longer than mated females, no significant difference in longevity was observed between the two groups of mated females. The fertility of eggs laid by females constantly with a male and females with a male until the first oviposition was 92.9% and 94.4%, respectively, and was not significantly different. These results suggest that mating(s) during the preoviposition period is sufficient for reproduction of the female rice leaf bug.