Induction Of Adult Diapause Research Articles

Induction of adult diapause in <i>Cletus punctiger</i> (Hemiptera: Coreidae) and the beginning of reproduction in post-hibernating females in Shiga Prefecture

Induction of adult diapause in <i>Cletus punctiger</i> (Hemiptera: Coreidae) and the beginning of reproduction in post-hibernating females in Shiga Prefecture

Why is the number of days required for induction of adult diapause in the linden bug Pyrrhocoris apterus fewer in the larval than in the adult stage?

Adult females of Pyrrhocoris apterus, programmed for diapause by short-day (SD) photoperiod and those programmed for reproduction by long-day (LD) retain photoperiodic information in continuous darkness (DD) until death. However, if the interruption of SD by DD is made in the course of diapause programming in adults, then the incidence of diapause depends on the number of SD cycles received before DD, with no evidence that the photoperiodic clock is free-running at DD to complete diapause induction. These results indicate that the photoperiodic clock is stopped after transfer to DD and the information accumulated before transfer to DD is maintained. Diapause programming in the adult stage requires 9–10 SD cycles to induce diapause in 80% of individuals. However, if the diapause programming starts after ecdysis of LD-larvae to the last instar, only 3 SD cycles before transfer to DD are required for diapause in 80% of individuals. Surprisingly, if the newly ecdysed last instar LD-larvae, sensitive to photoperiod, are transferred to DD (thus they did not experience any SD), diapause occurs in 40% of the individuals. Thus, diapause ‘information’ is present in LD-larvae and is responsible for a lower number of SD required for diapause induction in the larval than in the adult stage.

Diapause Response of Laboratory Reared and Native <I>Lygus hesperus</I> Knight (Hemiptera: Miridae)

Inconsistencies among results of previous studies on the induction of adult diapause in the western tarnished plant bug, Lygus hesperus Knight, could be either attributed to differences in the criteria being applied to assess diapause status or to differences in the sources of the bugs. To determine the cause of variation and to refine the criteria used to define diapause status, we obtained eggs from adults collected from the field and from long-term laboratory colonies. Concurrent experiments were conducted at two locations. L. hesperus were reared from egg to adulthood under photophases of either 10 or 14 h and at a constant temperature (26.6°C, Shafter, CA; 27.5°C, Maricopa, AZ). Adults were dissected at 10-d posteclosion to measure diapause status using both stringent and relaxed morphological criteria. Under both sets of criteria, offspring of field caught parents were more likely to enter diapause with short day exposure than those offspring from stock colonies. The relaxed criteria appeared appropriate for distinguishing diapause in males, whose reproductive organs can appear undeveloped after mating, although the stringent criteria appeared appropriate for females. Additional analyses were conducted to determine whether extended laboratory rearing influenced other behavioral or physiological traits. Bugs from stock colonies were more likely to mate, and to oviposit as virgins, than were bugs originating from the field. The results demonstrate a pronounced effect of colony rearing on L. hesperus physiology and behavior, and also have led to refinement of the criteria used to assess diapause status.

Morphological Characters of Diapause in Lygus hesperus Knight (Hemiptera: Miridae)

Development of management tactics that reduce reliance on conventional pesticides for control of the western tarnished plant bug, Lygus hesperus Knight, will require improved understanding of Lygus ecology. One poorly characterized aspect of Lygus ecology is the induction of adult diapause. Although photoperiod is a key regulator of diapause, previous research has reported inconsistent results, likely because of the different criteria used to distinguish diapause. To establish standardized criteria, we reared L. hesperus under photoperiods of 10- and 14-h and a constant temperature of 26.6°C. Adults were dissected at ages of 3, 7, 10, 14, and 17 days to evaluate associations among characteristics of the fat body and reproductive organs. Whereas most characters examined were at least weakly associated with others, we concluded that seminal vesicle condition, presence of a fatty sheath on the testis, and fat body color were not reliable indicators of L. hesperus physiological status. The most appropriate criteria for distinguishing diapause appeared to be hypertrophied fat bodies combined with undeveloped medial accessory glands (for males) or undeveloped ovaries (for females) in adults that were at least 10 days old. We also evaluated less stringent criteria, permitting some development of accessory glands or ovaries to accommodate the delayed reproductive development observed in some specimens reared under the 10-h photoperiod. The descriptions and illustrations of the morphological characters, combined with our suggested sets of criteria, should permit a more standardized assessment of L. hesperus physiological status, and thereby facilitate meaningful comparisons of research by different investigators.

Effects of photoperiod and temperature on the induction of adult diapause in Dolycoris baccarum (L.) (Heteroptera: Pentatomidae) from Osaka and Hokkaido, Japan

Effects of photoperiod and temperature on the induction of adult diapause were examined in Dolycoris baccarum (L.) collected in Osaka and Hokkaido, Japan. Adults started reproduction soon after adult emergence under long-day conditions, while they entered diapause under short-day conditions. The critical photoperiod for the induction of diapause was between 13 and 14 h and between 15 and 16 h in insects of the Osaka and Hokkaido populations, respectively. Under long-day conditions, most insects of the Osaka population emerged as reproductive adults at any temperature used, whereas those in the Hokkaido population tended to show lower incidence of diapause as the temperature increased. Preoviposition periods in females of the Osaka population were shorter than those of the Hokkaido population. The duration of diapause in the Osaka population was shorter at 30°C than at 25°C under short-day conditions. In Osaka, D. baccarum is assumed to produce three generations a year, like several other seed-sucking bugs. In Hokkaido, a greater proportion of adults produces the second generation in summer under long daylengths.

Environmental factors that determine the seasonal onset and termination of reproduction in seed-sucking bugs (Heteroptera) in Japan

The onset and termination of reproductive seasons in insects are determined by various environmental factors under natural conditions. These factors will be reviewed in seed-feeding heteropterans that have winter adult diapause in Japan. Most species use photoperiod to time the induction of adult diapause and therefore the termination of reproduction in autumn. In some species, however, temperature or the quality of food are also used as seasonal cues. For initiation of reproduction in spring, a temperature increase above the lower thermal threshold for postdiapause development is essential. The appearance of host plant seeds primarily determines the onset of reproduction in Dybowskyia reticulata, and the photoperiod plays a definitive role in Cletus punctiger. However, the proximate factors that determine the onset of reproduction in spring have not been examined as intensively as those for the termination of reproduction in autumn.

Effect of photoperiod on development and growth in a pentatomid bug, Dolycoris baccarum

AbstractThe effect of photoperiod on nymphal development, growth and adult size was examined in a pentatomid bug, Dolycoris baccarum, collected in Osaka (a warm temperate region) and Hokkaido (a subfrigid region), Japan. When insects were reared from eggs at 25°C, the developmental period was long and adult size was large under photoperiods close to the critical photoperiod for the induction of adult diapause. Adults of the Hokkaido population were larger than those of the Osaka population. There was no significant correlation between developmental period and adult size. Insects also showed variation in their growth rate: growth rate was low under photoperiods a little longer than the critical photoperiod for the induction of diapause. The ecological significance of variation in development and growth is discussed.

Timing of diapause induction outside the natural distribution range of a species: an outdoor experiment with the bean bug Riptortus clavatus

AbstractThe phytophagous bug Riptortus clavatus (Thunberg) (Heteroptera: Alydidae) produces two or three generations per year in Central Japan and overwinters in the adult stage. In bugs from the Kyoto population (35°00′ N, 135°45′ E), we studied (1) the effects of day‐length on the nymphal and preoviposition periods under constant photoperiod at 20.5 °C, and (2) photoperiodic induction of adult diapause at 20.5 °C and under a combination of constant photoperiod and natural daily rhythm of temperature in the forest‐steppe zone of Russia (50°38′ N, 35°58′ E). Then, we examined (3) the timing of diapause induction under quasi‐natural conditions in the same region, far outside the species' natural geographical range. At 20.5 °C, the nymphal period in both males and females was significantly longer under regimes with shorter photophases than under those with longer photophases. The preoviposition period in females was significantly longer under the near‐critical long‐day regime L14:D10 than under typical long‐day regimes (L15:D9, L16:D8, and L17:D7). The critical day‐length for diapause induction was shorter under conditions of natural daily rhythm of temperature than those reported at constant 20, 25, and 30 °C. Under quasi‐natural conditions in the forest‐steppe zone, R. clavatus entered diapause in September, much later than the local populations of true bugs studied to date. This experiment showed that R. clavatus was maladapted to new environmental conditions: diapause was induced too late with the result that all or most nymphs hatched in late August or early September will die.

A White-Eye Mutant of Protophormia terraenovae (Diptera: Calliphoridae): Mode of Inheritance and Photoperiodic Response

A spontaneous mutant, white , with the phenotype of white compound eyes was isolated from a laboratory culture of Protophormia terraenovae (Robineau-Desvoidy) that originated from Obihiro, Japan. Standard genetic crosses showed that the white trait is controlled by an autosomal recessive. The photoperiodic response for the induction of adult diapause was examined at different temperatures and light intensities. The wild-type P. terraenovae showed a long-day photoperiodic response under all conditions examined. When the light intensity of the photophase was 500 or 20,000 lux at 25°C, white adults reproduced directly without diapause both under long-day and short-day conditions. Under 500 lux at 20°C or under 0.5 lux at 25°C, however, the white strain showed a long-day photoperiodic response.

Induction of Adult Diapause by Photoperiod and Temperature in Protophormia terraenovae (Diptera: Calliphoridae) in Japan

The incidence of adult diapause was examined in Protophormia terraenovae (Robineau-Desvoidy) in the strain from Obihiro, Japan, under various photoperiodic and temperature conditions. Although at 30°C no adults entered diapause in either long-day or short-day conditions, between 17.5 and 27.5°C the insect showed a long-day photoperiodic response. The incidence of diapause was higher at lower temperatures under both long-day and short-day conditions.

Induction of adult diapause in a parasitoid wasp, Ooencyrtus nezarae under natural conditions

Entomologia Experimentalis et ApplicataVolume 76, Issue 3 p. 329-332 Induction of adult diapause in a parasitoid wasp, Ooencyrtus nezarae under natural conditions T. Teraoka, T. Teraoka Department of Biology, Faculty of Science, Osaka City University, Sumiyoshi, Osaka 558, JapanSearch for more papers by this authorH. Numata, H. Numata Department of Biology, Faculty of Science, Osaka City University, Sumiyoshi, Osaka 558, JapanSearch for more papers by this author T. Teraoka, T. Teraoka Department of Biology, Faculty of Science, Osaka City University, Sumiyoshi, Osaka 558, JapanSearch for more papers by this authorH. Numata, H. Numata Department of Biology, Faculty of Science, Osaka City University, Sumiyoshi, Osaka 558, JapanSearch for more papers by this author First published: September 1995 https://doi.org/10.1111/j.1570-7458.1995.tb01977.xCitations: 7AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Citing Literature Volume76, Issue3September 1995Pages 329-332 RelatedInformation

Threshold and quantitative photoperiodic responses exist in an insect

The photoperiodic response for the induction of adult diapause and that for the determination of nymphal body coloration were compared inPlautia stali Scott (Heteroptera: Pentatomidae). The former was an all-or-none response with a distinct threshold, but the latter was a graded response which varied quantitatively with the photophase duration. The photoperiodic clock in this species is discussed.

Two critical day lengths for the determination of wing forms and the induction of adult diapause in the water strider,Aquarius paludum

Two critical day lengths for the determination of wing forms and the induction of adult diapause in the water strider,Aquarius paludum

Induction of adult diapause and of low and high reproductive states in a parasitoid wasp, Ooencyrtus nezarae, by photoperiod and temperature

AbstractOoencyrtus nezarae Ishii (Hymenoptera: Encyrtidae) was reared on eggs of Riptortus clavatus (Thunberg) (Heteroptera: Alydidae) at various temperatures under long‐day (L16:D8) or short‐day (L10:D14) conditions. There was no diapause during egg, larval or pupal stages under any set of conditions examined. However, at 15 °C under short‐day conditions, vitellogenesis was arrested in all adult females and they entered diapause. At 15 °C under long‐day conditions, or at 20 °C under short‐day conditions, some adult females entered diapause. Under the latter set of conditions, the adult females laid eggs but they laid fewer eggs than under long‐day conditions. Even at 25 °C, under short‐day conditions, adult females laid fewer eggs than under long‐day conditions, and this low rate of oviposition was attributed to the retarded development of ovaries. Diapause adults reared at 15 °C were more resistant to low temperature than nondiapause adults reared at 25 °C.

Effects of diet, photoperiod and temperature on the postdiapause reproduction in the cabbage bug, Eurydema rugosa

In Eurydema rugosa Motschulsky (Heteroptera: Pentatomidae), the type of food supplied (i.e. seeds or leaves of the brown mustard, Brassica juncea Hemsel) and photoperiod, which control the induction of adult diapause, do not play a role in the initiation of reproduction after overwintering. A temperature above 13.2°C was required to start reproduction. After its initiation, however, short-day conditions on seeds induced diapause again in some adults. Although a diet of seeds under long-day conditions, in common with short-day conditions, induced diapause in young adults (Numata & Yamamoto, 1990), it did not reinduce diapause in adults after overwintering. Thus, E. rugosa that had overwintered became sensitive to diapause-inducing photoperiod again but not to dietary factors.

Induction of adult diapause in Pyrrhocoris apterus L. by short cold exposure.

The ripening of ovaries in the females of Pyrrhocoris apterus can be inhibited not only by short-day photoperiod but also by cold shocks during the first week of the adult life.Ovaries in a part of the females are prevented from ripening by transferring the bugs from 25° C and long-day photoperiod to substantially lower temperatures for 2 (or 4) days. The oviposition is inhibited at least for 3 weeks after the return to original conditions favourable for reproduction. This effect is achieved when cold treatment is combined either with darkness or with long day. A difference between 2 and 4 days of chilling was not recorded. The effect of cold exposure (evaluated in our experiments by the proportion of mature and immature females) depends on the temperature of the cold exposure and on the age of females at the time of transfer to cold. The incidence of immature females was higher when lower temperatures (+2 to +6° C) were used and when females were transferred to cold early (0-2 days) after the adult moult.