Varied Carpet Beetle Anthrenus Verbasci Research Articles

Resetting of the circannual rhythm of the varied carpet beetle Anthrenus verbasci by low‐temperature pulses

AbstractThe varied carpet beetle Anthrenus verbasci L. has a circannual pupation rhythm and pupates in the spring in the wild. The change in photoperiod acts as a predominant zeitgeber for this rhythm. However, it is unclear whether the change in ambient temperature acts as a zeitgeber. The present study examines the effects of low‐temperature pulses on this circannual rhythm by exposing larvae kept under constant short‐day conditions (LD 12 : 12 h) at 20 °C to a lower temperature of 15, 10 or 5 °C for 8 or 12 weeks at various phases. Larval development and pupation are suppressed during exposure to low temperature, with this pupation being induced in sufficiently grown larvae within 2 months of a return to 20 °C. These results are attributed to the exogenous suppression and stimulation of pupation, rather than being related to the circannual rhythm (i.e. masking of the circannual rhythm by temperature). Furthermore, long‐term observations demonstrate the existence of phase‐dependent phase shifts of circannual rhythm as a result of low‐temperature pulses. Circannual phase response curves to low temperature are constructed on the basis of the phase shifts obtained. A low‐temperature pulse as a winter signal can reset the circannual rhythm of A. verbasci. It is probable that both temperature and photoperiod play a role in the entrainment of this circannual rhythm to a natural year.

Circannual pupation timing is not correlated with circadian period in the varied carpet beetle Anthrenus verbasci

Anthrenus verbasci (Insecta, Coleoptera, Dermestidae) shows a circannual rhythm in pupation and a circadian rhythm in adult locomotor activity. The period length of the circannual rhythm will be correlated with the length of a circadian period if oscillations of these two rhythms share a common genetic background. We examined the relationship between the two rhythms and found no correlation between the pupation time determined by the circannual rhythm and the circadian period of the adult activity rhythm. This result suggests that the mechanism that produces the circannual rhythm of A. verbasci is not affected by the period of circadian rhythm.

Exhibition of circannual rhythm under constant light in the varied carpet beetle Anthrenus verbasci

The varied carpet beetle Anthrenus verbasci shows a clear circannual pupation rhythm under light/dark (LD) 12:12. We examined whether this rhythm is exhibited under constant light (LL) of 0.002 Wm−2 and 0.9 Wm−2 intensities. Rhythmic pupation was not observed when the larvae were continuously maintained under LL. Moreover, the circannual rhythmicity of pupation was not observed under LL after pre-exposure to LD 12:12 for 2 or 4 weeks but was observed after exposure for 8 weeks. Under LL of both light intensities, as the pre-exposure to LD 12:12 was longer, the first pupation peaks occurred earlier and almost synchronized with pre-exposure for 8 weeks with the first peak under continuous LD 12:12. However, the transition from LD 12:12 to LL did not reset the phase of this circannual rhythm. Pre-exposure to LD 12:12 probably synchronizes the asynchronous rhythm observed under LL so that a clear circannual pupation rhythm is exhibited.

A New Synthesis of (Z,E)‐Undec‐5‐enoic Acids, the Sex Pheromone of the Varied Carpet Beetle Anthrenus verbasci

AbstractFor Abstract see ChemInform Abstract in Full Text.

A phase response curve for circannual rhythm in the varied carpet beetle Anthrenus verbasci

We know that entrainment, a stable phase relationship with an environmental cycle, must be established for a biological clock to function properly. Phase response curves (PRCs), which are plots of phase shifts that result as a function of the phase of a stimulus, have been created to examine the mode of entrainment. In circadian rhythms, single-light pulse PRCs have been obtained by giving a light pulse to various phases of a free-running rhythm under continuous darkness. This successfully explains the entrainment to light-dark cycles. Some organisms show circannual rhythms. In some of these, changes in photoperiod entrain the circannual rhythms. However, no single-pulse PRCs have been created. Here we show the PRC to a long-day pulse superimposed for 4 weeks over constant short days in the circannual pupation rhythm in the varied carpet beetle Anthrenus verbasci. Because the shape of that PRC closely resembles that of the Type 0 PRC with large phase shifts in circadian rhythms, we suggest that an oscillator having a common feature in the phase response with the circadian clock, produces a circannual rhythm.

A new synthesis of (Z,E)-undec-5-enoic acids, the sex pheromone of the varied carpet beetle Anthrenus verbasci

A new synthesis of (Z,E)-undec-5-enoic acids with the natural isomer composition Z/E = 85 : 15, the sex pheromone of the varied carpet beetle Anthrenus verbasci was developed based on co-metathesis of cycloocta-1,5-diene and ethylene.

Evaluation of the Frequency Demultiplication Hypothesis of Circannual Pupation Rhythm in the Varied Carpet Beetle Anthrenus verbasci (Coleoptera: Dermestidae)

The present study was reported to examine whether the circannual pupation rhythm in Anthrenus verbasci is derived from a circadian rhythm through a process of frequency demultiplication. This frequency demultiplication hypothesis requires that the period of the circannual rhythm is proportional to the period of the entrained circadian rhythm. When larvae were reared under constant photoperiods of T = 20h, 22h, 24h and 26h at 20°C, the larval duration differed among the photoperiodic conditions, although there was no positive correlation between the period of T cycle and larval duration. The differences among photoperiods may have been caused by the duration of the photophase. Therefore, the results did not support the frequency demultiplication hypothesis.

Endogenous timing mechanism controlling the circannual pupation rhythm of the varied carpet beetle Anthrenus verbasci.

This paper describes the detailed characteristics of the circannual pupation rhythm in Anthrenus verbasci determined by laboratory experiments under various photoperiods and temperatures. The frequency distribution of larval duration showed a periodic pattern over 2-3 years and the period was 37-40 weeks under a constant short-day photoperiod (light:dark 12:12) at 20 degrees C. This rhythm showed temperature compensation to some extent under a short-day photoperiod between 17.5 degrees C and 27.5 degrees C. Under alternations of a long-day (light:dark 16:8) and a short-day photoperiod, pupation occurred 21-24.5 weeks after transfer from a long-day to a short-day photoperiod. Therefore, we concluded that the timing of pupation in A. verbasci is controlled by a circannual rhythm and its zeitgeber is a change in photoperiod. Furthermore, when larvae were transferred from a long-day to a short-day photoperiod at various ages, the larval duration after the photoperiodic transfer depended on the time of the transfer. This difference can be explained by phase-dependent phase shifts in the circannual rhythm.

A NOVEL MICROEMULSION FORMULATION OF PERMETHRIN FOR THE CONTROL OF MUSEUM INSECT PESTS

"A NOVEL MICROEMULSION FORMULATION OF PERMETHRIN FOR THE CONTROL OF MUSEUM INSECT PESTS." Studies in Conservation, 39(sup1), p. 24