Effects of Wolbachia Infection, Parasitic Order, And Time Interval On The Outcome of Inter-Strain Intrinsic Competition Between Bisexual Strain And Wolbachia-Induced Thelytokous Strain of Egg Parasitoid, Trichogramma Dendrolimi

Parasitoids may deposit a second clutch of eggs on a host that has been parasitized by the same parasitoid species. This is termed “superparasitism”. Wolbachia infection increases the superparasitism frequency of Trichogramma females. We investigated the outcome and fitness cost of inter-strain intrinsic competition between Wolbachia-infected thelytokous strain (TDW) and uninfected bisexual strain (TDB) of Trichogramma dendrolimi. To determine the developmental rate of both strains, the size of immature stages of T. dendrolimi offspring at different times after parasitization was measured in single parasitism and superparasitism conditions. The results showed increased superparasitism by Wolbachia-infected females compared to uninfected females, regardless of the time interval between oviposition; Trichogramma females were unable to distinguish between host eggs previously parasitized by TDB or TDW females. When the first oviposition was performed by TDB females, the TDB offspring outcompeted TDW offspring deposited later. However, although the TDW offspring was deposited 8 h earlier than the TDB offspring, it gained no advantage over TDB offspring. Regardless of parasitism conditions, the differences in development rate and time between TDW and TDB offspring were not significant. This study revealed that albeit TDW females presented a higher tendency of superparasitism than TDB females, TDB offspring outcompeted TDW offspring even when the latter was deposited 8 h earlier. The negative effects of Wolbachia infection on the competitive ability of TDW offspring inside the host eggs were due to offspring’s low fitness rather than delayed development.

Brood size manipulation reveals cost on the size of the second clutch in the earwig Anisolabis maritime

There may be a trade-off between the duration of parental care and future reproductive success. Traditionally, studies about the cost of parental care have included the removal of the parent. However, producing a secondary clutch after the failure of the first one is a compensatory behaviour that occurs in cases of brood failure. In this study, attempts were made to detect the cost of maternal care in the earwig, Anisolabis maritima (Dermaptera: Anisolabididae) by either extending the period of care or increasing the brood size to prevent compensation through the brood’s success. The results indicated that manipulation did not change the inter-clutch interval, although my previous study revealed shortening of these intervals after the removal of the clutch in this species. In this study, decreased clutch size manipulation increased the size of the following clutch.

Observation of Hermann’s Tortoise (Testudo hermanni) C Lutching without the Presence of Males and Eggshell Mortality on a Large Tortoise Farm in Slovenia Over a Three-Year Period

The aim of this study was to determine the percentage of hatched and fertilized eggs in female Hermann’s tortoises before and after the removal of males after breeding.A breeding group of Testudo hermanni boettgeri with 50 females and 12 males was included in the study. In the first year, all adults were together in the same habitat until reproductive activity was observed. After the end of May, the males and females were separated for the next two active seasons. The number of eggs and number of second clutches decreased gradually. In the first year, 76.0% of females laid eggs; in the second year, 24.0%; and in the third year, only 8.0%. Second clutches were observed in ten females (26.3%) in the first year, while in the next two years, one female had a second clutch. There was a small but significant correlation between the weight of a single tortoise and the number of eggs laid but no significant correlation between the weight of the tortoise and its average egg weight. The weight (15.1-16.8 g), length (33.9-36.1 mm) and width of each egg (27.5-28.0 mm) was measured.During the laying season, the eggs were put into incubators. The incubation length varied from 52 to 70 days. After the end of incubation, eggshell mortality and its causes (19.3-52.5%) were examined. In the first year, the viability rate of the incubated eggs was 80.7%; in the second year, 80.5%; and in the third year, 47.8%. Among the unhatched eggs in the first year, 62.5% were unfertilized, 53.1% were infected, 28.1% were dehydrated and 21.9% were found in various stages of embryonic development.

Earlier springs enable high-Arctic wolf spiders to produce a second clutch

Spiders at southern latitudes commonly produce multiple clutches, but this has not been observed at high latitudes where activity seasons are much shorter. Yet the timing of snowmelt is advancing in the Arctic, which may allow some species to produce an additional clutch. To determine if this is already happening, we used specimens of the wolf spider Pardosa glacialis caught by pitfall traps from the long-term (1996–2014) monitoring programme at Zackenberg, NE Greenland. We dissected individual egg sacs and counted the number of eggs and partially developed juveniles, and measured carapace width of the mothers. Upon the discovery of a bimodal frequency distribution of clutch sizes, as is typical for wolf spiders at lower latitudes producing a second clutch, we assigned egg sacs to being a first or second clutch depending on clutch size. We tested whether the median capture date differed among first and second clutches, whether clutch size was correlated to female size, and whether the proportion of second clutches produced within a season was related to climate. We found that assigned second clutches appeared significantly later in the season than first clutches. In years with earlier snowmelt, first clutches occurred earlier and the proportion of second clutches produced was larger. Likely, females produce their first clutch earlier in those years which allow them time to produce another clutch. Clutch size for first clutches was correlated to female size, while this was not the case for second clutches. Our results provide the first evidence for Arctic invertebrates producing additional clutches in response to warming. This could be a common but overlooked phenomenon due to the challenges associated with long-term collection of life-history data in the Arctic. Moreover, given that wolf spiders are a widely distributed, important tundra predator, we may expect to see population and food web consequences of their increased reproductive rates.

Measuring the Costs of Limb Regeneration and Their Transgenerational Consequences in Two Nearctic Lady Beetles (Coleoptera: Coccinellidae)

We examined the ability of Coleomegilla maculata DeGeer and Hippodamia convergens Guerin-Meneville to regenerate, during pupation, a foreleg amputated in the fourth instar. Leg regeneration was complete for 80.7% of amputated H. convergens larvae, with 12.5% regenerating partially, and 6.8% showing no regeneration. Regeneration in C. maculata was 72.2% complete, 20.5% partial, and 7.2% none, but mortality following ablation was slightly higher than for H. convergens (7.4 vs. 0.6%). Ablation/regeneration caused a slight delay in pupation, but pupation time, fresh mass at emergence, and reproductive performance remained unaffected in either species. Reciprocal crosses were made between regenerated and unoperated beetles, and 12 progeny reared from the second clutch of each female in all treatments. Mating treatment affected eclosion time in H. convergens, whereas in C. maculata, larval development and pupation time were also affected. Considering all treatments, larval mortality was higher in H. convergens than in C. maculata, but lower when both H. convergens parents regenerated. Parental mating treatment did not affect adult weight in either species, but development of C. maculata progeny was faster when only the sire regenerated, and slower when the only the dame regenerated, whereas progeny of regenerated sires completed pupated faster than those sired by controls. We infer that genes activated during regeneration have pleiotropic effects with subtle, gender-specific, epigenetic consequences. If these pleiotropic effects are genetically linked to important traits, regenerative genetic elements could be conserved in coccinellids via natural selection acting on these traits, rather than on regenerative ability per se.

Observations on the oviposition of Blythia reticulata (Blyth, 1854) with new distributional records from Mizoram State, NE India

The poorly known semi-fossorial snake Blythia reticulata is a small, oviparous, worm-eating species found in northeastern India and neighboring countries. Here we report on multiple new distribution localities that extend the known geographic range of the species. In addition, we provide new information on the reproductive biology of the species based on egg-laying behavior data from a captive gravid B. reticulata from Mizoram. The simultaneous presence of a second clutch of eight eggs in the oviduct of the female indicates the capacity of the species to exhibit multiple matings and egg clutches during a single reproductive season.

Earlier springs enable High-Arctic wolf spiders to produce a second clutch

ABSTRACTSpiders at southern latitudes commonly produce multiple clutches, but this has not been observed at high latitudes where activity seasons are much shorter. Yet the timing of snowmelt is advancing in the Arctic, and may allow some species to produce an additional clutch. To determine if this is already happening, we used specimens of the wolf spider Pardosa glacialis caught by pitfall traps from the long-term (1996-2014) monitoring program at Zackenberg, Northeast Greenland. We dissected individual egg sacs and counted the number of eggs and partially developed juveniles, and measured carapace width of the mothers. Upon discovery of a bimodal frequency distribution of clutch sizes, as is typical for wolf spiders at lower latitudes producing a second clutch, we assigned egg sacs to being a first or second clutch depending on clutch size. We tested whether the median capture date differed among first and second clutches, whether clutch size was correlated to female size, and whether the proportion of second clutches produced within a season was related to climate. We found that assigned second clutches appeared significantly later in the season than first clutches. In years with earlier snowmelt, first clutches occurred earlier and the proportion of second clutches produced was larger. This result, likely a result of female spiders producing first clutches earlier in those years, which allowed time for another clutch. Clutch size for first clutches was correlated to female size, while this was not the case for second clutches. Our results provide the first evidence for Arctic invertebrates producing additional clutches in response to warming. This could be a common but overlooked phenomenon due to the challenges associated with long-term collection of life history data in the Arctic. Moreover, given that wolf spiders are a widely distributed, important tundra predator, we may expect to see population and food web consequences of their increased reproductive rates.

Daurian redstart Phoenicurus auroreus is a host for the common cuckoo Cuculus canorus during the second, but not the first cultch

Background: Coevolution in cavity-nesting host-cuckoo systems may differ from those in open-nesting hosts due to unique conditions in cavity nests. We investigated brood parasitism in Daurian redstarts ( Phoenicurus auroreus ), a regular cavity-nesting host of common cuckoos ( Cuculus canorus ).Results: A total of 15.6% ( n =358) of host nests were parasitized by cuckoos. Cuckoos were highly successful in parasitizing Daurian redstart nests: nearly all cuckoo eggs were laid in the nest cup, and all cuckoo chicks evicted all host offspring. However, egg ejection by Daurian redstarts was egg morph specific, i.e. hosts laying white eggs ejected most real cuckoo eggs, while hosts laying blue eggs did not eject any. In contrast, hosts ejected most mimetic cuckoo eggs. Moreover, most Daurian redstarts moved to nearby villages during the second breeding attempts, where the risk of cuckoo parasitism was reduced. Parasitism only occurred during the second breeding attempt, since cuckoos had not yet arrived at the breeding grounds when hosts started to lay their first clutches, which may indicate a novel and unique anti-parasite defense, advancing breeding time of hosts.Conclusions: Our results suggest that Daurian redstarts suffer from high risk of cuckoo parasitism showing more intense egg ejection while building nests closer to human habitation in the second clutch. This suggests that cavity-nesting hosts may show adaptations to brood parasites that differ from those of open-nesting hosts.

Unusual late July observation of a fledgling Lapland longspur in low Arctic Greenland following the cool spring of 2018

We report an observation of a flightless fledgling Lapland longspur (Calcarius lapponicus (Linnaeus, 1758)) at a long-term study site near Kangerlussuaq, Greenland, in late July 2018. Based on our observations of longspur nests at the site dating back to 1993, we estimate that the fledgling observed in 2018 may have originated from a nest initiated 12–37 d later than nesting in previous years. Onset of spring in 2018 was late, but comparable with other years in which longspur nests were observed a full calendar month earlier than in 2018. An analysis including multiple candidate predictor variables revealed a strong negative association between estimated longspur nest initiation dates and mean May temperature, as well as a weaker association with the length of the annual period of vegetation green up at the site. Given the limitations of our data, however, we are unable to assign causality to the 2018 observation, and cannot rule out other possibilities, such as that it may have resulted from a second clutch.

Breeding biology of the house sparrow (Passer domesticus) in the Faroe Islands / Nøringin hjá føroyska gráspurvinum (Passer domesticus)

<p><strong>A</strong><strong>bstract</strong>: The breeding biology of the Faroese house sparrow (<em>Passer domesticus</em>) is described based on the results from nestlings that were ringed just before they were fledging. By means of dates and numbers, the beginning and duration of the breeding seasons are determined and the reproductive output is estimated. Our study has shown that Faroese house sparrows produce two, occasionally three, broods annually. Overall, eggs of the first, second and third clutch are normally laid in the beginning of May, in the middle of June and in the beginning of July, respectively. In a season, a female produced 6.3 nestlings, on average. For the whole period, the average brood size was 3.5 nestlings. During the first part of the time series (1985­1989), the breeding season became earlier each year, but then to be later again in the years 1990 to 1992. The first clutch was laid more than five weeks earlier in 1989 than in 1985 and the second clutch almost seven weeks earlier.</p><p> </p><p><strong>Úrtak</strong>: Árini frá 1985 til 1992 vóru tilsamans 347 gráspurvaungar (<em>Passer domesticus</em>) merktir í bygdini Nólsoy, beint áðrenn teir vóru floygdir. Við at nýta dagfestingina tá ungarnir vórðu merktir og talið av ungum er ásett, nær og hvussu ofta gráspurvurin verpur og hvussu nógvar ungar hann fær hvørja ferð. Kanningarnar vísa, at føroyski gráspurvurin verpur tvær ferðir um árið, viðhvørt tó tríggjar ferðir: Fyrstu urptin er í byrjanini av mai mánað, tann næsta er um miðjan juni og triðja urptin í byrjanini av juli mánað. Hvør bøga fær í miðal 6,3 ungar um árið. Í miðal vóru 3,5 ungar í hvørjari urpt. Úrslit okkara vísa, at tey fyrstu árini varp gráspurvurin fyrr og fyrr, fyri hvørt árið. Hetta broyttist tó tey seinru árini sum kanningin vardi: Í 1989 vórðu fyrstu eggini vorpin meira enn fimm vikur fyrri enn í 1985, og næstu urptin næstan sjey vikur fyrr.</p>