ABSTRACT
The ability of the females of the predatory ladybird Cheilomenes propinqua to survive and to retain reproductive potential in the absence of natural food (aphids) was estimated under various hydrothermal (temperatures of 7, 12, 17, 22, and 27 °C; air humidities of 50% and 80-90%) and trophic (starved vs. fed on the frozen eggs of the grain moth Sitotroga cerealella) conditions. The post-storage reproductive potential was estimated using the mean number of eggs laid over 20 days. The experiments showed that fed females can be stored at temperatures of 15-17 °C for 20 days with a rather low (about 20%) and for up to 80 days with an acceptable (not more than 50%) loss of the reproductive potential. The successful short-term (up to 3 days) storage or transportation of fed and starved females can occur at temperatures from 12 to 27 °C. However, storage for more than 10 days at temperatures of 7 °C and lower results in the 100% mortality of both the starved and fed beetles. These data suggest that (1) in greenhouses, C. propinqua can be used for the biological control of aphids by preventing colonization, although this would require the regular supplementation of factitious food, and (2) escaped individuals would not survive the winter even in the south of the temperate zone.
ABSTRACT
Six new species, Bracon (Bracon) kimchanghyoisp. nov., B. (B.) yeogisanensissp. nov., B. (Habrobracon) allevatussp. nov., B. (Osculobracon) perspicillatussp. nov., Syntomernus flavus sp. nov., and S. scabrosus sp. nov. are described from South Korea and short keys for their identification are presented. The genus Ficobracon van Achterberg & Weiblen, 2000, syn. nov. is considered a junior synonym of Syntomernus Enderlein, 1920 and new combinations are proposed for Syntomernus asphondyliae (Watanabe, 1940), comb. nov., S. brusi (van Achterberg & Weiblen, 2000), comb. nov., S. codonatus (Huang & van Achterberg, 2013), comb. nov., S. kashmirensis (Maqbool, Akbar & Wachkoo, 2018), comb. nov., S. rhiknosus (Huang & van Achterberg, 2013), comb. nov., S. sunosei (Maeto, 1991), comb. nov. (= Bracon flaccus Papp, 1996, syn. nov.), and S. tamabae (Maeto, 1991), comb. nov.
ABSTRACT
Adaptive grandmaternal thermal effect, wherein the grandmaternal thermal environment affects the induction of progeny diapause two generations later, has not been studied in any insect system. We have studied this effect in the parthenogenetic egg parasitoid Trichogramma telengai Sor. (Hymenoptera: Trichogrammatidae) under laboratory conditions. The grandmaternal generation developed at temperatures from 18 to 30 °C combined with short (L:D = 12:12) or long (L:D = 18:6) photoperiod. The maternal generation developed at the same two photoperiods combined with low (20 °C) or high (30 °C) temperature. The progeny generation developed at 14 °C and L:D = 12:12. The grandmaternal temperature response was consistent with an adaptive response (low temperature induces facultative prepupal winter diapause two generations later) and rather strong (ranged up to 20-25%). The experiments suggested that both grandmaternal and maternal thermal effects are based on the influence of temperature on photoperiodic induction of diapause. However, experiments also revealed substantial differences between the grandmaternal and maternal thermal responses. In particular, the grandmaternal thermal response was observed only at short-day grandmaternal photoperiod, whereas the maternal thermal response was independent both of maternal and grandmaternal photoperiods. Although under natural conditions the adaptive value of the grandmaternal thermal response in T. telengai is most probably low, this effect should be considered in physiological models of diapause induction and can be important for mass rearing of Trichogramma species.
Subject(s)
Diapause, Insect/physiology , Wasps/physiology , Animals , Cold Temperature , Epigenesis, Genetic , PhotoperiodABSTRACT
The present study is based on the genus Bracon Fabricius collected from the Khuzestan province in the southwestern part of Iran during 2016-2017. In total, 35 species including one subspecies were collected and identified, of which 10 species are recorded for the first time from Iran and Bracon (Osculobracon) pelliger rumezensis Samartsev Zargar ssp. n. is described. In addition, 24 species are recorded for the first time from Khuzestan province in southwestern Iran. Brief diagnoses with illustrations for new records from Iran and a faunistic list with distribution data are provided.
Subject(s)
Hymenoptera , Animals , IranABSTRACT
Four new species of braconid parasitoids of the subfamily Euphorinae (Braconidae) from South Korea are described and illustrated, Centistes (Centistes) ahni sp. nov., Leiophron (Leiophron) pubiscutum sp. nov., Perilitus koreanus sp. nov. and Peristenus brunigaster sp. nov.
Subject(s)
Hymenoptera , Wasps , Animals , Republic of KoreaABSTRACT
Four new species from the Russian Far East, Bracon kasparyani sp. nov., B. kotenkoi sp. nov., B. santachezae sp. nov. and Uncobracon belokobylskii sp. nov., are described and short keys for their identification are presented.
Subject(s)
Wasps , Animal Distribution , Animals , Asia, Eastern , Hymenoptera , RussiaABSTRACT
Bracon admotus Papp, 2000, and three species of the genus Habrobracon Ashmead, 1895, Habrobracon concolorans (Marshall, 1900), Habrobracon hebetor (Say, 1836) and Habrobracon pillerianae Fischer, 1980, were obtained from the larvae of Lobesia botrana (Denis & Schiffermüller, 1775) (Lepidoptera, Tortricidae) feeding on Daphne gnidium Linnaeus, 1753 (Thymelaeaceae) in the natural reserve of Migliarino-San Rossore-Massaciuccoli (Pisa-Central Italy). Bracon admotus, Habrobracon concolorans and Habrobracon pillerianae were found for the first time to be associated with Lobesia botrana, while Habrobracon hebetor was reared for the first time from the larvae of Cryptoblabes gnidiella (Millière, 1867) (Lepidoptera, Pyralidae, Phycitinae) that was found on the same host plant. Bracon admotus and Habrobracon pillerianae are new to the fauna of Italy and Western Europe. A key is proposed for the determination of Habrobracon species reared from Lobesia botrana and related Palaearctic species of this genus. Habrobracon lineatellae Fisher, 1968 is considered as a valid species.
ABSTRACT
It is known that in some insect species the incidence of diapause among the progeny of females that had undergone diapause is relatively low or zero even under strong diapause-inducing conditions. Moreover, the maternal inhibition, preventing the induction of a maladaptive diapause in spring, can persist over several generations. This multigenerational effect based on hypothetical 'interval timer' was thoroughly studied in Aphididae. We first described a similar phenomenon in Hymenoptera: laboratory experiments demonstrated that the proportion of diapausing progeny of Trichogramma females that had undergone diapause was practically zero independently of photoperiodic and temperature conditions used (day lengths of 12 and 18h and temperatures of 12-15°C). Then the ability to enter diapause recovered gradually and returned to the normal level over two (in Trichogramma telengai) or even five (in Trichogramma principium) generations. We conclude that the observed effect may be based on an interval timer similar to that in aphids.
Subject(s)
Diapause, Insect , Wasps/growth & development , Wasps/physiology , Animals , Female , Larva/growth & development , Moths/parasitology , Photoperiod , Seasons , Temperature , Time FactorsABSTRACT
The Palaearctic species of the S. exarator species group of the genus Spathius Nees with entirely sculptured mesopleuron are discussed. Four new species, Spathius austriacus sp. nov., S. intercontinentalis sp. nov., S. pseudodentatus sp. nov., and S. sculptipleurum sp. nov., are described and illustrated. Spathius curvicaudis Ratzeburg, 1944 treated here as junior synonym of S. erythrocephalus Wesmael, 1838 (syn. nov.) The key for determination of the Palaearctic species of this group with constantly or temporary sculptured mesopleuron is provided.
