<strong>Effects of heat stress on copulation, fecunditiy and longevity in newly-emerged adults of the predatory mite <em>Neoseiulus barkeri</em> (Acari: Phytoseiidae)</strong>

Abstract

Climate change predictions depict scenarios where arthropods will be more intensely and frequently exposed to extreme high temperatures. A short period of heat stress is unlikely to cause directly mortality but may modify population dynamics via impacting life history traits. In this study, the newly-emerged female and male adults of the predatory mite, Neoseiulus barkeri Hughes (Acari: Phytoseiidae) were exposed to 42 ºC for 4 hours to investigate the heat effects on the copulation, longevity, fecundity and egg hatchability through parental effects of the mite. The results showed that after heat stress, the females had a markedly extended pre-oviposition period, shortened oviposition period, and reduced fecundity and longevity. At the meantime, when females mated with the heat stressed males, the pre-oviposition period was prolonged, the oviposition period was shortened and the fecundity was reduced. A sex-specific effect of short term heat exposure on mating behavior was further observed in males where copulation duration of the stressed individuals were somewhat prolonged. In addition, a trade-off between survival and reproduction was observed in heat stressed females. However, heat stress had no effects on immediate mortality, pre-copulation period, post-oviposition period, male longevity and egg hatchability of the progeny generations. Our results confirmed that heat stress had a detrimental effect on reproduction, particularly by delaying the onset of oviposition and reducing reproductive output and thereby influencing the population dynamics of N. barkeri.

Larval developmental temperature and ambient temperature affect copulation duration in a seed beetle

“…Intraspecific variation in the duration of copula is substantial and has been associated with variation in the biotic environment experienced by adults, including male and female size, the operational sex ratio, risk of sperm competition, and male and female mating status, i.e., whether they are virgin or not (Simmons, 2001). It has also been associated with variation in ambient temperature Delisle et al, 2016), exposure to heat shock (Zhang et al, 2016), and photoperiod (Wang et al, 2013).…”

Effects of heat shock on survival and predation of an important whitefly predator,Serangium japonicum

“…Heat stress can regulate insect behavior such as mating, flight, positioning, and feeding (Wang et al, 2009;Liao et al, 2014;Bodlah et al, 2016Bodlah et al, , 2017Zhang et al, 2016;Sentis et al, 2017). Heat shock of 39 and 42°C significantly decreased B. tabaci egg predation by S. japonicum adult females, probably owing to the significant increase in the time that the females spent resting after heat shock, which forced them to reduce the time they spent on B. tabaci egg predation.…”

“…In addition to causing acute mortality, heat stress also causes nonlethal negative physiological and behavioral effects. Negative influences on mating capacity, fecundity, longevity, egg hatching rate, and developmental rate have frequently been observed (Mironidis & Savopoulou-Soultani, 2010;Liao et al, 2014;Sambucetti & Norry, 2015;Zhang et al, 2016;Cheng et al, 2017).…”

Response to Multiple Stressors: Enhanced Tolerance of Neoseiulus barkeri Hughes (Acari: Phytoseiidae) to Heat and Desiccation Stress through Acclimation

“…This may be the same case with terrestrial arthropods since synergistic interactions of multi-stressors were also common among laid within 24 h were collected, and then transferred into a 4 L translucent plastic box with enough flour mites and wheat bran, and held at 25 °C, 70%-80% RH and L:D = 14:10 in programmable temperature controllers, the same condition with conventional rearing. Six days after egg collection (more than 90% mites developed into adult [27]), mites were screened out again as described before [26]. Ten homogeneous female adults were transferred into a small acrylic cage that was adapted from Williams et al [28].…”

“…Then enough flour mite Aleuroglyphus ovatus and N. barkeri were separately added into these boxes that are placed in programmable temperature controllers (Ningbo Southeast Instrument Co. Ltd., RDN-300B-4, Ningbo, China) with temperature at 25 ± 1 • C, 70%-80% RH, and L:D = 14:10. Homogeneous adult female mites were prepared by the methods described in Zhang's study with some modifications [26]. Briefly, a plastic film with 10 cm diameter was placed on a round sponge that was soaked with distilled water in a Petri dish (15 cm in diameter).…”