Differential Response of Leafminer Flies Liriomyza trifolii (Burgess) and Liriomyza sativae (Blanchard) to Rapid Cold Hardening

Abstract

Rapid cold hardening (RCH) is a rapid and critical adaption of insects to sudden temperature changes but is often overlooked or underestimated as a component of survival. Thus, interspecific comparisons of RCH are needed to predict how phenotypes will adapt to temperature variability. RCH not only enhances cold survival but also protects against non-lethal cold injury by preserving essential functions such as locomotion, reproduction, and energy balance. This study investigated the difference in basal cold tolerance and RCH capacity of L. trifolii and L. sativae. In both species, the cold tolerance of pupae was significantly enhanced after short-term exposure to moderately cold temperatures. The effect of RCH last for 4 h in L. sativae but only 2 h in L. trifolii. Interestingly, L. trifolii adults had a RCH response but L. sativae adults failed to acclimate. Short-term acclimation also lowered the supercooling point significantly in the pupae of both species. Based on these results, we propose a hypothesis that these differences will eventually affect their competition in the context of climate change. This study also provides the basis for future metabolomic and transcriptomic studies that may ultimately uncover the underlying mechanisms of RCH and interspecific competition between L. trifolii and L. sativae.

The Effect of Ice-Nucleation-Active Bacteria on Metabolic Regulation in Evergestis extimalis (Scopoli) (Lepidoptera: Pyralidae) Overwintering Larvae on the Qinghai-Tibet Plateau

“…The supercooling point (SCP) is generally used to evaluate an insect’s cold tolerance because at this temperature, the insect’s bodies fluids spontaneously freeze [ 24 , 25 ]. The SCP represents the lowest lethal temperature for freeze-intolerant individuals.…”

Comparative transcriptome analysis of Liriomyza trifolii (Burgess) and Liriomyza sativae (Blanchard) (Diptera: Agromyzidae) in response to rapid cold hardening

“…trifolii and L . sativae based on our previous research were selected as material for this study [ 14 ]. Due to global warming, fluctuations in daily temperature have increased [ 55 ], resulting in enhanced temperature variation in winter hibernacula, and more freeze-thaw events [ 56 ].…”

“…Temperatures were selected based on our previous study [ 14 ]. Pupae of both species were exposed to the following conditions: control (maintained at 26°C), RCH (exposed to 1°C for 4 h), CS (cold shock, exposed to discriminating temperature for 2h, discriminating temperature; temperature caused 80 percent mortality, for L .…”

“…The RCH response has been evaluated in many insect species [ 13 ], including, Liriomyza trifolii (Burgess) and L sativae (Blanchard) (Diptera: Agromyzidae) which are economically important leafminer flies [ 14 ]. Both species are highly polyphagous and similar in morphology [ 15 ], life cycle and host range [ 16 , 17 ].…”

“…sativae was 2 °C more lowered than in L . trifolii after 4h cold hardening [ 14 ]. Based on these prior results, 7-d-old pupae that exhibited and showed obvious RCH effect in both L .…”