Data from: Thermal resilience may shape population abundance of two sympatric congeneric Cotesia species (Hymenoptera: Braconidae)

Basal and plasticity of thermal tolerance determine abundance,
biogeographical patterns and activity of insects over spatial and temporal
scales. For coexisting stemborer parasitoids, offering synergistic impact
to the efficacy of biological control, mismatches in thermal tolerance may
influence their ultimate impact in biocontrol programs under climate
variability. Using laboratory-reared congeneric parasitoid species Cotesia
sesamiae and Cotesia flavipes Cameron (Hymenoptera: Braconidae), we
examined basal thermal tolerance to understand potential impact of climate
variability on their survival and limits to activity. We measured upper-
and lower -lethal temperatures (ULTs and LLTs), critical thermal limits
[CTLs] (CTmin and CTmax), supercooling points (SCPs), chill-coma recovery
time (CCRT) and heat knock-down time (HKDT) of adults. Results showed LLTs
ranging -5 to 5°C and -15 to -1°C whilst ULTs ranged 35 to 42°C and 37 to
44°C for C. sesamiae and C. flavipes respectively. Cotesia flavipes had
significantly higher heat tolerance (measured as CTmax), as well as cold
tolerance (measured as CTmin) relative to C. sesamiae (P˂0.0001). While
SCPs did not vary significantly (P>0.05), C. flavipes recovered
significantly faster following chill-coma and had higher HKDT compared to
C. sesamiae. The results suggest marked differential basal thermal
tolerance responses between the two congeners, with C. flavipes having an
advantage at both temperature extremes. Thus, under predicted climate
change, the two species may differ in phenologies and biogeography with
consequences on their efficacy as biological control agents. These results
may assist in predicting spatio-temporal activity patterns which can be
used in integrated pest management programs under climate variability.