Work

Geographic origin of a factitious host shapes parasitoid performance in Trichogramma chilonis–Antheraea pernyi systems

Year: 2026

Type: article

Abstract: Geographical variation can profoundly influence host–parasitoid compatibility and mass-rearing performance in biological control programs. We assessed how the geographical origin of the Chinese oak silkworm ( Antheraea pernyi ) affects the reproductive performance of the egg parasitoid Trichogramma chilonis . Two A. pernyi populations from Jilin (JCOS) and Guizhou (GCOS) provinces, and two T. chilonis populations from the same regions (JL-TC and GZ-TC), were reciprocally tested to evaluate host suitability. Morphometric analyses revealed that JCOS exhibited a larger body size, a longer wingspan, and thicker eggshells than GCOS, indicating regional morphological differentiation. Parasitism and emergence rates were significantly higher on GCOS eggs (82–86% and 67–76%, respectively) than on JCOS eggs (70–75% and 41–47%), primarily because their thinner eggshells facilitated oviposition and adult emergence. Development duration was shorter on GCOS eggs, while the proportion of female progeny remained consistently high (>85%) across treatments. Although T. chilonis populations showed comparable parasitism levels, the JL-TC strain produced slightly more female offspring than GZ-TC, suggesting minor adaptive divergence. Regression analyses demonstrated a strong negative correlation between eggshell thickness and parasitoid emergence, confirming eggshell structure as a critical determinant of host suitability. These findings highlight that the geographical origin and morphological traits of A. pernyi influence the reproductive success of T. chilonis . Selecting optimal host populations, such as GCOS, can enhance parasitoid production efficiency and reliability, improving the sustainability of mass-rearing systems and biological control programs.

Source: Biological Control

DOI: 10.1016/j.biocontrol.2026.105991

Authors: Talha Tariq, Zhen Shen, Haneef Tariq, Yong-Ming Chen, Nicolas Desneux, Lian-Sheng Zang