Interspecific competition and comparative cold tolerance in two egg parasitoids of sunn pest, Eurygasterintegriceps

• Published in: BioControl (Dordrecht, Netherlands) Vol. 69; no. 2; pp. 103 - 114
• Main Authors: Iranipour, Shahzad, Michaud, J. P., Najafipour, M., Khaghaninia, S.
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01-04-2024; Springer Nature B.V
• Subjects: Agriculture; Animal Biochemistry; Animal Ecology; Behavioral Sciences; Biomedical and Life Sciences; Cold storage; Cold tolerance; Competition; Eggs; Entomology; Females; Life Sciences; Pests; Plant Pathology; Iran; Aggregation; Multiparasitism; Cold hardiness
• ISSN: 1386-6141; 1573-8248
• DOI: 10.1007/s10526-024-10246-5

Trissolcus
spp. are egg parasitoids of sunn pest,
Eurygaster
integriceps
Puton (Hemiptera: Scutelleridae). Direct (extrinsic) competition between female
T.
grandis
and
T.
vassilievi
was investigated in the laboratory by releasing different numbers (from one to 16) of one or both species into a multi-patch environment consisting different numbers of
E.
integriceps
egg masses. Larval (intrinsic) competition was examined in host eggs multiparasitized at intervals ranging from 0 to 48 h. Survival of females was also assayed when stored at 4 °C.
Trissolcus
grandis
reduced the searching efficiency of congeneric rivals more than did
T.
vassilievi
, and was a superior intrinsic competitor within multiparasitized eggs, although both species benefited from a significant ‘first attack’ advantage.
Trissolcus
vassilievi
was more efficient than
T.
grandis
when parasitizing host eggs at high conspecific densities. Mortality at 4 °C was lower in groups ≥ 10 than in groups ≤ 5, and
T.
grandis
survived longer than
T.
vassilievi
.