Six-year Malaise trapping of the leaf miner Chromatomyia fuscula (Diptera: Agromyzidae) and its chalcidoid parasitoid complex in a barley field and its boundary

Title:

Six-year Malaise trapping of the leaf miner Chromatomyia fuscula (Diptera: Agromyzidae) and its chalcidoid parasitoid complex in a barley field and its boundary

Creator:

Hågvar, Eline B., Hofsvang, Trond, Trandem, Nina, and Grendstad Saeterbø, Kristin

Identifier:

https://cdk.lib.cas.cz/client/handle/uuid:17de78c9-22af-4e15-b7de-8c7f0078f6c0
uuid:17de78c9-22af-4e15-b7de-8c7f0078f6c0

Subject:

Malaise, parasitoid, Chalcidoidea, Chromatomyia fuscula, Agromyzidae, leaf miner, boundary, and barley

Type:

article, model:article, and TEXT

Description:

The univoltine leaf miner Chromatomyia fuscula (Zetterstedt) (Diptera: Agromyzidae) is a regular cereal pest in Scandinavia. The fly and its most important parasitoids were studied in a 15.5 ha organically-grown field in southern Norway. Each year (1992-1997), one Malaise trap was placed in the spring barley part (2.5 ha) of the field, and (except for 1994) another along the nearest wooded boundary for the whole season. Because of crop rotation, the traps changed position every year. C. fuscula and 15 parasitoid species previously reared from C. fuscula were sorted from the catches. Few C. fuscula were trapped in the boundary, suggesting that at least the lower vegetation strata were unimportant for the overwintering fly (C. fuscula overwinters as an adult). The parasitoid complex was remarkably stable over years, and 13-15 of the species were: found each year (habitats combined); 0-6 of the species were not found in both habitats each year. Only 4 species attained fractions higher than 10% of the total annual catches in both habitats during the 6 years: the larval parasitoids Diglyphus begini (Ashmead) and Hemiptarsenus unguicellus (Zetterstedt), and the pupal parasitoids Cyrtogaster vulgaris Walker and Chrysocharis pubicornis (Zetterstedt). In the boundary, C. vulgaris dominated every year (43-83%). In the crop, this species alternated with D. begini (1992, 1994) or H. unguicellus (1997) as the dominant species. In most years, the catches of both the leaf miner and its parasitoids were larger in the crop than in the boundary, but the species number and composition were fairly similar in the two habitats. The parasitoid diversity (Shannon-Wiener H') tended to be higher in the crop (0.8-2.0) than in the boundary (0.8-1.8). Correspondingly, the evenness (both Shannon-Wiener J' and species rank on In abundance) was higher, and the dominance (Berger-Parker) lower, in the crop than in the boundary. Every year, overwintered C. fuscula invaded the crop, but only in 1993 and 1997 did the trapping reveal a distinct next generation, suggesting a very high pre-adult mortality the other years. In 1993 and 1997, C. vulgaris and D. begini had rather similar abundances in the crop, and the lowest combined fractions (less than 60%) of the years, leading to the highest diversity and the lowest dominance through the 6 years (in both habitats). Our results indicate that the boundary was part of the parasitoids' foraging/overwintering area, and that the boundary was more important to the parasitoids than to their leaf miner host. Boundaries therefore seem to be important for the control of C. fuscula.

Language:

English

Rights:

http://creativecommons.org/publicdomain/mark/1.0/
policy:public

Source:

European Journal of Entomology | 1998 Volume:95 | Number:4

Harvested from:

CDK

Metadata only:

false