ISSN:
1570-7458
Keywords:
Onion fly
;
Delia antiqua
;
Anthomyiidae
;
egg distribution
;
soil sampling
;
agar infusion
;
insecticide
;
Lorsban™ 15 G
;
chlorpyrifos
;
Dyfonate™ 15 G
;
fonofos
;
ovipositional behavior
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract A method for rapidly determining the vertical and horizontal distribution of insect eggs in fragile soil is described. Liquefied agar is allowed to permeate intact soil samples from below; after cooling, the resulting solid is cut into thin sections, from which eggs can be recovered by washes with hot water. This technique revealed that in organic (muck) soil in the laboratory, undisturbed onion flies, Delia antiqua (Meigen) (Diptera: Anthomyiidae), laid 95% of their eggs within a 10 mm diameter zone around the base of a surrogate onion ‘stem’ arising vertically from the soil. Ninety % of all eggs were found in the top 12 mm of soil, with an apparent maximum at depth of 2–4 mm. Increasing fly density from 30 to 200 flies per 30×30×42 cm cage flattened the horizontal distribution of eggs and extended the ovipositional range from c. 15 mm to beyond 60 mm, suggesting there was competition for the preferred ovipositional sites. Surface treatment of muck soil in the field by granular formulations of the insecticides Lorsban™ 15 G (active ingredient chlorpyrifos) and Dyfonate™ 15 G (fonofos) three weeks prior to bioassaying reduced egg-laying at depths greater than 8 mm. The relation between the measured egg distribution and mortality factors in soil (low moisture and high temperature) is discussed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00192777
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