DOI: 10.5061/dryad.7pvmcvdpr
title: Reprotoxic effects of the systemic insecticide fipronil on the butterfly Pieris brassicae

description: In addition to controlling pest organisms, the systemic neurotoxic
 pesticide fipronil can also have adverse effects on beneficial insects and
 other non-target organisms. Here, we report on the sublethal effects of
 fipronil on the farmland butterfly Pieris brassicae . Caterpillars were
 reared on plants that had been grown from seeds coated with fipronil or on
 leaf discs topically treated with a range of fipronil dosages (1–32 µg kg
 −1 on dry mass basis). Females that had developed on fipronil plants laid
 ca half the number of eggs than females that had developed on control
 plants. In the bioassay with leaf discs, longevity and lifetime egg
 production declined with increasing fipronil dosage. Remarkably, exposure
 to fipronil during larval development primarily affected the adult stage.
 Chemical analyses of leaf tissues collected from seed-treated plants
 revealed concentrations of fipronil and its degradation products close to
 the analytical limit of detection (less than or equal to 1 µg kg −1 ). The
 effective dosage was fivefold higher in the leaf-disc than in the
 whole-plant experiment. In the whole plant, degradation of fipronil to
 products that are more toxic than fipronil may explain this discrepancy.
 Neurotoxicity of insecticides at the level of detection decreases the
 probability of pinpointing insecticides as the causal agent of harmful
 effects on non-target organisms.
description: Data were collected in two experiments, a whole plant and a leaf
 disc bioassay. In the whole-plant experiment plants
 were grown from untreated control seeds (<em>Brassica
 oleracea</em>  var <em>gemmifera</em> cv Cyrus, Brussels
 sprouts) and seeds coated with fipronil. On each plant (20 control plants,
 19 fipronil plants) 5 neonate <em>Pieris brassicae</em>
 caterpillars were introduced and their survival to pupation was recorded.
 Pupae were collected and maintained together per plant until adult
 eclosion. From each plant, one female and one male were selected and they
 were placed together in a cage (40 x 40 x 60 cm), provided with 10% sugar
 water and a cabbage plant that served as substrate for oviposition. Plants
 were checked daily for eggs. Leaves with eggs were removed, or whole
 plants were replaced by new ones. The experiment was ended at day 24
 post-eclosion when most females had died and females that were still alive
 produced no or very few eggs. All eggs were counted providing lifetime egg
 production per female. In the leaf disc bioassay,
 neonate caterpillars (10 per dish) were fed leaf discs treated with
 approximated fipronil dosages of 0, 1, 2, 4, 8, 16.1, or 32.2 µg
 kg<sup>-1</sup> (10 dishes per dosage). Survival of the
 caterpillars was recorded until pupation. Leaf discs were replaced every
 other day until day 9. At this point the number of caterpillars was
 reduced to 5 caterpillars per dish and leaf discs were replaced daily.
 Pupae were collected and placed together per treatment dosage until adult
 eclosion. Per dosage, 5 times 6 butterflies, 3 females and 3 males, were
 randomly selected and placed in new cages. Each cage was provided with a
 cabbage plant and 10% sugar water. The plants were replaced by new ones
 every four days until day 12 and then every 2 days until day 35 when most
 females had died and only few eggs were laid by the females that were
 still alive. All eggs were counted. Dead butterflies were removed and
 recorded in both the oviposition cages and the cages with the remaining
 butterflies that were not released in the oviposition cages. 
description: There are two data files: whole_plant_exp.xlsx,
 dish_exp.xlsx. The whole_plant_exp.xlsx file contains
 data on pupal mass, larval mortality, pupal mass, development time to
 pupation, daily and cumulative agg production, longevity of adult females,
 respectivly that are presented in separate sheets. The
 dish exp_exp file contains data on on pupal mass, larval mortality, pupal
 mass, egg production per cage, egg production per female, respectivly,
 that are presented in separate sheets.