Insecticides

Assessment of ecological risks of agrochemicals requires a new framework

The widespread contamination of a significant proportion of the planet’s land and water with pesticides is undeniable. While this takes place, innumerable species of animals associated with agricultural landscapes are declining at rates that may put them on the brink to extinction in the span of a lifetime. It is evident, therefore, that our current risk assessment of agrochemicals has failed to protect the environment.

Leaf beetles: Even a tiny dose of pesticide will impair reproduction

In a new study, biologists at Bielefeld University show the effects of pesticides and how even slight traces lead to long-term damage to beetles. One finding is that leaf beetles lay roughly 35 per cent fewer eggs after coming into contact with traces of a frequently used pesticide: a pyrethroid. The researchers also showed that female offspring develop malformations through the poison. The biologists have published their study in the journal Environmental Pollution.

Midwestern streams were found to contain 52 pesticides on average

More than 180 pesticides and their by-products were detected in small streams throughout 11 Midwestern states, some at concentrations likely to harm aquatic insects, according to a new study by the U.S. Geological Survey. The mixtures of pesticides are more complex than previously reported by the USGS—94 pesticides and 89 pesticide byproducts were detected. On average, 52 pesticide compounds were identified in each stream.

Imidacloprid may impact bobwhite quail embryonic development and chick survival

The goal of this research was to investigate the effects of the neonicotinoid imidacloprid on the morphological and physiological development of northern bobwhite quail (Colinus virginianus). Bobwhite eggs (n = 390) were injected with imidacloprid concentrations of 0 (sham), 10, 50, 100, and 150 mg/kg of egg mass, which was administered at day 0 (pre-incubation), 3, 6, 9, or 12 of growth. Embryos were dissected, weighed, staged, and examined for any overt structural deformities after 19 days of incubation. The mass of the embryonic heart, liver, lungs and kidneys was also recorded.

Occurrence of imidacloprid in Italian house dust

The occurrence of pesticides intended for non-agricultural use was investigated in 206 dust samples drawn from vacuum-cleaner bags from residential flats in Italy. The results indicated the presence of imidacloprid (IMI) in 30% of the samples. According to the estimated dust intake in infants/toddlers aged 6–24 months (16–100 mg d−1) and cats (200 mg d−1), it was possible to obtain risk characterization with respect to the Acceptable Daily Intake (ADI) for IMI of 0.060 mg/kg body weight (bw) proposed by EFSA and the chronic Population Adjusted Dose (cPAD) of 0.019 mg/kg bw d−1 by US-EPA.

Photolysis on environmental surfaces increases toxicity of imidacloprid

Imidacloprid (IMD) is the most widely used neonicotinoid insecticide found on environmental surfaces and in water. Analysis of surface-bound IMD photolysis products was performed using attenuated total reflectance Fourier transfer infrared (ATR-FTIR) analysis, electrospray ionization (ESI-MS), direct analysis in real time mass spectrometry (DART-MS), and transmission FTIR for gas-phase products. Photolysis quantum yields (ϕ) for loss of IMD were determined to be (1.6 ± 0.6) × 10–3 (1s) at 305 nm and (8.5 ± 2.1) × 10–3 (1s) at 254 nm.

Comparative toxicity of imidacloprid and thiacloprid to different species of soil invertebrates

This study determined the toxicity of imidacloprid and thiacloprid to five species of soil invertebrates: earthworms (Eisenia andrei), enchytraeids (Enchytraeus crypticus), Collembola (Folsomia candida), oribatid mites (Oppia nitens) and isopods (Porcellio scaber). Tests focused on survival and reproduction or growth, after 3–5 weeks exposure in natural LUFA 2.2 standard soil. Imidacloprid was more toxic than thiacloprid for all species tested. F. candida and E.

Comparative ecotoxicity of imidacloprid and dinotefuran to aquatic insects in rice mesocosms

In this study, effects of two neonicotinoid insecticides, imidacloprid and dinotefuran, on aquatic insect assemblages were evaluated in experimental rice mesocosms. During the 5-month period of the rice-growing season, residual concentrations of imidacloprid were 5–10 times higher than those of dinotefuran in both soil and water. Imidacloprid treatment (10 kg/ha) reduced significantly the populations of, Crocothemis servilia mariannae and Lyriothemis pachygastra nymphs, whereas those of Orthetrum albistylum speciosum increased slightly throughout the experimental period.

Die Insekten sterben lautlos

Dass die Insekten auf dem Rückzug sind, ist vielen Menschen nicht bewusst. Eine Ausnahme bilden die Bienen. Ihr Niedergang ist bereits länger bekannt, was unter anderem daran liegt, dass sie als fleissige und nützliche Tiere gelten. Der Rest ist meistens nur lästig. Erst langsam spricht sich herum, dass auch Falter, Fliegen und Wespen bedroht sind.