Premium
Significance of penetration, excretion, and transovarial uptake to toxicity of three insect growth regulators in predatory lacewing adults
Author(s) -
Medina Pilar,
Smagghe Guy,
Budia Flor,
del Estal Pedro,
Tirry Luc,
Viñuela Elisa
Publication year - 2002
Publication title -
archives of insect biochemistry and physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.576
H-Index - 66
eISSN - 1520-6327
pISSN - 0739-4462
DOI - 10.1002/arch.10053
Subject(s) - biology , pyriproxyfen , fecundity , insect , diflubenzuron , insect growth regulator , excretion , toxicity , toxicology , neuroptera , larva , botany , medicine , endocrinology , population , demography , sociology
Abstract Topical treatment of the predatory lacewing adults, Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae) before and after the onset of oviposition with diflubenzuron (DFB) at doses based on the maximum field recommended concentration resulted in a total inhibition of egg hatch due to death of the embryo. In contrast, pyriproxyfen (PYR) and tebufenozide (TEB) did not affect fecundity and egg fertility. To explain these differences in toxicity, the patterns of penetration through the cuticle, distribution inside the insect body, and excretion were studied using [ 14 C]‐labeled isotopes of each insect growth regulator (IGR). Penetration of DFB and TEB reached about 16 and 26% in 7 days, whereas 88% of PYR had penetrated in 24 h. However, the rate of excretion for PYR was very high, compared to that of DFB and TEB. Low amounts of absorbed radioactivity were recovered from the female body with the exception of DFB, the ovaries and the eggs deposited during a week. DFB and PYR concentration reached a peak in the eggs deposited at the fourth and second day after treatment, respectively. The current data indicate the importance of penetration through the insect cuticle. However, other mechanisms are likely to be involved in the selectivity of the current IGRs towards this beneficial insect. Arch. Insect Biochem. Physiol. 51:91–101, 2002. © 2002 Wiley‐Liss, Inc.