Ecotoxicological hazards of herbicides on biological attributes of Zygogramma bicolorata Pallister (Coleoptera: Chrysomelidae) Fazil Hasan * , M. Shaq Ansari Department of Plant Protection, Faculty of Agricultural Sciences, Aligarh Muslim University, Aligarh 202002, India highlights graphical abstract Glyphosate was slightly toxic and 2, 4-D was highly toxic to Zygogramma bicolorata. Daily fecundity (m x ), net reproduc- tive rate (R 0 ), intrinsic rate of increase (r m ) and nite rate of increase (l) was lowest on 2, 4-D treated group. A signicantly greater number of fe- males were produced in control than treated with glyphosate. None of the tested herbicide except glyphosate can be classied as safe to Z. bicolorata. article info Article history: Received 23 November 2015 Received in revised form 29 March 2016 Accepted 31 March 2016 Handling Editor: Jim Lazorchak Keywords: Zygogramma bicolorata Herbicides Ecotoxicology Life table Sex ratio abstract Ecotoxic effects of commonly used herbicides i.e. glyphosate, atrazine, metribuzin, alachlor and 2, 4-D were evaluated on the biological and demographic parameters of Zygogramma bicolorata Pallister on parthenium in laboratory. The herbicides used in the bioassay were within a minimum range of their recommended eld dose. In direct toxicity experiment, 2,4-D and alachlor caused the highest mortality of 3rd instars and prolonged the development time. Fecundity and eggs viability were also signicantly reduced in all treatments. Indirect toxicity (carryover effect) was evaluated through life table analysis of F 1 progenies developed from surviving 3rd instars treated for direct toxicity experiment. Incubation period and overall development time was considerably prolonged in all treatments especially in 2, 4-D treated group. Daily fecundity and population growth parameters were signicantly lowest in 2, 4-D treated groups compared to other tested herbicides. A signicantly greater number of females were produced in glyphosate treatment than other treatments. Based on the present study, none of the tested herbicide can be classied as safe to Zygogramma bicolorata, while glyphosate was found to be least toxic. Therefore, it can be concluded that application of eld recommended dose of glyphosate might be used in integration with Z. bicolorata for effective management of parthenium, however this needs to be conducted under natural eld conditions. © 2016 Elsevier Ltd. All rights reserved. 1. Introduction Parthenium, Parthenium hysterophorus L. (Asteraceae) is considered as one of the most noxious weeds causing several health problems in human being and animals besides loss to crop productivity and destroys plant biodiversity (Sushilkumar, 2012). It * Corresponding author. E-mail address: fazilento10@gmail.com (F. Hasan). Contents lists available at ScienceDirect Chemosphere journal homepage: www.elsevier.com/locate/chemosphere http://dx.doi.org/10.1016/j.chemosphere.2016.03.137 0045-6535/© 2016 Elsevier Ltd. All rights reserved. Chemosphere 154 (2016) 398e407