BASE LINE SUSCEPTIBILITY OF BEMISIA TABACI (HEMIPTERA: ALEYRODIDAE) TO PYRIPROXYFEN UNDER LAB CONDITIONS

Zulfiqar Ali; Maqbool Shah; Ahmed Nawaz; Muhammad Nadeem; Muhammad Rafiq Shahid; Muhammad Farooq

Zulfiqar Ali Pest warning and Quality Control of Pesticides Mianwali, Pakistan
Maqbool Shah Pest warning and Quality Control of Pesticides Bahawalpur, Pakistan
Ahmed Nawaz Pest warning and Quality Control of Pesticides, Multan, Pakistan
Muhammad Nadeem Arid Zone Research Institute, Bhakkar
Muhammad Rafiq Shahid Cotton Research Institute, Faisalabad
Muhammad Farooq Entomological Research Institute, Faisalabad

Keywords: Baseline susceptibility, pyriproxyfen, Bamisia tabaci, cotton, Host plants

Abstract

A systemic bioassay was carried out using cuttings of stem from cotton seedlings for baseline susceptibility of whitefly from district Bahawalpur, Punjab Pakistan. Bioassay studies were conducted by using a leaf dip bioassay method to determine the susceptibility of Bemisia tabaci to pyriproxyfen. Experiments were conducted for a susceptible laboratory colony and for 10 field collected populations during 2011 and 2012.. It was observed that all the B. tabaci populations were susceptible to pyriproxyfen. Baseline data of the susceptible colony showed a pooled LC₅₀ and RR₅₀ values of 0.039 and 2.316 mg ai L^-1, respectively. LC₅₀ values for field populations of B. tabaci ranged from 0.63 to 0.86 mg [AI] l^-1 during 2011 and from 0.46 to 2.08 mg[AI]l-1 during 2012. No population had a RR₅₀ value over 3.5 in either year and the fiducially limits of the LC₅₀values for the field and laboratory populations overlapped, indicating no differences among them. Pyriproxyfenis a promising tool in integrated pest management programs for B. tabaci, particularly where field populations have developed resistance to other insecticide groups. The laboratory and field baseline toxicity data generated in this study of field populations of B. tabaci confirmed their susceptibility to pyriproxyfen and would be useful in documentingany future changes in the susceptibility of the whitefly to the insecticide.