EFFICIENCY OF SOME INSECTICIDES SEQUENCE ON COTTON BOLLWORMS AND HISTOPATHOLOGICAL EFFECTS OF SOME BIOCIDES ON PINK BOLLWORM LARVAE | ||||
| Egyptian Journal of Agricultural Research | ||||
| Article 4, Volume 91, Issue 2, July 2013, Page 429-448 PDF (726.43 K) | ||||
| Document Type: Original Article | ||||
| DOI: 10.21608/ejar.2013.163443 | ||||
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| Abstract | ||||
| The experiments were carried out during the cotton seasons of 2008 and 2009 in Sakha Agricultural Research Station Farm, Kafr El-Sheikh Governorate to evaluate the efficiency of certain insecticidal sequences against pink and spiny bollworms larvae. The aim of the insecticidal sequences is to get the most effective control one against the bollworms. The data revealed that the infestation of cotton fields with both bollworms in both successive seasons started with few number of 1st and 2nd instar larvae on late July, but increased gradually till the end of each season. In general all treatments had slight and moderate reduction in bollworms where the reduction rates ranged between 34.18 and 52.43%. The sequences of biocides (Spinosad, Azadirachtin and Bacillus thuringiensis) was efficient in reducing larval population when sprayed three times alone or alternative with other three sprays at 15 days intervals. Spinosad in three successive sprays was the best sequences in controlling bollworms induced 48.66% average reduction, using the conventional insecticides with biocides, IGRs and antimolting compounds caused good average reduction on larval population. While the sequence of methomyl followed by oxymatrine + prosuler and lambdacyhalothrin induced the least reduction which being 38.02% reduction.With respect to the histopathological effects of the tested biocides, midgut histological sections were carried out on the 2nd and 4th instar larvae of Pink bollworm (PBW) with field concentration of the three tested biocides. Spinosad was the most effective compounds in causing aberrations in the midgut layers. Also, the pathological effect of the tested biocides was more serious on the 2nd instar larvae than the 4th one. Accordingly, spinosad, IGRs, antimolting compounds and biocides could be included with conventional insecticides to get the highest reduction in bollworms population. | ||||
| Keywords | ||||
| INSECTICIDES SEQUENCE; BOLLWORM LARVAE | ||||
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