Assessment of infestations caused by maize stem borer Chillo partellus (Crambidae- Swinhoe) and its larval and pupa parasitoids in Zanzibar (A case study of Unguja island)

Stem borers from the order of Lepidoptera, Chilo. partellus (Swinhoe) are important pests that attack maize crops and causing adverse effects. The study aimed to examine infestation of stem-borers on maize crops in agro ecological zones, also to evaluate the strategies taken by the farmers for controlling C. partellus. The study was carried out in Unguja,United republic of Tanzania, in seven villages /Shehias namely Bungi, Jendele, Donge, Tunguu, Bambi, Kizimkazi, and Kitumba. The data was analyzed using a Statistical Package for Social Sciences (SPSS) software version 20 Where by Pearson correlation was used to find the association between infestation levels and rain fall variability at 95% of confidence level. One-way Analysis of Variance (ANOVA) was used to compare the means. Cross Sectional study design was used and the data from 83 respondents was collected using interviews furthermore experiments were done to evaluate the emerged of moth and parasitoids. The results showed that most of respondents (48.2%) experienced fewer damages caused by impact of stem borers and infestation level was 25%. Furthermore (24.1%) experienced moderate effect of infestation of 50%, though (18.1%) and (9.6%) of the respondents were highly affected with infestation levels of 75% and 100% respectively. There was a significant negative relationship between infestation levels and the number of respondents (r (6) =-949 (p0.05. Implying that both could be used as biological control method of stem borers.