Crop Protection 21 (2002) 757–761 Effects of field infestation by Rastrococcus invadens Williams (Hemiptera: Pseudococcidae) on the morphology and nutritional status of mango fruits, Mangifera indica L. F.O. Tobih a , A.A. Omoloye b, *, M.F. Ivbijaro b , D.A Enobakhare c a Department of Agronomy, Faculty of Agriculture, Delta State University, Asaba Campus, Asaba, Nigeria b Department of Crop Protection and Environmental Biology, Faculty of Agriculture and Forestry, University of Ibadan, Nigeria c Department of Crop Science, Faculty of Agriculture, P.M.B 1154, University of Benin, Benin City, Nigeria Received 6 August 2001; received in revised form 10 September 2001; accepted 29 January 2002 Abstract Investigations at Ibadan, Southwest Nigeria assessed the effects of field infestations of Rastrococcus invadens on the morphology and nutritional contents of mango, Mangifera indica L. fruit. Five ripe and unripe fruits were plucked from each of the four randomly selected fruit bearing trees (>135 cm diameter at breast height by 9.7 m high) with different levels of crown infestation. Infestation of fruits caused significant (Po0:05) reduction in weight and size of fresh mango fruits compared to the uninfested control. Similarly, field infestation also caused significant (Po0:05) reduction in the ash content, crude fibre and reducing sugar levels of both ripe and unripe fruits compared to the control. Fat content of infested and uninfested unripe fruits were not significantly different (P > 0:05). Ripe mango fruits contained significantly higher (Po0:05) crude protein than unripe fruits. Potassium, phosphorus and sodium in ripe and unripe fruits were significantly (Po0:05) higher than other available elements on a dry matter basis. Severe infestation did not significantly (P > 0:05) affect the status of microelements (iron, sodium and copper) compared to the control. r 2002 Elsevier Science Ltd. All rights reserved. Keywords: Morphology; Nutritional component; Macroelements; Infestation; Yield 1. Introduction The mango-mealybug, Rastrococcus invadens Wil- liams (Hemiptera: Pseudococcidae) is an important pest of mango (Mangifera indica L.) and other ornamental plants in Nigeria (Ivbijaro and Udensi, 1988). It is an exotic insect pest native to Southeast Asia and was first recorded and probably introduced through plant materials from Ghana and Togo, Benin and Cote d’Ivore to Nigeria in 1987 (Agounke et al., 1988; Ivbijaro and Udensi, 1988; Akinlosotu et al., 1994). Since then, it has become a serious pest of mango and many other fruit trees and ornamental plants causing enormous damage (Akinlosotu, 1989). It is dispersed by wind and through movement of contaminated materials across international boundaries (Akinlosotu et al., 1988). R. invadens is highly polyphagous infesting about 21 species but the major host plants are mango (Mangifera indica, Family—Anacardiacea), Citrus (Citrus spp, Family—Rutaceae), Frangipani (Plumaria rubra, Family—Apocynaceae), and Fig (Ficus spp, Family— Moraceae) (Ivbijaro et al., 1991). Of the 21 species, fruit trees constituted 43% while shade and ornamentals constituted 42%. Other food crops particularly cereals, tubers and vegetables jointly accounted for the rest 15% (Ivbijaro et al., 1991). Both adult and immature stages are pestiferous causing serious damage to leaves, inflorescences and fruits. Severe infestation causes heavy accumulation of the excreted honey dew that results in the formation of sooty mould and which in turn arrests normal growth, photosynthesis, flowering and fruiting of the attacked plants (Pitan et al., 2000). The most common method used by the local farmers to control R. invadens is cutting down of infested trees (Agricola et al., 1989). The use of biological control agents such as Gyranusoidea tebygii Noyes and Anagyrus mangicola Noyes has been explored and reports obtained indicated some degree of success (Pitan et al, 2000). *Corresponding author. E-mail address: bayoomoloye@yahoo.com (A.A. Omoloye). 0261-2194/02/$ - see front matter r 2002 Elsevier Science Ltd. All rights reserved. PII:S0261-2194(02)00033-9