Population dynamics of the African rice gall midge Orseolia oryzivora (Diptera: Cecidomyiidae) and its parasitoids in the forest and southern Guinea savanna zones of Nigeria

Abstract

The African rice gall midge (AfRGM) Orseolia oryzivora Harris and Gagné is an important insect pest of rice in Nigeria. Studies were conducted at Ogidiga (forest zone) and Edozhigi (southern Guinea savanna) in Nigeria, under rainfed lowland conditions during the 2006 and 2007 rainy seasons, on the population dynamics of AfRGM adults using light trap and random sampling of % tiller infestation (plant damage due to AfRGM) and % parasitism by Platygaster diplosisae Risbec and Aprostocetus procerae Risbec (parasitized larvae and pupae and parasitoid species present in dissected tillers). The results obtained showed that AfRGM populations were relatively low in June and July -the beginning of the 2006 and 2007 rainy seasons, respectively -and increased abruptly from September, reaching a peak in October at both locations. The increase was attributed to the rapid build-up of the pest populations at both locations. There were strong positive correlations between adult populations from light-trap catches and % tiller infestation, and between % tiller infestation and parasitism. The peak period of parasitism by P. diplosisae and A. procerae occurred towards the end of the rainy season in October, coinciding with high level of % tiller infestation. It is concluded that conservation of the parasitoids early in the cropping season (i.e. to improve their synchronization with the host) could become an effective management strategy against AfRGM.

Biology of the African rice gall midge Orseolia oryzivora (Diptera: Cecidomyiidae) and its incidence on wet-season rice in Nigeria

“…The African rice gall midge (AfRGM) Orseolia oryzivora Harris and Gagné (Diptera: Cecidomyiidae) is the most serious insect pest of lowland and irrigated rice (Williams et al, 1999;Ogah et al, 2005Ogah et al, , 2009Nwilene et al, 2006). Indigenous to Africa, the insect's status has changed during the last two decades from a minor to a major pest, and in several countries in Africa, it causes perennial economic damage to rice (Nacro et al, 1996;Singh et al, 2004).…”

Climate-Based Modeling and Prediction of Rice Gall Midge Populations Using Count Time Series and Machine Learning Approaches

“…The bulb was illuminated daily from 6:00 pm to 6:00 am. In the morning, the collected rice gall midges were brought to the laboratory and the number of individuals caught per day were manually counted, summed and presented as weekly cumulative catches [31]. If the insect catches were too large, the population was divided into different equal subgroups, one subgroup was counted and then multiplied with the remaining number of subgroups.…”

Komunitas Hymenoptera Parasitoid pada Areal Hutan Sagu (Metroxylon spp.) di Maluku [Community of Hymenopterous Parasitoid on Sago Forest Area (Metroxylon spp.) in Maluku]

“…Parasitoid Platygaster oryzae Cameron (Hymenoptera: Platygasteridae) melimpah apabila letak pertanaman kelapa sawit yang berdekatan dengan pertanaman pertanian. P. oryzae dikenal sebagai salah satu parasitoid penting yang terdapat pada area pertanian dan menjadi parasitoid potensial untuk mengendalikan hama pertanian (Ogah et al, 2009). Scolia erratica Smith (Scoliidae) ditemukan di Malaysia sebagai parasitoid R. ferrugineus yang bersifat ektoparasit larva Scarabaeidae dan Curculionidae (Mazza et al, 2014).…”