HOST SUITABILITY OF RED PUMPKIN BEETLE, AULACOPHORA FOVEICOLLIS (LUCAS) AMONG DIFFERENT CUCURBITACEOUS HOSTS
The red pumpkin beetle, Aulacophora foveicollis (Lucas) is a common, serious and major pest of a wide range of cucurbitaceous vegetables. It is injurious to the crops and cause severe damage to almost all cucurbits. The present study was conducted to find out the host suitability of red pumpkin beetle, Aulacophora foveicollis (Lucas) among different cucurbit hosts in the Laboratory and Field Laboratory of the Department of Entomology, Bangladesh Agricultural University, Mymensingh. This study was investigated with a view to explore a resistant host to this pest. The experiment was laid out in the completely randomized design (CRD) and Randomized Complete Block Design (RCBD) in laboratory and field respectively with five replications. Three cucurbit hosts such as sweet gourd (Var. BARI Sweet gourd1), bitter gourd (Var. Hybrid Nepali) and bottle gourd (Var. Kajla) were selected to conduct this research work. Host suitability was determined depending on the average number of beetles present per plant in field. But in the laboratory host suitability was measured following force feeding and choice feeding bioassays. In the field at three different stages of the plant the highest number of beetle per plant was observed on the sweet gourd and the lowest number was found on bitter gourd. Similarly both in force feeding and choice feeding bioassays the highest leaf feeding was observed on sweet gourd and the lowest leaf feeding was determined on the bitter gourd. Both in the laboratory and field among the three cucurbit hosts sweet gourd was the most suitable and bitter gourd was the least suitable host for red pumpkin beetle.
INSECT AND NON-INSECT PESTS INFESTING POINTED GOURD (TRICHOSANTHES DIOICA ROXB.) IN WEST BENGAL
Pointed gourd (Trichosanthes dioica Roxb.) was found to be infested by seven insect and non-insect pests viz. Epilachna dodecastigma (Wied.), Aulacophora foveicollis (Lucas),Diaphania indica(Saunders), Bactrocera cucurbitae (Coquillett), Bemisia tabaci (Gennandius), Tetranychus urticae (Koch) and Meloidogyne incognita (Kofoid and White). Peak incidences of mite in last week of April to first fortnight of May, of leaf roller in third week of January, first to second week of March, first to second week of April, first fortnight of May, first week of June, second week of July, of fruit fly usually, in third week of May to first week of June and that of epilachna beetle in March, first fortnight of April, May, third week of July were obtained. Maximum temperature, morning and evening RH% and bright sun shine hour (BSS) had significant association on the mite population. Max temp., min temp., morning RH%, evening RH%, rainfall, soil temperature and BSS had significant association with leaf roller population. Max temp., min temp., morning RH% and soil temperature had significant association with fruit fly population. Max temp., morning RH%, evening RH%, rainfall and BSS had significant association with epilachna population.
Effect of host on the oviposition and development and survival of the larvae of Aulacophora foveicollis Lucas (Chrysomelidae, Coleoptera)
The development and mortality of the larvae of Aulacophora foveicollis reared on flowers and leaves of Citrullus vulgaris, Cucumis melo, Lagenaria vulgaris, Luffa aegyptica and Momordica charantia, were investigated in the laboratory at 21.5 °C and 52 – 60% relative humidity. Aulacophora foveicollis had four larval instars and its growth curve on L. vulgaris was S-shaped. The number of viable eggs and the survival of the larvae were relatively high on L. vulgaris, C. melo, and C. vulgaris. The larval developmental time was similar and the percentage of malformed adults was low on L. vulgaris and C. melo. The number of viable eggs was the lowest and the newly hatched larvae were unable to survive for more than 3 days on M. charantia.