Problems in rearing of hemispherical scales and its parasitoid M. Metaphycus helvolus

Abdul Ghani Ibrahim, . (1986) Problems in rearing of hemispherical scales and its parasitoid M. Metaphycus helvolus. [Proceedings Paper]

The hemispherical scale Saissetia coffeae was a tropical pest found in world-wide heated glasshouses. The pest was normally controlled by pesticides but some of these pesticides were phytotoxic to ornamental plants. The scales was mass bred on many hostplants such as potato and ornamentals for the biological control programme. Eventhough the number of settled scales on soillness potato sprouts were less than those on potted Aphelendra plants the scales were of bigger size yielding on an average 1544 eggs per mother scale. Many problems were experienced while rearing Metaphycus helvolus endo-parasitoid of the scale. Not all eggs of the parisitoid were able to develop successfully because the host-scale was capable of destroying them by encapsulation. Inspite of this the parasitoid was found to produce an average of 8.5 progeny per female when allowed to parasitise for 48 hours. High temperatures favoured the survival of host-scales because of greater percentage of encapsulation of parasitoids' eggs. When the density of parasitoids was high there was a lesser chance of successful oviposition for the female parasitoid due to greater host feeding and lesser number of host scales.

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Abstract

The hemispherical scale Saissetia coffeae was a tropical pest found in world-wide heated glasshouses. The pest was normally controlled by pesticides but some of these pesticides were phytotoxic to ornamental plants. The scales was mass bred on many hostplants such as potato and ornamentals for the biological control programme. Eventhough the number of settled scales on soillness potato sprouts were less than those on potted Aphelendra plants the scales were of bigger size yielding on an average 1544 eggs per mother scale. Many problems were experienced while rearing Metaphycus helvolus endo-parasitoid of the scale. Not all eggs of the parisitoid were able to develop successfully because the host-scale was capable of destroying them by encapsulation. Inspite of this the parasitoid was found to produce an average of 8.5 progeny per female when allowed to parasitise for 48 hours. High temperatures favoured the survival of host-scales because of greater percentage of encapsulation of parasitoids' eggs. When the density of parasitoids was high there was a lesser chance of successful oviposition for the female parasitoid due to greater host feeding and lesser number of host scales.

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Item Type:	Proceedings Paper
Additional Information:	13 ref. Summary En
AGROVOC Term:	SAISSETIA
AGROVOC Term:	PARASITOS
AGROVOC Term:	ORGANISMOS PARA CONTROL BIOLOGICO
Geographical Term:	MALAYSIA
Depositing User:	Ms. Norfaezah Khomsan
Last Modified:	24 Apr 2025 05:25
URI:	http://webagris.upm.edu.my/id/eprint/14457

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