Matsucoccus josephi

Matsucoccus josephi Bodenhiemer and Harpaz

Common name: Israeli pine bast scale.

Taxonomic placing: Insecta, Hemimetabola, Hemiptera, Sternorrhyncha, Coccomorpha, Coccoidea, Margarodidae.

Geographical distribution: Iraq, The Middle East, including Cyprus, and Greece, including Crete.

Host plants: Various pines, like Pinus halepensis Miller (the Aleppo pine), Pinus. brutia Tenore (the Turkish pine ) and Pinus roxburghii Sarg.

Morphology: Body of female brown, wingless and legless, about 2.6 mm long, covered by a white ovisac. The male body is brown, about 1.6 mm long, elongated, with two large eyes and a pair of forewings; the hindwings are reduced. The larva (crawler) is yellow, about 0.4 mm long, its abdomen bears two long setae. After the first molt it is apodous, 1.5 mm in length; the female larvae are grey, the male larvae are black.

Life history: Only the young larvae have functional legs. Their low threshold of development (2.4°C) enables them to develop during winter. After the first molt the insect gradually changes its color, the female larvae becomes greyish, the male larva black. The female continues to feed and grow under its ovisac, whereas the male has only non-feeding prepupal and pupal stages.

Economic importance: The feeding of the pest causes bud drying, shortening of needles and twisting of twigs and of young branches, which lead to dry, sparse tree crowns and the death of young pines within a few months. Affected branches dry from the lower ones up. The trunks of heavily infested trees turn reddish, with premature cork scale cracking and peeling, and the exudation of numerous resin drops. This bast scale is the major cause of the death of Aleppo pine and Turkish pine trees in the Middle East. Pest outbreaks result in great losses of planted forest and recreation sites. Due to the large number of affected trees, the average rotation period of Aleppo pine stands is shortened from 60 to 30 years and necessitate costly thinning operations. In addition, the thinned canopies expose the forest floor to sun radiation, which promotes inter-tree plant growth. This results in the accumulation of dry combustible ground cover, increasing the risk of fire.

Management

Monitoring: The inspection of stands for typical injury symptoms is based on marking the extent of drying up of the tree canopy, the twisting of twigs, flagging and dry needles. Pest presence is seen as remains of larvae, empty ovisacs at the base of the brachyblasts, and by removing loose bark flakes of partial scaly-bark stem sections. Pest population density can be estimated by counting the number of ovisacs on a 15- to 20-centimetre-wide jute belt wrapped around each tree, at 1.5 to 2 m above ground. Sticky traps baited with the female sex pheromone can be used as a system that warns about a sudden increase of pest numbers.

Horticultural methods: Pruning the lower branches, and extensive thinning of dense regeneration. Planted stands of Aleppo pine that are more than 10 years old should be thinned. At least two thinning cycles are required to ensure moderate opening of the canopy and to avoid thinning stress. Trees with big crowns are less susceptible to pest attack.

Plant Resistance: Some pines, like Pinus brutia, are resistant to the scale, as seen when larvae that try to feed on these trees die within a few days.

Chemical control: Insect growth regulators (IGRs) sprayed onto the canopy of young trees, and the systemic insecticide imidacloprid applied to the soil, effectively control the pest.

Biological control: The anthocorid Elatophilus hebraicus is a specific, common predator of M. josephi, to whose pheromone it is attracted.

References

Dunkelblum, E., Harel, M., Assael, F., Mori, K and Mendel, Z. 2000. Specificity of pheromonal and kairomonal response of the Israeli pine bast scale Matsucoccus josephi and its predator Elatophilus hebraicus. Journal of Chemical Ecology 26: 1649-1657.

Liphschitz, N. and Mendel, Z. 1989. Interactions between hosts and non-hosts of Pinus spp. and Matsucoccus josephi: anatomical responses of stems to infestation. New Phytologist 113: 135-142.

Mendel, Z. 1992. Occurrence of Matsucoccus josephi in Cyprus and Turkey and its relation to decline of Aleppo pine (Homoptera: Matsucoccidae). Entomologia Generalis 17: 299-306.

Mendel, Z. 1998. Biogeography of Matsucoccus josephi (Homoptera: Matsucoccidae) as related to host resistance in Pinus brutia and Pinus halepensis. Canadian Journal of Forest Research 28: 323-330.

Mendel, Z., Assael, F., Saphir, N., Zehavi, A. and Kafisheh, W. 1994. New distribution records of Matsucoccus josephi and Pineus pini (Homoptera) on pine trees in parts of the Near East. Phytoparasitica 22: 9-18.

Mendel, Z. and Rosenberg, U. 1988. Trials to control Matsucoccus josephi (Homoptera: Margarodidae) with fenoxycarb. Journal of Economic Entomology81: 1143-1147.

Mendel, Z., Saphir, N. and Robison, D. 1990. Mass rearing of the Israeli pine bast scale, Matsucoccus josephi (Homoptera: Margarodidae), with notes on its biology and mating behavior. Annals of the Entomological Society of America 83: 532-537.

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