Aspidiotus rigidus Reyne (Hemiptera: Diaspididae): a devastating pest of coconut in the Philippines

Abstract

1 The Philippines is the second largest producer of coconut products and, in some areas, coconut farming is the main source of livelihood. 2 A damaging armoured scale insect (Hemiptera: Diaspididae) infesting coconut palms was first found in the Philippines on Luzon Island (Batangas province) in 2009, and is now affecting most of the provinces of southern Luzon. 3 The scale pest is still spreading in the Visayan Islands and Mindanao. 4 Infestation stops photosynthesis; the leaves yellow and dry; fruits form less nutmeat and the coconut-water is sour; weak new leaflets bend over or break off; and the tree dies in 6 months or less. 5 The scale pest is identified in the present study as Aspidiotus rigidus Reyne; it presents a significant quarantine threat to coconut-producing countries worldwide. 6 Characters enabling the identification of A. rigidus, its host range and distribution are given. 7 Some literature on the natural enemies and control of A. rigidus is reviewed briefly.

Unraveling the genetic structure of the coconut scale insect pest (Aspidiotus rigidusReyne) outbreak populations in the Philippines

“…Prior to the renewed interest on A. rigidus due to the outbreak in the Philippines, historical and observational data on the spread of the invasive coconut pest has been scarce. Other than the most recent observation published by Watson et al . (2015), the last known study on the biology of this invasive species was conducted by Reyne (1947, 1948) with full documentation of the outbreak in the island of Sangi (North Celebes) in Indonesia from mid-1925 to 1928.…”

“…The decrease in A. rigidus population may have been associated with natural enemies that regulated the pest population overtime. However, the outbreaks from the localities infested with A. rigidus in the Philippines took longer times to recover (Watson et al ., 2015), e.g., six years for the northern province of Batangas, or still on-going for the southern areas, i.e., Basilan, Zamboanga Peninsula, and the Caraga Region.…”

Effect of Aspidiotus rigidus infestation on the volatile chemical profile of the host plant Garcinia mangostana

“…The infestation caused a great decline in the coconut palms of the area, aff ecting around 50-70% of the coconut farms in 2013 (Watson et al, 2015). Another economically important host of the scale is mangosteen, Garcinia mangostana L. (Clusiaceae).…”

“…Aspidiotus rigidus settles on the lower surface of the leaf, blocking the stomata and preventing the plant to photosynthesize which may even result to death (Watson et al, 2015). Little is known about the interBrought to you by | MIT Libraries Authenticated Download Date | 5/12/18 6:12 PM action of A. rigidus with the host plant and information about scale insect -induced volatile compounds is scarce.…”

“…In this study, the eff ect of A. rigidus infestation on the volatile chemical profi le of the host plant G. mangostana was investigated. Aspidiotus rigidus is the only scale species infesting mangosteen (Watson et al, 2015) and hence its selection as host plant in the experiments eliminates the possibility for infestation of the plant tissue by other similar scale insect species, e.g. Aspidiotus desctructor Signoret (Hemiptera: Diaspididae), infesting coconut.…”