Interim profile, incomplete information
Taxonomic name: Toumeyella parvicornis (Cockerell, 1897)
Synonyms: Toumeyella numismaticum
Common names: cochenille-tortue du pin (French), Pine tortoise scale (English)
Organism type: insect
The Pine tortoise scale, Toumeyella parvicornis native to Eastern United States and Southern Canda, was reported for the first time on Middle Caicos, Turks and Caicos islands in 2005 infesting the endemic, Pinus caribaea var. bahamensis. The scale infestation causes a reduction in the vigour of the trees and curtails seed production. It also causes dieback and often leads to mortality of the pine trees. T. parvicornis has since caused major declines in numbers of its host species with reports of between 90-95% loss.
The covers of a mature female Toumeyella parvicornis are 1/4 inch long, hemispherical and dark brown to black with light brown to cream coloured mottling. Males are typically small and inconspicuous. T. parvicornis has one generation and overwinters as immatures on twigs. Crawlers usually hatch the last two weeks of June (Malinoski & Clements, 2003). T. parvicornis is preyed upon by the lady beetle (Hyperaspis binotata) (Bishop & Bristow, 2003). T. parvicornis can easily be distinguished from all other species of Toumeyella by its dorsal bilocular pore aggregations (Williams & Kondo, 2009).
Please follow this link T. parvircornis images.
Toumeyella parvicornis was first reported in the 1920's in the state of Wisconsin, United States (Natural Resources Canada, 2005). Its native range consists of the Eastern United States and Southern Canda, where it is found on Scots Pine (Pinus sylvestris), Jack Pine (P. banksiana), Austrian Pine (P. nigra) and Red Pine (P. resinosa) trees (Sanchez, 2008). It also been reported to be found on Virginia pine (P. virginiana), Swiss mountain pine, white loblolly pine, shortleaf pine (P. echinata), slash pine (P. elliottii) and Chinese pines (Malinoski & Clements, 2003). In Jack Pine forests of Central Michigan, United States, T. parvicornis is found almost exclusively in areas where Mouldy Ant (Formica exsectoides) is present (Bishop & Bristow, 2003). On the Turks and Caicos Islands (which are part of the United Kingdom Overseas Territories) T. parvicornis has been discovered on P. caribaea var. bahamensis which an endemic species to the Bahamas Archipelago (Hamilton, 2007).
Toumeyella parvicornis has been found to reduce the vigour of Pinus caribaea var. bahamensis, cause dieback, reduce seed production, and often lead to mortality of the tree. T. parvicornis also secretes a sugary honeydew which encourages growth of a sooty mould which now covers most of the understory in the P. caribaea var. bahamensis pineyards of The Turks and Caicos Islands and inhibits their growth.
The introduction of T. parvicornis has seen a 90% mortaility rate of P. caribaea var. bahamensis on the Turks and Caicos Islands (Hamilton, 2007; KEW, 2010). This amount of deceased dry material also increases the likelihood of forest fires within the pineyards, causing not only damage to Pine populations but surrounding populations also (Hamilton, 2007). These effects coupled with proposed sea-level rise are likely to have detrimental impacts on P. caribaea var. bahamensis (Ross et al, 2009). P. caribaea var. bahamensis is now currently threaten within its home range, which is not only detrimental ecologically but also culturally as it is considered the national tree of the Turks and Caicos Islands (Hamilton, 2007).
Current data from the Pine Recovery Project has shown that all areas on The Caicos Islands with live trees have scale insect, with an average infestation of 3 (5 being completely infested) and an average canopy decline of 3-4 (5 being completely dead). An average of 44-50% of the 140 plots sampled by the project had no seedlings present and an average of 50% of the trees within the plots were dead. (Sanchez, 2008).
Native range: Northern United States and Southern Canada. It is also reported to be found in the states of Nebraska and North and South Dakota.
Known introduced range: Found on North Caicos, Middle Caicos and Pine Cay on the Caicos Islands Group of the Turks and Caicos Islands. This distribution is related to the distribution of its host species, Pinus caribaea var. bahamensis (Hamilton, 2007).
Physical: To monitor for Toumeyella parvicornis, it is suggested to look for ants (seeking honeydew), honeydew, and sooty mold near branch terminals. In the spring the large female T. parvicornis are found at the base of needles on twigs (Bishop & Bristow, 2003).
Fire is also being explored as a tool for management, potentially extinguishing Pine Scale numbers, whilst encouraging new P. caribaea var. bahamensis growth (KEW Community Poster, 2010).
Chemical: Dormant oil sprays are effective in reducing overwintering populations. Summer rate of horticultural oil or insecticidal soap sprays may be used in late June to kill crawlers. If infestations are very heavy, a contact insecticide may be used in April to mid May (Malinoski & Clements, 2003). Work by Smirnoff and Valero (1975) showed that pines treated with urea N fertilizer increased total pine tortoise scale populations, whereas potassium treated plots decreased infestations from 42% to 21% (as seen in Scheffer & Williams, 1987) Scheffer & Williams (1987) also mention that the use of insecticides has the potential to increase scale populations due to the reduction of predators, reduction of intraspecific competition for food and increased plant growth leading to increased nutritional value of the host plant.
Biological: Within the P. caribaea var. bahamensis nursery, work is also being conducted to propagate individuals immune to the Pine Scale threat (KEW Connections, 2010).
Integrated management: On the Turks and Caicos Islands government services (TCI, Royal Botanic Gardens Kew, US Forest Service, Department of Environment and Coastal Resources) and non-government organizations (Turks and Caicos National Trust, TNC) are working together on creation of nurseries, the mapping and monitoring of the T. parvicornis infestation and developing an international pine scale working group, the TCI Pine Recovery Project has been established to deal with preventing and managing the spread and impacts of pine scale (KEW, 2010; Salamanca et al, 2010). Nurseries and seed collection of P. caribaea var. bahamensis are intended to establish sources in case there's desecration of natural populations due to T. parvicornis infestation (Hamilton, 2007). Cultural: Public awareness campaigns using posters and other tools have been initiated in an effort to raise public knowledge of the problem amonsgt the general public and in schools.
Toumeyella parvicornis has an altered lifecycle when comparing its habitance in either temperate or tropical biotas. In temperate regions there are distinct seasons with cold winters which leads to the adult females to hibernate inside the bark of its host, which allows for only one generation per year. However in tropical regions where it is warmer all year round, the adult female is active all year creating several generations per year (Sanchez, 2008). Typical lifecycle east of the Rockies: Adults (Jan-June) -> Eggs (June) -> Crawlers (June-July) -> Nymphs (July) -> Adults (Sanchez, 2008).
Compiled by: IUCN SSC Invasive Species Specialist Group (ISSG) with support from the Overseas Territories Environmental Programme (OTEP) project XOT603, a joint project with the Cayman Islands Government - Department of Environment
Last Modified: Wednesday, 2 June 2010