Breeding performance and longevity of Tomicus destruens on Mediterranean and continental pine species

Abstract

The pine shoot beetle Tomicus destruens (Wollaston) (Coleoptera: Curculionidae: Scolytinae) is one of the main pests of Mediterranean forests, where it is oligophagous on Mediterranean pines. However, possible global warming may make the insect move to higher latitudes and altitudes, allowing it to attack new pine species. In this respect, the aim of the present article was to assess both the acceptance and performance of T. destruens offered host and non-host pine species. A no-choice breeding experiment was set up under laboratory conditions, using logs of three Mediterranean ( Pinus pinea L. , Pinus pinaster Miller, and Pinus halepensis Aiton) and two continental ( Pinus nigra Arnold and Pinus sylvestris L.) pine species. Log debarking at the end of adult emergence assessed parent fecundity, egg, and larval mortality. The quality of callow adults emerging from each tested pine was evaluated on the basis of their longevity on a semiartificial diet. Tomicus destruens colonised all tested pine species, but did not reproduce in Scots pine, taking about 79 days to complete development with no differences among pines tested. The best breeding performance, evaluated as female fecundity and adult production, was observed in P. halepensis , and the lowest in P. pinaster . On average, adults emerging from P. pinea survived longer (83 days) than from other pines, and adult longevity was the lowest in males emerging from P. nigra . Austrian pine, which under natural conditions is usually not a host of T. destruens , allowed insect development and adult production similar to P. pinea and P. pinaster .

Response of <I>Tomicus yunnanensis</I> (Coleoptera: Scolytinae) to Infested and Uninfested <I>Pinus yunnanensis</I> Bolts

“…For example, in comparison to the 7.2-cm-long average T. brevipilosus maternal gallery in this study, others have reported mean values of 4-8 cm for T. destruens (Faccoli 2007), 7.1-11.0 cm for T. piniperda (Långström and Hellqvist 1985), and 9.6-10.6 cm for T. yunnanensis (Ye and Ding 1999). However, an inverse relationship has been reported between attack density and average length of maternal galleries in some Tomicus species (Salonen 1973, Långström 1984, Faccoli 2009), but this relationship has not yet been investigated in T. brevipilosus.…”

“…Bark beetles in the genus Tomicus (Coleoptera: Curculionidae, Scolytinae), with the exception of Tomicus puellus (Reitter) that infests primarily Picea trees, are well-known pests of pine (Pinus) trees in most Eurasian countries where pine is native (Bakke 1968, Ye 1991, Faccoli 2007, Kirkendall et al 2008, Lieutier et al 2015. These univoltine bark beetles are commonly called shoot beetles because the newly emerged adults feed inside living shoots of their host trees during the summer months as they become sexually mature, which often results in death of the infested shoots (Långström 1983, Ye 1994a, Kohlmayr et al 2002.…”

Preference–performance relationship and influence of plant relatedness on host use by Pityogenes chalcographus L.

“…Although adult preference and larval performance among different host trees are decisive parameters for assessing the ability of bark beetles to cause extensive damage, they have been poorly studied in Europe (Walker & Ross, 1975; Chararas et al, 1982; Lieutier et al, 1997; Faccoli, 2007). Pityogenes chalcographus exhibited a positive relationship between adult preference and larval performance, suggesting that preferred host species are more likely to undergo damage.…”

Predicting the distribution of the two bark beetlesTomicus destruensandTomicus piniperdain Europe and the Mediterranean region

“…Overall, T. destruens was found all around the Mediterranean Basin up to the Atlantic regions of France and develops on several Mediterranean Pinus species (Kerdelhué et al, 2002;Gallego et al, 2004;Horn et al, 2006;Vasconcelos et al, 2006;Faccoli, 2007Faccoli, , 2009. These data are so far discrete presence/absence data obtained in a number of localities.…”