Riom, J., Gerbinot, B., Boulbria, A., & Fabre, J.P. 1971 Éléments de la bioécologie de Matsucoccus feytaudi Duc. (Coccoidea, Margarodidae) et de ses predateurs dans le Sud-Ouest de la France.. Annales de Zoologie - Ecologie Animale Spec. No. 1971: 153-176.
Notes: Title in English: [Elements of the bioecology of atsucoccus feytaudi uc. (Coccoidea, Margarodidae) and its predators in the south-east and south-west of France.] Surveys in 1967-69 showed that Matsucoccus feytaudi Ducasse, which has been the primary cause of the death of large numbers of maritime pines [Pinus pinaster] in the extreme south-east of France in recent years [cf. RAE/A 61, 3435, etc.], is endemic in about three quarters of the wooded areas covered by P. pinaster in Europe and North Africa, but usually causes little damage. It has been found in all the stands of P. pinaster in Spain [58, 3728] and Portugal and in forests in the Middle Atlas region of Morocco. It was not found during surveys in Tunisia and Corsica. In continental France, it is present along the entire Atlantic coast, as far north as, but excluding, Brittany, and also in some stands in the Departments of Gard and Sarthe. The rapid spread of infestation along the south-eastern coast of France [cf. 61, 3435] suggests that M. feytaudi was introduced into that area relatively recently. A comparison was therefore made between the ecology of the Coccid in the Maures region (in the south-east) [cf. 52, p. 499] and in the Landes region (in the south-west), where it causes little damage [cf. 34, p. 329]. A detailed account is given of the studies. No ecological differences were found between the strains of Matsucoccus or the strains of P. pinaster present in the two regions, and the action of predators did not seem sufficient to account for the differences between the population dynamics of the Coccid in the two areas. In the Landes, there is considerable mortality of newly hatched individuals (75% or more) before they move away from the wax that covers the oviposition area and attach themselves. Evidence was obtained that this mortality is caused by the presence of considerable amounts of water on the trunks (dew, condensation and precipiation) during the hatching period. Further studies are needed to determine whether this is a major factor limiting populations. Elatophilus nigricornis (Zett.) was found to be the most abundant predator of M. feytaudi in both regions. In the Landes, populations of this Anthocorid are small but constant. In the Maures region, they fluctuate widely both with locality and with the extent to which the trees have been weakened. The predator was most abundant in spring and autumn. The original forest of Maures has virtually disappeared, but a new forest is growing up from natural regeneration. The young trees can support only small populations of Matsucoccus, and that only after they are 6-7 years old. Owing to the limited number of cracks in the bark to provide shelter, trees 9-10 years old support no more than 1-2 insects/cm2, which is considerably less than the 5-10cm2 observed on heavily infested trees at the height of the outbreak. It is hoped, therefore, that in the new forest the pattern of infestation will be that of an endemic pest not causing excessive damage.