Shoot feeding, oviposition, and development of M onochamus galloprovincialis on P inus pinea relative to other pine species

Transmission of the causing agent of the pine wilt disease, B ursaphelenchus xylophilus ( S teiner & B uhrer) ( N ematoda: A phelenchoididae), among P inus pinaster A iton ( P inaceae) trees in P ortugal is known to occur during pine sawyer, M onochamus galloprovincialis ( O livier) ( C oleoptera: C erambycidae), adult feeding on twigs of healthy trees or during female oviposition on dying or dead trees. Still, the disease does not affect the other potentially susceptible local pine species, P inus pinea L . Several experiments evaluated the suitability of P . pinea as a host for M . galloprovincialis feeding, oviposition, and progeny development. Feeding responses were studied in two‐choice experiments pairing P .  pinea twigs with P . pinaster , P inus halepensis M iller, P inus sylvestris L ., P inus uncinata M iller, and P inus nigra A rnold. Another test assessed the effect of increased dosages of limonene applied to P . pinaster twigs on M .  galloprovincialis feeding. Oviposition preferences for P .  pinaster , with either intact or manipulated bark thickness, P . pinea , and P . sylvestris were also studied in two‐choice tests. Finally, suitability of P . pinea as a substrate for the development of M .  galloprovincialis offspring was tested. Results showed that P . pinea could be an acceptable host for the pine sawyer feeding under laboratory conditions. Only P . sylvestris and P . pinaster twigs were significantly more consumed than those from P . pinea . Control and limonene‐treated twigs were eaten similarly, but feeding decreased as dose increased, suggesting an inhibitory effect of limonene. Oviposition wounds, both egg‐containing and eggless, occurred more on P . pinea than on P . sylvestris or P . pinaster , though the percentages of wounds indicating successful egg laying were significantly higher on P . pinaster and P . sylvestris . M onochamus galloprovincialis progeny completed its development on P . pinea , but emergence was lower than on P . sylvestris , likely due to higher mortality during egg and early larval stages. Thus, results on vector host preferences do not explain the observed absence of nematode‐killed P . pinea trees in the field.