Resistance of Drosophila suzukii to the larval parasitoids Leptopilina heterotoma and Asobara japonica is related to haemocyte load

Unlike other Drosophila species, the invasive Drosophila suzukii Matsumura (Diptera: Drosophilidae) shows a remarkable pest status. Among the physiological traits that may explain the high level of resistance to parasitoids of Drosophila larvae, the haemocyte load is shown repeatedly to play an important role. To determine whether haemocyte load can explain immunity resistance of D. suzukii to parasitoids, the haemocytes of parasitized and healthy larvae are quantified in two Japanese and three French populations of D. suzukii. Parasitization tests are conducted with two larval parasitoids: the paleartic Leptopilina heterotoma Thomson (Hymenoptera: Figitidae) and the Asian Asobara japonica Belokobylskij (Hymenoptera: Braconidae). Based on morphological and functional criteria, D. suzukii has classes of haemocytes similar to those described in Drosophila melanogaster. However, healthy larvae of the five populations tested possess particularly large numbers of haemocytes compared with D. melanogaster. Haemocyte load is also higher in larvae from the French populations than in the Japanese strains. The ability of D. suzukii larvae to encapsulate eggs of L. heterotoma is associated with a particularly high load of circulating haemocytes. However, it is notable that A. japonica induces a strong depression of the haemocyte population in this resistant host associated with an inability to encapsulate parasitoid eggs. The results show that the cellular immune system plays a major role in the failure of larval parasitoids to develop in most instances in larvae of D. suzukii, possibly contributing to the success of this species as an invader.     

Characterization of 14 polymorphic microsatellite loci for the lesser horseshoe bat,Rhinolophus hipposideros (Rhinolophidae,Chiroptera)

Fourteen polymorphic microsatellites isolated in the lesser horseshoe bat, Rhinolophus hipposideros, are described. A subset of eight loci successfully coamplified in a multiplex polymerase chain reaction (PCR), and allowed to confirm that expected heterozygosity was relatively high for the eight loci (0.56–0.83). This set of eight microsatellites indeed permits to build genetic tags that distinguish all individuals in colonies consisting of up to more than 1000 individuals.     

Geographic variation in nest-defence behaviour of the Red-tailed Hawk Buteo jamaicensis

A close fit was found between the number of years since European settlement and the call and dive-rates of Red-tailed Hawks. Call-rates were highest in the most recently settled sites.