The hypothesis that small body size is correlated with preference for young leaves was tested in a community of leaf-chewing insect herbivores feeding on Ficus wassa in a humid tropical forest in Papua New Guinea. Feeding experiments on 48 species of herbivorous insects revealed a negative correlation between body size and a preference for feeding on young leaves. While small species preferred young leaves, large species showed no preferences, or preferred young leaves only slightly. This relationship was found for the entire leaf-chewing community, as well as for many of the constituent taxa on several taxonomic levels, from orders to genera. Taxonomic position of a species played little role in determining its preferences. It is proposed that higher toughness and lower nutrient content may act as complementary defences, which prevent small insects from feeding on mature foliage. While the low nutrient content of mature leaves may affect smaller herbivores due to their relatively higher metabolic rate and lower digestion efficiency, their toughness complicates feeding mechanically and may prevent the compensatory feeding necessary to offset the low nutritive value of mature leaves.
Manus Island is part of the Admiralty Islands, a herpetologically rich but poorly studied area. Seven species of Cornufer (von Tschudi, 1838) are known to occur on the island, five of which have been described. Based on material collected from Manus Island in 2014, we here describe the first female of Cornufer manus and the first male of Cornufer vogti. Additionally, we provide new information on intraspecific variation from a further eight adult males of C. manus, two subadults of C. vogti, as well as the first photographs of both species in life.
Two new nematode species, Paragendria papuanensis sp. n. (Quimperiidae) and Rhabdochona papuanensis sp. n. (Rhabdochonidae), are described from the intestine of freshwater fishes Glossamia gjellerupi (Weber et Beaufort) (Apogonidae) and Melanotaenia affinis (Weber) (Melanotaeniidae), respectively, from the Sogeram River (Ramu River basin), Madang Province, northern Papua New Guinea. The former species is characterized mainly by the absence of oesophageal teeth, the presence of conspicuously inflated papillae of the last two subventral pairs, a gubernaculum, spicules 69-75 µm long, eggs measuring 57-66 × 39-45 µm, and by a small body (male and female 3.2-3.7 and 5.8 mm long, respectively). Paragendria is considered a valid genus, to which P. aori (Khan et Yaseen, 1969) comb. n., P. guptai (Gupta et Masoodi, 2000) comb. n., P. hanumanthai (Gupta et Jaiswal, 1988) comb. n. and P. vermae (Gupta et Masoodi, 2000) comb. n. are newly transferred. Rhabdochona papuanensis differs from all congeners mainly in having hammer-shaped deirids and from individual species also in other characters. Both findings represent the first records of species of Paragendria and Rhabdochona from the Australian zoogeographical region and the first records of the representatives of these genera from fishes of the families Apogonidae and Melanotaeniidae, respectively.