Effects of mixed cropping and barrier crops on the population density and parasitism of the diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), were evaluated in field plots of cabbage grown in Bali, Indonesia. The densities of P. xylostella at larval and pupal stages, as well as the overall density at larval plus pupal stages, were significantly lower in cabbage/coriander mixed cropping subplots than in cabbage monoculture subplots. Parasitism of P. xylostella by the larval parasitoid Diadegma semiclausum (Hellen) (Hymenoptera: Ichneumonidae) was not significantly different between the mixed and monocultural cropping systems. These results do not support the so-called enemies hypothesis, but suggest that disruption of the host searching behavior of female moths by neighboring non-host plants is the mechanism behind the associational resistance observed in the coriander mixed cropping system. The inclusion of a Napier grass barrier between mixed crop and monoculture subplots did not affect the influence of mixed cropping on larval and pupal densities. Therefore, Napier grass, which is used locally as a fence for preventing livestock invasion of fields, would not obstruct the pest-reducing effect of coriander/cabbage mixed cropping.

A new species, Sycanus aurantiacus, of the assassin bug subfamily Harpactorinae is described on the basis of specimens collected from Bali, Indonesia. This species is distinguished from the other species of Sycanus by its antennal segment I having two orange annulations; the posterior pronotal lobe being weakly tumid in the middle near the posterior margin; the scutellar spine being erect, short, and rounded at the apex; each femur having two incomplete orange annulations; the hemelytral corium being blackish with the veins yellow to yellowish brown; and the abdominal laterotergites being weakly extended dorsad. This species is notable because it feeds on some serious lepidopteran pests of cabbage.

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