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Diadromus collaris (Gravenhorst) is an important pupal parasitoid of the diamondback moth, Plutella xylostella (L.), a major insect pest of cruciferous vegetables worldwide. We studied the development of immature stage of D. collaris by dissecting parasitized hosts in the laboratory at 25 ± 1°C and 50–80% relative humidity. The results show that all immature stages complete their development within the same host in 11≈12 d. The egg is hymenopteriform and appears to be anhydropic. There are four larval instars. The first instar is transparent with a sclerotized rectangular chitinous head capsule and distinct mandibles. Head capsule of the second instar turns into more isosceles trapeziumshaped. The third instar looks similar to the second instar but proportionally much larger. The sclerization and dimension of the fourth instar increases significantly. The pupa is a typical exarate form and lacks a cocoon. All life history was fully documented with detailed photomicrographs. Our study will be useful for understanding the physiological interactions between D. collaris and P. xylostella.

As part of a study on the inquilinous cynipids belonging to the tribe Synergini (Hymenoptera: Cynipidae: Cynipinae) in the Chinese fauna, we report in the present paper three species of the genus Ceroptres Hartig from that country, including C. masudaiAbe, 1997 and two new species, C. distinctus sp. nov. and C. setosus sp. nov. In addition to detailed descriptions of the new species, we also provide an illustrated key to the species of the genus known from the Palaearctic region and a brief comparison between the Palaearctic and Nearctic Ceroptres species. Type specimens of the new species are deposited in the Parasitic Hymenoptera Collection, Zhejiang University, Hangzhou, China (ZJUH).

A new species of Minanga Cameron (Hymenoptera: Braconidae: Sigalphinae), Minanga brevicarinata Tan & Chen, sp. nov., from China is described and illustrated, Previously known mainly from the Afrotropical region (eight species), with one species recently described from the Nearctic region, the genus is recorded for the first time from the boundary of Palearctic and Oriental regions. A new subgenus, Anopliminanga subgen. nov., is proposed to include two species (Minanga achterbergi Sharkey and Minanga brevicarinata sp. nov.). A key to species of the genus Minanga is updated. The distribution of Minanga and the new subgenus are briefly discussed.

Diadegma semiclausum (Hellén) (Hymenoptera: Ichneumonidae) is one of the most important biological control agents of the diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae). Each immature stage of D. semiclausum was studied by dissecting parasitized hosts in the laboratory at 22 ± 1°C and 70–75% RH. Results show that the egg is hymenopteriform, lacking appendages. The larvae seem to be hypermetamorphic, with four instars. The pupal period has two distinct phases: 1) phase I, larval-like with remarkable groups of urate cells; and 2) phase II, exarate pupal appearance with a pigmentation sequence of eyes, ocelli, mandibles, thorax, abdomen, and antennae. All stages and sequences are illustrated with detailed photomicrographs.

Cotesia vestalis (Haliday) (Hymenoptera: Braconidae) is one of the most important biological control agents of the diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae). Immature development of C. vestalis was studied by dissecting parasitized hosts in the laboratory at 25 ± 1°C and 60–65% RH. Results showed that the egg matured in 2 d. Larvae seemed to have three instars; the first two larval instars molted inside the host, and the third instar emerged from the host to spin a cocoon. The first, second, and third instars lasted 2, 5, and 1 d, respectively. The first instar is transparent and caudate-mandibulate with a large head, distinct mandibles, and a caudal projection. The second instar is semitransparent with an anal vesicle. The third instar larva is yellowish green and the body is slightly curved. The pupa develops for 5 d and is bright yellow with transparent antennae, wings, and legs. All stages were fully documented with microscopic photos.

The species of the genera Aspidobracon van Achterberg, 1984 and Philomacroploea Cameron, 1905 in China are revised. Five species are recognized, and two new species, Aspidobracon flavithorax sp. nov. and Aspidobracon longyanensis sp. nov., are described and illustrated. The genus Philomacroploea Cameron and the species Aspidobracon hesperivorus van Achterberg and Philomacroploea basimacula Cameron are reported from China for the first time. A key to the species of the genus Aspidobracon van Achterberg is provided.

The immature development and morphological characteristics of Opius caricivorae Fischer (Hymenoptera: Braconidae), an endoparasitoid of dipteran leafminers, were studied under laboratory conditions at 25°C constant temperature on the host Liriomyza sativae Blanchard (Diptera: Agromyzidae). Most of the parasitoid females prefer to oviposit into the third instars of the host. They always laid a single egg per ovipositor insertion and superparasitized the same host in a few occasions when hosts were limited. Parasitoid eggs are of the hymenopteriform type. During the embryonic development (49 h) the eggs increased in size more than two-fold. Five instars occurred in this species. The first instar is of the caudate-mandibulate type bearing falcate appendages, whereas the second to fifth instars are hymenopteriform with simple mandibles, and they are similar to each other. The first instar remains inside its chorion after hatching until it molts into a second instar. A new structure, namely, transverse sclerite, in the cephalic structure of the fifth instar was found located between the maxillary palpi. Under laboratory conditions, the duration of the total immature stages lasted ≈327 h. The immature stages are described and illustrated using light microscopy, and they are compared with those of other apocritan parasitoids.