Bibliography of the world literature of the Bethylidae (Hymenoptera: Bethyloidea)

The Bethylidae are a primitive family of aculeate Hymenoptera which presently consists of about 2,200 nominal species. They are worldwide in distribution and all species are primary, external parasites of Lepidoptera and Coleoptera larvae. Due t o their host associations, bethylids are potentially useful for the biological control of various agricultural pests in the aforementioned groups. Unfortunately, the true potential of bethylids in applied biological control cannot be ascertained now because they have been used infrequently. Some species show strong promise, but t h e i r use is handicapped by a relative lack of basic taxonomic and biological knowledge. The most recent world catalog for bethylids is Kieffer (1914). A world catalog is forthcoming (Gordh, in prep.). There has never been a compilation of the world literature

A New Parechthrodryinus Girault, 1916 Attacking Xylococculus Morrison, 1927 in California, with a Discussion of the Host Relationship (Hymenoptera: Encyrtidae; Homoptera: Margarodidae.)

Parechthrodryinus xylococculi New Species is described from material taken at several localities in California. The species parasitizes Xylococculus macrocarpae (Coleman). This account represents the first bona fide recored of an encyrtid attacking representatives of the Xylococcinae, a primitive subfamily of margarodid

BIBLIOGRAPHY OF THE WORLD LITERATURE OF THE BETHYLIDAE (HYMENOPTERA: BETHYLOIDEA)

The Bethylidae are a primitive family of aculeate Hymenoptera which presently consists of about 2,200 nominal species. They are worldwide in distribution and all species are primary, external parasites of Lepidoptera and Coleoptera larvae. Due t o their host associations, bethylids are potentially useful for the biological control of various agricultural pests in the aforementioned groups. Unfortunately, the true potential of bethylids in applied biological control cannot be ascertained now because they have been used infrequently. Some species show strong promise, but t h e i r use is handicapped by a relative lack of basic taxonomic and biological knowledge. The most recent world catalog for bethylids is Kieffer (1914). A world catalog is forthcoming (Gordh, in prep.). There has never been a compilation of the world literature

Book Review

The Indo‐Australian Agaoninae (pollinators of figs). J. T. Wiebe

Development of Trichogramma australicum Girault (Hymenoptera: Trichogrammatidae) in eggs of Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) and in artificial diet

Development of Trichogramma australicum in eggs of Helicoverpa armigera and in artificial diet was compared. Females required significantly more time to insert their ovipositors into artificial eggs than into host eggs. The number of eggs deposited by a female wasp in artificial diet was significantly higher than in H. armigera eggs. Duration of egg, larval and prepupal stages was longer in artificial diet than in host eggs, but the pupal stage was shorter in artificial diet. Immatures and adults of T. australicum reared in artificial diet were significantly larger than those reared in host eggs. Compared with controls, mortality of immature T. australicum was not significantly different in host eggs, but was significantly different in artificial diet. A higher number of abnormal wasps emerged from artificial diet, whereas no abnormal wasps emerged from host eggs. Differences in the amount of diet or ooplasm consumption, varying chemical constituents and physical properties of artificial diet and host eggs may have contributed to the observed differences in development of T. australicum

Influence of rearing hosts on host size acceptance by Trichogramma australicum

We investigated the acceptance of different sized host models by Trichogramma australicum in the laboratory. We used isoline cultures of T. australicum reared in hosts of different sizes. Helicoverpa armigera represent relatively large hosts, and those of Sitotroga cerealella are small, termed the Ha and Sc biotypes, respectively. Five sizes of glass beads were tested for acceptance: diameter 0.5, 0.75, 1.0, 1.5 and 2.0 mm. The acceptance of a host model was determined by persistent attempted drilling of a glass bead by a female. The relationship between host egg size and number of eggs laid by a female was also investigated. We used three sizes of artificial egg (diameter 0.75, 1.00, and 1.50 mm of hemispherical cupules) each containing artificial diet. Ha biotype wasps accepted host models in the range 0.75-1.50 mm dia. (vol. 0.166-1.325 mu l), whereas those of the Sc biotype accepted host models in the range 0.50-1.00 mm dia. (vol. 0.05-0.393 mu l). This evidence suggests a lineal (possibly genetic) influence to host size acceptance for T. australicum, dependent on the size of the host in which the wasp has been reared. Also T. australicum lay fewer eggs in smaller artificial eggs than in larger ones. The role of host size in host acceptance and number of eggs delivered, and its implications, is discussed

External morphology of antennal sensilla of Trichogramma australicum girault (Hymenoptera: Trichogrammatidae)

External morphology of antennal sensilla on female and male Trichogramma australicum (Hymenoptera: Trichogrammatidae) was examined using scanning electron microscopy. Antennae show strong sexual dimorphism in structure and types of sensilla. The female antenna displays 14 types of sensilla: basiconic capitate peg sensilla (types 1 and 2), campaniform sensilla, chaetica sensilla (types 1-3), coeloconic sensilla, falcate sensilla, placoid sensilla (types 1 and 2), styloconic sensilla and trichoid sensilla (types 1- 3). The male antenna displays 12 types of sensilla: basiconic capitate peg sensilla (type 2), campaniform sensilla, chaetica sensilla (types 1-5), coeloconic sensilla, placoid sensilla (type 1), and trichoid sensilla (types 3-5). Falcate and styloconic sensilla occur only on the female antenna. Both sensilla probably are associated with host examination, host discrimination and oviposition behaviour. Male antennal trichoid sensilla types 4 and 5 are probably associated with courtship behaviour, because these types occur only on the male. We propose the term 'falcate sensilla' for a unique female antennal sensilla; the number of falcate sensilla may be used for identification of Trichogramma spp. In addition, we report the presence of placoid sensilla type 2 and difference in structure of coeloconic sensilla in T. australicum. Variation in structure and position of antennal sensilla are discussed

Inundative Release of Trichogrammatoidea bactrae for Biological Control of Pink Bollworm

Replicated, small-plot studies were conducted in 1991 to evaluate control of pink bollworm (PBW), Pectinophora gossypiella, by inundative releases of a newly imported Australian egg parasitoid, Trichogrammatoidea bactrae. Weekly release of parasitoids at equivalent rates of 165,000/HA beginning in mid-June significantly reduced egg and larval populations of PBW in comparison with control plots until mid-August, but provided no control thereafter. Rates of parasitism on artificially-placed PBW egg cards exceeded 90% until mid-July and then declined, becoming somewhat variable over the latter half of the season. Parasitism rates dropped near zero on three dates coinciding with drift from aerial pesticide application at a neighboring cotton field. The seasonal decline in rates of parasitism was not significantly related to increasing plant leaf area, vigor of released parasitoids, or ambient temperature. Parasitism of indigenous PBW eggs on cotton bolls was extremely low and this, along with moth migration from surrounding cotton, may have contributed to the lack of mid- to late-season control in our small plots. Results are encouraging and suggest that larger-scale release studies are warranted