A survey of black scale,Saissetia oleae [Hom.: Coccidae] parasitoids [Hym.: Chalcidoidea] in southern California

A survey of black scaleSaissetia oleae (Olivier) parasitoids present in southern California was conducted between September 1987 and September 1989. From 308 collections of black scale-infested citrus, olive, and oleander twigs from 19 sites in southern California, 1,610 specimens were collected. Nine primary and six secondary parasitoid species were identified. Four primary species were abundant in southern California:Metaphycus bartletti Annecke & Mynhardt,M. helvolus (Compere),Scutellista caerulea (Fonscolombe) (=S. cyanea Motschulsky), andDiversinervus elegans Silvestri. The most common secondary parasitoids wereMarietta mexicana (Howard),Cheiloneurus noxius Compere, andTetrastichus minutus (Howard). In the coastal region of southern California,M. bartletti was the most abundant parasitoid, followed in order byD. elegans, S. Caerulea, andM. helvolus. In the intermediate and interior regions,M. helvolus was most abundant.D. elegans was second most abundant in the intermediate region, but was rare in the interior region.M. bartletti was second in abundance in the interior region and third in the intermediate region.      

The natural dynamics of the eulophid parasitoid Melittobia australica

Abstract. 1. The ecology of the eulophid parasitoid Melittobia australica Girault was studied in the laboratory and field in Jamaica. Further field observations were conducted in Trinidad. 2. The sphecid, mud-daubing wasp Sceliphion assimile (Dahlbom) was the main host in Jamaica, but nineteen out of twenty-two investigated species of sphecid, eumenid and pompilid wasps, and apid and megachilid bees were attacked in Jamaica and Trinidad. The nineteen susceptible hosts suffered an average of 23.6% mortality due to Melittobia. Resin is a totally effective deterrent, spaces within the nest less so. 3. Laboratory studies on Sceliphron hosts estimated that developmental survival was greatest at 26°C and 83% r.h., duration of development shortest at 32°C and 72% r.h., longevity of adult fliers greatest (>13 days) at <25°C and 80% r.h., and fecundity greatest (454 eggs/female) at 28°C and 90% r.h. A separate experiment gave a maximum fecundity of 461. 4. At 27°C and 71% r.h. the duration of development (egg-adult) in the laboratory was 13.1 days for males, 13.9 days for crawlers and 17.4 days for fliers. 5. Field studies showed that developmental mortality was low, while laboratory studies revealed it to be density dependent, ranging from 13% at the lowest densities to 39% at the highest. Estimated mortality at field densities was ～25% on Sceliphron. 6. Field estimates of fecundity gave a mean of 429.5 eggs/female on Sceliphron but are positively biased by superparasitism. Fecundity is probably reduced to about 346 eggs in the field and further to about 289 as a result of superparasitism. Other hosts generally reduced the parasitoid's fecundity, and this always occurs when Melittobia becomes a hyperparasite. 7. Superparasitism in the field on Sceliphron was 2.3 females/host for crawler morph females, 1.2 females/host for jumper females and 1.2 females/host for flier females. 8. A cyclic budget using log₁₀K; values (Freeman, 1976) revealed that the effect of superparasitism (K₀= 0.124), the physical environment (K₀= 0.078), developmental mortality (K₁= 0.125), and the loss to males (K₂= 0.020) to be small, but losses of dispersing females (k₃= 2.326) to be massive. 9. The individual chance for the three female morphs of finding a new host are very different. For crawlers (which search the natal host nest) it is 0.034 (1 in 29), for jumpers (which search the host nesting site) it is 0.0098 (1 in 102) and for fliers (which seek distant host nesting sites) 0.0021 (1 in 485). Risk is thus directly proportional to distance travelled (cm, m and km). Morph production is related to this risk.     

Parasitoid complex of citrus leafminer, Phyllocnistis citrellaon lemon in the Central Jordan Valley

From March 1997 to June 1999, samples of lemonleaves infested with citrus leafminer (CLM),Phyllocnistis citrella Stainton(Lepidoptera: Gracillariidae), were collectedfrom the Al-Masalha Citrus Orchard in theCentral Jordan Valley in order to rear CLMparasitoids and to study their populationtrends. Nine species of eulophid parasitoidswere reared from CLM larvae; these were Cirrospilus ingenuus Gahan, C. pictusNees, Pnigalio agraules, Pnigalio sp. B,Pnigalio sp. C, Citrostichusphyllocnistoides Narayanan, Ratzeburgiolaincompleata Boucek, Semielacherpetiolatus Girault, and Zagrammosoma sp.Cirrospilus ingenuus was the most commonparasitoid of CLM from March 1997 to June 1999and could be a good potential biologicalcontrol agent after rearing and releasing it incitrus orchards in the Jordan Valley. Onehyperparasitoid species was reared fromimmatures of parasitoids of CLM larvae, andidentified as Tyndrichus sp. An increasein the activity of parasitoids was observed inautumn 1999 when the temperature was between 15–20 °C and the relative humidity was between 55–65%.     

Parasitism of different larval stages of Cameraria ohridella

About 20 species of parasitic Hymenoptera havebeen reported from the horse chestnutleafminer, Cameraria ohridella Deschka & Dimic (Lepidoptera: Gracillariidae). Generally,parasitism is low compared to other closelyrelated leafminers and the parasitism levelvaries considerably. Among other reasons,parasitism rates depend on the developmentalstage of the moth and therefore vary with thesampling date. In the current study,investigations on the parasitism of the moth'sfirst generation were carried out in order todetermine which preimaginal stages areparasitized by the most abundant parasiticwasps. Minotetrastichus frontalis (Nees),Pnigalio agraules (Walker) and Chrysocharis nephereus (Walker) (allHymenoptera: Eulophidae) developed as larval orpupal parasitoids and preferred later larvalinstars of the moth. Egg parasitism did notoccur. Overall, the last two of the six larvalinstars (the spinning instars) of the leafminersuffered the heaviest attack. In concordancewith the fairly low parasitism rates, theeffect of the four most abundant chalcidoids onthe leafminer population was negligible, havingno significant influence on the mortality ofC. ohridella. Although the speciescomposition of the parasitoid complex of C. ohridella shows similarities with thesituation found in other closely relatedleafmining moths, it is unlikely that thenaturally occurring chalcidoids will be able toprevent the horse chestnut leafminer fromdeveloping epidemic population densities in thenear future.     

中国宽脉啮小蜂属(膜翅目:姬小蜂科)的种类及鉴定

本研究对我国姬小蜂科Eulophidae宽脉啮小蜂属Dzhanokmenia Kostjukov,1977进行分类和比较形态学研究,记录该属7种,其中中国新记录2种,提供了7种的鉴别特征及生物学和地理分布信息。比较形态学研究结果表明:宽脉啮小蜂属在头部、触角、腹部背板、腿节以及雌性外生殖器着生位置等结构上存在明显的形态特化和种间差异,这些结构特征能有效应用于属内物种鉴定,为该类群物种的准确鉴定提供依据。基于上述研究结果,本研究编制了该属的分种检索表。     

鳞卵金小蜂属在我国发现并记述一新种(膜翅目:小蜂总科,金小蜂科)

鳞卵金小蜂属Agiommatus寄生蚕蛾、天蛾、弄蝶等鳞翅目蝶蛾类害虫的卵,为重要的寄生性天敌。主要分布非洲、亚洲南部和澳大利亚。我国以前没有本属分布的记载。1986年,福建省林科所的杨嘉寰先生从闪蛱蝶卵中养出1种寄生蜂。经作者鉴定,属于本属,为1新种,现记述如下。这是鳞卵金小蜂属在我国的首次发现。新种的模式标本保存于西北林学院天敌昆虫研究室。     

Oviposition mechanisms in the whitefly parasitoids Encarsia transvena and Eretmocerus mundus

The ovipositors of two whitefly parasitoids, Encarsia transvena and Eretmocerus mundus were examined using scanning and transmission electron microscopy. That of Encarsia is straight, has an apparently hard and sharply pointed upper valve, and appears well-suited to penetrating a hard substrate. That of Eretmocerus is curved, thick-walled, but has a blunt and apparently flexible tip. These features correlate well with what is known of the mode of oviposition and host feeding in the two taxa, with Encarsia and Eretmocerus ovipositing internally and externally respectively.     

Four new species of Anagrus Haliday (Hymenoptera: Mymaridae) from India,with a key to Indian species

Four new species of Anagrus (Anagrus) Haliday (Hymenoptera: Mymaridae) are described from India: A. (Anagrus) karnatakus Triapitsyn sp. n., A. (Anagrus) kolhapurensis Manickavasagam & Sankararaman sp. n., A. (Anagrus) latus Manickavasagam & Sankararaman sp. n. and A. (Anagrus) sujathae Manickavasagam & Sankararaman sp. n. A key to females of the 15 described and one undescribed species of Anagrus known from India is provided.www.zoobank.org/urn:lsid:zoobank.org:pub:99ED388D-BE3E-4FBA-A383-3482D96DA42F.