基于COI基因序列的九种真蝽属昆虫的分子系统学研究(半翅目:蝽科)

通过对真蝽属Pentatoma 9种昆虫线粒体COI基因约798bp的序列进行分子进化分析,并以同蝽科宽铗同蝽Acanthosoma labiduroides为外群,采用最大简约法、最大似然法和邻接法构建了分子系统树,来探讨真蝽属的系统发育关系.研究结果支持褐真蝽群P. semiannulata-group的划分,绿角真蝽Pentatoma viridicornuta应划归到褐真蝽群P. Semiannulata-group;红足真蝽群中的角肩真蝽P. angulata与红足真蝽P. rufipes遗传距离较小,它们是否为1个物种值得关注;真蝽属各群之间的系统发育关系以及是否可分为3个属值得进一步研究.     

Dissemination of the biocontrol agent Vairimorpha necatrix by the spined soldier bug, Podisus maculiventris

The ability of the spined soldier bug, Podisus maculiventris (Say) (Heteroptera: Pentatomidae), to disseminate infective forms of two lepidopteran pathogens, Vairimorpha necatrix (Kramer) (Microspora: Microsporidia) and Lacanobia oleracea granulovirus (LoGV) was investigated. Individual female P. maculiventris that had fed on Lacanobia oleracea L. (Lepidoptera: Noctuidae) larvae, infected with V. necatrix, excreted approximately 6 × 10⁸V. necatrix spores during the subsequent 7 days. Excreted spores were fed to L. oleracea larvae, causing 100% mortality, indicating that the spores remained viable after passing through the gut of the predator. Podisus maculiventris that had fed on V. necatrix or LoGV‐infected larvae were allowed to defecate on the foliage of tomato plants, prior to the infestation of the plants with L. oleracea or Spodoptera littoralis (Boisduval) (Lepidoptera: Noctuidae) larvae. This proved to be an effective way of infecting the pest larvae with the pathogens, particularly when five predatory bugs were used per plant. After 20 days, the number of S. littoralis and L. oleracea surviving on the plants was reduced by 75% and 61%, respectively. Female P. maculiventris maintained on V. necatrix‐infected prey showed reduced egg production and longevity, whilst those fed on LoGV‐infected prey showed only reduced egg production. The potential for P. maculiventris to disseminate insect pathogens is discussed in the context of improved biological control of lepidopteran pests.     

珀蝽属中国种类记述（半翅目：蝽科）

本文为珀蝽属中国种类的一次修订,共记述５个种和１个亚种,其中包括２个新种（邻珀蝽、黄珀蝽）和１个新亚种（庐山珀蝽云南亚种）。并对与中国区系有关的Ｐ．ｓｐｌｅｎｄｅｎｓ Ｄｉｓｔａｎｔ和Ｐ．ｖｉｒｉｄｉｃｏｌｌｉｓ模式标本作了重新描述。     

Prevalence of a trypanosomatid in the southern green stink bug, Nezara viridula

The southern green stink bug, Nezara viridula (L.), and certain of its host plants were examined to determine the prevalence and biological characteristics of an intestinal trypanosomatid. Promastigotes with short (< or = 17.5 microm excluding flagellum) and long forms (> or = 25.0 microm) usually infected < 50% of the bugs before August and > 50% (maximum 95%) during August-October, but prevalence was not host-density dependent. The flagellate was detected in adults and in all nymphal instars, at all sampling sites where at least 10 bugs were captured, and in bugs from all host plants sampled (soybean, red clover, vetch). Of bugs with flagellates, 27% were heavily infected (> 20 flagellates per 160X microscope field). Weights of infected and uninfected adults did not differ. Live flagellates were detected in bug feces and in one stem of red clover. When bugs were fed soybean pods, tomatoes, or snap beans in the laboratory, only once were flagellates detected in plant tissue (snap beans). The flagellate was cultured in modified Medium 199. This flagellate is prevalent in N. viridula populations in Louisiana and apparently does not cause significant pathological effects in N. viridula or its host plants, including soybean.     

广东薄蝽属一新种（半翅目：蝽科：蝽亚科）

记述采自广东省连州市广东南岭国家级自然保护区大东山管理站的蝽亚科薄蝽属１新种,叉头薄蝽Ｂｒａｃｈｙｍｎａ ｂｉｆｉｃｅｐｓ,ｓｐ．ｎｏｖ．,模式保存于中山大学昆虫标本馆。     

Host preference and suitability of grasses for Oebalus pugnax

The rice stink bug, Oebalus pugnax (Fabricius) (Hemiptera: Pentatomidae: Carpocorini), though graminaceous, discriminates among its numerous host grass species. This could represent a feeding preference, it could be related to host suitability for growth and development. To clarify the role of host grass discrimination, two laboratory studies were conducted: (1) free‐choice tests to evaluate preferences of O. pugnax among 11 wild host grass species found in three rice‐producing counties of the central Mississippi Delta (MS, USA), and (2) no‐choice tests to evaluate the impact of rice (Oryza sativa L.), junglerice [Echinochloa colona (L.) Link], and dallisgrass (Paspalum dilatatum Poir.) (all Poaceae), on the development of O. pugnax from second instar to adult. In the free‐choice test, four experiments were conducted, each with four sets of host grass species and observed 1, 2, 4, 8, and 16 h after release in cages. Approximately 4 h was necessary for O. pugnax to settle on preferred host grasses. Oebalus pugnax showed a feeding preference for junglerice over all 10 other grass species. Bahiagrass, Paspalum notatum Flueggé, was the least preferred. The no‐choice tests showed significant effect of host grass species on O. pugnax mean development time of nymphal survival to adults. Survival of nymphs was lower and mean development time was longer on dallisgrass compared to rice and junglerice. Knowledge of O. pugnax rate of growth and development on host grasses could be useful in the future development of rice integrated pest management strategies.     

Response of the parasitoid Telenomus podisi to induced volatiles from soybean damaged by stink bug herbivory and oviposition

Abstract

Egg parasitoids have a short time frame in which their host eggs are suitable for parasitism, and in several systems these parasitoids respond to plant volatiles induced by oviposition on the plant (either in isolation or in combination with feeding damage) as a means of finding suitable hosts. It is known that the parasitoid of pentatomid eggs Telenomus podisi responds to damage done to soybeans by female Euschistus heros, its preferred host. In this study our aim was to determine the type of E. heros damage to soybean (herbivory, oviposition or a combination of both) necessary for attraction of T. podisi. In a Y-tube olfactometer the parasitoid has shown to respond to the undamaged plant over clean air and herbivory-damaged plants over undamaged plants. However, the parasitoids did not respond to the treatments where oviposition occurred, either in isolation or in combination with herbivory. Analysis of volatile blends revealed that herbivory plus oviposition damage to soybean induced a volatile blend different to those induced when herbivory or oviposition occurred separately. These results, along with other results from this system, suggest that T. podisi uses plant volatile cues associated with female E. heros damage in order to be present when E. heros lays its eggs, and thus ensure its resource is optimal for parasitism.     

Biological activities of juvenile hormone III skipped bisepoxide in last instar nymphs and adults of a stink bug, Plautia stali

Juvenile hormone III skipped bisepoxide (JHSB₃), methyl (2R,3S,10R)-2,3;10,11-bisepoxyfarnesoate was recently determined as a novel juvenile hormone (JH) in a stink bug, Plautia stali. To further confirm the biological function of JHSB₃ in this insect, its juvenilizing, reproduction-stimulating and diapause-terminating activities and the presence in the hemolymph were examined. Topical application of JHSB₃ to last instar nymphs inhibited their metamorphosis in a dose-dependent fashion. In allatectomized and diapausing adults, JHSB₃ application exerted stimulatory effects on the development of ovaries and ectadenia in females and males, respectively. JHSB₃ was detected from the hemolymph of reproductively active females by gas chromatography-mass spectrometry analysis while its titer in the hemolymph collected from diapausing adults was too low to be detected. These results demonstrated that JHSB₃ has biological function as a JH in P. stali. Topical application of JHSB₃, its stereoisomers and 10R-JH III also indicated that compounds with the 2R,3S-configuration were more potent than those with the 2S,3R-configuration and 2,3-double bond.     

A molecular tool to identify Anastatus parasitoids of the brown marmorated stink bug

Globally, Anastatus species (Hymenoptera: Eupelmidae) are associated with the invasive agricultural pest Halyomorpha halys (Stål) (Hemiptera: Pentatomidae). In Europe, the polyphagous Anastatus bifasciatus (Geoffroy) is the most prevalent native egg parasitoid on H. halys eggs and is currently being tested as a candidate for augmentative biological control. Anastatus bifasciatus frequently displays behavior without oviposition, and induces additional host mortality through oviposition damage and host feeding that is not measured with offspring emergence. This exacerbates accurate assessment of parasitism and host impact, which is crucial for efficacy evaluation as well as for pre‐ and post‐release risk assessment. To address this, a general Anastatus primer set amplifying a 318‐bp fragment within the barcoding region of the cytochrome oxidase I (COI) gene was developed. When challenged with DNA of three Anastatus species —A. bifasciatus, Anastatus japonicus Ashmead, and Anastatus sp.—, five scelionid parasitoid species that might be encountered in the same host environments and 11 pentatomid host species, only Anastatus DNA was successfully amplified. When applied to eggs of the target host, H. halys, and an exemplary non‐target host, Dendrolimus pini L. (Lepidoptera: Lasiocampidae), subjected to host feeding, no Anastatus amplicons were produced. Eggs of the two host species containing A. bifasciatus parasitoid stages, from 1‐h‐old eggs to pupae, and emerged eggs yielded Anastatus fragments. Confirmation of parasitoid presence with dissections and subsequent PCRs with the developed primer pair resulted in 95% success for 1‐h‐old parasitoid eggs. For both host species, field‐exposed sentinel emerged eggs stored dry for 6 months, 100% of the specimens produced Anastatus amplicons. This DNA‐based screening method can be used in combination with conventional methods to better interpret host‐parasitoid and parasitoid‐parasitoid interactions. It will help address ecological questions related to an environmentally friendly approach for the control of H. halys in invaded areas.     

Stink bug rostrum length vs. stylet penetration potential

Stink bugs (Hemiptera: Pentatomidae) and related species continue to plague cotton, Gossypium hirsutum L. (Malvaceae), worldwide. Stink bugs utilize their stylets (housed within the rostrum) to feed upon cotton bolls and transmit pathogens that cause seed and boll rot of cotton. Stylet penetration potential of stink bugs is influenced by species and recent observations indicated a phenomenon whereby stink bugs with shorter rostra yielded deeper stylet penetration estimates. The objective of this study was to elucidate the relationship between rostrum length and known stylet penetration estimates for two pairs of similar‐sized pentatomid species: Chinavia hilaris (Say) vs. Euschistus servus (Say), and Oebalus pugnax (Fabricius) vs. Piezodorus guildinii Westwood. For each species, individual rostral segments were measured to yield total lengths, and measurements were compared against known stylet penetration estimates. Chinavia hilaris and P. guildinii have longer rostra than E. servus and O. pugnax, respectively, yet E. servus and O. pugnax yielded deeper stylet penetration estimates. Deeper stylet penetration by species with shorter rostra can be attributed to differences in the lengths of rostral segments 1 and 2. Euschistus servus and O. pugnax each had significantly longer rostral segments 1 and 2 than C. hilaris and P. guildinii, respectively. Also, the cumulative lengths of rostral segments 1 and 2 comprised a higher overall proportion of the entire rostrum length in E. servus and O. pugnax vs. C. hilaris and P. guildinii, respectively. Rostral segments 1 and 2 are instrumental in the feeding mechanics of these phytophagous species; it is clear that their greater length and their role in stylet penetration model calculations – including the lengths of segments 3 and 4 – override the presumption that total rostrum length equates to stylet penetration potential. This novel finding contributes to the general knowledge of stink bug feeding mechanics.