Hideshi Naka

Green lacewing phylogeny, based on three nuclear genes (Chrysopidae, Neuroptera)

Abstract Systematic relationships among higher taxa within Chrysopidae, a large and agriculturally significant neuropteran family, are poorly understood. A molecular phylogenetic survey of Chrysopidae was performed with three nuclear genes, namely wingless (546 bp), phosphoenolpyruvate carboxykinase (483 bp), and sodium/potassium ATPase alpha subunit (410 bp). We examined 83 species in 24 genera, mainly from Japan, Eurasia and Africa. Parsimony and Bayesian analyses of combined datasets of a total of 1439 bp demonstrated that (1) monophyly of the subfamily Chrysopinae was supported but the relationship between Nothochrysinae and Apochrysinae was unclear, although the two subfamilies together may constitute the sister taxon of Chrysopinae; (2) of the three tribes examined within Chrysopinae (Ankylopterygini, Belonopterygini and Chrysopini), monophyly of Ankylopterygini and Belonopterygini was supported, but the relationships among the three remain unclear; (3) seven sub‐clades in Chrysopini were indicated, namely (i) Brinckochrysa, (ii) Chrysemosa + Suarius, (iii) Chrysotropia + Nineta, (iv) Mallada + Chrysoperla + Peyerimhoffina, (v) Cunctochrysa + Meleoma + Nipponochrysa + Apertochrysa albolineatoides, (vi) Chrysopa + Plesiochrysa, and (vii) Dichochrysa + Apertochrysa eurydera; and (4) most genera were monophyletic, except for Apertochrysa and Cunctochrysa, each of which was shown to have two distinct origins. Our molecular analysis allowed the assignment of several species of uncertain affinities to known genera. There was some disagreement between the molecular and previously published morphological phylogenies, but in general our results confirmed existing morphological hypotheses of evolution within the family.

Mitochondrial Phylogeny of Cryptic Species of the Lacewing Chrysoperla nipponensis (Neuroptera: Chrysopidae) in Japan

Abstract We surveyed a 1,033-bp fragment of the cytochrome oxidase subunit I (COI) sequence to look for a useful diagnostic marker for discrimination between the Japanese cryptic species Chrysoperla nipponensis (Okamoto) (Neuroptera: Chrysopidae) (types A and B) and the commercially introduced Chrysoperla carnea s. str. from Germany. Phylogenetic analysis showed four distinct haplotype groups: one group corresponded to C. nipponensis type B and one group to C. carnea s. str., and the remaining two distinct groups, A1 and A2, corresponded to the same song phenotype, C. nipponensis type A. A2 was linked with the group of C. carnea s. str. and A1 was linked with the group of C. nipponensis type B. Cross-testing between A1 and A2 revealed their reproductive compatibility. Mitochondrial polyphyly within C. nipponensis type A may, therefore, originate from introgression or incomplete lineage sorting. Within the mitochondrial COI region presented here, there were 17 variable nucleotide sites useful for discriminating the four haplotype groups from each other.

Larval Cannibalism and Intraguild Predation Between the Introduced Green Lacewing, Chrysoperla carnea, and the Indigenous Trash-Carrying Green Lacewing, Mallada desjardinsi (Neuroptera: Chrysopidae), as a Case Study of Potential Nontarget Effect Assessment

Abstract To study the potential competitive risk of the introduced Chrysoperla carnea (Stephens) on the indigenous trash-carrying chrysopid Mallada desjardinsi (Navás), we studied the occurrence of cannibalism and intraguild predation (IGP) at different prey densities. In C. carnea, 100% cannibalism was observed in the absence of aphids. In M. desjardinsi, cannibalism was also observed, but absence of cannibalism occurred at 35% in pairs of second- + third-instar larvae and at 70% in pairs of third- + third-instar larvae. In pairs of M. desjardinsi larvae whose trash package had been artificially removed, all third-instar larvae ate second-instar larvae. The trash package may play a role in the reduced mortality of younger larvae by cannibalism. IGP occurred in all pairs. In the absence of aphids, the interaction was symmetric between second-instar larvae, but asymmetric for second- versus third- and third- versus third-instar larvae, and the interaction was similar when M. desjardinsi larvae with or without trash package were paired with C. carnea larvae. When third-instar larvae of both species were paired, C. carnea larvae ate significantly greater numbers of M. desjardinsi larvae than vice versa. The trash package of M. desjardinsi larvae may thus not play a defensive role against IGP by C. carnea. Increasing the availability of aphids tended to decrease both cannibalism and IGP levels. Nontarget effects such as competitive displacement resulting in loss of potentially beneficial attributes of the indigenous M. desjardinsi by the exotic C. carnea are likely to be negligible under conditions of abundant aphids.

Synthesis and Characterization of 3,13- and 2,13-Octadecadienyl Compounds for Identification of the Sex Pheromone Secreted by a Clearwing Moth, Nokona pernix

Several geometrical isomers of 3,13- and 2,13-octadecadien-1-ols and their acetates were synthesized starting from 1,8-octanediol or 1,9-nonanediol utilizing acetylene coupling reactions. In addition to commercially available compounds, all geometrical isomers of each dienyl compound were analyzed by NMR and GC-MS to accumulate chemical data for studies of sex pheromones secreted from clearwing moths classified into the family Sesiidae of Lepidoptera. Although acetoxy derivatives of the 3,13- and 2,13-dienes showed almost the same mass spectra, the alcohols were distinguished by comparing the relative intensities of [M−18]+ at m⁄z 248, indicating direct differentiation of the two positional isomers without derivatization. Furthermore, each geometrical isomer eluted from a high-polar GC column with a different retention time. Base on these data, a pheromone gland extract of a sesiid moth, Nokona pernix, was analyzed by GC-EAD and GC-MS, and two EAG-active components were identified, viz., the (3E,13Z)- and (3Z,13Z)-isomers of 3,13-octadecadien-1-ol in a ratio of 9:1. In the field, the synthetic compounds mixed in 9:1 ratio attracted N. pernix males well, while a single component scarcely attracted the males. The number of attracted males peaked in the middle of June, and a small second peak was observed in August.

Synthesis and characterization of hexadecadienyl compounds with a conjugated diene system, sex pheromone of the persimmon fruit moth and related compounds.

Hexadecadien-1-ol and the derivatives (acetate and aldehyde) with a conjugated diene system have recently been identified from a pheromone gland extract of the persimmon fruit moth (Stathmopoda masinissa), a pest insect of persimmon fruits distributed in East Asia. The alcohol and acetate showed their base peaks at m/z 79 in a GC-MS analysis by electron impact ionization, but the aldehyde produced a unique base peak at m/z 84, suggesting a 4,6-diene structure. To confirm this inference, four geometrical isomers of each 4,6-hexadecadienyl compound were synthesized by two different routes in which one of two double bonds was furnished in a highly stereoselective manner. Separation of the two isomers synthesized together by each route was facilely accomplished by preparative HPLC. Their mass spectra coincided well with those of natural components, indicating that they were available for use as authentic standards for determining the configuration of the natural pheromone. Furthermore, other hexadecadienyl compounds, including the conjugated diene system between the 3- and 10-positions, were synthesized to accumulate the spectral data of pheromone candidates. 5,7-Hexadecadienal interestingly showed the base peak at m/z 80; meanwhile, the base peaks of its alcohol and acetate were detected at m/z 79 like the corresponding 4,6-dienes. The base peaks of all 6,8-, 7,9-, and 8,10-dienes universally appeared at m/z 67 like 9,11-, 10,12-, and 13,15-dienes, the spectra of which have already been published. Although 3,5-hexadecadienal was not prepared, base peaks at m/z 67 and 79 were recorded for the alcohol and acetate, respectively.

Sex pheromone of the persimmon fruit moth, Stathmopoda masinissa: Identification and laboratory bioassay of (4E, 6Z)-4,6-hexadecadien-1-ol derivatives

Three electroantennogram (EAG)-active components were detected by gas chromatography coupled to an electroantennographic detector (GC–EAD) analysis of a hexane extract of the pheromone glands of the persimmon fruit moth, Stathmopoda masinissa. These compounds were identified as (4E,6Z)-4,6-hexadecadienal (E4,Z6-16:Ald) and the corresponding acetate (E4,Z6-16: OAc) and alcohol (E4,Z6-16:OH) by mass spectral, GC retention time (RT), and microchemical test data. The characteristic base peak of the aldehyde at m/z 84 provided a crucial piece of information suggesting the possibility of a 4,6-diene structure. The (4E,6Z)-isomer elicited the strongest EAG responses among the four geometrical isomers of each synthetic 4,6-hexadecadienyl compound. In a laboratory bioassay, only E4,Z6-16:OAc elicited male moth behavioral activity significantly different from the control; the activity of the acetate was not affected by addition of the aldehyde and alcohol. A preliminary field trial confirmed that E4,Z6-16:OAc as a single component attracted male moths. The possible roles of E4,Z6-16:Ald and E4,Z6-16:OH as components of lures for field use remain to be determined.

Laboratory Hybridization Between the Introduced and the Indigenous Green Lacewings (Neuroptera: Chrysopidae: Chrysoperla) in Japan

Abstract We report on laboratory hybridization between the indigenous Chrysoperla nipponensis and its close relative, C. carnea, which has been imported since 2001 from Germany to Japan as a biological control agent. Interspecific hybrids were obtained, and fully viable and fertile F1 and F2 generations were produced. Crosses between C. carnea females and C. nipponensis males showed 41.3% fertility, but the reciprocal cross showed only 9.5% fertility. Despite the low fertility of interspecific crosses, most F1 hybrids were fertile and were successfully backcrossed to both parental species. However, F1 males from C. carnea females × C. nipponensis males showed low fertility (zero except for 20% in one case) when crossed with any females (F1 or backcross). In the one combination resulting in 20% fertility, an extremely long preoviposition period was observed, caused presumably by a mating delay. The absence of change in hatchability, adult emergence rate, total developmental period, or deviation from the 50:50 sex ratio from parents to the F2 generation of hybrids suggests that there is no genetic incompatibility between C. carnea and C. nipponensis resulting from hybrid breakdown. Because the courtship songs of the introduced C. carnea and the indigenous C. nipponensis are quite different, interspecific mating between the two close relatives may not occur under natural conditions. It will be necessary to monitor the establishment of the introduced C. carnea and its possible hybrids with the indigenous C. nipponensis in the wild to minimize any irreversible ecological risks, such as loss of genetic identity.

Identification and field evaluation of sex pheromones in two hawk moths Deilephila elpenor lewisii and Theretra oldenlandiae oldenlandiae (Lepidoptera: Sphingidae)

The sex pheromones of two species of hawk moth, Deilephila elpenor lewisii (Butler) and Theretra oldenlandiae oldenlandiae (Fabricius), were analyzed using gas chromatography–electroantennographic detection (GC–EAD) and GC–mass spectrometry (GC–MS). Two and three EAD-active components were found in D. elpenor lewisii and T. oldenlandiae oldenlandiae, respectively. GC–MS analyses using authentic compounds and extracts derivatized by dimethyl disulfide and 4-methyl-1,2,4-triazoline-3,5-dione identified the two components in D. elpenor lewisii as (E)-11-hexadecenal (E11–16:Ald) and (10E,12E)-10,12-hexadecadienal (E10,E12–16:Ald), and the three in T. oldenlandiae oldenlandiae as E11–16:Ald, E10,E12–16:Ald, and (10E,12Z)-10,12-hexadecadienal (E10,Z12–16:Ald). In field-trap tests, no males of either species were attracted to any single components. Male moths of D. elpenor lewisii were specifically attracted to a binary blend of E11–16:Ald and E10,E12–16:Ald at a ratio of 85:15, whereas males of T. oldenlandiae oldenlandiae were attracted to a ternary blend of E11–16:Ald, E10,Z12–16:Ald and E10,E12–16:Ald at a ratio of 30:40:30. We therefore conclude that the sex pheromone of D. elpenor lewisii is a mixture of E11–16:Ald and E10,E12–16:Ald and that of T. oldenlandiae oldenlandiae is E11–16:Ald, E10,Z12–16:Ald and E10,E12–16:Ald.

Identification of the sex pheromone secreted by Synanthedon tenuis (Lepidoptera: Sesiidae)

The Japanese persimmon treeborer, Synanthedon tenuis (Butler) (Lepidoptera: Sesiidae), is a harmful pest of persimmon trees (Diospyros spp.). Because males of this species are known to be attracted by (3Z,13Z)-3,13-octadecadienyl acetate (Z3,Z13-18:OAc), a mating disruptant composed of a 1:1 mixture of Z3,Z13-18:OAc and the (3E,13Z)-isomer, the original target of which is an allied pest, S. hector (Butler), has been diverted to control S. tenuis. However, the sex pheromone secreted by S. tenuis females has not been characterized. Analyses of pheromone gland extracts using gas chromatography (GC) equipped with an electroantennographic detector (GC-EAD) and GC combined with mass spectrometry (GC–MS) detected only Z3,Z13-18:OAc, and no other known sesiid pheromone components were found. In a persimmon orchard, S. tenuis males were selectively attracted by a lure baited with Z3,Z13-18:OAc among four geometrical isomers of 3,13-octadecadienyl acetate, indicating that males strictly discriminated among the configurations of the two double bonds. Lures baited with single Z3,Z13-18:OAc attracted only S. tenuis. Further field experiments revealed that the attractiveness of Z3,Z13-18:OAc is significantly inhibited by the addition of the (3E,13Z) isomer or the parent alcohol.

Reexamination of the Female Sex Pheromone of the Sweet Potato Vine Borer Moth: Identification and Field Evaluation of a Tricosatriene

The sweet potato vine borer moth, Omphisa anastomosalis (Pyraloidea: Crambidae), is a serious pest in tropical and subtropical Asia-Pacific regions. In previous work using a population from Okinawa, Japan, (10E,14E)-10,14-hexadecadienal (E10,E14-16:Ald) was identified as the major pheromone component, with hexadecanal, (E)-10-hexadecenal, and (E)-14-hexadecenal as minor components. However, traps baited with the synthetic compounds were less effective at attracting males in the field than those baited with virgin females. While Pyraloidea females usually produce only Type I pheromone components (unsaturated fatty alcohols and their derivatives), the pheromones of some Pyraloidea species have been shown to involve a combination of both Type I and Type II components (unsaturated hydrocarbons and their epoxides). We examined an extract of the pheromone glands of female O. anastomosalis from Vietnam by gas chromatography coupled to mass spectrometry and detected (3Z,6Z,9Z)-3,6,9-tricosatriene (Z3,Z6,Z9-23:H) in addition to the compounds identified previously. All four isomers of 10,14–16:Ald were synthesized. A mixture of synthetic E10,E14-16:Ald and Z3,Z6,Z9-23:H in a ratio of 1:0.2–1:2 was attractive to male moths in Vietnam, indicating the strong synergistic effect of the Type II compound. Addition of the other minor pheromone components to the binary blend did not increase the number of male moths captured. Combinations of Z3,Z6,Z9-23:H with the other three geometrical isomers of E10,E14-16:Ald attracted no males, further substantiating the 10E,14E configuration of the natural diene component. E10,E14-16:Ald mixed with other polyunsaturated hydrocarbons showed that mixtures that included a C21 triene, a C22 triene, or a C23 pentaene attracted as many males as did the mixture with Z3,Z6,Z9-23:H. The identification of a highly attractive sex pheromone will help in developing efficient strategies for monitoring and control of O. anastomosalis populations in sweet potato fields.